Commit Graph

2579 Commits

Author SHA1 Message Date
Arnd Bergmann
c40845e319 kbuild: make -Woverride-init warnings more consistent
The -Woverride-init warn about code that may be intentional or not,
but the inintentional ones tend to be real bugs, so there is a bit of
disagreement on whether this warning option should be enabled by default
and we have multiple settings in scripts/Makefile.extrawarn as well as
individual subsystems.

Older versions of clang only supported -Wno-initializer-overrides with
the same meaning as gcc's -Woverride-init, though all supported versions
now work with both. Because of this difference, an earlier cleanup of
mine accidentally turned the clang warning off for W=1 builds and only
left it on for W=2, while it's still enabled for gcc with W=1.

There is also one driver that only turns the warning off for newer
versions of gcc but not other compilers, and some but not all the
Makefiles still use a cc-disable-warning conditional that is no
longer needed with supported compilers here.

Address all of the above by removing the special cases for clang
and always turning the warning off unconditionally where it got
in the way, using the syntax that is supported by both compilers.

Fixes: 2cd3271b7a ("kbuild: avoid duplicate warning options")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Hamza Mahfooz <hamza.mahfooz@amd.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Andrew Jeffery <andrew@codeconstruct.com.au>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-03-31 11:32:26 +09:00
Yang Li
fc253215f8
fs: Add kernel-doc comments to proc_create_net_data_write()
This commit adds kernel-doc style comments with complete parameter
descriptions for the function proc_create_net_data_write.

Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Link: https://lore.kernel.org/r/20240315073805.77463-1-yang.lee@linux.alibaba.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-03-26 09:01:18 +01:00
Linus Torvalds
902861e34c - Sumanth Korikkar has taught s390 to allocate hotplug-time page frames
from hotplugged memory rather than only from main memory.  Series
   "implement "memmap on memory" feature on s390".
 
 - More folio conversions from Matthew Wilcox in the series
 
 	"Convert memcontrol charge moving to use folios"
 	"mm: convert mm counter to take a folio"
 
 - Chengming Zhou has optimized zswap's rbtree locking, providing
   significant reductions in system time and modest but measurable
   reductions in overall runtimes.  The series is "mm/zswap: optimize the
   scalability of zswap rb-tree".
 
 - Chengming Zhou has also provided the series "mm/zswap: optimize zswap
   lru list" which provides measurable runtime benefits in some
   swap-intensive situations.
 
 - And Chengming Zhou further optimizes zswap in the series "mm/zswap:
   optimize for dynamic zswap_pools".  Measured improvements are modest.
 
 - zswap cleanups and simplifications from Yosry Ahmed in the series "mm:
   zswap: simplify zswap_swapoff()".
 
 - In the series "Add DAX ABI for memmap_on_memory", Vishal Verma has
   contributed several DAX cleanups as well as adding a sysfs tunable to
   control the memmap_on_memory setting when the dax device is hotplugged
   as system memory.
 
 - Johannes Weiner has added the large series "mm: zswap: cleanups",
   which does that.
 
 - More DAMON work from SeongJae Park in the series
 
 	"mm/damon: make DAMON debugfs interface deprecation unignorable"
 	"selftests/damon: add more tests for core functionalities and corner cases"
 	"Docs/mm/damon: misc readability improvements"
 	"mm/damon: let DAMOS feeds and tame/auto-tune itself"
 
 - In the series "mm/mempolicy: weighted interleave mempolicy and sysfs
   extension" Rakie Kim has developed a new mempolicy interleaving policy
   wherein we allocate memory across nodes in a weighted fashion rather
   than uniformly.  This is beneficial in heterogeneous memory environments
   appearing with CXL.
 
 - Christophe Leroy has contributed some cleanup and consolidation work
   against the ARM pagetable dumping code in the series "mm: ptdump:
   Refactor CONFIG_DEBUG_WX and check_wx_pages debugfs attribute".
 
 - Luis Chamberlain has added some additional xarray selftesting in the
   series "test_xarray: advanced API multi-index tests".
 
 - Muhammad Usama Anjum has reworked the selftest code to make its
   human-readable output conform to the TAP ("Test Anything Protocol")
   format.  Amongst other things, this opens up the use of third-party
   tools to parse and process out selftesting results.
 
 - Ryan Roberts has added fork()-time PTE batching of THP ptes in the
   series "mm/memory: optimize fork() with PTE-mapped THP".  Mainly
   targeted at arm64, this significantly speeds up fork() when the process
   has a large number of pte-mapped folios.
 
 - David Hildenbrand also gets in on the THP pte batching game in his
   series "mm/memory: optimize unmap/zap with PTE-mapped THP".  It
   implements batching during munmap() and other pte teardown situations.
   The microbenchmark improvements are nice.
 
 - And in the series "Transparent Contiguous PTEs for User Mappings" Ryan
   Roberts further utilizes arm's pte's contiguous bit ("contpte
   mappings").  Kernel build times on arm64 improved nicely.  Ryan's series
   "Address some contpte nits" provides some followup work.
 
 - In the series "mm/hugetlb: Restore the reservation" Breno Leitao has
   fixed an obscure hugetlb race which was causing unnecessary page faults.
   He has also added a reproducer under the selftest code.
 
 - In the series "selftests/mm: Output cleanups for the compaction test",
   Mark Brown did what the title claims.
 
 - Kinsey Ho has added the series "mm/mglru: code cleanup and refactoring".
 
 - Even more zswap material from Nhat Pham.  The series "fix and extend
   zswap kselftests" does as claimed.
 
 - In the series "Introduce cpu_dcache_is_aliasing() to fix DAX
   regression" Mathieu Desnoyers has cleaned up and fixed rather a mess in
   our handling of DAX on archiecctures which have virtually aliasing data
   caches.  The arm architecture is the main beneficiary.
 
 - Lokesh Gidra's series "per-vma locks in userfaultfd" provides dramatic
   improvements in worst-case mmap_lock hold times during certain
   userfaultfd operations.
 
 - Some page_owner enhancements and maintenance work from Oscar Salvador
   in his series
 
 	"page_owner: print stacks and their outstanding allocations"
 	"page_owner: Fixup and cleanup"
 
 - Uladzislau Rezki has contributed some vmalloc scalability improvements
   in his series "Mitigate a vmap lock contention".  It realizes a 12x
   improvement for a certain microbenchmark.
 
 - Some kexec/crash cleanup work from Baoquan He in the series "Split
   crash out from kexec and clean up related config items".
 
 - Some zsmalloc maintenance work from Chengming Zhou in the series
 
 	"mm/zsmalloc: fix and optimize objects/page migration"
 	"mm/zsmalloc: some cleanup for get/set_zspage_mapping()"
 
 - Zi Yan has taught the MM to perform compaction on folios larger than
   order=0.  This a step along the path to implementaton of the merging of
   large anonymous folios.  The series is named "Enable >0 order folio
   memory compaction".
 
 - Christoph Hellwig has done quite a lot of cleanup work in the
   pagecache writeback code in his series "convert write_cache_pages() to
   an iterator".
 
 - Some modest hugetlb cleanups and speedups in Vishal Moola's series
   "Handle hugetlb faults under the VMA lock".
 
 - Zi Yan has changed the page splitting code so we can split huge pages
   into sizes other than order-0 to better utilize large folios.  The
   series is named "Split a folio to any lower order folios".
 
 - David Hildenbrand has contributed the series "mm: remove
   total_mapcount()", a cleanup.
 
 - Matthew Wilcox has sought to improve the performance of bulk memory
   freeing in his series "Rearrange batched folio freeing".
 
 - Gang Li's series "hugetlb: parallelize hugetlb page init on boot"
   provides large improvements in bootup times on large machines which are
   configured to use large numbers of hugetlb pages.
 
 - Matthew Wilcox's series "PageFlags cleanups" does that.
 
 - Qi Zheng's series "minor fixes and supplement for ptdesc" does that
   also.  S390 is affected.
 
 - Cleanups to our pagemap utility functions from Peter Xu in his series
   "mm/treewide: Replace pXd_large() with pXd_leaf()".
 
 - Nico Pache has fixed a few things with our hugepage selftests in his
   series "selftests/mm: Improve Hugepage Test Handling in MM Selftests".
 
 - Also, of course, many singleton patches to many things.  Please see
   the individual changelogs for details.
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Merge tag 'mm-stable-2024-03-13-20-04' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - Sumanth Korikkar has taught s390 to allocate hotplug-time page frames
   from hotplugged memory rather than only from main memory. Series
   "implement "memmap on memory" feature on s390".

 - More folio conversions from Matthew Wilcox in the series

	"Convert memcontrol charge moving to use folios"
	"mm: convert mm counter to take a folio"

 - Chengming Zhou has optimized zswap's rbtree locking, providing
   significant reductions in system time and modest but measurable
   reductions in overall runtimes. The series is "mm/zswap: optimize the
   scalability of zswap rb-tree".

 - Chengming Zhou has also provided the series "mm/zswap: optimize zswap
   lru list" which provides measurable runtime benefits in some
   swap-intensive situations.

 - And Chengming Zhou further optimizes zswap in the series "mm/zswap:
   optimize for dynamic zswap_pools". Measured improvements are modest.

 - zswap cleanups and simplifications from Yosry Ahmed in the series
   "mm: zswap: simplify zswap_swapoff()".

 - In the series "Add DAX ABI for memmap_on_memory", Vishal Verma has
   contributed several DAX cleanups as well as adding a sysfs tunable to
   control the memmap_on_memory setting when the dax device is
   hotplugged as system memory.

 - Johannes Weiner has added the large series "mm: zswap: cleanups",
   which does that.

 - More DAMON work from SeongJae Park in the series

	"mm/damon: make DAMON debugfs interface deprecation unignorable"
	"selftests/damon: add more tests for core functionalities and corner cases"
	"Docs/mm/damon: misc readability improvements"
	"mm/damon: let DAMOS feeds and tame/auto-tune itself"

 - In the series "mm/mempolicy: weighted interleave mempolicy and sysfs
   extension" Rakie Kim has developed a new mempolicy interleaving
   policy wherein we allocate memory across nodes in a weighted fashion
   rather than uniformly. This is beneficial in heterogeneous memory
   environments appearing with CXL.

 - Christophe Leroy has contributed some cleanup and consolidation work
   against the ARM pagetable dumping code in the series "mm: ptdump:
   Refactor CONFIG_DEBUG_WX and check_wx_pages debugfs attribute".

 - Luis Chamberlain has added some additional xarray selftesting in the
   series "test_xarray: advanced API multi-index tests".

 - Muhammad Usama Anjum has reworked the selftest code to make its
   human-readable output conform to the TAP ("Test Anything Protocol")
   format. Amongst other things, this opens up the use of third-party
   tools to parse and process out selftesting results.

 - Ryan Roberts has added fork()-time PTE batching of THP ptes in the
   series "mm/memory: optimize fork() with PTE-mapped THP". Mainly
   targeted at arm64, this significantly speeds up fork() when the
   process has a large number of pte-mapped folios.

 - David Hildenbrand also gets in on the THP pte batching game in his
   series "mm/memory: optimize unmap/zap with PTE-mapped THP". It
   implements batching during munmap() and other pte teardown
   situations. The microbenchmark improvements are nice.

 - And in the series "Transparent Contiguous PTEs for User Mappings"
   Ryan Roberts further utilizes arm's pte's contiguous bit ("contpte
   mappings"). Kernel build times on arm64 improved nicely. Ryan's
   series "Address some contpte nits" provides some followup work.

 - In the series "mm/hugetlb: Restore the reservation" Breno Leitao has
   fixed an obscure hugetlb race which was causing unnecessary page
   faults. He has also added a reproducer under the selftest code.

 - In the series "selftests/mm: Output cleanups for the compaction
   test", Mark Brown did what the title claims.

 - Kinsey Ho has added the series "mm/mglru: code cleanup and
   refactoring".

 - Even more zswap material from Nhat Pham. The series "fix and extend
   zswap kselftests" does as claimed.

 - In the series "Introduce cpu_dcache_is_aliasing() to fix DAX
   regression" Mathieu Desnoyers has cleaned up and fixed rather a mess
   in our handling of DAX on archiecctures which have virtually aliasing
   data caches. The arm architecture is the main beneficiary.

 - Lokesh Gidra's series "per-vma locks in userfaultfd" provides
   dramatic improvements in worst-case mmap_lock hold times during
   certain userfaultfd operations.

 - Some page_owner enhancements and maintenance work from Oscar Salvador
   in his series

	"page_owner: print stacks and their outstanding allocations"
	"page_owner: Fixup and cleanup"

 - Uladzislau Rezki has contributed some vmalloc scalability
   improvements in his series "Mitigate a vmap lock contention". It
   realizes a 12x improvement for a certain microbenchmark.

 - Some kexec/crash cleanup work from Baoquan He in the series "Split
   crash out from kexec and clean up related config items".

 - Some zsmalloc maintenance work from Chengming Zhou in the series

	"mm/zsmalloc: fix and optimize objects/page migration"
	"mm/zsmalloc: some cleanup for get/set_zspage_mapping()"

 - Zi Yan has taught the MM to perform compaction on folios larger than
   order=0. This a step along the path to implementaton of the merging
   of large anonymous folios. The series is named "Enable >0 order folio
   memory compaction".

 - Christoph Hellwig has done quite a lot of cleanup work in the
   pagecache writeback code in his series "convert write_cache_pages()
   to an iterator".

 - Some modest hugetlb cleanups and speedups in Vishal Moola's series
   "Handle hugetlb faults under the VMA lock".

 - Zi Yan has changed the page splitting code so we can split huge pages
   into sizes other than order-0 to better utilize large folios. The
   series is named "Split a folio to any lower order folios".

 - David Hildenbrand has contributed the series "mm: remove
   total_mapcount()", a cleanup.

 - Matthew Wilcox has sought to improve the performance of bulk memory
   freeing in his series "Rearrange batched folio freeing".

 - Gang Li's series "hugetlb: parallelize hugetlb page init on boot"
   provides large improvements in bootup times on large machines which
   are configured to use large numbers of hugetlb pages.

 - Matthew Wilcox's series "PageFlags cleanups" does that.

 - Qi Zheng's series "minor fixes and supplement for ptdesc" does that
   also. S390 is affected.

 - Cleanups to our pagemap utility functions from Peter Xu in his series
   "mm/treewide: Replace pXd_large() with pXd_leaf()".

 - Nico Pache has fixed a few things with our hugepage selftests in his
   series "selftests/mm: Improve Hugepage Test Handling in MM
   Selftests".

 - Also, of course, many singleton patches to many things. Please see
   the individual changelogs for details.

* tag 'mm-stable-2024-03-13-20-04' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (435 commits)
  mm/zswap: remove the memcpy if acomp is not sleepable
  crypto: introduce: acomp_is_async to expose if comp drivers might sleep
  memtest: use {READ,WRITE}_ONCE in memory scanning
  mm: prohibit the last subpage from reusing the entire large folio
  mm: recover pud_leaf() definitions in nopmd case
  selftests/mm: skip the hugetlb-madvise tests on unmet hugepage requirements
  selftests/mm: skip uffd hugetlb tests with insufficient hugepages
  selftests/mm: dont fail testsuite due to a lack of hugepages
  mm/huge_memory: skip invalid debugfs new_order input for folio split
  mm/huge_memory: check new folio order when split a folio
  mm, vmscan: retry kswapd's priority loop with cache_trim_mode off on failure
  mm: add an explicit smp_wmb() to UFFDIO_CONTINUE
  mm: fix list corruption in put_pages_list
  mm: remove folio from deferred split list before uncharging it
  filemap: avoid unnecessary major faults in filemap_fault()
  mm,page_owner: drop unnecessary check
  mm,page_owner: check for null stack_record before bumping its refcount
  mm: swap: fix race between free_swap_and_cache() and swapoff()
  mm/treewide: align up pXd_leaf() retval across archs
  mm/treewide: drop pXd_large()
  ...
2024-03-14 17:43:30 -07:00
Linus Torvalds
7ea65c89d8 vfs-6.9.misc
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Merge tag 'vfs-6.9.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull misc vfs updates from Christian Brauner:
 "Misc features, cleanups, and fixes for vfs and individual filesystems.

  Features:

   - Support idmapped mounts for hugetlbfs.

   - Add RWF_NOAPPEND flag for pwritev2(). This allows us to fix a bug
     where the passed offset is ignored if the file is O_APPEND. The new
     flag allows a caller to enforce that the offset is honored to
     conform to posix even if the file was opened in append mode.

   - Move i_mmap_rwsem in struct address_space to avoid false sharing
     between i_mmap and i_mmap_rwsem.

   - Convert efs, qnx4, and coda to use the new mount api.

   - Add a generic is_dot_dotdot() helper that's used by various
     filesystems and the VFS code instead of open-coding it multiple
     times.

   - Recently we've added stable offsets which allows stable ordering
     when iterating directories exported through NFS on e.g., tmpfs
     filesystems. Originally an xarray was used for the offset map but
     that caused slab fragmentation issues over time. This switches the
     offset map to the maple tree which has a dense mode that handles
     this scenario a lot better. Includes tests.

   - Finally merge the case-insensitive improvement series Gabriel has
     been working on for a long time. This cleanly propagates case
     insensitive operations through ->s_d_op which in turn allows us to
     remove the quite ugly generic_set_encrypted_ci_d_ops() operations.
     It also improves performance by trying a case-sensitive comparison
     first and then fallback to case-insensitive lookup if that fails.
     This also fixes a bug where overlayfs would be able to be mounted
     over a case insensitive directory which would lead to all sort of
     odd behaviors.

  Cleanups:

   - Make file_dentry() a simple accessor now that ->d_real() is
     simplified because of the backing file work we did the last two
     cycles.

   - Use the dedicated file_mnt_idmap helper in ntfs3.

   - Use smp_load_acquire/store_release() in the i_size_read/write
     helpers and thus remove the hack to handle i_size reads in the
     filemap code.

   - The SLAB_MEM_SPREAD is a nop now. Remove it from various places in
     fs/

   - It's no longer necessary to perform a second built-in initramfs
     unpack call because we retain the contents of the previous
     extraction. Remove it.

   - Now that we have removed various allocators kfree_rcu() always
     works with kmem caches and kmalloc(). So simplify various places
     that only use an rcu callback in order to handle the kmem cache
     case.

   - Convert the pipe code to use a lockdep comparison function instead
     of open-coding the nesting making lockdep validation easier.

   - Move code into fs-writeback.c that was located in a header but can
     be made static as it's only used in that one file.

   - Rewrite the alignment checking iterators for iovec and bvec to be
     easier to read, and also significantly more compact in terms of
     generated code. This saves 270 bytes of text on x86-64 (with
     clang-18) and 224 bytes on arm64 (with gcc-13). In profiles it also
     saves a bit of time for the same workload.

   - Switch various places to use KMEM_CACHE instead of
     kmem_cache_create().

   - Use inode_set_ctime_to_ts() in inode_set_ctime_current()

   - Use kzalloc() in name_to_handle_at() to avoid kernel infoleak.

   - Various smaller cleanups for eventfds.

  Fixes:

   - Fix various comments and typos, and unneeded initializations.

   - Fix stack allocation hack for clang in the select code.

   - Improve dump_mapping() debug code on a best-effort basis.

   - Fix build errors in various selftests.

   - Avoid wrap-around instrumentation in various places.

   - Don't allow user namespaces without an idmapping to be used for
     idmapped mounts.

   - Fix sysv sb_read() call.

   - Fix fallback implementation of the get_name() export operation"

* tag 'vfs-6.9.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (70 commits)
  hugetlbfs: support idmapped mounts
  qnx4: convert qnx4 to use the new mount api
  fs: use inode_set_ctime_to_ts to set inode ctime to current time
  libfs: Drop generic_set_encrypted_ci_d_ops
  ubifs: Configure dentry operations at dentry-creation time
  f2fs: Configure dentry operations at dentry-creation time
  ext4: Configure dentry operations at dentry-creation time
  libfs: Add helper to choose dentry operations at mount-time
  libfs: Merge encrypted_ci_dentry_ops and ci_dentry_ops
  fscrypt: Drop d_revalidate once the key is added
  fscrypt: Drop d_revalidate for valid dentries during lookup
  fscrypt: Factor out a helper to configure the lookup dentry
  ovl: Always reject mounting over case-insensitive directories
  libfs: Attempt exact-match comparison first during casefolded lookup
  efs: remove SLAB_MEM_SPREAD flag usage
  jfs: remove SLAB_MEM_SPREAD flag usage
  minix: remove SLAB_MEM_SPREAD flag usage
  openpromfs: remove SLAB_MEM_SPREAD flag usage
  proc: remove SLAB_MEM_SPREAD flag usage
  qnx6: remove SLAB_MEM_SPREAD flag usage
  ...
2024-03-11 09:38:17 -07:00
Chengming Zhou
c762b979c7 proc: remove SLAB_MEM_SPREAD flag usage
The SLAB_MEM_SPREAD flag used to be implemented in SLAB, which was
removed as of v6.8-rc1 (see [1]), so it became a dead flag since the
commit 16a1d96835 ("mm/slab: remove mm/slab.c and slab_def.h"). And
the series[1] went on to mark it obsolete explicitly to avoid confusion
for users. Here we can just remove all its users, which has no any
functional change.

Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Link: https://lore.kernel.org/all/20240223-slab-cleanup-flags-v2-1-02f1753e8303@suse.cz [1]
Link: https://lore.kernel.org/r/20240224135048.829987-1-chengming.zhou@linux.dev
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-02-27 11:21:32 +01:00
Linus Torvalds
66a97c2ec9 We still have some races in filesystem methods when exposed to RCU
pathwalk.  This series is a result of code audit (the second round
 of it) and it should deal with most of that stuff.  Exceptions: ntfs3
 ->d_hash()/->d_compare() and ceph_d_revalidate().  Up to maintainers (a
 note for NTFS folks - when documentation says that a method may not block,
 it *does* imply that blocking allocations are to be avoided.  Really).
 
 Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Merge tag 'pull-fixes.pathwalk-rcu-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull RCU pathwalk fixes from Al Viro:
 "We still have some races in filesystem methods when exposed to RCU
  pathwalk. This series is a result of code audit (the second round of
  it) and it should deal with most of that stuff.

  Still pending: ntfs3 ->d_hash()/->d_compare() and ceph_d_revalidate().
  Up to maintainers (a note for NTFS folks - when documentation says
  that a method may not block, it *does* imply that blocking allocations
  are to be avoided. Really)"

[ More explanations for people who aren't familiar with the vagaries of
  RCU path walking: most of it is hidden from filesystems, but if a
  filesystem actively participates in the low-level path walking it
  needs to make sure the fields involved in that walk are RCU-safe.

  That "actively participate in low-level path walking" includes things
  like having its own ->d_hash()/->d_compare() routines, or by having
  its own directory permission function that doesn't just use the common
  helpers.  Having a ->d_revalidate() function will also have this issue.

  Note that instead of making everything RCU safe you can also choose to
  abort the RCU pathwalk if your operation cannot be done safely under
  RCU, but that obviously comes with a performance penalty. One common
  pattern is to allow the simple cases under RCU, and abort only if you
  need to do something more complicated.

  So not everything needs to be RCU-safe, and things like the inode etc
  that the VFS itself maintains obviously already are. But these fixes
  tend to be about properly RCU-delaying things like ->s_fs_info that
  are maintained by the filesystem and that got potentially released too
  early.   - Linus ]

* tag 'pull-fixes.pathwalk-rcu-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  ext4_get_link(): fix breakage in RCU mode
  cifs_get_link(): bail out in unsafe case
  fuse: fix UAF in rcu pathwalks
  procfs: make freeing proc_fs_info rcu-delayed
  procfs: move dropping pde and pid from ->evict_inode() to ->free_inode()
  nfs: fix UAF on pathwalk running into umount
  nfs: make nfs_set_verifier() safe for use in RCU pathwalk
  afs: fix __afs_break_callback() / afs_drop_open_mmap() race
  hfsplus: switch to rcu-delayed unloading of nls and freeing ->s_fs_info
  exfat: move freeing sbi, upcase table and dropping nls into rcu-delayed helper
  affs: free affs_sb_info with kfree_rcu()
  rcu pathwalk: prevent bogus hard errors from may_lookup()
  fs/super.c: don't drop ->s_user_ns until we free struct super_block itself
2024-02-25 09:29:05 -08:00
Al Viro
e31f0a57ae procfs: make freeing proc_fs_info rcu-delayed
makes proc_pid_ns() safe from rcu pathwalk (put_pid_ns()
is still synchronous, but that's not a problem - it does
rcu-delay everything that needs to be)

Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-02-25 02:10:32 -05:00
Al Viro
47458802f6 procfs: move dropping pde and pid from ->evict_inode() to ->free_inode()
that keeps both around until struct inode is freed, making access
to them safe from rcu-pathwalk

Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-02-25 02:10:32 -05:00
Baoquan He
443cbaf9e2 crash: split vmcoreinfo exporting code out from crash_core.c
Now move the relevant codes into separate files:
kernel/crash_reserve.c, include/linux/crash_reserve.h.

And add config item CRASH_RESERVE to control its enabling.

And also update the old ifdeffery of CONFIG_CRASH_CORE, including of
<linux/crash_core.h> and config item dependency on CRASH_CORE
accordingly.

And also do renaming as follows:
 - arch/xxx/kernel/{crash_core.c => vmcore_info.c}
because they are only related to vmcoreinfo exporting on x86, arm64,
riscv.

And also Remove config item CRASH_CORE, and rely on CONFIG_KEXEC_CORE to
decide if build in crash_core.c.

[yang.lee@linux.alibaba.com: remove duplicated include in vmcore_info.c]
  Link: https://lkml.kernel.org/r/20240126005744.16561-1-yang.lee@linux.alibaba.com
Link: https://lkml.kernel.org/r/20240124051254.67105-3-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Acked-by: Hari Bathini <hbathini@linux.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Pingfan Liu <piliu@redhat.com>
Cc: Klara Modin <klarasmodin@gmail.com>
Cc: Michael Kelley <mhklinux@outlook.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-23 17:48:22 -08:00
Hui Zhu
cabbb6d51e fs/proc/task_mmu.c: add_to_pagemap: remove useless parameter addr
Function parameter addr of add_to_pagemap() is useless.  Remove it.

Link: https://lkml.kernel.org/r/20240111084533.40038-1-teawaterz@linux.alibaba.com
Signed-off-by: Hui Zhu <teawater@antgroup.com>
Reviewed-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Tested-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrei Vagin <avagin@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-21 16:00:04 -08:00
Matthew Wilcox (Oracle)
7101422464 proc: use pfn_swap_entry_folio where obvious
These callers only pass the result to PageAnon(), so we can save the extra
call to compound_head() by using pfn_swap_entry_folio().

Link: https://lkml.kernel.org/r/20240111152429.3374566-3-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-21 16:00:03 -08:00
Oleg Nesterov
7601df8031 fs/proc: do_task_stat: use sig->stats_lock to gather the threads/children stats
lock_task_sighand() can trigger a hard lockup.  If NR_CPUS threads call
do_task_stat() at the same time and the process has NR_THREADS, it will
spin with irqs disabled O(NR_CPUS * NR_THREADS) time.

Change do_task_stat() to use sig->stats_lock to gather the statistics
outside of ->siglock protected section, in the likely case this code will
run lockless.

Link: https://lkml.kernel.org/r/20240123153357.GA21857@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Dylan Hatch <dylanbhatch@google.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-07 21:20:33 -08:00
Oleg Nesterov
60f92acb60 fs/proc: do_task_stat: move thread_group_cputime_adjusted() outside of lock_task_sighand()
Patch series "fs/proc: do_task_stat: use sig->stats_".

do_task_stat() has the same problem as getrusage() had before "getrusage:
use sig->stats_lock rather than lock_task_sighand()": a hard lockup.  If
NR_CPUS threads call lock_task_sighand() at the same time and the process
has NR_THREADS, spin_lock_irq will spin with irqs disabled O(NR_CPUS *
NR_THREADS) time.


This patch (of 3):

thread_group_cputime() does its own locking, we can safely shift
thread_group_cputime_adjusted() which does another for_each_thread loop
outside of ->siglock protected section.

Not only this removes for_each_thread() from the critical section with
irqs disabled, this removes another case when stats_lock is taken with
siglock held.  We want to remove this dependency, then we can change the
users of stats_lock to not disable irqs.

Link: https://lkml.kernel.org/r/20240123153313.GA21832@redhat.com
Link: https://lkml.kernel.org/r/20240123153355.GA21854@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Dylan Hatch <dylanbhatch@google.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-02-07 21:20:33 -08:00
Andrew Morton
fe33c0fbed Merge branch 'master' into mm-hotfixes-stable 2024-01-17 12:58:28 -08:00
Linus Torvalds
7f5e47f785 17 hotfixes. 10 address post-6.7 issues and the other 7 are cc:stable.
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Merge tag 'mm-hotfixes-stable-2024-01-12-16-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull misc hotfixes from Andrew Morton:
 "For once not mostly MM-related.

  17 hotfixes. 10 address post-6.7 issues and the other 7 are cc:stable"

* tag 'mm-hotfixes-stable-2024-01-12-16-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  userfaultfd: avoid huge_zero_page in UFFDIO_MOVE
  MAINTAINERS: add entry for shrinker
  selftests: mm: hugepage-vmemmap fails on 64K page size systems
  mm/memory_hotplug: fix memmap_on_memory sysfs value retrieval
  mailmap: switch email for Tanzir Hasan
  mailmap: add old address mappings for Randy
  kernel/crash_core.c: make __crash_hotplug_lock static
  efi: disable mirror feature during crashkernel
  kexec: do syscore_shutdown() in kernel_kexec
  mailmap: update entry for Manivannan Sadhasivam
  fs/proc/task_mmu: move mmu notification mechanism inside mm lock
  mm: zswap: switch maintainers to recently active developers and reviewers
  scripts/decode_stacktrace.sh: optionally use LLVM utilities
  kasan: avoid resetting aux_lock
  lib/Kconfig.debug: disable CONFIG_DEBUG_INFO_BTF for Hexagon
  MAINTAINERS: update LTP maintainers
  kdump: defer the insertion of crashkernel resources
2024-01-17 09:31:36 -08:00
Muhammad Usama Anjum
4cccb6221c fs/proc/task_mmu: move mmu notification mechanism inside mm lock
Move mmu notification mechanism inside mm lock to prevent race condition
in other components which depend on it.  The notifier will invalidate
memory range.  Depending upon the number of iterations, different memory
ranges would be invalidated.

The following warning would be removed by this patch:
WARNING: CPU: 0 PID: 5067 at arch/x86/kvm/../../../virt/kvm/kvm_main.c:734 kvm_mmu_notifier_change_pte+0x860/0x960 arch/x86/kvm/../../../virt/kvm/kvm_main.c:734

There is no behavioural and performance change with this patch when
there is no component registered with the mmu notifier.

[akpm@linux-foundation.org: narrow the scope of `range', per Sean]
Link: https://lkml.kernel.org/r/20240109112445.590736-1-usama.anjum@collabora.com
Fixes: 52526ca7fd ("fs/proc/task_mmu: implement IOCTL to get and optionally clear info about PTEs")
Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Reported-by: syzbot+81227d2bd69e9dedb802@syzkaller.appspotmail.com
Link: https://lore.kernel.org/all/000000000000f6d051060c6785bc@google.com/
Reviewed-by: Sean Christopherson <seanjc@google.com>
Cc: Andrei Vagin <avagin@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Cc: Peter Xu <peterx@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-01-12 15:20:46 -08:00
Linus Torvalds
488926926a misc cleanups (the part that hadn't been picked by individual fs trees)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Merge tag 'pull-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull misc filesystem updates from Al Viro:
 "Misc cleanups (the part that hadn't been picked by individual fs
  trees)"

* tag 'pull-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  apparmorfs: don't duplicate kfree_link()
  orangefs: saner arguments passing in readdir guts
  ocfs2_find_match(): there's no such thing as NULL or negative ->d_parent
  reiserfs_add_entry(): get rid of pointless namelen checks
  __ocfs2_add_entry(), ocfs2_prepare_dir_for_insert(): namelen checks
  ext4_add_entry(): ->d_name.len is never 0
  befs: d_obtain_alias(ERR_PTR(...)) will do the right thing
  affs: d_obtain_alias(ERR_PTR(...)) will do the right thing
  /proc/sys: use d_splice_alias() calling conventions to simplify failure exits
  hostfs: use d_splice_alias() calling conventions to simplify failure exits
  udf_fiiter_add_entry(): check for zero ->d_name.len is bogus...
  udf: d_obtain_alias(ERR_PTR(...)) will do the right thing...
  udf: d_splice_alias() will do the right thing on ERR_PTR() inode
  nfsd: kill stale comment about simple_fill_super() requirements
  bfs_add_entry(): get rid of pointless ->d_name.len checks
  nilfs2: d_obtain_alias(ERR_PTR(...)) will do the right thing...
  zonefs: d_splice_alias() will do the right thing on ERR_PTR() inode
2024-01-11 20:23:50 -08:00
Linus Torvalds
a05aea98d4 sysctl-6.8-rc1
To help make the move of sysctls out of kernel/sysctl.c not incur a size
 penalty sysctl has been changed to allow us to not require the sentinel, the
 final empty element on the sysctl array. Joel Granados has been doing all this
 work. On the v6.6 kernel we got the major infrastructure changes required to
 support this. For v6.7 we had all arch/ and drivers/ modified to remove
 the sentinel. For v6.8-rc1 we get a few more updates for fs/ directory only.
 The kernel/ directory is left but we'll save that for v6.9-rc1 as those patches
 are still being reviewed. After that we then can expect also the removal of the
 no longer needed check for procname == NULL.
 
 Let us recap the purpose of this work:
 
   - this helps reduce the overall build time size of the kernel and run time
     memory consumed by the kernel by about ~64 bytes per array
   - the extra 64-byte penalty is no longer inncurred now when we move sysctls
     out from kernel/sysctl.c to their own files
 
 Thomas Weißschuh also sent a few cleanups, for v6.9-rc1 we expect to see further
 work by Thomas Weißschuh with the constificatin of the struct ctl_table.
 
 Due to Joel Granados's work, and to help bring in new blood, I have suggested
 for him to become a maintainer and he's accepted. So for v6.9-rc1 I look forward
 to seeing him sent you a pull request for further sysctl changes. This also
 removes Iurii Zaikin as a maintainer as he has moved on to other projects and
 has had no time to help at all.
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Merge tag 'sysctl-6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux

Pull sysctl updates from Luis Chamberlain:
 "To help make the move of sysctls out of kernel/sysctl.c not incur a
  size penalty sysctl has been changed to allow us to not require the
  sentinel, the final empty element on the sysctl array. Joel Granados
  has been doing all this work.

  In the v6.6 kernel we got the major infrastructure changes required to
  support this. For v6.7 we had all arch/ and drivers/ modified to
  remove the sentinel. For v6.8-rc1 we get a few more updates for fs/
  directory only.

  The kernel/ directory is left but we'll save that for v6.9-rc1 as
  those patches are still being reviewed. After that we then can expect
  also the removal of the no longer needed check for procname == NULL.

  Let us recap the purpose of this work:

   - this helps reduce the overall build time size of the kernel and run
     time memory consumed by the kernel by about ~64 bytes per array

   - the extra 64-byte penalty is no longer inncurred now when we move
     sysctls out from kernel/sysctl.c to their own files

  Thomas Weißschuh also sent a few cleanups, for v6.9-rc1 we expect to
  see further work by Thomas Weißschuh with the constificatin of the
  struct ctl_table.

  Due to Joel Granados's work, and to help bring in new blood, I have
  suggested for him to become a maintainer and he's accepted. So for
  v6.9-rc1 I look forward to seeing him sent you a pull request for
  further sysctl changes. This also removes Iurii Zaikin as a maintainer
  as he has moved on to other projects and has had no time to help at
  all"

* tag 'sysctl-6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux:
  sysctl: remove struct ctl_path
  sysctl: delete unused define SYSCTL_PERM_EMPTY_DIR
  coda: Remove the now superfluous sentinel elements from ctl_table array
  sysctl: Remove the now superfluous sentinel elements from ctl_table array
  fs: Remove the now superfluous sentinel elements from ctl_table array
  cachefiles: Remove the now superfluous sentinel element from ctl_table array
  sysclt: Clarify the results of selftest run
  sysctl: Add a selftest for handling empty dirs
  sysctl: Fix out of bounds access for empty sysctl registers
  MAINTAINERS: Add Joel Granados as co-maintainer for proc sysctl
  MAINTAINERS: remove Iurii Zaikin from proc sysctl
2024-01-10 17:44:36 -08:00
Linus Torvalds
063a7ce32d lsm/stable-6.8 PR 20240105
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Merge tag 'lsm-pr-20240105' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm

Pull security module updates from Paul Moore:

 - Add three new syscalls: lsm_list_modules(), lsm_get_self_attr(), and
   lsm_set_self_attr().

   The first syscall simply lists the LSMs enabled, while the second and
   third get and set the current process' LSM attributes. Yes, these
   syscalls may provide similar functionality to what can be found under
   /proc or /sys, but they were designed to support multiple,
   simultaneaous (stacked) LSMs from the start as opposed to the current
   /proc based solutions which were created at a time when only one LSM
   was allowed to be active at a given time.

   We have spent considerable time discussing ways to extend the
   existing /proc interfaces to support multiple, simultaneaous LSMs and
   even our best ideas have been far too ugly to support as a kernel
   API; after +20 years in the kernel, I felt the LSM layer had
   established itself enough to justify a handful of syscalls.

   Support amongst the individual LSM developers has been nearly
   unanimous, with a single objection coming from Tetsuo (TOMOYO) as he
   is worried that the LSM_ID_XXX token concept will make it more
   difficult for out-of-tree LSMs to survive. Several members of the LSM
   community have demonstrated the ability for out-of-tree LSMs to
   continue to exist by picking high/unused LSM_ID values as well as
   pointing out that many kernel APIs rely on integer identifiers, e.g.
   syscalls (!), but unfortunately Tetsuo's objections remain.

   My personal opinion is that while I have no interest in penalizing
   out-of-tree LSMs, I'm not going to penalize in-tree development to
   support out-of-tree development, and I view this as a necessary step
   forward to support the push for expanded LSM stacking and reduce our
   reliance on /proc and /sys which has occassionally been problematic
   for some container users. Finally, we have included the linux-api
   folks on (all?) recent revisions of the patchset and addressed all of
   their concerns.

 - Add a new security_file_ioctl_compat() LSM hook to handle the 32-bit
   ioctls on 64-bit systems problem.

   This patch includes support for all of the existing LSMs which
   provide ioctl hooks, although it turns out only SELinux actually
   cares about the individual ioctls. It is worth noting that while
   Casey (Smack) and Tetsuo (TOMOYO) did not give explicit ACKs to this
   patch, they did both indicate they are okay with the changes.

 - Fix a potential memory leak in the CALIPSO code when IPv6 is disabled
   at boot.

   While it's good that we are fixing this, I doubt this is something
   users are seeing in the wild as you need to both disable IPv6 and
   then attempt to configure IPv6 labeled networking via
   NetLabel/CALIPSO; that just doesn't make much sense.

   Normally this would go through netdev, but Jakub asked me to take
   this patch and of all the trees I maintain, the LSM tree seemed like
   the best fit.

 - Update the LSM MAINTAINERS entry with additional information about
   our process docs, patchwork, bug reporting, etc.

   I also noticed that the Lockdown LSM is missing a dedicated
   MAINTAINERS entry so I've added that to the pull request. I've been
   working with one of the major Lockdown authors/contributors to see if
   they are willing to step up and assume a Lockdown maintainer role;
   hopefully that will happen soon, but in the meantime I'll continue to
   look after it.

 - Add a handful of mailmap entries for Serge Hallyn and myself.

* tag 'lsm-pr-20240105' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm: (27 commits)
  lsm: new security_file_ioctl_compat() hook
  lsm: Add a __counted_by() annotation to lsm_ctx.ctx
  calipso: fix memory leak in netlbl_calipso_add_pass()
  selftests: remove the LSM_ID_IMA check in lsm/lsm_list_modules_test
  MAINTAINERS: add an entry for the lockdown LSM
  MAINTAINERS: update the LSM entry
  mailmap: add entries for Serge Hallyn's dead accounts
  mailmap: update/replace my old email addresses
  lsm: mark the lsm_id variables are marked as static
  lsm: convert security_setselfattr() to use memdup_user()
  lsm: align based on pointer length in lsm_fill_user_ctx()
  lsm: consolidate buffer size handling into lsm_fill_user_ctx()
  lsm: correct error codes in security_getselfattr()
  lsm: cleanup the size counters in security_getselfattr()
  lsm: don't yet account for IMA in LSM_CONFIG_COUNT calculation
  lsm: drop LSM_ID_IMA
  LSM: selftests for Linux Security Module syscalls
  SELinux: Add selfattr hooks
  AppArmor: Add selfattr hooks
  Smack: implement setselfattr and getselfattr hooks
  ...
2024-01-09 12:57:46 -08:00
Linus Torvalds
fb46e22a9e Many singleton patches against the MM code. The patch series which
are included in this merge do the following:
 
 - Peng Zhang has done some mapletree maintainance work in the
   series
 
 	"maple_tree: add mt_free_one() and mt_attr() helpers"
 	"Some cleanups of maple tree"
 
 - In the series "mm: use memmap_on_memory semantics for dax/kmem"
   Vishal Verma has altered the interworking between memory-hotplug
   and dax/kmem so that newly added 'device memory' can more easily
   have its memmap placed within that newly added memory.
 
 - Matthew Wilcox continues folio-related work (including a few
   fixes) in the patch series
 
 	"Add folio_zero_tail() and folio_fill_tail()"
 	"Make folio_start_writeback return void"
 	"Fix fault handler's handling of poisoned tail pages"
 	"Convert aops->error_remove_page to ->error_remove_folio"
 	"Finish two folio conversions"
 	"More swap folio conversions"
 
 - Kefeng Wang has also contributed folio-related work in the series
 
 	"mm: cleanup and use more folio in page fault"
 
 - Jim Cromie has improved the kmemleak reporting output in the
   series "tweak kmemleak report format".
 
 - In the series "stackdepot: allow evicting stack traces" Andrey
   Konovalov to permits clients (in this case KASAN) to cause
   eviction of no longer needed stack traces.
 
 - Charan Teja Kalla has fixed some accounting issues in the page
   allocator's atomic reserve calculations in the series "mm:
   page_alloc: fixes for high atomic reserve caluculations".
 
 - Dmitry Rokosov has added to the samples/ dorectory some sample
   code for a userspace memcg event listener application.  See the
   series "samples: introduce cgroup events listeners".
 
 - Some mapletree maintanance work from Liam Howlett in the series
   "maple_tree: iterator state changes".
 
 - Nhat Pham has improved zswap's approach to writeback in the
   series "workload-specific and memory pressure-driven zswap
   writeback".
 
 - DAMON/DAMOS feature and maintenance work from SeongJae Park in
   the series
 
 	"mm/damon: let users feed and tame/auto-tune DAMOS"
 	"selftests/damon: add Python-written DAMON functionality tests"
 	"mm/damon: misc updates for 6.8"
 
 - Yosry Ahmed has improved memcg's stats flushing in the series
   "mm: memcg: subtree stats flushing and thresholds".
 
 - In the series "Multi-size THP for anonymous memory" Ryan Roberts
   has added a runtime opt-in feature to transparent hugepages which
   improves performance by allocating larger chunks of memory during
   anonymous page faults.
 
 - Matthew Wilcox has also contributed some cleanup and maintenance
   work against eh buffer_head code int he series "More buffer_head
   cleanups".
 
 - Suren Baghdasaryan has done work on Andrea Arcangeli's series
   "userfaultfd move option".  UFFDIO_MOVE permits userspace heap
   compaction algorithms to move userspace's pages around rather than
   UFFDIO_COPY'a alloc/copy/free.
 
 - Stefan Roesch has developed a "KSM Advisor", in the series
   "mm/ksm: Add ksm advisor".  This is a governor which tunes KSM's
   scanning aggressiveness in response to userspace's current needs.
 
 - Chengming Zhou has optimized zswap's temporary working memory
   use in the series "mm/zswap: dstmem reuse optimizations and
   cleanups".
 
 - Matthew Wilcox has performed some maintenance work on the
   writeback code, both code and within filesystems.  The series is
   "Clean up the writeback paths".
 
 - Andrey Konovalov has optimized KASAN's handling of alloc and
   free stack traces for secondary-level allocators, in the series
   "kasan: save mempool stack traces".
 
 - Andrey also performed some KASAN maintenance work in the series
   "kasan: assorted clean-ups".
 
 - David Hildenbrand has gone to town on the rmap code.  Cleanups,
   more pte batching, folio conversions and more.  See the series
   "mm/rmap: interface overhaul".
 
 - Kinsey Ho has contributed some maintenance work on the MGLRU
   code in the series "mm/mglru: Kconfig cleanup".
 
 - Matthew Wilcox has contributed lruvec page accounting code
   cleanups in the series "Remove some lruvec page accounting
   functions".
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Merge tag 'mm-stable-2024-01-08-15-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:
 "Many singleton patches against the MM code. The patch series which are
  included in this merge do the following:

   - Peng Zhang has done some mapletree maintainance work in the series

	'maple_tree: add mt_free_one() and mt_attr() helpers'
	'Some cleanups of maple tree'

   - In the series 'mm: use memmap_on_memory semantics for dax/kmem'
     Vishal Verma has altered the interworking between memory-hotplug
     and dax/kmem so that newly added 'device memory' can more easily
     have its memmap placed within that newly added memory.

   - Matthew Wilcox continues folio-related work (including a few fixes)
     in the patch series

	'Add folio_zero_tail() and folio_fill_tail()'
	'Make folio_start_writeback return void'
	'Fix fault handler's handling of poisoned tail pages'
	'Convert aops->error_remove_page to ->error_remove_folio'
	'Finish two folio conversions'
	'More swap folio conversions'

   - Kefeng Wang has also contributed folio-related work in the series

	'mm: cleanup and use more folio in page fault'

   - Jim Cromie has improved the kmemleak reporting output in the series
     'tweak kmemleak report format'.

   - In the series 'stackdepot: allow evicting stack traces' Andrey
     Konovalov to permits clients (in this case KASAN) to cause eviction
     of no longer needed stack traces.

   - Charan Teja Kalla has fixed some accounting issues in the page
     allocator's atomic reserve calculations in the series 'mm:
     page_alloc: fixes for high atomic reserve caluculations'.

   - Dmitry Rokosov has added to the samples/ dorectory some sample code
     for a userspace memcg event listener application. See the series
     'samples: introduce cgroup events listeners'.

   - Some mapletree maintanance work from Liam Howlett in the series
     'maple_tree: iterator state changes'.

   - Nhat Pham has improved zswap's approach to writeback in the series
     'workload-specific and memory pressure-driven zswap writeback'.

   - DAMON/DAMOS feature and maintenance work from SeongJae Park in the
     series

	'mm/damon: let users feed and tame/auto-tune DAMOS'
	'selftests/damon: add Python-written DAMON functionality tests'
	'mm/damon: misc updates for 6.8'

   - Yosry Ahmed has improved memcg's stats flushing in the series 'mm:
     memcg: subtree stats flushing and thresholds'.

   - In the series 'Multi-size THP for anonymous memory' Ryan Roberts
     has added a runtime opt-in feature to transparent hugepages which
     improves performance by allocating larger chunks of memory during
     anonymous page faults.

   - Matthew Wilcox has also contributed some cleanup and maintenance
     work against eh buffer_head code int he series 'More buffer_head
     cleanups'.

   - Suren Baghdasaryan has done work on Andrea Arcangeli's series
     'userfaultfd move option'. UFFDIO_MOVE permits userspace heap
     compaction algorithms to move userspace's pages around rather than
     UFFDIO_COPY'a alloc/copy/free.

   - Stefan Roesch has developed a 'KSM Advisor', in the series 'mm/ksm:
     Add ksm advisor'. This is a governor which tunes KSM's scanning
     aggressiveness in response to userspace's current needs.

   - Chengming Zhou has optimized zswap's temporary working memory use
     in the series 'mm/zswap: dstmem reuse optimizations and cleanups'.

   - Matthew Wilcox has performed some maintenance work on the writeback
     code, both code and within filesystems. The series is 'Clean up the
     writeback paths'.

   - Andrey Konovalov has optimized KASAN's handling of alloc and free
     stack traces for secondary-level allocators, in the series 'kasan:
     save mempool stack traces'.

   - Andrey also performed some KASAN maintenance work in the series
     'kasan: assorted clean-ups'.

   - David Hildenbrand has gone to town on the rmap code. Cleanups, more
     pte batching, folio conversions and more. See the series 'mm/rmap:
     interface overhaul'.

   - Kinsey Ho has contributed some maintenance work on the MGLRU code
     in the series 'mm/mglru: Kconfig cleanup'.

   - Matthew Wilcox has contributed lruvec page accounting code cleanups
     in the series 'Remove some lruvec page accounting functions'"

* tag 'mm-stable-2024-01-08-15-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (361 commits)
  mm, treewide: rename MAX_ORDER to MAX_PAGE_ORDER
  mm, treewide: introduce NR_PAGE_ORDERS
  selftests/mm: add separate UFFDIO_MOVE test for PMD splitting
  selftests/mm: skip test if application doesn't has root privileges
  selftests/mm: conform test to TAP format output
  selftests: mm: hugepage-mmap: conform to TAP format output
  selftests/mm: gup_test: conform test to TAP format output
  mm/selftests: hugepage-mremap: conform test to TAP format output
  mm/vmstat: move pgdemote_* out of CONFIG_NUMA_BALANCING
  mm: zsmalloc: return -ENOSPC rather than -EINVAL in zs_malloc while size is too large
  mm/memcontrol: remove __mod_lruvec_page_state()
  mm/khugepaged: use a folio more in collapse_file()
  slub: use a folio in __kmalloc_large_node
  slub: use folio APIs in free_large_kmalloc()
  slub: use alloc_pages_node() in alloc_slab_page()
  mm: remove inc/dec lruvec page state functions
  mm: ratelimit stat flush from workingset shrinker
  kasan: stop leaking stack trace handles
  mm/mglru: remove CONFIG_TRANSPARENT_HUGEPAGE
  mm/mglru: add dummy pmd_dirty()
  ...
2024-01-09 11:18:47 -08:00
Linus Torvalds
c604110e66 vfs-6.8.misc
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Merge tag 'vfs-6.8.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull misc vfs updates from Christian Brauner:
 "This contains the usual miscellaneous features, cleanups, and fixes
  for vfs and individual fses.

  Features:

   - Add Jan Kara as VFS reviewer

   - Show correct device and inode numbers in proc/<pid>/maps for vma
     files on stacked filesystems. This is now easily doable thanks to
     the backing file work from the last cycles. This comes with
     selftests

  Cleanups:

   - Remove a redundant might_sleep() from wait_on_inode()

   - Initialize pointer with NULL, not 0

   - Clarify comment on access_override_creds()

   - Rework and simplify eventfd_signal() and eventfd_signal_mask()
     helpers

   - Process aio completions in batches to avoid needless wakeups

   - Completely decouple struct mnt_idmap from namespaces. We now only
     keep the actual idmapping around and don't stash references to
     namespaces

   - Reformat maintainer entries to indicate that a given subsystem
     belongs to fs/

   - Simplify fput() for files that were never opened

   - Get rid of various pointless file helpers

   - Rename various file helpers

   - Rename struct file members after SLAB_TYPESAFE_BY_RCU switch from
     last cycle

   - Make relatime_need_update() return bool

   - Use GFP_KERNEL instead of GFP_USER when allocating superblocks

   - Replace deprecated ida_simple_*() calls with their current ida_*()
     counterparts

  Fixes:

   - Fix comments on user namespace id mapping helpers. They aren't
     kernel doc comments so they shouldn't be using /**

   - s/Retuns/Returns/g in various places

   - Add missing parameter documentation on can_move_mount_beneath()

   - Rename i_mapping->private_data to i_mapping->i_private_data

   - Fix a false-positive lockdep warning in pipe_write() for watch
     queues

   - Improve __fget_files_rcu() code generation to improve performance

   - Only notify writer that pipe resizing has finished after setting
     pipe->max_usage otherwise writers are never notified that the pipe
     has been resized and hang

   - Fix some kernel docs in hfsplus

   - s/passs/pass/g in various places

   - Fix kernel docs in ntfs

   - Fix kcalloc() arguments order reported by gcc 14

   - Fix uninitialized value in reiserfs"

* tag 'vfs-6.8.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (36 commits)
  reiserfs: fix uninit-value in comp_keys
  watch_queue: fix kcalloc() arguments order
  ntfs: dir.c: fix kernel-doc function parameter warnings
  fs: fix doc comment typo fs tree wide
  selftests/overlayfs: verify device and inode numbers in /proc/pid/maps
  fs/proc: show correct device and inode numbers in /proc/pid/maps
  eventfd: Remove usage of the deprecated ida_simple_xx() API
  fs: super: use GFP_KERNEL instead of GFP_USER for super block allocation
  fs/hfsplus: wrapper.c: fix kernel-doc warnings
  fs: add Jan Kara as reviewer
  fs/inode: Make relatime_need_update return bool
  pipe: wakeup wr_wait after setting max_usage
  file: remove __receive_fd()
  file: stop exposing receive_fd_user()
  fs: replace f_rcuhead with f_task_work
  file: remove pointless wrapper
  file: s/close_fd_get_file()/file_close_fd()/g
  Improve __fget_files_rcu() code generation (and thus __fget_light())
  file: massage cleanup of files that failed to open
  fs/pipe: Fix lockdep false-positive in watchqueue pipe_write()
  ...
2024-01-08 10:26:08 -08:00
Joel Granados
9d5b947535 fs: Remove the now superfluous sentinel elements from ctl_table array
This commit comes at the tail end of a greater effort to remove the
empty elements at the end of the ctl_table arrays (sentinels) which
will reduce the overall build time size of the kernel and run time
memory bloat by ~64 bytes per sentinel (further information Link :
https://lore.kernel.org/all/ZO5Yx5JFogGi%2FcBo@bombadil.infradead.org/)

Remove sentinel elements ctl_table struct. Special attention was placed in
making sure that an empty directory for fs/verity was created when
CONFIG_FS_VERITY_BUILTIN_SIGNATURES is not defined. In this case we use the
register sysctl call that expects a size.

Signed-off-by: Joel Granados <j.granados@samsung.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-12-28 04:57:57 -08:00
Joel Granados
315552310c sysctl: Fix out of bounds access for empty sysctl registers
When registering tables to the sysctl subsystem there is a check to see
if header is a permanently empty directory (used for mounts). This check
evaluates the first element of the ctl_table. This results in an out of
bounds evaluation when registering empty directories.

The function register_sysctl_mount_point now passes a ctl_table of size
1 instead of size 0. It now relies solely on the type to identify
a permanently empty register.

Make sure that the ctl_table has at least one element before testing for
permanent emptiness.

Signed-off-by: Joel Granados <j.granados@samsung.com>
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202311201431.57aae8f3-oliver.sang@intel.com
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-12-28 04:57:57 -08:00
Al Viro
1eae9a4783 /proc/sys: use d_splice_alias() calling conventions to simplify failure exits
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2023-12-21 12:51:01 -05:00
Andrei Vagin
3efdc78fdc
fs/proc: show correct device and inode numbers in /proc/pid/maps
/proc/pid/maps shows device and inode numbers of vma->vm_file-s. Here is
an issue. If a mapped file is on a stackable file system (e.g.,
overlayfs), vma->vm_file is a backing file whose f_inode is on the
underlying filesystem. To show correct numbers, we need to get a user
file and shows its numbers. The same trick is used to show file paths in
/proc/pid/maps.

Cc: Alexander Mikhalitsyn <alexander@mihalicyn.com>
Suggested-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Andrei Vagin <avagin@google.com>
Link: https://lore.kernel.org/r/20231214064439.1023011-1-avagin@google.com
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-12-21 13:17:54 +01:00
Ryan Roberts
3485b88390 mm: thp: introduce multi-size THP sysfs interface
In preparation for adding support for anonymous multi-size THP, introduce
new sysfs structure that will be used to control the new behaviours.  A
new directory is added under transparent_hugepage for each supported THP
size, and contains an `enabled` file, which can be set to "inherit" (to
inherit the global setting), "always", "madvise" or "never".  For now, the
kernel still only supports PMD-sized anonymous THP, so only 1 directory is
populated.

The first half of the change converts transhuge_vma_suitable() and
hugepage_vma_check() so that they take a bitfield of orders for which the
user wants to determine support, and the functions filter out all the
orders that can't be supported, given the current sysfs configuration and
the VMA dimensions.  The resulting functions are renamed to
thp_vma_suitable_orders() and thp_vma_allowable_orders() respectively. 
Convenience functions that take a single, unencoded order and return a
boolean are also defined as thp_vma_suitable_order() and
thp_vma_allowable_order().

The second half of the change implements the new sysfs interface.  It has
been done so that each supported THP size has a `struct thpsize`, which
describes the relevant metadata and is itself a kobject.  This is pretty
minimal for now, but should make it easy to add new per-thpsize files to
the interface if needed in future (e.g.  per-size defrag).  Rather than
keep the `enabled` state directly in the struct thpsize, I've elected to
directly encode it into huge_anon_orders_[always|madvise|inherit]
bitfields since this reduces the amount of work required in
thp_vma_allowable_orders() which is called for every page fault.

See Documentation/admin-guide/mm/transhuge.rst, as modified by this
commit, for details of how the new sysfs interface works.

[ryan.roberts@arm.com: fix build warning when CONFIG_SYSFS is disabled]
  Link: https://lkml.kernel.org/r/20231211125320.3997543-1-ryan.roberts@arm.com
Link: https://lkml.kernel.org/r/20231207161211.2374093-4-ryan.roberts@arm.com
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: Barry Song <v-songbaohua@oppo.com>
Tested-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Tested-by: John Hubbard <jhubbard@nvidia.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Rientjes <rientjes@google.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Itaru Kitayama <itaru.kitayama@gmail.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yin Fengwei <fengwei.yin@intel.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-20 14:48:12 -08:00
Andrei Vagin
e6a9a2cbc1 fs/proc/task_mmu: report SOFT_DIRTY bits through the PAGEMAP_SCAN ioctl
The PAGEMAP_SCAN ioctl returns information regarding page table entries. 
It is more efficient compared to reading pagemap files.  CRIU can start to
utilize this ioctl, but it needs info about soft-dirty bits to track
memory changes.

We are aware of a new method for tracking memory changes implemented in
the PAGEMAP_SCAN ioctl.  For CRIU, the primary advantage of this method is
its usability by unprivileged users.  However, it is not feasible to
transparently replace the soft-dirty tracker with the new one.  The main
problem here is userfault descriptors that have to be preserved between
pre-dump iterations.  It means criu continues supporting the soft-dirty
method to avoid breakage for current users.  The new method will be
implemented as a separate feature.

[avagin@google.com: update tools/include/uapi/linux/fs.h]
  Link: https://lkml.kernel.org/r/20231107164139.576046-1-avagin@google.com
Link: https://lkml.kernel.org/r/20231106220959.296568-1-avagin@google.com
Signed-off-by: Andrei Vagin <avagin@google.com>
Reviewed-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-10 16:51:35 -08:00
Peter Xu
4980e837ca mm/pagemap: fix wr-protect even if PM_SCAN_WP_MATCHING not set
The new pagemap ioctl contains a fast path for wr-protections without
looking into category masks.  It forgets to check PM_SCAN_WP_MATCHING
before applying the wr-protections.  It can cause, e.g., pte markers
installed on archs that do not even support uffd wr-protect.

WARNING: CPU: 0 PID: 5059 at mm/memory.c:1520 zap_pte_range mm/memory.c:1520 [inline]

Link: https://lkml.kernel.org/r/20231116201547.536857-3-peterx@redhat.com
Fixes: 12f6b01a0b ("fs/proc/task_mmu: add fast paths to get/clear PAGE_IS_WRITTEN flag")
Signed-off-by: Peter Xu <peterx@redhat.com>
Reported-by: syzbot+7ca4b2719dc742b8d0a4@syzkaller.appspotmail.com
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Andrei Vagin <avagin@gmail.com>
Cc: Muhammad Usama Anjum <usama.anjum@collabora.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-06 16:12:45 -08:00
Peter Xu
0dff1b407d mm/pagemap: fix ioctl(PAGEMAP_SCAN) on vma check
Patch series "mm/pagemap: A few fixes to the recent PAGEMAP_SCAN".

This series should fix two known reports from syzbot on the new
PAGEMAP_SCAN ioctl():

https://lore.kernel.org/all/000000000000b0e576060a30ee3b@google.com/
https://lore.kernel.org/all/000000000000773fa7060a31e2cc@google.com/

The 3rd patch is something I found when testing these patches.


This patch (of 3):

The new ioctl(PAGEMAP_SCAN) relies on vma wr-protect capability provided
by userfault, however in the vma test it didn't explicitly require the vma
to have wr-protect function enabled, even if PM_SCAN_WP_MATCHING flag is
set.

It means the pagemap code can now apply uffd-wp bit to a page in the vma
even if not registered to userfaultfd at all.

Then in whatever way as long as the pte got written and page fault
resolved, we'll apply the write bit even if uffd-wp bit is set.  We'll see
a pte that has both UFFD_WP and WRITE bit set.  Anything later that looks
up the pte for uffd-wp bit will trigger the warning:

WARNING: CPU: 1 PID: 5071 at arch/x86/include/asm/pgtable.h:403 pte_uffd_wp arch/x86/include/asm/pgtable.h:403 [inline]

Fix it by doing proper check over the vma attributes when
PM_SCAN_WP_MATCHING is specified.

Link: https://lkml.kernel.org/r/20231116201547.536857-1-peterx@redhat.com
Link: https://lkml.kernel.org/r/20231116201547.536857-2-peterx@redhat.com
Fixes: 52526ca7fd ("fs/proc/task_mmu: implement IOCTL to get and optionally clear info about PTEs")
Signed-off-by: Peter Xu <peterx@redhat.com>
Reported-by: syzbot+e94c5aaf7890901ebf9b@syzkaller.appspotmail.com
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Andrei Vagin <avagin@gmail.com>
Reviewed-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-06 16:12:44 -08:00
Casey Schaufler
267c068e5f proc: Use lsmids instead of lsm names for attrs
Use the LSM ID number instead of the LSM name to identify which
security module's attibute data should be shown in /proc/self/attr.
The security_[gs]etprocattr() functions have been changed to expect
the LSM ID. The change from a string comparison to an integer comparison
in these functions will provide a minor performance improvement.

Cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Serge Hallyn <serge@hallyn.com>
Reviewed-by: Mickael Salaun <mic@digikod.net>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2023-11-12 22:54:42 -05:00
Linus Torvalds
8f6f76a6a2 As usual, lots of singleton and doubleton patches all over the tree and
there's little I can say which isn't in the individual changelogs.
 
 The lengthier patch series are
 
 - "kdump: use generic functions to simplify crashkernel reservation in
   arch", from Baoquan He.  This is mainly cleanups and consolidation of
   the "crashkernel=" kernel parameter handling.
 
 - After much discussion, David Laight's "minmax: Relax type checks in
   min() and max()" is here.  Hopefully reduces some typecasting and the
   use of min_t() and max_t().
 
 - A group of patches from Oleg Nesterov which clean up and slightly fix
   our handling of reads from /proc/PID/task/...  and which remove
   task_struct.therad_group.
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Merge tag 'mm-nonmm-stable-2023-11-02-14-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull non-MM updates from Andrew Morton:
 "As usual, lots of singleton and doubleton patches all over the tree
  and there's little I can say which isn't in the individual changelogs.

  The lengthier patch series are

   - 'kdump: use generic functions to simplify crashkernel reservation
     in arch', from Baoquan He. This is mainly cleanups and
     consolidation of the 'crashkernel=' kernel parameter handling

   - After much discussion, David Laight's 'minmax: Relax type checks in
     min() and max()' is here. Hopefully reduces some typecasting and
     the use of min_t() and max_t()

   - A group of patches from Oleg Nesterov which clean up and slightly
     fix our handling of reads from /proc/PID/task/... and which remove
     task_struct.thread_group"

* tag 'mm-nonmm-stable-2023-11-02-14-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (64 commits)
  scripts/gdb/vmalloc: disable on no-MMU
  scripts/gdb: fix usage of MOD_TEXT not defined when CONFIG_MODULES=n
  .mailmap: add address mapping for Tomeu Vizoso
  mailmap: update email address for Claudiu Beznea
  tools/testing/selftests/mm/run_vmtests.sh: lower the ptrace permissions
  .mailmap: map Benjamin Poirier's address
  scripts/gdb: add lx_current support for riscv
  ocfs2: fix a spelling typo in comment
  proc: test ProtectionKey in proc-empty-vm test
  proc: fix proc-empty-vm test with vsyscall
  fs/proc/base.c: remove unneeded semicolon
  do_io_accounting: use sig->stats_lock
  do_io_accounting: use __for_each_thread()
  ocfs2: replace BUG_ON() at ocfs2_num_free_extents() with ocfs2_error()
  ocfs2: fix a typo in a comment
  scripts/show_delta: add __main__ judgement before main code
  treewide: mark stuff as __ro_after_init
  fs: ocfs2: check status values
  proc: test /proc/${pid}/statm
  compiler.h: move __is_constexpr() to compiler.h
  ...
2023-11-02 20:53:31 -10:00
Linus Torvalds
ecae0bd517 Many singleton patches against the MM code. The patch series which are
included in this merge do the following:
 
 - Kemeng Shi has contributed some compation maintenance work in the
   series "Fixes and cleanups to compaction".
 
 - Joel Fernandes has a patchset ("Optimize mremap during mutual
   alignment within PMD") which fixes an obscure issue with mremap()'s
   pagetable handling during a subsequent exec(), based upon an
   implementation which Linus suggested.
 
 - More DAMON/DAMOS maintenance and feature work from SeongJae Park i the
   following patch series:
 
 	mm/damon: misc fixups for documents, comments and its tracepoint
 	mm/damon: add a tracepoint for damos apply target regions
 	mm/damon: provide pseudo-moving sum based access rate
 	mm/damon: implement DAMOS apply intervals
 	mm/damon/core-test: Fix memory leaks in core-test
 	mm/damon/sysfs-schemes: Do DAMOS tried regions update for only one apply interval
 
 - In the series "Do not try to access unaccepted memory" Adrian Hunter
   provides some fixups for the recently-added "unaccepted memory' feature.
   To increase the feature's checking coverage.  "Plug a few gaps where
   RAM is exposed without checking if it is unaccepted memory".
 
 - In the series "cleanups for lockless slab shrink" Qi Zheng has done
   some maintenance work which is preparation for the lockless slab
   shrinking code.
 
 - Qi Zheng has redone the earlier (and reverted) attempt to make slab
   shrinking lockless in the series "use refcount+RCU method to implement
   lockless slab shrink".
 
 - David Hildenbrand contributes some maintenance work for the rmap code
   in the series "Anon rmap cleanups".
 
 - Kefeng Wang does more folio conversions and some maintenance work in
   the migration code.  Series "mm: migrate: more folio conversion and
   unification".
 
 - Matthew Wilcox has fixed an issue in the buffer_head code which was
   causing long stalls under some heavy memory/IO loads.  Some cleanups
   were added on the way.  Series "Add and use bdev_getblk()".
 
 - In the series "Use nth_page() in place of direct struct page
   manipulation" Zi Yan has fixed a potential issue with the direct
   manipulation of hugetlb page frames.
 
 - In the series "mm: hugetlb: Skip initialization of gigantic tail
   struct pages if freed by HVO" has improved our handling of gigantic
   pages in the hugetlb vmmemmep optimizaton code.  This provides
   significant boot time improvements when significant amounts of gigantic
   pages are in use.
 
 - Matthew Wilcox has sent the series "Small hugetlb cleanups" - code
   rationalization and folio conversions in the hugetlb code.
 
 - Yin Fengwei has improved mlock()'s handling of large folios in the
   series "support large folio for mlock"
 
 - In the series "Expose swapcache stat for memcg v1" Liu Shixin has
   added statistics for memcg v1 users which are available (and useful)
   under memcg v2.
 
 - Florent Revest has enhanced the MDWE (Memory-Deny-Write-Executable)
   prctl so that userspace may direct the kernel to not automatically
   propagate the denial to child processes.  The series is named "MDWE
   without inheritance".
 
 - Kefeng Wang has provided the series "mm: convert numa balancing
   functions to use a folio" which does what it says.
 
 - In the series "mm/ksm: add fork-exec support for prctl" Stefan Roesch
   makes is possible for a process to propagate KSM treatment across
   exec().
 
 - Huang Ying has enhanced memory tiering's calculation of memory
   distances.  This is used to permit the dax/kmem driver to use "high
   bandwidth memory" in addition to Optane Data Center Persistent Memory
   Modules (DCPMM).  The series is named "memory tiering: calculate
   abstract distance based on ACPI HMAT"
 
 - In the series "Smart scanning mode for KSM" Stefan Roesch has
   optimized KSM by teaching it to retain and use some historical
   information from previous scans.
 
 - Yosry Ahmed has fixed some inconsistencies in memcg statistics in the
   series "mm: memcg: fix tracking of pending stats updates values".
 
 - In the series "Implement IOCTL to get and optionally clear info about
   PTEs" Peter Xu has added an ioctl to /proc/<pid>/pagemap which permits
   us to atomically read-then-clear page softdirty state.  This is mainly
   used by CRIU.
 
 - Hugh Dickins contributed the series "shmem,tmpfs: general maintenance"
   - a bunch of relatively minor maintenance tweaks to this code.
 
 - Matthew Wilcox has increased the use of the VMA lock over file-backed
   page faults in the series "Handle more faults under the VMA lock".  Some
   rationalizations of the fault path became possible as a result.
 
 - In the series "mm/rmap: convert page_move_anon_rmap() to
   folio_move_anon_rmap()" David Hildenbrand has implemented some cleanups
   and folio conversions.
 
 - In the series "various improvements to the GUP interface" Lorenzo
   Stoakes has simplified and improved the GUP interface with an eye to
   providing groundwork for future improvements.
 
 - Andrey Konovalov has sent along the series "kasan: assorted fixes and
   improvements" which does those things.
 
 - Some page allocator maintenance work from Kemeng Shi in the series
   "Two minor cleanups to break_down_buddy_pages".
 
 - In thes series "New selftest for mm" Breno Leitao has developed
   another MM self test which tickles a race we had between madvise() and
   page faults.
 
 - In the series "Add folio_end_read" Matthew Wilcox provides cleanups
   and an optimization to the core pagecache code.
 
 - Nhat Pham has added memcg accounting for hugetlb memory in the series
   "hugetlb memcg accounting".
 
 - Cleanups and rationalizations to the pagemap code from Lorenzo
   Stoakes, in the series "Abstract vma_merge() and split_vma()".
 
 - Audra Mitchell has fixed issues in the procfs page_owner code's new
   timestamping feature which was causing some misbehaviours.  In the
   series "Fix page_owner's use of free timestamps".
 
 - Lorenzo Stoakes has fixed the handling of new mappings of sealed files
   in the series "permit write-sealed memfd read-only shared mappings".
 
 - Mike Kravetz has optimized the hugetlb vmemmap optimization in the
   series "Batch hugetlb vmemmap modification operations".
 
 - Some buffer_head folio conversions and cleanups from Matthew Wilcox in
   the series "Finish the create_empty_buffers() transition".
 
 - As a page allocator performance optimization Huang Ying has added
   automatic tuning to the allocator's per-cpu-pages feature, in the series
   "mm: PCP high auto-tuning".
 
 - Roman Gushchin has contributed the patchset "mm: improve performance
   of accounted kernel memory allocations" which improves their performance
   by ~30% as measured by a micro-benchmark.
 
 - folio conversions from Kefeng Wang in the series "mm: convert page
   cpupid functions to folios".
 
 - Some kmemleak fixups in Liu Shixin's series "Some bugfix about
   kmemleak".
 
 - Qi Zheng has improved our handling of memoryless nodes by keeping them
   off the allocation fallback list.  This is done in the series "handle
   memoryless nodes more appropriately".
 
 - khugepaged conversions from Vishal Moola in the series "Some
   khugepaged folio conversions".
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Merge tag 'mm-stable-2023-11-01-14-33' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:
 "Many singleton patches against the MM code. The patch series which are
  included in this merge do the following:

   - Kemeng Shi has contributed some compation maintenance work in the
     series 'Fixes and cleanups to compaction'

   - Joel Fernandes has a patchset ('Optimize mremap during mutual
     alignment within PMD') which fixes an obscure issue with mremap()'s
     pagetable handling during a subsequent exec(), based upon an
     implementation which Linus suggested

   - More DAMON/DAMOS maintenance and feature work from SeongJae Park i
     the following patch series:

	mm/damon: misc fixups for documents, comments and its tracepoint
	mm/damon: add a tracepoint for damos apply target regions
	mm/damon: provide pseudo-moving sum based access rate
	mm/damon: implement DAMOS apply intervals
	mm/damon/core-test: Fix memory leaks in core-test
	mm/damon/sysfs-schemes: Do DAMOS tried regions update for only one apply interval

   - In the series 'Do not try to access unaccepted memory' Adrian
     Hunter provides some fixups for the recently-added 'unaccepted
     memory' feature. To increase the feature's checking coverage. 'Plug
     a few gaps where RAM is exposed without checking if it is
     unaccepted memory'

   - In the series 'cleanups for lockless slab shrink' Qi Zheng has done
     some maintenance work which is preparation for the lockless slab
     shrinking code

   - Qi Zheng has redone the earlier (and reverted) attempt to make slab
     shrinking lockless in the series 'use refcount+RCU method to
     implement lockless slab shrink'

   - David Hildenbrand contributes some maintenance work for the rmap
     code in the series 'Anon rmap cleanups'

   - Kefeng Wang does more folio conversions and some maintenance work
     in the migration code. Series 'mm: migrate: more folio conversion
     and unification'

   - Matthew Wilcox has fixed an issue in the buffer_head code which was
     causing long stalls under some heavy memory/IO loads. Some cleanups
     were added on the way. Series 'Add and use bdev_getblk()'

   - In the series 'Use nth_page() in place of direct struct page
     manipulation' Zi Yan has fixed a potential issue with the direct
     manipulation of hugetlb page frames

   - In the series 'mm: hugetlb: Skip initialization of gigantic tail
     struct pages if freed by HVO' has improved our handling of gigantic
     pages in the hugetlb vmmemmep optimizaton code. This provides
     significant boot time improvements when significant amounts of
     gigantic pages are in use

   - Matthew Wilcox has sent the series 'Small hugetlb cleanups' - code
     rationalization and folio conversions in the hugetlb code

   - Yin Fengwei has improved mlock()'s handling of large folios in the
     series 'support large folio for mlock'

   - In the series 'Expose swapcache stat for memcg v1' Liu Shixin has
     added statistics for memcg v1 users which are available (and
     useful) under memcg v2

   - Florent Revest has enhanced the MDWE (Memory-Deny-Write-Executable)
     prctl so that userspace may direct the kernel to not automatically
     propagate the denial to child processes. The series is named 'MDWE
     without inheritance'

   - Kefeng Wang has provided the series 'mm: convert numa balancing
     functions to use a folio' which does what it says

   - In the series 'mm/ksm: add fork-exec support for prctl' Stefan
     Roesch makes is possible for a process to propagate KSM treatment
     across exec()

   - Huang Ying has enhanced memory tiering's calculation of memory
     distances. This is used to permit the dax/kmem driver to use 'high
     bandwidth memory' in addition to Optane Data Center Persistent
     Memory Modules (DCPMM). The series is named 'memory tiering:
     calculate abstract distance based on ACPI HMAT'

   - In the series 'Smart scanning mode for KSM' Stefan Roesch has
     optimized KSM by teaching it to retain and use some historical
     information from previous scans

   - Yosry Ahmed has fixed some inconsistencies in memcg statistics in
     the series 'mm: memcg: fix tracking of pending stats updates
     values'

   - In the series 'Implement IOCTL to get and optionally clear info
     about PTEs' Peter Xu has added an ioctl to /proc/<pid>/pagemap
     which permits us to atomically read-then-clear page softdirty
     state. This is mainly used by CRIU

   - Hugh Dickins contributed the series 'shmem,tmpfs: general
     maintenance', a bunch of relatively minor maintenance tweaks to
     this code

   - Matthew Wilcox has increased the use of the VMA lock over
     file-backed page faults in the series 'Handle more faults under the
     VMA lock'. Some rationalizations of the fault path became possible
     as a result

   - In the series 'mm/rmap: convert page_move_anon_rmap() to
     folio_move_anon_rmap()' David Hildenbrand has implemented some
     cleanups and folio conversions

   - In the series 'various improvements to the GUP interface' Lorenzo
     Stoakes has simplified and improved the GUP interface with an eye
     to providing groundwork for future improvements

   - Andrey Konovalov has sent along the series 'kasan: assorted fixes
     and improvements' which does those things

   - Some page allocator maintenance work from Kemeng Shi in the series
     'Two minor cleanups to break_down_buddy_pages'

   - In thes series 'New selftest for mm' Breno Leitao has developed
     another MM self test which tickles a race we had between madvise()
     and page faults

   - In the series 'Add folio_end_read' Matthew Wilcox provides cleanups
     and an optimization to the core pagecache code

   - Nhat Pham has added memcg accounting for hugetlb memory in the
     series 'hugetlb memcg accounting'

   - Cleanups and rationalizations to the pagemap code from Lorenzo
     Stoakes, in the series 'Abstract vma_merge() and split_vma()'

   - Audra Mitchell has fixed issues in the procfs page_owner code's new
     timestamping feature which was causing some misbehaviours. In the
     series 'Fix page_owner's use of free timestamps'

   - Lorenzo Stoakes has fixed the handling of new mappings of sealed
     files in the series 'permit write-sealed memfd read-only shared
     mappings'

   - Mike Kravetz has optimized the hugetlb vmemmap optimization in the
     series 'Batch hugetlb vmemmap modification operations'

   - Some buffer_head folio conversions and cleanups from Matthew Wilcox
     in the series 'Finish the create_empty_buffers() transition'

   - As a page allocator performance optimization Huang Ying has added
     automatic tuning to the allocator's per-cpu-pages feature, in the
     series 'mm: PCP high auto-tuning'

   - Roman Gushchin has contributed the patchset 'mm: improve
     performance of accounted kernel memory allocations' which improves
     their performance by ~30% as measured by a micro-benchmark

   - folio conversions from Kefeng Wang in the series 'mm: convert page
     cpupid functions to folios'

   - Some kmemleak fixups in Liu Shixin's series 'Some bugfix about
     kmemleak'

   - Qi Zheng has improved our handling of memoryless nodes by keeping
     them off the allocation fallback list. This is done in the series
     'handle memoryless nodes more appropriately'

   - khugepaged conversions from Vishal Moola in the series 'Some
     khugepaged folio conversions'"

[ bcachefs conflicts with the dynamically allocated shrinkers have been
  resolved as per Stephen Rothwell in

     https://lore.kernel.org/all/20230913093553.4290421e@canb.auug.org.au/

  with help from Qi Zheng.

  The clone3 test filtering conflict was half-arsed by yours truly ]

* tag 'mm-stable-2023-11-01-14-33' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (406 commits)
  mm/damon/sysfs: update monitoring target regions for online input commit
  mm/damon/sysfs: remove requested targets when online-commit inputs
  selftests: add a sanity check for zswap
  Documentation: maple_tree: fix word spelling error
  mm/vmalloc: fix the unchecked dereference warning in vread_iter()
  zswap: export compression failure stats
  Documentation: ubsan: drop "the" from article title
  mempolicy: migration attempt to match interleave nodes
  mempolicy: mmap_lock is not needed while migrating folios
  mempolicy: alloc_pages_mpol() for NUMA policy without vma
  mm: add page_rmappable_folio() wrapper
  mempolicy: remove confusing MPOL_MF_LAZY dead code
  mempolicy: mpol_shared_policy_init() without pseudo-vma
  mempolicy trivia: use pgoff_t in shared mempolicy tree
  mempolicy trivia: slightly more consistent naming
  mempolicy trivia: delete those ancient pr_debug()s
  mempolicy: fix migrate_pages(2) syscall return nr_failed
  kernfs: drop shared NUMA mempolicy hooks
  hugetlbfs: drop shared NUMA mempolicy pretence
  mm/damon/sysfs-test: add a unit test for damon_sysfs_set_targets()
  ...
2023-11-02 19:38:47 -10:00
Linus Torvalds
426ee5196d sysctl-6.7-rc1
To help make the move of sysctls out of kernel/sysctl.c not incur a size
 penalty sysctl has been changed to allow us to not require the sentinel, the
 final empty element on the sysctl array. Joel Granados has been doing all this
 work. On the v6.6 kernel we got the major infrastructure changes required to
 support this. For v6.7-rc1 we have all arch/ and drivers/ modified to remove
 the sentinel. Both arch and driver changes have been on linux-next for a bit
 less than a month. It is worth re-iterating the value:
 
   - this helps reduce the overall build time size of the kernel and run time
      memory consumed by the kernel by about ~64 bytes per array
   - the extra 64-byte penalty is no longer inncurred now when we move sysctls
     out from kernel/sysctl.c to their own files
 
 For v6.8-rc1 expect removal of all the sentinels and also then the unneeded
 check for procname == NULL.
 
 The last 2 patches are fixes recently merged by Krister Johansen which allow
 us again to use softlockup_panic early on boot. This used to work but the
 alias work broke it. This is useful for folks who want to detect softlockups
 super early rather than wait and spend money on cloud solutions with nothing
 but an eventual hung kernel. Although this hadn't gone through linux-next it's
 also a stable fix, so we might as well roll through the fixes now.
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Merge tag 'sysctl-6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux

Pull sysctl updates from Luis Chamberlain:
 "To help make the move of sysctls out of kernel/sysctl.c not incur a
  size penalty sysctl has been changed to allow us to not require the
  sentinel, the final empty element on the sysctl array. Joel Granados
  has been doing all this work. On the v6.6 kernel we got the major
  infrastructure changes required to support this. For v6.7-rc1 we have
  all arch/ and drivers/ modified to remove the sentinel. Both arch and
  driver changes have been on linux-next for a bit less than a month. It
  is worth re-iterating the value:

   - this helps reduce the overall build time size of the kernel and run
     time memory consumed by the kernel by about ~64 bytes per array

   - the extra 64-byte penalty is no longer inncurred now when we move
     sysctls out from kernel/sysctl.c to their own files

  For v6.8-rc1 expect removal of all the sentinels and also then the
  unneeded check for procname == NULL.

  The last two patches are fixes recently merged by Krister Johansen
  which allow us again to use softlockup_panic early on boot. This used
  to work but the alias work broke it. This is useful for folks who want
  to detect softlockups super early rather than wait and spend money on
  cloud solutions with nothing but an eventual hung kernel. Although
  this hadn't gone through linux-next it's also a stable fix, so we
  might as well roll through the fixes now"

* tag 'sysctl-6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux: (23 commits)
  watchdog: move softlockup_panic back to early_param
  proc: sysctl: prevent aliased sysctls from getting passed to init
  intel drm: Remove now superfluous sentinel element from ctl_table array
  Drivers: hv: Remove now superfluous sentinel element from ctl_table array
  raid: Remove now superfluous sentinel element from ctl_table array
  fw loader: Remove the now superfluous sentinel element from ctl_table array
  sgi-xp: Remove the now superfluous sentinel element from ctl_table array
  vrf: Remove the now superfluous sentinel element from ctl_table array
  char-misc: Remove the now superfluous sentinel element from ctl_table array
  infiniband: Remove the now superfluous sentinel element from ctl_table array
  macintosh: Remove the now superfluous sentinel element from ctl_table array
  parport: Remove the now superfluous sentinel element from ctl_table array
  scsi: Remove now superfluous sentinel element from ctl_table array
  tty: Remove now superfluous sentinel element from ctl_table array
  xen: Remove now superfluous sentinel element from ctl_table array
  hpet: Remove now superfluous sentinel element from ctl_table array
  c-sky: Remove now superfluous sentinel element from ctl_talbe array
  powerpc: Remove now superfluous sentinel element from ctl_table arrays
  riscv: Remove now superfluous sentinel element from ctl_table array
  x86/vdso: Remove now superfluous sentinel element from ctl_table array
  ...
2023-11-01 20:51:41 -10:00
Linus Torvalds
1b10d2c8c6 Bootconfig for v6.7:
- Documentation update for /proc/cmdline, which includes both the
    parameters from bootloader and the embedded parameters in the kernel.
 
  - fs/proc: Add bootloader argument as a comment line to /proc/bootconfig
    so that the user can distinguish what parameters were passed from
    bootloader even if bootconfig modified that.
 
  - Documentation fix to add /proc/bootconfig to proc.rst.
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Merge tag 'bootconfig-v6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull bootconfig updates from Masami Hiramatsu:

 - Documentation update for /proc/cmdline, which includes both the
   parameters from bootloader and the embedded parameters in the kernel

 - fs/proc: Add bootloader argument as a comment line to
   /proc/bootconfig so that the user can distinguish what parameters
   were passed from bootloader even if bootconfig modified that

 - Documentation fix to add /proc/bootconfig to proc.rst

* tag 'bootconfig-v6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  doc: Add /proc/bootconfig to proc.rst
  fs/proc: Add boot loader arguments as comment to /proc/bootconfig
  doc: Update /proc/cmdline documentation to include boot config
2023-11-01 16:07:05 -10:00
Yang Li
639931020e fs/proc/base.c: remove unneeded semicolon
./fs/proc/base.c:3829:2-3: Unneeded semicolon

Link: https://lkml.kernel.org/r/20231026005634.6581-1-yang.lee@linux.alibaba.com
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=7057
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-11-01 12:46:59 -07:00
Oleg Nesterov
1df4bd83cd do_io_accounting: use sig->stats_lock
Rather than lock_task_sighand(), sig->stats_lock was specifically designed
for this type of use.

This way the "if (whole)" branch runs lockless in the likely case.

Link: https://lkml.kernel.org/r/20231023153405.GA4639@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-11-01 12:46:59 -07:00
Oleg Nesterov
2320222067 do_io_accounting: use __for_each_thread()
Rather than while_each_thread() which should be avoided when possible.

This makes the code more clear and allows the next change.

Link: https://lkml.kernel.org/r/20231023153343.GA4629@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-11-01 12:46:58 -07:00
Krister Johansen
8b793bcda6 watchdog: move softlockup_panic back to early_param
Setting softlockup_panic from do_sysctl_args() causes it to take effect
later in boot.  The lockup detector is enabled before SMP is brought
online, but do_sysctl_args runs afterwards.  If a user wants to set
softlockup_panic on boot and have it trigger should a softlockup occur
during onlining of the non-boot processors, they could do this prior to
commit f117955a22 ("kernel/watchdog.c: convert {soft/hard}lockup boot
parameters to sysctl aliases").  However, after this commit the value
of softlockup_panic is set too late to be of help for this type of
problem.  Restore the prior behavior.

Signed-off-by: Krister Johansen <kjlx@templeofstupid.com>
Cc: stable@vger.kernel.org
Fixes: f117955a22 ("kernel/watchdog.c: convert {soft/hard}lockup boot parameters to sysctl aliases")
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-11-01 12:10:02 -07:00
Krister Johansen
8001f49394 proc: sysctl: prevent aliased sysctls from getting passed to init
The code that checks for unknown boot options is unaware of the sysctl
alias facility, which maps bootparams to sysctl values.  If a user sets
an old value that has a valid alias, a message about an invalid
parameter will be printed during boot, and the parameter will get passed
to init.  Fix by checking for the existence of aliased parameters in the
unknown boot parameter code.  If an alias exists, don't return an error
or pass the value to init.

Signed-off-by: Krister Johansen <kjlx@templeofstupid.com>
Cc: stable@vger.kernel.org
Fixes: 0a477e1ae2 ("kernel/sysctl: support handling command line aliases")
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-11-01 12:10:02 -07:00
Linus Torvalds
14ab6d425e vfs-6.7.ctime
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Merge tag 'vfs-6.7.ctime' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs

Pull vfs inode time accessor updates from Christian Brauner:
 "This finishes the conversion of all inode time fields to accessor
  functions as discussed on list. Changing timestamps manually as we
  used to do before is error prone. Using accessors function makes this
  robust.

  It does not contain the switch of the time fields to discrete 64 bit
  integers to replace struct timespec and free up space in struct inode.
  But after this, the switch can be trivially made and the patch should
  only affect the vfs if we decide to do it"

* tag 'vfs-6.7.ctime' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs: (86 commits)
  fs: rename inode i_atime and i_mtime fields
  security: convert to new timestamp accessors
  selinux: convert to new timestamp accessors
  apparmor: convert to new timestamp accessors
  sunrpc: convert to new timestamp accessors
  mm: convert to new timestamp accessors
  bpf: convert to new timestamp accessors
  ipc: convert to new timestamp accessors
  linux: convert to new timestamp accessors
  zonefs: convert to new timestamp accessors
  xfs: convert to new timestamp accessors
  vboxsf: convert to new timestamp accessors
  ufs: convert to new timestamp accessors
  udf: convert to new timestamp accessors
  ubifs: convert to new timestamp accessors
  tracefs: convert to new timestamp accessors
  sysv: convert to new timestamp accessors
  squashfs: convert to new timestamp accessors
  server: convert to new timestamp accessors
  client: convert to new timestamp accessors
  ...
2023-10-30 09:47:13 -10:00
Linus Torvalds
3b3f874cc1 vfs-6.7.misc
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Merge tag 'vfs-6.7.misc' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs

Pull misc vfs updates from Christian Brauner:
 "This contains the usual miscellaneous features, cleanups, and fixes
  for vfs and individual fses.

  Features:

   - Rename and export helpers that get write access to a mount. They
     are used in overlayfs to get write access to the upper mount.

   - Print the pretty name of the root device on boot failure. This
     helps in scenarios where we would usually only print
     "unknown-block(1,2)".

   - Add an internal SB_I_NOUMASK flag. This is another part in the
     endless POSIX ACL saga in a way.

     When POSIX ACLs are enabled via SB_POSIXACL the vfs cannot strip
     the umask because if the relevant inode has POSIX ACLs set it might
     take the umask from there. But if the inode doesn't have any POSIX
     ACLs set then we apply the umask in the filesytem itself. So we end
     up with:

      (1) no SB_POSIXACL -> strip umask in vfs
      (2) SB_POSIXACL    -> strip umask in filesystem

     The umask semantics associated with SB_POSIXACL allowed filesystems
     that don't even support POSIX ACLs at all to raise SB_POSIXACL
     purely to avoid umask stripping. That specifically means NFS v4 and
     Overlayfs. NFS v4 does it because it delegates this to the server
     and Overlayfs because it needs to delegate umask stripping to the
     upper filesystem, i.e., the filesystem used as the writable layer.

     This went so far that SB_POSIXACL is raised eve on kernels that
     don't even have POSIX ACL support at all.

     Stop this blatant abuse and add SB_I_NOUMASK which is an internal
     superblock flag that filesystems can raise to opt out of umask
     handling. That should really only be the two mentioned above. It's
     not that we want any filesystems to do this. Ideally we have all
     umask handling always in the vfs.

   - Make overlayfs use SB_I_NOUMASK too.

   - Now that we have SB_I_NOUMASK, stop checking for SB_POSIXACL in
     IS_POSIXACL() if the kernel doesn't have support for it. This is a
     very old patch but it's only possible to do this now with the wider
     cleanup that was done.

   - Follow-up work on fake path handling from last cycle. Citing mostly
     from Amir:

     When overlayfs was first merged, overlayfs files of regular files
     and directories, the ones that are installed in file table, had a
     "fake" path, namely, f_path is the overlayfs path and f_inode is
     the "real" inode on the underlying filesystem.

     In v6.5, we took another small step by introducing of the
     backing_file container and the file_real_path() helper. This change
     allowed vfs and filesystem code to get the "real" path of an
     overlayfs backing file. With this change, we were able to make
     fsnotify work correctly and report events on the "real" filesystem
     objects that were accessed via overlayfs.

     This method works fine, but it still leaves the vfs vulnerable to
     new code that is not aware of files with fake path. A recent
     example is commit db1d1e8b98 ("IMA: use vfs_getattr_nosec to get
     the i_version"). This commit uses direct referencing to f_path in
     IMA code that otherwise uses file_inode() and file_dentry() to
     reference the filesystem objects that it is measuring.

     This contains work to switch things around: instead of having
     filesystem code opt-in to get the "real" path, have generic code
     opt-in for the "fake" path in the few places that it is needed.

     Is it far more likely that new filesystems code that does not use
     the file_dentry() and file_real_path() helpers will end up causing
     crashes or averting LSM/audit rules if we keep the "fake" path
     exposed by default.

     This change already makes file_dentry() moot, but for now we did
     not change this helper just added a WARN_ON() in ovl_d_real() to
     catch if we have made any wrong assumptions.

     After the dust settles on this change, we can make file_dentry() a
     plain accessor and we can drop the inode argument to ->d_real().

   - Switch struct file to SLAB_TYPESAFE_BY_RCU. This looks like a small
     change but it really isn't and I would like to see everyone on
     their tippie toes for any possible bugs from this work.

     Essentially we've been doing most of what SLAB_TYPESAFE_BY_RCU for
     files since a very long time because of the nasty interactions
     between the SCM_RIGHTS file descriptor garbage collection. So
     extending it makes a lot of sense but it is a subtle change. There
     are almost no places that fiddle with file rcu semantics directly
     and the ones that did mess around with struct file internal under
     rcu have been made to stop doing that because it really was always
     dodgy.

     I forgot to put in the link tag for this change and the discussion
     in the commit so adding it into the merge message:

       https://lore.kernel.org/r/20230926162228.68666-1-mjguzik@gmail.com

  Cleanups:

   - Various smaller pipe cleanups including the removal of a spin lock
     that was only used to protect against writes without pipe_lock()
     from O_NOTIFICATION_PIPE aka watch queues. As that was never
     implemented remove the additional locking from pipe_write().

   - Annotate struct watch_filter with the new __counted_by attribute.

   - Clarify do_unlinkat() cleanup so that it doesn't look like an extra
     iput() is done that would cause issues.

   - Simplify file cleanup when the file has never been opened.

   - Use module helper instead of open-coding it.

   - Predict error unlikely for stale retry.

   - Use WRITE_ONCE() for mount expiry field instead of just commenting
     that one hopes the compiler doesn't get smart.

  Fixes:

   - Fix readahead on block devices.

   - Fix writeback when layztime is enabled and inodes whose timestamp
     is the only thing that changed reside on wb->b_dirty_time. This
     caused excessively large zombie memory cgroup when lazytime was
     enabled as such inodes weren't handled fast enough.

   - Convert BUG_ON() to WARN_ON_ONCE() in open_last_lookups()"

* tag 'vfs-6.7.misc' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs: (26 commits)
  file, i915: fix file reference for mmap_singleton()
  vfs: Convert BUG_ON to WARN_ON_ONCE in open_last_lookups
  writeback, cgroup: switch inodes with dirty timestamps to release dying cgwbs
  chardev: Simplify usage of try_module_get()
  ovl: rely on SB_I_NOUMASK
  fs: fix umask on NFS with CONFIG_FS_POSIX_ACL=n
  fs: store real path instead of fake path in backing file f_path
  fs: create helper file_user_path() for user displayed mapped file path
  fs: get mnt_writers count for an open backing file's real path
  vfs: stop counting on gcc not messing with mnt_expiry_mark if not asked
  vfs: predict the error in retry_estale as unlikely
  backing file: free directly
  vfs: fix readahead(2) on block devices
  io_uring: use files_lookup_fd_locked()
  file: convert to SLAB_TYPESAFE_BY_RCU
  vfs: shave work on failed file open
  fs: simplify misleading code to remove ambiguity regarding ihold()/iput()
  watch_queue: Annotate struct watch_filter with __counted_by
  fs/pipe: use spinlock in pipe_read() only if there is a watch_queue
  fs/pipe: remove unnecessary spinlock from pipe_write()
  ...
2023-10-30 09:14:19 -10:00
Hugh Dickins
ddc1a5cbc0 mempolicy: alloc_pages_mpol() for NUMA policy without vma
Shrink shmem's stack usage by eliminating the pseudo-vma from its folio
allocation.  alloc_pages_mpol(gfp, order, pol, ilx, nid) becomes the
principal actor for passing mempolicy choice down to __alloc_pages(),
rather than vma_alloc_folio(gfp, order, vma, addr, hugepage).

vma_alloc_folio() and alloc_pages() remain, but as wrappers around
alloc_pages_mpol().  alloc_pages_bulk_*() untouched, except to provide the
additional args to policy_nodemask(), which subsumes policy_node(). 
Cleanup throughout, cutting out some unhelpful "helpers".

It would all be much simpler without MPOL_INTERLEAVE, but that adds a
dynamic to the constant mpol: complicated by v3.6 commit 09c231cb8b
("tmpfs: distribute interleave better across nodes"), which added ino bias
to the interleave, hidden from mm/mempolicy.c until this commit.

Hence "ilx" throughout, the "interleave index".  Originally I thought it
could be done just with nid, but that's wrong: the nodemask may come from
the shared policy layer below a shmem vma, or it may come from the task
layer above a shmem vma; and without the final nodemask then nodeid cannot
be decided.  And how ilx is applied depends also on page order.

The interleave index is almost always irrelevant unless MPOL_INTERLEAVE:
with one exception in alloc_pages_mpol(), where the NO_INTERLEAVE_INDEX
passed down from vma-less alloc_pages() is also used as hint not to use
THP-style hugepage allocation - to avoid the overhead of a hugepage arg
(though I don't understand why we never just added a GFP bit for THP - if
it actually needs a different allocation strategy from other pages of the
same order).  vma_alloc_folio() still carries its hugepage arg here, but
it is not used, and should be removed when agreed.

get_vma_policy() no longer allows a NULL vma: over time I believe we've
eradicated all the places which used to need it e.g.  swapoff and madvise
used to pass NULL vma to read_swap_cache_async(), but now know the vma.

[hughd@google.com: handle NULL mpol being passed to __read_swap_cache_async()]
  Link: https://lkml.kernel.org/r/ea419956-4751-0102-21f7-9c93cb957892@google.com
Link: https://lkml.kernel.org/r/74e34633-6060-f5e3-aee-7040d43f2e93@google.com
Link: https://lkml.kernel.org/r/1738368e-bac0-fd11-ed7f-b87142a939fe@google.com
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tejun heo <tj@kernel.org>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Cc: Domenico Cerasuolo <mimmocerasuolo@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-25 16:47:16 -07:00
Amir Goldstein
08582d678f
fs: create helper file_user_path() for user displayed mapped file path
Overlayfs uses backing files with "fake" overlayfs f_path and "real"
underlying f_inode, in order to use underlying inode aops for mapped
files and to display the overlayfs path in /proc/<pid>/maps.

In preparation for storing the overlayfs "fake" path instead of the
underlying "real" path in struct backing_file, define a noop helper
file_user_path() that returns f_path for now.

Use the new helper in procfs and kernel logs whenever a path of a
mapped file is displayed to users.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Link: https://lore.kernel.org/r/20231009153712.1566422-3-amir73il@gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-10-19 11:03:15 +02:00
Christian Brauner
0ede61d858
file: convert to SLAB_TYPESAFE_BY_RCU
In recent discussions around some performance improvements in the file
handling area we discussed switching the file cache to rely on
SLAB_TYPESAFE_BY_RCU which allows us to get rid of call_rcu() based
freeing for files completely. This is a pretty sensitive change overall
but it might actually be worth doing.

The main downside is the subtlety. The other one is that we should
really wait for Jann's patch to land that enables KASAN to handle
SLAB_TYPESAFE_BY_RCU UAFs. Currently it doesn't but a patch for this
exists.

With SLAB_TYPESAFE_BY_RCU objects may be freed and reused multiple times
which requires a few changes. So it isn't sufficient anymore to just
acquire a reference to the file in question under rcu using
atomic_long_inc_not_zero() since the file might have already been
recycled and someone else might have bumped the reference.

In other words, callers might see reference count bumps from newer
users. For this reason it is necessary to verify that the pointer is the
same before and after the reference count increment. This pattern can be
seen in get_file_rcu() and __files_get_rcu().

In addition, it isn't possible to access or check fields in struct file
without first aqcuiring a reference on it. Not doing that was always
very dodgy and it was only usable for non-pointer data in struct file.
With SLAB_TYPESAFE_BY_RCU it is necessary that callers first acquire a
reference under rcu or they must hold the files_lock of the fdtable.
Failing to do either one of this is a bug.

Thanks to Jann for pointing out that we need to ensure memory ordering
between reallocations and pointer check by ensuring that all subsequent
loads have a dependency on the second load in get_file_rcu() and
providing a fixup that was folded into this patch.

Cc: Jann Horn <jannh@google.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-10-19 11:02:48 +02:00
Alexey Dobriyan
ead5a72773 proc: save LOC by using while loop
Use while loop instead of infinite loop with "break;".

Also move some variable to the inner scope where they belong.

Link: https://lkml.kernel.org/r/82c8f8e7-8ded-46ca-8857-e60b991d6205@p183
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-18 14:43:22 -07:00
Alexey Dobriyan
860a2e7fa4 proc: use initializer for clearing some buffers
Save LOC by using dark magic of initialisation instead of memset().

Those buffer aren't passed to userspace directly so padding is not
an issue.

Link: https://lkml.kernel.org/r/3821d3a2-6e10-4629-b0d5-9519d828ab72@p183
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-18 14:43:22 -07:00
Muhammad Usama Anjum
12f6b01a0b fs/proc/task_mmu: add fast paths to get/clear PAGE_IS_WRITTEN flag
Adding fast code paths to handle specifically only get and/or clear
operation of PAGE_IS_WRITTEN, increases its performance by 0-35%.  The
results of some test cases are given below:

Test-case-1
t1 = (Get + WP) time
t2 = WP time
                       t1            t2
Without this patch:    140-170mcs    90-115mcs
With this patch:       110mcs        80mcs
Worst case diff:       35% faster    30% faster

Test-case-2
t3 = atomic Get and WP
                      t3
Without this patch:   120-140mcs
With this patch:      100-110mcs
Worst case diff:      21% faster

Link: https://lkml.kernel.org/r/20230821141518.870589-4-usama.anjum@collabora.com
Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Alex Sierra <alex.sierra@amd.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Gustavo A. R. Silva <gustavoars@kernel.org>
Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Miroslaw <emmir@google.com>
Cc: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Nadav Amit <namit@vmware.com>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Paul Gofman <pgofman@codeweavers.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yun Zhou <yun.zhou@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-18 14:34:13 -07:00
Muhammad Usama Anjum
52526ca7fd fs/proc/task_mmu: implement IOCTL to get and optionally clear info about PTEs
The PAGEMAP_SCAN IOCTL on the pagemap file can be used to get or optionally
clear the info about page table entries. The following operations are
supported in this IOCTL:
- Scan the address range and get the memory ranges matching the provided
  criteria. This is performed when the output buffer is specified.
- Write-protect the pages. The PM_SCAN_WP_MATCHING is used to write-protect
  the pages of interest. The PM_SCAN_CHECK_WPASYNC aborts the operation if
  non-Async Write Protected pages are found. The ``PM_SCAN_WP_MATCHING``
  can be used with or without PM_SCAN_CHECK_WPASYNC.
- Both of those operations can be combined into one atomic operation where
  we can get and write protect the pages as well.

Following flags about pages are currently supported:
- PAGE_IS_WPALLOWED - Page has async-write-protection enabled
- PAGE_IS_WRITTEN - Page has been written to from the time it was write protected
- PAGE_IS_FILE - Page is file backed
- PAGE_IS_PRESENT - Page is present in the memory
- PAGE_IS_SWAPPED - Page is in swapped
- PAGE_IS_PFNZERO - Page has zero PFN
- PAGE_IS_HUGE - Page is THP or Hugetlb backed

This IOCTL can be extended to get information about more PTE bits. The
entire address range passed by user [start, end) is scanned until either
the user provided buffer is full or max_pages have been found.

[akpm@linux-foundation.org: update it for "mm: hugetlb: add huge page size param to set_huge_pte_at()"]
[akpm@linux-foundation.org: fix CONFIG_HUGETLB_PAGE=n warning]
[arnd@arndb.de: hide unused pagemap_scan_backout_range() function]
  Link: https://lkml.kernel.org/r/20230927060257.2975412-1-arnd@kernel.org
[sfr@canb.auug.org.au: fix "fs/proc/task_mmu: hide unused pagemap_scan_backout_range() function"]
  Link: https://lkml.kernel.org/r/20230928092223.0625c6bf@canb.auug.org.au
Link: https://lkml.kernel.org/r/20230821141518.870589-3-usama.anjum@collabora.com
Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reviewed-by: Andrei Vagin <avagin@gmail.com>
Reviewed-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Cc: Alex Sierra <alex.sierra@amd.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Gustavo A. R. Silva <gustavoars@kernel.org>
Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Miroslaw <emmir@google.com>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Nadav Amit <namit@vmware.com>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Paul Gofman <pgofman@codeweavers.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yun Zhou <yun.zhou@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-18 14:34:12 -07:00
Jeff Layton
200d942170
proc: convert to new timestamp accessors
Convert to using the new inode timestamp accessor functions.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://lore.kernel.org/r/20231004185347.80880-59-jlayton@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-10-18 14:08:26 +02:00
Paul E. McKenney
717c7c894d fs/proc: Add boot loader arguments as comment to /proc/bootconfig
In kernels built with CONFIG_BOOT_CONFIG_FORCE=y, /proc/cmdline will
show all kernel boot parameters, both those supplied by the boot loader
and those embedded in the kernel image.  This works well for those who
just want to see all of the kernel boot parameters, but is not helpful to
those who need to see only those parameters supplied by the boot loader.
This is especially important when these parameters are presented to the
boot loader by automation that might gather them from diverse sources.
It is also useful when booting the next kernel via kexec(), in which
case it is necessary to supply only those kernel command-line arguments
from the boot loader, and most definitely not those that were embedded
into the current kernel.

Therefore, add comments to /proc/bootconfig of the form:

	# Parameters from bootloader:
	# root=UUID=ac0f0548-a69d-43ca-a06b-7db01bcbd5ad ro quiet ...

The second added line shows only those kernel boot parameters supplied
by the boot loader.

Link: https://lore.kernel.org/all/20231005171747.541123-2-paulmck@kernel.org/

Link: https://lore.kernel.org/all/CAHk-=wjpVAW3iRq_bfKnVfs0ZtASh_aT67bQBG11b4W6niYVUw@mail.gmail.com/
Link: https://lore.kernel.org/all/20230731233130.424913-1-paulmck@kernel.org/
Co-developed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Arnd Bergmann <arnd@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: <linux-trace-kernel@vger.kernel.org>
Cc: <linux-fsdevel@vger.kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2023-10-07 10:45:56 +09:00
Oleg Nesterov
7904e53ed5 fs/proc: do_task_stat: use __for_each_thread()
do/while_each_thread should be avoided when possible.

Link: https://lkml.kernel.org/r/20230909164501.GA11581@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-04 10:41:57 -07:00
Oleg Nesterov
33a9813825 introduce __next_thread(), fix next_tid() vs exec() race
Patch series "introduce __next_thread(), change next_thread()".

After commit dce8f8ed1d ("document while_each_thread(), change
first_tid() to use for_each_thread()") + this series

1. We have only one lockless user of next_thread(), task_group_seq_get_next().
   I think it should be changed too.

2. We have only one user of task_struct->thread_group, thread_group_empty().
   The next patches will change thread_group_empty() and kill ->thread_group.


This patch (of 2):

next_tid(start) does:

	rcu_read_lock();
	if (pid_alive(start)) {
		pos = next_thread(start);
		if (thread_group_leader(pos))
			pos = NULL;
		else
			get_task_struct(pos);

it should return pos = NULL when next_thread() wraps to the 1st thread
in the thread group, group leader, and the thread_group_leader() check
tries to detect this case.

But this can race with exec. To simplify, suppose we have a main thread
M and a single sub-thread T, next_tid(T) should return NULL.

Now suppose that T execs. If next_tid(T) is called after T changes the
leadership and before it does release_task() which removes the old leader
from list, then next_thread() returns M and thread_group_leader(M) = F.

Lockless use of next_thread() should be avoided. After this change only
task_group_seq_get_next() does this, and I believe it should be changed
as well.

Link: https://lkml.kernel.org/r/20230824143112.GA31208@redhat.com
Link: https://lkml.kernel.org/r/20230824143142.GA31222@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-04 10:41:56 -07:00
Qi Zheng
1720f5dd8d fs: super: dynamically allocate the s_shrink
In preparation for implementing lockless slab shrink, use new APIs to
dynamically allocate the s_shrink, so that it can be freed asynchronously
via RCU. Then it doesn't need to wait for RCU read-side critical section
when releasing the struct super_block.

Link: https://lkml.kernel.org/r/20230911094444.68966-39-zhengqi.arch@bytedance.com
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: David Sterba <dsterba@suse.com>
Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Abhinav Kumar <quic_abhinavk@quicinc.com>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Anna Schumaker <anna@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Bob Peterson <rpeterso@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Carlos Llamas <cmllamas@google.com>
Cc: Chandan Babu R <chandan.babu@oracle.com>
Cc: Chao Yu <chao@kernel.org>
Cc: Christian Koenig <christian.koenig@amd.com>
Cc: Chuck Lever <cel@kernel.org>
Cc: Coly Li <colyli@suse.de>
Cc: Dai Ngo <Dai.Ngo@oracle.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: "Darrick J. Wong" <djwong@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Airlie <airlied@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Cc: Gao Xiang <hsiangkao@linux.alibaba.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Huang Rui <ray.huang@amd.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Jeffle Xu <jefflexu@linux.alibaba.com>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Kirill Tkhai <tkhai@ya.ru>
Cc: Marijn Suijten <marijn.suijten@somainline.org>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Mike Snitzer <snitzer@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nadav Amit <namit@vmware.com>
Cc: Neil Brown <neilb@suse.de>
Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Cc: Olga Kornievskaia <kolga@netapp.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Sean Paul <sean@poorly.run>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Song Liu <song@kernel.org>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Steven Price <steven.price@arm.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Cc: Yue Hu <huyue2@coolpad.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-04 10:32:26 -07:00
Adrian Hunter
e538a58209 proc/kcore: do not try to access unaccepted memory
Support for unaccepted memory was added recently, refer commit
dcdfdd40fa ("mm: Add support for unaccepted memory"), whereby a virtual
machine may need to accept memory before it can be used.

Do not try to access unaccepted memory because it can cause the guest to
fail.

For /proc/kcore, which is read-only and does not support mmap, this means a
read of unaccepted memory will return zeros.

Link: https://lkml.kernel.org/r/20230911112114.91323-3-adrian.hunter@intel.com
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-04 10:32:22 -07:00
Ben Wolsieffer
fe44198016 proc: nommu: fix empty /proc/<pid>/maps
On no-MMU, /proc/<pid>/maps reads as an empty file.  This happens because
find_vma(mm, 0) always returns NULL (assuming no vma actually contains the
zero address, which is normally the case).

To fix this bug and improve the maintainability in the future, this patch
makes the no-MMU implementation as similar as possible to the MMU
implementation.

The only remaining differences are the lack of hold/release_task_mempolicy
and the extra code to shoehorn the gate vma into the iterator.

This has been tested on top of 6.5.3 on an STM32F746.

Link: https://lkml.kernel.org/r/20230915160055.971059-2-ben.wolsieffer@hefring.com
Fixes: 0c563f1480 ("proc: remove VMA rbtree use from nommu")
Signed-off-by: Ben Wolsieffer <ben.wolsieffer@hefring.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Giulio Benetti <giulio.benetti@benettiengineering.com>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-09-19 13:21:34 -07:00
Ben Wolsieffer
578d7699e5 proc: nommu: /proc/<pid>/maps: release mmap read lock
The no-MMU implementation of /proc/<pid>/map doesn't normally release
the mmap read lock, because it uses !IS_ERR_OR_NULL(_vml) to determine
whether to release the lock.  Since _vml is NULL when the end of the
mappings is reached, the lock is not released.

Reading /proc/1/maps twice doesn't cause a hang because it only
takes the read lock, which can be taken multiple times and therefore
doesn't show any problem if the lock isn't released. Instead, you need
to perform some operation that attempts to take the write lock after
reading /proc/<pid>/maps. To actually reproduce the bug, compile the
following code as 'proc_maps_bug':

#include <stdio.h>
#include <unistd.h>
#include <sys/mman.h>

int main(int argc, char *argv[]) {
        void *buf;
        sleep(1);
        buf = mmap(NULL, 4096, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
        puts("mmap returned");
        return 0;
}

Then, run:

  ./proc_maps_bug &; cat /proc/$!/maps; fg

Without this patch, mmap() will hang and the command will never
complete.
	
This code was incorrectly adapted from the MMU implementation, which at
the time released the lock in m_next() before returning the last entry.

The MMU implementation has diverged further from the no-MMU version since
then, so this patch brings their locking and error handling into sync,
fixing the bug and hopefully avoiding similar issues in the future.

Link: https://lkml.kernel.org/r/20230914163019.4050530-2-ben.wolsieffer@hefring.com
Fixes: 47fecca15c ("fs/proc/task_nommu.c: don't use priv->task->mm")
Signed-off-by: Ben Wolsieffer <ben.wolsieffer@hefring.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Giulio Benetti <giulio.benetti@benettiengineering.com>
Cc: Greg Ungerer <gerg@uclinux.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-09-19 13:21:34 -07:00
Linus Torvalds
5eea5820c7 - Stefan Roesch has added ksm statistics to /proc/pid/smaps
- Also a number of singleton patches, mainly cleanups and leftovers.
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Merge tag 'mm-stable-2023-09-04-14-00' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull more MM updates from Andrew Morton:

 - Stefan Roesch has added ksm statistics to /proc/pid/smaps

 - Also a number of singleton patches, mainly cleanups and leftovers

* tag 'mm-stable-2023-09-04-14-00' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  mm/kmemleak: move up cond_resched() call in page scanning loop
  mm: page_alloc: remove stale CMA guard code
  MAINTAINERS: add rmap.h to mm entry
  rmap: remove anon_vma_link() nommu stub
  proc/ksm: add ksm stats to /proc/pid/smaps
  mm/hwpoison: rename hwp_walk* to hwpoison_walk*
  mm: memory-failure: add PageOffline() check
2023-09-05 10:56:27 -07:00
Stefan Roesch
8b47933544 proc/ksm: add ksm stats to /proc/pid/smaps
With madvise and prctl KSM can be enabled for different VMA's.  Once it is
enabled we can query how effective KSM is overall.  However we cannot
easily query if an individual VMA benefits from KSM.

This commit adds a KSM section to the /prod/<pid>/smaps file.  It reports
how many of the pages are KSM pages.  Note that KSM-placed zeropages are
not included, only actual KSM pages.

Here is a typical output:

7f420a000000-7f421a000000 rw-p 00000000 00:00 0
Size:             262144 kB
KernelPageSize:        4 kB
MMUPageSize:           4 kB
Rss:               51212 kB
Pss:                8276 kB
Shared_Clean:        172 kB
Shared_Dirty:      42996 kB
Private_Clean:       196 kB
Private_Dirty:      7848 kB
Referenced:        15388 kB
Anonymous:         51212 kB
KSM:               41376 kB
LazyFree:              0 kB
AnonHugePages:         0 kB
ShmemPmdMapped:        0 kB
FilePmdMapped:         0 kB
Shared_Hugetlb:        0 kB
Private_Hugetlb:       0 kB
Swap:             202016 kB
SwapPss:            3882 kB
Locked:                0 kB
THPeligible:    0
ProtectionKey:         0
ksm_state:          0
ksm_skip_base:      0
ksm_skip_count:     0
VmFlags: rd wr mr mw me nr mg anon

This information also helps with the following workflow:
- First enable KSM for all the VMA's of a process with prctl.
- Then analyze with the above smaps report which VMA's benefit the most
- Change the application (if possible) to add the corresponding madvise
calls for the VMA's that benefit the most

[shr@devkernel.io: v5]
  Link: https://lkml.kernel.org/r/20230823170107.1457915-1-shr@devkernel.io
Link: https://lkml.kernel.org/r/20230822180539.1424843-1-shr@devkernel.io
Signed-off-by: Stefan Roesch <shr@devkernel.io>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Rik van Riel <riel@surriel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-09-02 15:17:33 -07:00
Linus Torvalds
df57721f9a Add x86 shadow stack support
Convert IBT selftest to asm to fix objtool warning
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Merge tag 'x86_shstk_for_6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 shadow stack support from Dave Hansen:
 "This is the long awaited x86 shadow stack support, part of Intel's
  Control-flow Enforcement Technology (CET).

  CET consists of two related security features: shadow stacks and
  indirect branch tracking. This series implements just the shadow stack
  part of this feature, and just for userspace.

  The main use case for shadow stack is providing protection against
  return oriented programming attacks. It works by maintaining a
  secondary (shadow) stack using a special memory type that has
  protections against modification. When executing a CALL instruction,
  the processor pushes the return address to both the normal stack and
  to the special permission shadow stack. Upon RET, the processor pops
  the shadow stack copy and compares it to the normal stack copy.

  For more information, refer to the links below for the earlier
  versions of this patch set"

Link: https://lore.kernel.org/lkml/20220130211838.8382-1-rick.p.edgecombe@intel.com/
Link: https://lore.kernel.org/lkml/20230613001108.3040476-1-rick.p.edgecombe@intel.com/

* tag 'x86_shstk_for_6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (47 commits)
  x86/shstk: Change order of __user in type
  x86/ibt: Convert IBT selftest to asm
  x86/shstk: Don't retry vm_munmap() on -EINTR
  x86/kbuild: Fix Documentation/ reference
  x86/shstk: Move arch detail comment out of core mm
  x86/shstk: Add ARCH_SHSTK_STATUS
  x86/shstk: Add ARCH_SHSTK_UNLOCK
  x86: Add PTRACE interface for shadow stack
  selftests/x86: Add shadow stack test
  x86/cpufeatures: Enable CET CR4 bit for shadow stack
  x86/shstk: Wire in shadow stack interface
  x86: Expose thread features in /proc/$PID/status
  x86/shstk: Support WRSS for userspace
  x86/shstk: Introduce map_shadow_stack syscall
  x86/shstk: Check that signal frame is shadow stack mem
  x86/shstk: Check that SSP is aligned on sigreturn
  x86/shstk: Handle signals for shadow stack
  x86/shstk: Introduce routines modifying shstk
  x86/shstk: Handle thread shadow stack
  x86/shstk: Add user-mode shadow stack support
  ...
2023-08-31 12:20:12 -07:00
Linus Torvalds
adfd671676 sysctl-6.6-rc1
Long ago we set out to remove the kitchen sink on kernel/sysctl.c arrays and
 placings sysctls to their own sybsystem or file to help avoid merge conflicts.
 Matthew Wilcox pointed out though that if we're going to do that we might as
 well also *save* space while at it and try to remove the extra last sysctl
 entry added at the end of each array, a sentintel, instead of bloating the
 kernel by adding a new sentinel with each array moved.
 
 Doing that was not so trivial, and has required slowing down the moves of
 kernel/sysctl.c arrays and measuring the impact on size by each new move.
 
 The complex part of the effort to help reduce the size of each sysctl is being
 done by the patient work of el señor Don Joel Granados. A lot of this is truly
 painful code refactoring and testing and then trying to measure the savings of
 each move and removing the sentinels. Although Joel already has code which does
 most of this work, experience with sysctl moves in the past shows is we need to
 be careful due to the slew of odd build failures that are possible due to the
 amount of random Kconfig options sysctls use.
 
 To that end Joel's work is split by first addressing the major housekeeping
 needed to remove the sentinels, which is part of this merge request. The rest
 of the work to actually remove the sentinels will be done later in future
 kernel releases.
 
 At first I was only going to send his first 7 patches of his patch series,
 posted 1 month ago, but in retrospect due to the testing the changes have
 received in linux-next and the minor changes they make this goes with the
 entire set of patches Joel had planned: just sysctl house keeping. There are
 networking changes but these are part of the house keeping too.
 
 The preliminary math is showing this will all help reduce the overall build
 time size of the kernel and run time memory consumed by the kernel by about
 ~64 bytes per array where we are able to remove each sentinel in the future.
 That also means there is no more bloating the kernel with the extra ~64 bytes
 per array moved as no new sentinels are created.
 
 Most of this has been in linux-next for about a month, the last 7 patches took
 a minor refresh 2 week ago based on feedback.
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Merge tag 'sysctl-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux

Pull sysctl updates from Luis Chamberlain:
 "Long ago we set out to remove the kitchen sink on kernel/sysctl.c
  arrays and placings sysctls to their own sybsystem or file to help
  avoid merge conflicts. Matthew Wilcox pointed out though that if we're
  going to do that we might as well also *save* space while at it and
  try to remove the extra last sysctl entry added at the end of each
  array, a sentintel, instead of bloating the kernel by adding a new
  sentinel with each array moved.

  Doing that was not so trivial, and has required slowing down the moves
  of kernel/sysctl.c arrays and measuring the impact on size by each new
  move.

  The complex part of the effort to help reduce the size of each sysctl
  is being done by the patient work of el señor Don Joel Granados. A lot
  of this is truly painful code refactoring and testing and then trying
  to measure the savings of each move and removing the sentinels.
  Although Joel already has code which does most of this work,
  experience with sysctl moves in the past shows is we need to be
  careful due to the slew of odd build failures that are possible due to
  the amount of random Kconfig options sysctls use.

  To that end Joel's work is split by first addressing the major
  housekeeping needed to remove the sentinels, which is part of this
  merge request. The rest of the work to actually remove the sentinels
  will be done later in future kernel releases.

  The preliminary math is showing this will all help reduce the overall
  build time size of the kernel and run time memory consumed by the
  kernel by about ~64 bytes per array where we are able to remove each
  sentinel in the future. That also means there is no more bloating the
  kernel with the extra ~64 bytes per array moved as no new sentinels
  are created"

* tag 'sysctl-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux:
  sysctl: Use ctl_table_size as stopping criteria for list macro
  sysctl: SIZE_MAX->ARRAY_SIZE in register_net_sysctl
  vrf: Update to register_net_sysctl_sz
  networking: Update to register_net_sysctl_sz
  netfilter: Update to register_net_sysctl_sz
  ax.25: Update to register_net_sysctl_sz
  sysctl: Add size to register_net_sysctl function
  sysctl: Add size arg to __register_sysctl_init
  sysctl: Add size to register_sysctl
  sysctl: Add a size arg to __register_sysctl_table
  sysctl: Add size argument to init_header
  sysctl: Add ctl_table_size to ctl_table_header
  sysctl: Use ctl_table_header in list_for_each_table_entry
  sysctl: Prefer ctl_table_header in proc_sysctl
2023-08-29 17:39:15 -07:00
Linus Torvalds
d68b4b6f30 - An extensive rework of kexec and crash Kconfig from Eric DeVolder
("refactor Kconfig to consolidate KEXEC and CRASH options").
 
 - kernel.h slimming work from Andy Shevchenko ("kernel.h: Split out a
   couple of macros to args.h").
 
 - gdb feature work from Kuan-Ying Lee ("Add GDB memory helper
   commands").
 
 - vsprintf inclusion rationalization from Andy Shevchenko
   ("lib/vsprintf: Rework header inclusions").
 
 - Switch the handling of kdump from a udev scheme to in-kernel handling,
   by Eric DeVolder ("crash: Kernel handling of CPU and memory hot
   un/plug").
 
 - Many singleton patches to various parts of the tree
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Merge tag 'mm-nonmm-stable-2023-08-28-22-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull non-MM updates from Andrew Morton:

 - An extensive rework of kexec and crash Kconfig from Eric DeVolder
   ("refactor Kconfig to consolidate KEXEC and CRASH options")

 - kernel.h slimming work from Andy Shevchenko ("kernel.h: Split out a
   couple of macros to args.h")

 - gdb feature work from Kuan-Ying Lee ("Add GDB memory helper
   commands")

 - vsprintf inclusion rationalization from Andy Shevchenko
   ("lib/vsprintf: Rework header inclusions")

 - Switch the handling of kdump from a udev scheme to in-kernel
   handling, by Eric DeVolder ("crash: Kernel handling of CPU and memory
   hot un/plug")

 - Many singleton patches to various parts of the tree

* tag 'mm-nonmm-stable-2023-08-28-22-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (81 commits)
  document while_each_thread(), change first_tid() to use for_each_thread()
  drivers/char/mem.c: shrink character device's devlist[] array
  x86/crash: optimize CPU changes
  crash: change crash_prepare_elf64_headers() to for_each_possible_cpu()
  crash: hotplug support for kexec_load()
  x86/crash: add x86 crash hotplug support
  crash: memory and CPU hotplug sysfs attributes
  kexec: exclude elfcorehdr from the segment digest
  crash: add generic infrastructure for crash hotplug support
  crash: move a few code bits to setup support of crash hotplug
  kstrtox: consistently use _tolower()
  kill do_each_thread()
  nilfs2: fix WARNING in mark_buffer_dirty due to discarded buffer reuse
  scripts/bloat-o-meter: count weak symbol sizes
  treewide: drop CONFIG_EMBEDDED
  lockdep: fix static memory detection even more
  lib/vsprintf: declare no_hash_pointers in sprintf.h
  lib/vsprintf: split out sprintf() and friends
  kernel/fork: stop playing lockless games for exe_file replacement
  adfs: delete unused "union adfs_dirtail" definition
  ...
2023-08-29 14:53:51 -07:00
Linus Torvalds
b96a3e9142 - Some swap cleanups from Ma Wupeng ("fix WARN_ON in add_to_avail_list")
- Peter Xu has a series (mm/gup: Unify hugetlb, speed up thp") which
   reduces the special-case code for handling hugetlb pages in GUP.  It
   also speeds up GUP handling of transparent hugepages.
 
 - Peng Zhang provides some maple tree speedups ("Optimize the fast path
   of mas_store()").
 
 - Sergey Senozhatsky has improved te performance of zsmalloc during
   compaction (zsmalloc: small compaction improvements").
 
 - Domenico Cerasuolo has developed additional selftest code for zswap
   ("selftests: cgroup: add zswap test program").
 
 - xu xin has doe some work on KSM's handling of zero pages.  These
   changes are mainly to enable the user to better understand the
   effectiveness of KSM's treatment of zero pages ("ksm: support tracking
   KSM-placed zero-pages").
 
 - Jeff Xu has fixes the behaviour of memfd's
   MEMFD_NOEXEC_SCOPE_NOEXEC_ENFORCED sysctl ("mm/memfd: fix sysctl
   MEMFD_NOEXEC_SCOPE_NOEXEC_ENFORCED").
 
 - David Howells has fixed an fscache optimization ("mm, netfs, fscache:
   Stop read optimisation when folio removed from pagecache").
 
 - Axel Rasmussen has given userfaultfd the ability to simulate memory
   poisoning ("add UFFDIO_POISON to simulate memory poisoning with UFFD").
 
 - Miaohe Lin has contributed some routine maintenance work on the
   memory-failure code ("mm: memory-failure: remove unneeded PageHuge()
   check").
 
 - Peng Zhang has contributed some maintenance work on the maple tree
   code ("Improve the validation for maple tree and some cleanup").
 
 - Hugh Dickins has optimized the collapsing of shmem or file pages into
   THPs ("mm: free retracted page table by RCU").
 
 - Jiaqi Yan has a patch series which permits us to use the healthy
   subpages within a hardware poisoned huge page for general purposes
   ("Improve hugetlbfs read on HWPOISON hugepages").
 
 - Kemeng Shi has done some maintenance work on the pagetable-check code
   ("Remove unused parameters in page_table_check").
 
 - More folioification work from Matthew Wilcox ("More filesystem folio
   conversions for 6.6"), ("Followup folio conversions for zswap").  And
   from ZhangPeng ("Convert several functions in page_io.c to use a
   folio").
 
 - page_ext cleanups from Kemeng Shi ("minor cleanups for page_ext").
 
 - Baoquan He has converted some architectures to use the GENERIC_IOREMAP
   ioremap()/iounmap() code ("mm: ioremap: Convert architectures to take
   GENERIC_IOREMAP way").
 
 - Anshuman Khandual has optimized arm64 tlb shootdown ("arm64: support
   batched/deferred tlb shootdown during page reclamation/migration").
 
 - Better maple tree lockdep checking from Liam Howlett ("More strict
   maple tree lockdep").  Liam also developed some efficiency improvements
   ("Reduce preallocations for maple tree").
 
 - Cleanup and optimization to the secondary IOMMU TLB invalidation, from
   Alistair Popple ("Invalidate secondary IOMMU TLB on permission
   upgrade").
 
 - Ryan Roberts fixes some arm64 MM selftest issues ("selftests/mm fixes
   for arm64").
 
 - Kemeng Shi provides some maintenance work on the compaction code ("Two
   minor cleanups for compaction").
 
 - Some reduction in mmap_lock pressure from Matthew Wilcox ("Handle most
   file-backed faults under the VMA lock").
 
 - Aneesh Kumar contributes code to use the vmemmap optimization for DAX
   on ppc64, under some circumstances ("Add support for DAX vmemmap
   optimization for ppc64").
 
 - page-ext cleanups from Kemeng Shi ("add page_ext_data to get client
   data in page_ext"), ("minor cleanups to page_ext header").
 
 - Some zswap cleanups from Johannes Weiner ("mm: zswap: three
   cleanups").
 
 - kmsan cleanups from ZhangPeng ("minor cleanups for kmsan").
 
 - VMA handling cleanups from Kefeng Wang ("mm: convert to
   vma_is_initial_heap/stack()").
 
 - DAMON feature work from SeongJae Park ("mm/damon/sysfs-schemes:
   implement DAMOS tried total bytes file"), ("Extend DAMOS filters for
   address ranges and DAMON monitoring targets").
 
 - Compaction work from Kemeng Shi ("Fixes and cleanups to compaction").
 
 - Liam Howlett has improved the maple tree node replacement code
   ("maple_tree: Change replacement strategy").
 
 - ZhangPeng has a general code cleanup - use the K() macro more widely
   ("cleanup with helper macro K()").
 
 - Aneesh Kumar brings memmap-on-memory to ppc64 ("Add support for memmap
   on memory feature on ppc64").
 
 - pagealloc cleanups from Kemeng Shi ("Two minor cleanups for pcp list
   in page_alloc"), ("Two minor cleanups for get pageblock migratetype").
 
 - Vishal Moola introduces a memory descriptor for page table tracking,
   "struct ptdesc" ("Split ptdesc from struct page").
 
 - memfd selftest maintenance work from Aleksa Sarai ("memfd: cleanups
   for vm.memfd_noexec").
 
 - MM include file rationalization from Hugh Dickins ("arch: include
   asm/cacheflush.h in asm/hugetlb.h").
 
 - THP debug output fixes from Hugh Dickins ("mm,thp: fix sloppy text
   output").
 
 - kmemleak improvements from Xiaolei Wang ("mm/kmemleak: use
   object_cache instead of kmemleak_initialized").
 
 - More folio-related cleanups from Matthew Wilcox ("Remove _folio_dtor
   and _folio_order").
 
 - A VMA locking scalability improvement from Suren Baghdasaryan
   ("Per-VMA lock support for swap and userfaults").
 
 - pagetable handling cleanups from Matthew Wilcox ("New page table range
   API").
 
 - A batch of swap/thp cleanups from David Hildenbrand ("mm/swap: stop
   using page->private on tail pages for THP_SWAP + cleanups").
 
 - Cleanups and speedups to the hugetlb fault handling from Matthew
   Wilcox ("Change calling convention for ->huge_fault").
 
 - Matthew Wilcox has also done some maintenance work on the MM subsystem
   documentation ("Improve mm documentation").
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Merge tag 'mm-stable-2023-08-28-18-26' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - Some swap cleanups from Ma Wupeng ("fix WARN_ON in
   add_to_avail_list")

 - Peter Xu has a series (mm/gup: Unify hugetlb, speed up thp") which
   reduces the special-case code for handling hugetlb pages in GUP. It
   also speeds up GUP handling of transparent hugepages.

 - Peng Zhang provides some maple tree speedups ("Optimize the fast path
   of mas_store()").

 - Sergey Senozhatsky has improved te performance of zsmalloc during
   compaction (zsmalloc: small compaction improvements").

 - Domenico Cerasuolo has developed additional selftest code for zswap
   ("selftests: cgroup: add zswap test program").

 - xu xin has doe some work on KSM's handling of zero pages. These
   changes are mainly to enable the user to better understand the
   effectiveness of KSM's treatment of zero pages ("ksm: support
   tracking KSM-placed zero-pages").

 - Jeff Xu has fixes the behaviour of memfd's
   MEMFD_NOEXEC_SCOPE_NOEXEC_ENFORCED sysctl ("mm/memfd: fix sysctl
   MEMFD_NOEXEC_SCOPE_NOEXEC_ENFORCED").

 - David Howells has fixed an fscache optimization ("mm, netfs, fscache:
   Stop read optimisation when folio removed from pagecache").

 - Axel Rasmussen has given userfaultfd the ability to simulate memory
   poisoning ("add UFFDIO_POISON to simulate memory poisoning with
   UFFD").

 - Miaohe Lin has contributed some routine maintenance work on the
   memory-failure code ("mm: memory-failure: remove unneeded PageHuge()
   check").

 - Peng Zhang has contributed some maintenance work on the maple tree
   code ("Improve the validation for maple tree and some cleanup").

 - Hugh Dickins has optimized the collapsing of shmem or file pages into
   THPs ("mm: free retracted page table by RCU").

 - Jiaqi Yan has a patch series which permits us to use the healthy
   subpages within a hardware poisoned huge page for general purposes
   ("Improve hugetlbfs read on HWPOISON hugepages").

 - Kemeng Shi has done some maintenance work on the pagetable-check code
   ("Remove unused parameters in page_table_check").

 - More folioification work from Matthew Wilcox ("More filesystem folio
   conversions for 6.6"), ("Followup folio conversions for zswap"). And
   from ZhangPeng ("Convert several functions in page_io.c to use a
   folio").

 - page_ext cleanups from Kemeng Shi ("minor cleanups for page_ext").

 - Baoquan He has converted some architectures to use the
   GENERIC_IOREMAP ioremap()/iounmap() code ("mm: ioremap: Convert
   architectures to take GENERIC_IOREMAP way").

 - Anshuman Khandual has optimized arm64 tlb shootdown ("arm64: support
   batched/deferred tlb shootdown during page reclamation/migration").

 - Better maple tree lockdep checking from Liam Howlett ("More strict
   maple tree lockdep"). Liam also developed some efficiency
   improvements ("Reduce preallocations for maple tree").

 - Cleanup and optimization to the secondary IOMMU TLB invalidation,
   from Alistair Popple ("Invalidate secondary IOMMU TLB on permission
   upgrade").

 - Ryan Roberts fixes some arm64 MM selftest issues ("selftests/mm fixes
   for arm64").

 - Kemeng Shi provides some maintenance work on the compaction code
   ("Two minor cleanups for compaction").

 - Some reduction in mmap_lock pressure from Matthew Wilcox ("Handle
   most file-backed faults under the VMA lock").

 - Aneesh Kumar contributes code to use the vmemmap optimization for DAX
   on ppc64, under some circumstances ("Add support for DAX vmemmap
   optimization for ppc64").

 - page-ext cleanups from Kemeng Shi ("add page_ext_data to get client
   data in page_ext"), ("minor cleanups to page_ext header").

 - Some zswap cleanups from Johannes Weiner ("mm: zswap: three
   cleanups").

 - kmsan cleanups from ZhangPeng ("minor cleanups for kmsan").

 - VMA handling cleanups from Kefeng Wang ("mm: convert to
   vma_is_initial_heap/stack()").

 - DAMON feature work from SeongJae Park ("mm/damon/sysfs-schemes:
   implement DAMOS tried total bytes file"), ("Extend DAMOS filters for
   address ranges and DAMON monitoring targets").

 - Compaction work from Kemeng Shi ("Fixes and cleanups to compaction").

 - Liam Howlett has improved the maple tree node replacement code
   ("maple_tree: Change replacement strategy").

 - ZhangPeng has a general code cleanup - use the K() macro more widely
   ("cleanup with helper macro K()").

 - Aneesh Kumar brings memmap-on-memory to ppc64 ("Add support for
   memmap on memory feature on ppc64").

 - pagealloc cleanups from Kemeng Shi ("Two minor cleanups for pcp list
   in page_alloc"), ("Two minor cleanups for get pageblock
   migratetype").

 - Vishal Moola introduces a memory descriptor for page table tracking,
   "struct ptdesc" ("Split ptdesc from struct page").

 - memfd selftest maintenance work from Aleksa Sarai ("memfd: cleanups
   for vm.memfd_noexec").

 - MM include file rationalization from Hugh Dickins ("arch: include
   asm/cacheflush.h in asm/hugetlb.h").

 - THP debug output fixes from Hugh Dickins ("mm,thp: fix sloppy text
   output").

 - kmemleak improvements from Xiaolei Wang ("mm/kmemleak: use
   object_cache instead of kmemleak_initialized").

 - More folio-related cleanups from Matthew Wilcox ("Remove _folio_dtor
   and _folio_order").

 - A VMA locking scalability improvement from Suren Baghdasaryan
   ("Per-VMA lock support for swap and userfaults").

 - pagetable handling cleanups from Matthew Wilcox ("New page table
   range API").

 - A batch of swap/thp cleanups from David Hildenbrand ("mm/swap: stop
   using page->private on tail pages for THP_SWAP + cleanups").

 - Cleanups and speedups to the hugetlb fault handling from Matthew
   Wilcox ("Change calling convention for ->huge_fault").

 - Matthew Wilcox has also done some maintenance work on the MM
   subsystem documentation ("Improve mm documentation").

* tag 'mm-stable-2023-08-28-18-26' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (489 commits)
  maple_tree: shrink struct maple_tree
  maple_tree: clean up mas_wr_append()
  secretmem: convert page_is_secretmem() to folio_is_secretmem()
  nios2: fix flush_dcache_page() for usage from irq context
  hugetlb: add documentation for vma_kernel_pagesize()
  mm: add orphaned kernel-doc to the rst files.
  mm: fix clean_record_shared_mapping_range kernel-doc
  mm: fix get_mctgt_type() kernel-doc
  mm: fix kernel-doc warning from tlb_flush_rmaps()
  mm: remove enum page_entry_size
  mm: allow ->huge_fault() to be called without the mmap_lock held
  mm: move PMD_ORDER to pgtable.h
  mm: remove checks for pte_index
  memcg: remove duplication detection for mem_cgroup_uncharge_swap
  mm/huge_memory: work on folio->swap instead of page->private when splitting folio
  mm/swap: inline folio_set_swap_entry() and folio_swap_entry()
  mm/swap: use dedicated entry for swap in folio
  mm/swap: stop using page->private on tail pages for THP_SWAP
  selftests/mm: fix WARNING comparing pointer to 0
  selftests: cgroup: fix test_kmem_memcg_deletion kernel mem check
  ...
2023-08-29 14:25:26 -07:00
Linus Torvalds
b4a04f92a4 v6.6-fs.proc.uapi
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Merge tag 'v6.6-fs.proc.uapi' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull procfs fixes from Christian Brauner:
 "Mode changes to files under /proc/<pid>/ aren't supported ever since
  commit 6d76fa58b0 ("Don't allow chmod() on the /proc/<pid>/ files").

  Due to an oversight in commit 1b3044e39a ("procfs: fix pthread
  cross-thread naming if !PR_DUMPABLE") in switching from REG to NOD,
  mode changes on /proc/thread-self/comm were accidently allowed.

  Similar, mode changes for all files beneath /proc/<pid>/net/ are
  blocked but mode changes on /proc/<pid>/net itself were accidently
  allowed.

  Both issues come down to not using the generic proc_setattr() helper
  which blocks all mode changes. This is rectified with this pull
  request.

  This also removes a strange nolibc test that abused /proc/<pid>/net
  for testing mode changes. Using procfs for this test never made a lot
  of sense given procfs has special semantics for almost everything
  anway.

  Both changes are minor user-visible changes. It is however very
  unlikely that mode changes on proc/<pid>/net and
  /proc/thread-self/comm are something that userspace relies on"

* tag 'v6.6-fs.proc.uapi' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  procfs: block chmod on /proc/thread-self/comm
  proc: use generic setattr() for /proc/$PID/net
  selftests/nolibc: drop test chmod_net
2023-08-28 11:43:19 -07:00
Linus Torvalds
615e95831e v6.6-vfs.ctime
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Merge tag 'v6.6-vfs.ctime' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull vfs timestamp updates from Christian Brauner:
 "This adds VFS support for multi-grain timestamps and converts tmpfs,
  xfs, ext4, and btrfs to use them. This carries acks from all relevant
  filesystems.

  The VFS always uses coarse-grained timestamps when updating the ctime
  and mtime after a change. This has the benefit of allowing filesystems
  to optimize away a lot of metadata updates, down to around 1 per
  jiffy, even when a file is under heavy writes.

  Unfortunately, this has always been an issue when we're exporting via
  NFSv3, which relies on timestamps to validate caches. A lot of changes
  can happen in a jiffy, so timestamps aren't sufficient to help the
  client decide to invalidate the cache.

  Even with NFSv4, a lot of exported filesystems don't properly support
  a change attribute and are subject to the same problems with timestamp
  granularity. Other applications have similar issues with timestamps
  (e.g., backup applications).

  If we were to always use fine-grained timestamps, that would improve
  the situation, but that becomes rather expensive, as the underlying
  filesystem would have to log a lot more metadata updates.

  This introduces fine-grained timestamps that are used when they are
  actively queried.

  This uses the 31st bit of the ctime tv_nsec field to indicate that
  something has queried the inode for the mtime or ctime. When this flag
  is set, on the next mtime or ctime update, the kernel will fetch a
  fine-grained timestamp instead of the usual coarse-grained one.

  As POSIX generally mandates that when the mtime changes, the ctime
  must also change the kernel always stores normalized ctime values, so
  only the first 30 bits of the tv_nsec field are ever used.

  Filesytems can opt into this behavior by setting the FS_MGTIME flag in
  the fstype. Filesystems that don't set this flag will continue to use
  coarse-grained timestamps.

  Various preparatory changes, fixes and cleanups are included:

   - Fixup all relevant places where POSIX requires updating ctime
     together with mtime. This is a wide-range of places and all
     maintainers provided necessary Acks.

   - Add new accessors for inode->i_ctime directly and change all
     callers to rely on them. Plain accesses to inode->i_ctime are now
     gone and it is accordingly rename to inode->__i_ctime and commented
     as requiring accessors.

   - Extend generic_fillattr() to pass in a request mask mirroring in a
     sense the statx() uapi. This allows callers to pass in a request
     mask to only get a subset of attributes filled in.

   - Rework timestamp updates so it's possible to drop the @now
     parameter the update_time() inode operation and associated helpers.

   - Add inode_update_timestamps() and convert all filesystems to it
     removing a bunch of open-coding"

* tag 'v6.6-vfs.ctime' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (107 commits)
  btrfs: convert to multigrain timestamps
  ext4: switch to multigrain timestamps
  xfs: switch to multigrain timestamps
  tmpfs: add support for multigrain timestamps
  fs: add infrastructure for multigrain timestamps
  fs: drop the timespec64 argument from update_time
  xfs: have xfs_vn_update_time gets its own timestamp
  fat: make fat_update_time get its own timestamp
  fat: remove i_version handling from fat_update_time
  ubifs: have ubifs_update_time use inode_update_timestamps
  btrfs: have it use inode_update_timestamps
  fs: drop the timespec64 arg from generic_update_time
  fs: pass the request_mask to generic_fillattr
  fs: remove silly warning from current_time
  gfs2: fix timestamp handling on quota inodes
  fs: rename i_ctime field to __i_ctime
  selinux: convert to ctime accessor functions
  security: convert to ctime accessor functions
  apparmor: convert to ctime accessor functions
  sunrpc: convert to ctime accessor functions
  ...
2023-08-28 09:31:32 -07:00
Linus Torvalds
6f0edbb833 18 hotfixes. 13 are cc:stable and the remainder pertain to post-6.4 issues
or aren't considered suitable for a -stable backport.
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Merge tag 'mm-hotfixes-stable-2023-08-25-11-07' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull misc fixes from Andrew Morton:
 "18 hotfixes. 13 are cc:stable and the remainder pertain to post-6.4
  issues or aren't considered suitable for a -stable backport"

* tag 'mm-hotfixes-stable-2023-08-25-11-07' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  shmem: fix smaps BUG sleeping while atomic
  selftests: cachestat: catch failing fsync test on tmpfs
  selftests: cachestat: test for cachestat availability
  maple_tree: disable mas_wr_append() when other readers are possible
  madvise:madvise_free_pte_range(): don't use mapcount() against large folio for sharing check
  madvise:madvise_free_huge_pmd(): don't use mapcount() against large folio for sharing check
  madvise:madvise_cold_or_pageout_pte_range(): don't use mapcount() against large folio for sharing check
  mm: multi-gen LRU: don't spin during memcg release
  mm: memory-failure: fix unexpected return value in soft_offline_page()
  radix tree: remove unused variable
  mm: add a call to flush_cache_vmap() in vmap_pfn()
  selftests/mm: FOLL_LONGTERM need to be updated to 0x100
  nilfs2: fix general protection fault in nilfs_lookup_dirty_data_buffers()
  mm/gup: handle cont-PTE hugetlb pages correctly in gup_must_unshare() via GUP-fast
  selftests: cgroup: fix test_kmem_basic less than error
  mm: enable page walking API to lock vmas during the walk
  smaps: use vm_normal_page_pmd() instead of follow_trans_huge_pmd()
  mm/gup: reintroduce FOLL_NUMA as FOLL_HONOR_NUMA_FAULT
2023-08-25 11:44:43 -07:00
Oleg Nesterov
dce8f8ed1d document while_each_thread(), change first_tid() to use for_each_thread()
Add the comment to explain that while_each_thread(g,t) is not rcu-safe
unless g is stable (e.g.  current).  Even if g is a group leader and thus
can't exit before t, t or another sub-thread can exec and remove g from
the thread_group list.

The only lockless user of while_each_thread() is first_tid() and it is
fine in that it can't loop forever, yet for_each_thread() looks better and
I am going to change while_each_thread/next_thread.

Link: https://lkml.kernel.org/r/20230823170806.GA11724@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-24 16:25:15 -07:00
Andrew Morton
5994eabf3b merge mm-hotfixes-stable into mm-stable to pick up depended-upon changes 2023-08-21 14:26:20 -07:00
Hugh Dickins
daa60ae64c mm,thp: fix smaps THPeligible output alignment
Extract from current /proc/self/smaps output:

Swap:                  0 kB
SwapPss:               0 kB
Locked:                0 kB
THPeligible:    0
ProtectionKey:         0

That's not the alignment shown in Documentation/filesystems/proc.rst: it's
an ugly artifact from missing out the %8 other fields are using; but
there's even one selftest which expects it to look that way.  Hoping no
other smaps parsers depend on THPeligible to look so ugly, fix these.

Link: https://lkml.kernel.org/r/cfb81f7a-f448-5bc2-b0e1-8136fcd1dd8c@google.com
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-21 13:38:01 -07:00
Kefeng Wang
3f32c49ed6 mm: memtest: convert to memtest_report_meminfo()
It is better to not expose too many internal variables of memtest,
add a helper memtest_report_meminfo() to show memtest results.

Link: https://lkml.kernel.org/r/20230808033359.174986-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Tomas Mudrunka <tomas.mudrunka@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-21 13:37:47 -07:00
Kefeng Wang
11250fd12e mm: factor out VMA stack and heap checks
Patch series "mm: convert to vma_is_initial_heap/stack()", v3.

Add vma_is_initial_stack() and vma_is_initial_heap() helpers and use them
to simplify code.


This patch (of 4):

Factor out VMA stack and heap checks and name them vma_is_initial_stack()
and vma_is_initial_heap() for general use.

Link: https://lkml.kernel.org/r/20230728050043.59880-1-wangkefeng.wang@huawei.com
Link: https://lkml.kernel.org/r/20230728050043.59880-2-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Christian Göttsche <cgzones@googlemail.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Christian Göttsche <cgzones@googlemail.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: David Airlie <airlied@gmail.com>
Cc: Eric Paris <eparis@parisplace.org>
Cc: Felix Kuehling <felix.kuehling@amd.com>
Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-21 13:37:31 -07:00
Johannes Weiner
42c06a0e8e mm: kill frontswap
The only user of frontswap is zswap, and has been for a long time.  Have
swap call into zswap directly and remove the indirection.

[hannes@cmpxchg.org: remove obsolete comment, per Yosry]
  Link: https://lkml.kernel.org/r/20230719142832.GA932528@cmpxchg.org
[fengwei.yin@intel.com: don't warn if none swapcache folio is passed to zswap_load]
  Link: https://lkml.kernel.org/r/20230810095652.3905184-1-fengwei.yin@intel.com
Link: https://lkml.kernel.org/r/20230717160227.GA867137@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Yin Fengwei <fengwei.yin@intel.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Nhat Pham <nphamcs@gmail.com>
Acked-by: Yosry Ahmed <yosryahmed@google.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-21 13:37:26 -07:00
Suren Baghdasaryan
49b0638502 mm: enable page walking API to lock vmas during the walk
walk_page_range() and friends often operate under write-locked mmap_lock. 
With introduction of vma locks, the vmas have to be locked as well during
such walks to prevent concurrent page faults in these areas.  Add an
additional member to mm_walk_ops to indicate locking requirements for the
walk.

The change ensures that page walks which prevent concurrent page faults
by write-locking mmap_lock, operate correctly after introduction of
per-vma locks.  With per-vma locks page faults can be handled under vma
lock without taking mmap_lock at all, so write locking mmap_lock would
not stop them.  The change ensures vmas are properly locked during such
walks.

A sample issue this solves is do_mbind() performing queue_pages_range()
to queue pages for migration.  Without this change a concurrent page
can be faulted into the area and be left out of migration.

Link: https://lkml.kernel.org/r/20230804152724.3090321-2-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org>
Suggested-by: Jann Horn <jannh@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Laurent Dufour <ldufour@linux.ibm.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Michel Lespinasse <michel@lespinasse.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-21 13:07:20 -07:00
David Hildenbrand
8b9c1cc041 smaps: use vm_normal_page_pmd() instead of follow_trans_huge_pmd()
We shouldn't be using a GUP-internal helper if it can be avoided.

Similar to smaps_pte_entry() that uses vm_normal_page(), let's use
vm_normal_page_pmd() that similarly refuses to return the huge zeropage.

In contrast to follow_trans_huge_pmd(), vm_normal_page_pmd():

(1) Will always return the head page, not a tail page of a THP.

 If we'd ever call smaps_account with a tail page while setting "compound
 = true", we could be in trouble, because smaps_account() would look at
 the memmap of unrelated pages.

 If we're unlucky, that memmap does not exist at all. Before we removed
 PG_doublemap, we could have triggered something similar as in
 commit 24d7275ce2 ("fs/proc: task_mmu.c: don't read mapcount for
 migration entry").

 This can theoretically happen ever since commit ff9f47f6f0 ("mm: proc:
 smaps_rollup: do not stall write attempts on mmap_lock"):

  (a) We're in show_smaps_rollup() and processed a VMA
  (b) We release the mmap lock in show_smaps_rollup() because it is
      contended
  (c) We merged that VMA with another VMA
  (d) We collapsed a THP in that merged VMA at that position

 If the end address of the original VMA falls into the middle of a THP
 area, we would call smap_gather_stats() with a start address that falls
 into a PMD-mapped THP. It's probably very rare to trigger when not
 really forced.

(2) Will succeed on a is_pci_p2pdma_page(), like vm_normal_page()

 Treat such PMDs here just like smaps_pte_entry() would treat such PTEs.
 If such pages would be anonymous, we most certainly would want to
 account them.

(3) Will skip over pmd_devmap(), like vm_normal_page() for pte_devmap()

 As noted in vm_normal_page(), that is only for handling legacy ZONE_DEVICE
 pages. So just like smaps_pte_entry(), we'll now also ignore such PMD
 entries.

 Especially, follow_pmd_mask() never ends up calling
 follow_trans_huge_pmd() on pmd_devmap(). Instead it calls
 follow_devmap_pmd() -- which will fail if neither FOLL_GET nor FOLL_PIN
 is set.

 So skipping pmd_devmap() pages seems to be the right thing to do.

(4) Will properly handle VM_MIXEDMAP/VM_PFNMAP, like vm_normal_page()

 We won't be returning a memmap that should be ignored by core-mm, or
 worse, a memmap that does not even exist. Note that while
 walk_page_range() will skip VM_PFNMAP mappings, walk_page_vma() won't.

 Most probably this case doesn't currently really happen on the PMD level,
 otherwise we'd already be able to trigger kernel crashes when reading
 smaps / smaps_rollup.

So most probably only (1) is relevant in practice as of now, but could only
cause trouble in extreme corner cases.

Let's move follow_trans_huge_pmd() to mm/internal.h to discourage future
reuse in wrong context.

Link: https://lkml.kernel.org/r/20230803143208.383663-3-david@redhat.com
Fixes: ff9f47f6f0 ("mm: proc: smaps_rollup: do not stall write attempts on mmap_lock")
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: liubo <liubo254@huawei.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-21 13:07:20 -07:00
xu xin
6080d19f07 ksm: add ksm zero pages for each process
As the number of ksm zero pages is not included in ksm_merging_pages per
process when enabling use_zero_pages, it's unclear of how many actual
pages are merged by KSM. To let users accurately estimate their memory
demands when unsharing KSM zero-pages, it's necessary to show KSM zero-
pages per process. In addition, it help users to know the actual KSM
profit because KSM-placed zero pages are also benefit from KSM.

since unsharing zero pages placed by KSM accurately is achieved, then
tracking empty pages merging and unmerging is not a difficult thing any
longer.

Since we already have /proc/<pid>/ksm_stat, just add the information of
'ksm_zero_pages' in it.

Link: https://lkml.kernel.org/r/20230613030938.185993-1-yang.yang29@zte.com.cn
Signed-off-by: xu xin <xu.xin16@zte.com.cn>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Xiaokai Ran <ran.xiaokai@zte.com.cn>
Reviewed-by: Yang Yang <yang.yang29@zte.com.cn>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Xuexin Jiang <jiang.xuexin@zte.com.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-18 10:12:10 -07:00
Joel Granados
53f3811dfd sysctl: Use ctl_table_size as stopping criteria for list macro
This is a preparation commit to make it easy to remove the sentinel
elements (empty end markers) from the ctl_table arrays. It both allows
the systematic removal of the sentinels and adds the ctl_table_size
variable to the stopping criteria of the list_for_each_table_entry macro
that traverses all ctl_table arrays. Once all the sentinels are removed
by subsequent commits, ctl_table_size will become the only stopping
criteria in the macro. We don't actually remove any elements in this
commit, but it sets things up to for the removal process to take place.

By adding header->ctl_table_size as an additional stopping criteria for
the list_for_each_table_entry macro, it will execute until it finds an
"empty" ->procname or until the size runs out. Therefore if a ctl_table
array with a sentinel is passed its size will be too big (by one
element) but it will stop on the sentinel. On the other hand, if the
ctl_table array without a sentinel is passed its size will be just write
and there will be no need for a sentinel.

Signed-off-by: Joel Granados <j.granados@samsung.com>
Suggested-by: Jani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-08-15 15:26:18 -07:00
Joel Granados
3bc269cfd3 sysctl: Add size arg to __register_sysctl_init
This commit adds table_size to __register_sysctl_init in preparation for
the removal of the sentinel elements in the ctl_table arrays (last empty
markers). And though we do *not* remove any sentinels in this commit, we
set things up by calculating the ctl_table array size with ARRAY_SIZE.

We add a table_size argument to __register_sysctl_init and modify the
register_sysctl_init macro to calculate the array size with ARRAY_SIZE.
The original callers do not need to be updated as they will go through
the new macro.

Signed-off-by: Joel Granados <j.granados@samsung.com>
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-08-15 15:26:17 -07:00
Joel Granados
9edbfe92a0 sysctl: Add size to register_sysctl
This commit adds table_size to register_sysctl in preparation for the
removal of the sentinel elements in the ctl_table arrays (last empty
markers). And though we do *not* remove any sentinels in this commit, we
set things up by either passing the table_size explicitly or using
ARRAY_SIZE on the ctl_table arrays.

We replace the register_syctl function with a macro that will add the
ARRAY_SIZE to the new register_sysctl_sz function. In this way the
callers that are already using an array of ctl_table structs do not
change. For the callers that pass a ctl_table array pointer, we pass the
table_size to register_sysctl_sz instead of the macro.

Signed-off-by: Joel Granados <j.granados@samsung.com>
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-08-15 15:26:17 -07:00
Joel Granados
bff97cf11b sysctl: Add a size arg to __register_sysctl_table
We make these changes in order to prepare __register_sysctl_table and
its callers for when we remove the sentinel element (empty element at
the end of ctl_table arrays). We don't actually remove any sentinels in
this commit, but we *do* make sure to use ARRAY_SIZE so the table_size
is available when the removal occurs.

We add a table_size argument to __register_sysctl_table and adjust
callers, all of which pass ctl_table pointers and need an explicit call
to ARRAY_SIZE. We implement a size calculation in register_net_sysctl in
order to forward the size of the array pointer received from the network
register calls.

The new table_size argument does not yet have any effect in the
init_header call which is still dependent on the sentinel's presence.
table_size *does* however drive the `kzalloc` allocation in
__register_sysctl_table with no adverse effects as the allocated memory
is either one element greater than the calculated ctl_table array (for
the calls in ipc_sysctl.c, mq_sysctl.c and ucount.c) or the exact size
of the calculated ctl_table array (for the call from sysctl_net.c and
register_sysctl). This approach will allows us to "just" remove the
sentinel without further changes to __register_sysctl_table as
table_size will represent the exact size for all the callers at that
point.

Signed-off-by: Joel Granados <j.granados@samsung.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-08-15 15:26:17 -07:00
Joel Granados
b1f01e2bae sysctl: Add size argument to init_header
In this commit, we add a table_size argument to the init_header function
in order to initialize the ctl_table_size variable in ctl_table_header.
Even though the size is not yet used, it is now initialized within the
sysctl subsys. We need this commit for when we start adding the
table_size arguments to the sysctl functions (e.g. register_sysctl,
__register_sysctl_table and __register_sysctl_init).

Note that in __register_sysctl_table we temporarily use a calculated
size until we add the size argument to that function in subsequent
commits.

Signed-off-by: Joel Granados <j.granados@samsung.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-08-15 15:26:17 -07:00
Joel Granados
18d4b42e9d sysctl: Use ctl_table_header in list_for_each_table_entry
We replace the ctl_table with the ctl_table_header pointer in
list_for_each_table_entry which is the macro responsible for traversing
the ctl_table arrays. This is a preparation commit that will make it
easier to add the ctl_table array size (that will be added to
ctl_table_header in subsequent commits) to the already existing loop
logic based on empty ctl_table elements (so called sentinels).

Signed-off-by: Joel Granados <j.granados@samsung.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-08-15 15:26:17 -07:00
Joel Granados
cc9f7ee01e sysctl: Prefer ctl_table_header in proc_sysctl
This is a preparation commit that replaces ctl_table with
ctl_table_header as the pointer that is passed around in proc_sysctl.c.
This will become necessary in subsequent commits when the size of the
ctl_table array can no longer be calculated by searching for an empty
sentinel (last empty ctl_table element) but will be carried along inside
the ctl_table_header struct.

Signed-off-by: Joel Granados <j.granados@samsung.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-08-15 15:26:17 -07:00
Linus Torvalds
190bf7b14b 14 hotfixes. 11 of these are cc:stable and the remainder address post-6.4
issues, or are not considered suitable for -stable backporting.
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Merge tag 'mm-hotfixes-stable-2023-08-11-13-44' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull misc fixes from Andrew Morton:
 "14 hotfixes. 11 of these are cc:stable and the remainder address
  post-6.4 issues, or are not considered suitable for -stable
  backporting"

* tag 'mm-hotfixes-stable-2023-08-11-13-44' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  mm/damon/core: initialize damo_filter->list from damos_new_filter()
  nilfs2: fix use-after-free of nilfs_root in dirtying inodes via iput
  selftests: cgroup: fix test_kmem_basic false positives
  fs/proc/kcore: reinstate bounce buffer for KCORE_TEXT regions
  MAINTAINERS: add maple tree mailing list
  mm: compaction: fix endless looping over same migrate block
  selftests: mm: ksm: fix incorrect evaluation of parameter
  hugetlb: do not clear hugetlb dtor until allocating vmemmap
  mm: memory-failure: avoid false hwpoison page mapped error info
  mm: memory-failure: fix potential unexpected return value from unpoison_memory()
  mm/swapfile: fix wrong swap entry type for hwpoisoned swapcache page
  radix tree test suite: fix incorrect allocation size for pthreads
  crypto, cifs: fix error handling in extract_iter_to_sg()
  zsmalloc: fix races between modifications of fullness and isolated
2023-08-11 14:19:20 -07:00
Jeff Layton
0d72b92883 fs: pass the request_mask to generic_fillattr
generic_fillattr just fills in the entire stat struct indiscriminately
today, copying data from the inode. There is at least one attribute
(STATX_CHANGE_COOKIE) that can have side effects when it is reported,
and we're looking at adding more with the addition of multigrain
timestamps.

Add a request_mask argument to generic_fillattr and have most callers
just pass in the value that is passed to getattr. Have other callers
(e.g. ksmbd) just pass in STATX_BASIC_STATS. Also move the setting of
STATX_CHANGE_COOKIE into generic_fillattr.

Acked-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Reviewed-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: "Paulo Alcantara (SUSE)" <pc@manguebit.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Message-Id: <20230807-mgctime-v7-2-d1dec143a704@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-09 08:56:36 +02:00
Linus Torvalds
0a2c2baafa
proc: fix missing conversion to 'iterate_shared'
I'm looking at the directory handling due to the discussion about f_pos
locking (see commit 797964253d: "file: reinstate f_pos locking
optimization for regular files"), and wanting to clean that up.

And one source of ugliness is how we were supposed to move filesystems
over to the '->iterate_shared()' function that only takes the inode lock
for reading many many years ago, but several filesystems still use the
bad old '->iterate()' that takes the inode lock for exclusive access.

See commit 6192269444 ("introduce a parallel variant of ->iterate()")
that also added some documentation stating

      Old method is only used if the new one is absent; eventually it will
      be removed.  Switch while you still can; the old one won't stay.

and that was back in April 2016.  Here we are, many years later, and the
old version is still clearly sadly alive and well.

Now, some of those old style iterators are probably just because the
filesystem may end up having per-inode mutable data that it uses for
iterating a directory, but at least one case is just a mistake.

Al switched over most filesystems to use '->iterate_shared()' back when
it was introduced.  In particular, the /proc filesystem was converted as
one of the first ones in commit f50752eaa0 ("switch all procfs
directories ->iterate_shared()").

But then later one new user of '->iterate()' was then re-introduced by
commit 6d9c939dbe ("procfs: add smack subdir to attrs").

And that's clearly not what we wanted, since that new case just uses the
same 'proc_pident_readdir()' and 'proc_pident_lookup()' helper functions
that other /proc pident directories use, and they are most definitely
safe to use with the inode lock held shared.

So just fix it.

This still leaves a fair number of oddball filesystems using the
old-style directory iterator (ceph, coda, exfat, jfs, ntfs, ocfs2,
overlayfs, and vboxsf), but at least we don't have any remaining in the
core filesystems.

I'm going to add a wrapper function that just drops the read-lock and
takes it as a write lock, so that we can clean up the core vfs layer and
make all the ugly 'this filesystem needs exclusive inode locking' be
just filesystem-internal warts.

I just didn't want to make that conversion when we still had a core user
left.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-06 15:08:35 +02:00
Lorenzo Stoakes
1745778400 fs/proc/kcore: reinstate bounce buffer for KCORE_TEXT regions
Some architectures do not populate the entire range categorised by
KCORE_TEXT, so we must ensure that the kernel address we read from is
valid.

Unfortunately there is no solution currently available to do so with a
purely iterator solution so reinstate the bounce buffer in this instance
so we can use copy_from_kernel_nofault() in order to avoid page faults
when regions are unmapped.

This change partly reverts commit 2e1c017077 ("fs/proc/kcore: avoid
bounce buffer for ktext data"), reinstating the bounce buffer, but adapts
the code to continue to use an iterator.

[lstoakes@gmail.com: correct comment to be strictly correct about reasoning]
  Link: https://lkml.kernel.org/r/525a3f14-74fa-4c22-9fca-9dab4de8a0c3@lucifer.local
Link: https://lkml.kernel.org/r/20230731215021.70911-1-lstoakes@gmail.com
Fixes: 2e1c017077 ("fs/proc/kcore: avoid bounce buffer for ktext data")
Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Reported-by: Jiri Olsa <olsajiri@gmail.com>
Closes: https://lore.kernel.org/all/ZHc2fm+9daF6cgCE@krava
Tested-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Will Deacon <will@kernel.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Liu Shixin <liushixin2@huawei.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Thorsten Leemhuis <regressions@leemhuis.info>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-04 13:03:42 -07:00
Rick Edgecombe
0ee44885fe x86: Expose thread features in /proc/$PID/status
Applications and loaders can have logic to decide whether to enable
shadow stack. They usually don't report whether shadow stack has been
enabled or not, so there is no way to verify whether an application
actually is protected by shadow stack.

Add two lines in /proc/$PID/status to report enabled and locked features.

Since, this involves referring to arch specific defines in asm/prctl.h,
implement an arch breakout to emit the feature lines.

[Switched to CET, added to commit log]

Co-developed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Tested-by: Pengfei Xu <pengfei.xu@intel.com>
Tested-by: John Allen <john.allen@amd.com>
Tested-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/all/20230613001108.3040476-37-rick.p.edgecombe%40intel.com
2023-08-02 15:01:51 -07:00
Dan Carpenter
641db40f3a proc/vmcore: fix signedness bug in read_from_oldmem()
The bug is the error handling:

	if (tmp < nr_bytes) {

"tmp" can hold negative error codes but because "nr_bytes" is type size_t
the negative error codes are treated as very high positive values
(success).  Fix this by changing "nr_bytes" to type ssize_t.  The
"nr_bytes" variable is used to store values between 1 and PAGE_SIZE and
they can fit in ssize_t without any issue.

Link: https://lkml.kernel.org/r/b55f7eed-1c65-4adc-95d1-6c7c65a54a6e@moroto.mountain
Fixes: 5d8de293c2 ("vmcore: convert copy_oldmem_page() to take an iov_iter")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-07-27 13:07:05 -07:00
Jeff Layton
e9d7d3cb9f procfs: convert to ctime accessor functions
In later patches, we're going to change how the inode's ctime field is
used. Switch to using accessor functions instead of raw accesses of
inode->i_ctime.

Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Message-Id: <20230705190309.579783-65-jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-07-24 10:30:03 +02:00
Aleksa Sarai
ccf61486fe
procfs: block chmod on /proc/thread-self/comm
Due to an oversight in commit 1b3044e39a ("procfs: fix pthread
cross-thread naming if !PR_DUMPABLE") in switching from REG to NOD,
chmod operations on /proc/thread-self/comm were no longer blocked as
they are on almost all other procfs files.

A very similar situation with /proc/self/environ was used to as a root
exploit a long time ago, but procfs has SB_I_NOEXEC so this is simply a
correctness issue.

Ref: https://lwn.net/Articles/191954/
Ref: 6d76fa58b0 ("Don't allow chmod() on the /proc/<pid>/ files")
Fixes: 1b3044e39a ("procfs: fix pthread cross-thread naming if !PR_DUMPABLE")
Cc: stable@vger.kernel.org # v4.7+
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
Message-Id: <20230713141001.27046-1-cyphar@cyphar.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-07-13 16:30:52 +02:00
Thomas Weißschuh
18e66ae676
proc: use generic setattr() for /proc/$PID/net
All other files in /proc/$PID/ use proc_setattr().

Not using it allows the usage of chmod() on /proc/$PID/net, even on
other processes owned by the same user.
The same would probably also be true for other attributes to be changed.

As this technically represents an ABI change it is not marked for
stable so any unlikely regressions are caught during a full release cycle.

Fixes: e9720acd72 ("[NET]: Make /proc/net a symlink on /proc/self/net (v3)")
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://lore.kernel.org/lkml/d0d111ef-edae-4760-83fb-36db84278da1@t-8ch.de/
Fixes: b4844fa0bd ("selftests/nolibc: implement a few tests for various syscalls")
Tested-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Message-Id: <20230624-proc-net-setattr-v1-2-73176812adee@weissschuh.net>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-07-13 13:55:14 +02:00
Yu-cheng Yu
54007f8182 mm: Introduce VM_SHADOW_STACK for shadow stack memory
New hardware extensions implement support for shadow stack memory, such
as x86 Control-flow Enforcement Technology (CET). Add a new VM flag to
identify these areas, for example, to be used to properly indicate shadow
stack PTEs to the hardware.

Shadow stack VMA creation will be tightly controlled and limited to
anonymous memory to make the implementation simpler and since that is all
that is required. The solution will rely on pte_mkwrite() to create the
shadow stack PTEs, so it will not be required for vm_get_page_prot() to
learn how to create shadow stack memory. For this reason document that
VM_SHADOW_STACK should not be mixed with VM_SHARED.

Co-developed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
Tested-by: Mark Brown <broonie@kernel.org>
Tested-by: Pengfei Xu <pengfei.xu@intel.com>
Tested-by: John Allen <john.allen@amd.com>
Tested-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/all/20230613001108.3040476-15-rick.p.edgecombe%40intel.com
2023-07-11 14:12:19 -07:00
Linus Torvalds
7b82e90411 asm-generic updates for 6.5
These are cleanups for architecture specific header files:
 
  - the comments in include/linux/syscalls.h have gone out of sync
    and are really pointless, so these get removed
 
  - The asm/bitsperlong.h header no longer needs to be architecture
    specific on modern compilers, so use a generic version for newer
    architectures that use new enough userspace compilers
 
  - A cleanup for virt_to_pfn/virt_to_bus to have proper type
    checking, forcing the use of pointers
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Merge tag 'asm-generic-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic

Pull asm-generic updates from Arnd Bergmann:
 "These are cleanups for architecture specific header files:

   - the comments in include/linux/syscalls.h have gone out of sync and
     are really pointless, so these get removed

   - The asm/bitsperlong.h header no longer needs to be architecture
     specific on modern compilers, so use a generic version for newer
     architectures that use new enough userspace compilers

   - A cleanup for virt_to_pfn/virt_to_bus to have proper type checking,
     forcing the use of pointers"

* tag 'asm-generic-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
  syscalls: Remove file path comments from headers
  tools arch: Remove uapi bitsperlong.h of hexagon and microblaze
  asm-generic: Unify uapi bitsperlong.h for arm64, riscv and loongarch
  m68k/mm: Make pfn accessors static inlines
  arm64: memory: Make virt_to_pfn() a static inline
  ARM: mm: Make virt_to_pfn() a static inline
  asm-generic/page.h: Make pfn accessors static inlines
  xen/netback: Pass (void *) to virt_to_page()
  netfs: Pass a pointer to virt_to_page()
  cifs: Pass a pointer to virt_to_page() in cifsglob
  cifs: Pass a pointer to virt_to_page()
  riscv: mm: init: Pass a pointer to virt_to_page()
  ARC: init: Pass a pointer to virt_to_pfn() in init
  m68k: Pass a pointer to virt_to_pfn() virt_to_page()
  fs/proc/kcore.c: Pass a pointer to virt_addr_valid()
2023-07-06 10:06:04 -07:00
Tom Rix
7fffbc7107 sysctl: set variable sysctl_mount_point storage-class-specifier to static
smatch reports
fs/proc/proc_sysctl.c:32:18: warning: symbol
  'sysctl_mount_point' was not declared. Should it be static?

This variable is only used in its defining file, so it should be static.

Signed-off-by: Tom Rix <trix@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-06-30 16:19:47 -07:00
Linus Torvalds
6a8cbd9253 v6.5-rc1-sysctl-next
The changes queued up for v6.5-rc1 for sysctl are in line with
 prior efforts to stop usage of deprecated routines which incur
 recursion and also make it hard to remove the empty array element
 in each sysctl array declaration. The most difficult user to modify
 was parport which required a bit of re-thinking of how to declare shared
 sysctls there, Joel Granados has stepped up to the plate to do most of
 this work and eventual removal of register_sysctl_table(). That work
 ended up saving us about 1465 bytes according to bloat-o-meter. Since
 we gained a few bloat-o-meter karma points I moved two rather small
 sysctl arrays from kernel/sysctl.c leaving us only two more sysctl
 arrays to move left.
 
 Most changes have been tested on linux-next for about a month. The last
 straggler patches are a minor parport fix, changes to the sysctl
 kernel selftest so to verify correctness and prevent regressions for
 the future change he made to provide an alternative solution for the
 special sysctl mount point target which was using the now deprecated
 sysctl child element.
 
 This is all prep work to now finally be able to remove the empty
 array element in all sysctl declarations / registrations which is
 expected to save us a bit of bytes all over the kernel. That work
 will be tested early after v6.5-rc1 is out.
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Merge tag 'v6.5-rc1-sysctl-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux

Pull sysctl updates from Luis Chamberlain:
 "The changes for sysctl are in line with prior efforts to stop usage of
  deprecated routines which incur recursion and also make it hard to
  remove the empty array element in each sysctl array declaration.

  The most difficult user to modify was parport which required a bit of
  re-thinking of how to declare shared sysctls there, Joel Granados has
  stepped up to the plate to do most of this work and eventual removal
  of register_sysctl_table(). That work ended up saving us about 1465
  bytes according to bloat-o-meter. Since we gained a few bloat-o-meter
  karma points I moved two rather small sysctl arrays from
  kernel/sysctl.c leaving us only two more sysctl arrays to move left.

  Most changes have been tested on linux-next for about a month. The
  last straggler patches are a minor parport fix, changes to the sysctl
  kernel selftest so to verify correctness and prevent regressions for
  the future change he made to provide an alternative solution for the
  special sysctl mount point target which was using the now deprecated
  sysctl child element.

  This is all prep work to now finally be able to remove the empty array
  element in all sysctl declarations / registrations which is expected
  to save us a bit of bytes all over the kernel. That work will be
  tested early after v6.5-rc1 is out"

* tag 'v6.5-rc1-sysctl-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux:
  sysctl: replace child with an enumeration
  sysctl: Remove debugging dump_stack
  test_sysclt: Test for registering a mount point
  test_sysctl: Add an option to prevent test skip
  test_sysctl: Add an unregister sysctl test
  test_sysctl: Group node sysctl test under one func
  test_sysctl: Fix test metadata getters
  parport: plug a sysctl register leak
  sysctl: move security keys sysctl registration to its own file
  sysctl: move umh sysctl registration to its own file
  signal: move show_unhandled_signals sysctl to its own file
  sysctl: remove empty dev table
  sysctl: Remove register_sysctl_table
  sysctl: Refactor base paths registrations
  sysctl: stop exporting register_sysctl_table
  parport: Removed sysctl related defines
  parport: Remove register_sysctl_table from parport_default_proc_register
  parport: Remove register_sysctl_table from parport_device_proc_register
  parport: Remove register_sysctl_table from parport_proc_register
  parport: Move magic number "15" to a define
2023-06-28 16:05:21 -07:00
Linus Torvalds
77b1a7f7a0 - Arnd Bergmann has fixed a bunch of -Wmissing-prototypes in
top-level directories.
 
 - Douglas Anderson has added a new "buddy" mode to the hardlockup
   detector.  It permits the detector to work on architectures which
   cannot provide the required interrupts, by having CPUs periodically
   perform checks on other CPUs.
 
 - Zhen Lei has enhanced kexec's ability to support two crash regions.
 
 - Petr Mladek has done a lot of cleanup on the hard lockup detector's
   Kconfig entries.
 
 - And the usual bunch of singleton patches in various places.
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Merge tag 'mm-nonmm-stable-2023-06-24-19-23' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull non-mm updates from Andrew Morton:

 - Arnd Bergmann has fixed a bunch of -Wmissing-prototypes in top-level
   directories

 - Douglas Anderson has added a new "buddy" mode to the hardlockup
   detector. It permits the detector to work on architectures which
   cannot provide the required interrupts, by having CPUs periodically
   perform checks on other CPUs

 - Zhen Lei has enhanced kexec's ability to support two crash regions

 - Petr Mladek has done a lot of cleanup on the hard lockup detector's
   Kconfig entries

 - And the usual bunch of singleton patches in various places

* tag 'mm-nonmm-stable-2023-06-24-19-23' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (72 commits)
  kernel/time/posix-stubs.c: remove duplicated include
  ocfs2: remove redundant assignment to variable bit_off
  watchdog/hardlockup: fix typo in config HARDLOCKUP_DETECTOR_PREFER_BUDDY
  powerpc: move arch_trigger_cpumask_backtrace from nmi.h to irq.h
  devres: show which resource was invalid in __devm_ioremap_resource()
  watchdog/hardlockup: define HARDLOCKUP_DETECTOR_ARCH
  watchdog/sparc64: define HARDLOCKUP_DETECTOR_SPARC64
  watchdog/hardlockup: make HAVE_NMI_WATCHDOG sparc64-specific
  watchdog/hardlockup: declare arch_touch_nmi_watchdog() only in linux/nmi.h
  watchdog/hardlockup: make the config checks more straightforward
  watchdog/hardlockup: sort hardlockup detector related config values a logical way
  watchdog/hardlockup: move SMP barriers from common code to buddy code
  watchdog/buddy: simplify the dependency for HARDLOCKUP_DETECTOR_PREFER_BUDDY
  watchdog/buddy: don't copy the cpumask in watchdog_next_cpu()
  watchdog/buddy: cleanup how watchdog_buddy_check_hardlockup() is called
  watchdog/hardlockup: remove softlockup comment in touch_nmi_watchdog()
  watchdog/hardlockup: in watchdog_hardlockup_check() use cpumask_copy()
  watchdog/hardlockup: don't use raw_cpu_ptr() in watchdog_hardlockup_kick()
  watchdog/hardlockup: HAVE_NMI_WATCHDOG must implement watchdog_hardlockup_probe()
  watchdog/hardlockup: keep kernel.nmi_watchdog sysctl as 0444 if probe fails
  ...
2023-06-28 10:59:38 -07:00
Linus Torvalds
6e17c6de3d - Yosry Ahmed brought back some cgroup v1 stats in OOM logs.
- Yosry has also eliminated cgroup's atomic rstat flushing.
 
 - Nhat Pham adds the new cachestat() syscall.  It provides userspace
   with the ability to query pagecache status - a similar concept to
   mincore() but more powerful and with improved usability.
 
 - Mel Gorman provides more optimizations for compaction, reducing the
   prevalence of page rescanning.
 
 - Lorenzo Stoakes has done some maintanance work on the get_user_pages()
   interface.
 
 - Liam Howlett continues with cleanups and maintenance work to the maple
   tree code.  Peng Zhang also does some work on maple tree.
 
 - Johannes Weiner has done some cleanup work on the compaction code.
 
 - David Hildenbrand has contributed additional selftests for
   get_user_pages().
 
 - Thomas Gleixner has contributed some maintenance and optimization work
   for the vmalloc code.
 
 - Baolin Wang has provided some compaction cleanups,
 
 - SeongJae Park continues maintenance work on the DAMON code.
 
 - Huang Ying has done some maintenance on the swap code's usage of
   device refcounting.
 
 - Christoph Hellwig has some cleanups for the filemap/directio code.
 
 - Ryan Roberts provides two patch series which yield some
   rationalization of the kernel's access to pte entries - use the provided
   APIs rather than open-coding accesses.
 
 - Lorenzo Stoakes has some fixes to the interaction between pagecache
   and directio access to file mappings.
 
 - John Hubbard has a series of fixes to the MM selftesting code.
 
 - ZhangPeng continues the folio conversion campaign.
 
 - Hugh Dickins has been working on the pagetable handling code, mainly
   with a view to reducing the load on the mmap_lock.
 
 - Catalin Marinas has reduced the arm64 kmalloc() minimum alignment from
   128 to 8.
 
 - Domenico Cerasuolo has improved the zswap reclaim mechanism by
   reorganizing the LRU management.
 
 - Matthew Wilcox provides some fixups to make gfs2 work better with the
   buffer_head code.
 
 - Vishal Moola also has done some folio conversion work.
 
 - Matthew Wilcox has removed the remnants of the pagevec code - their
   functionality is migrated over to struct folio_batch.
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Merge tag 'mm-stable-2023-06-24-19-15' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull mm updates from Andrew Morton:

 - Yosry Ahmed brought back some cgroup v1 stats in OOM logs

 - Yosry has also eliminated cgroup's atomic rstat flushing

 - Nhat Pham adds the new cachestat() syscall. It provides userspace
   with the ability to query pagecache status - a similar concept to
   mincore() but more powerful and with improved usability

 - Mel Gorman provides more optimizations for compaction, reducing the
   prevalence of page rescanning

 - Lorenzo Stoakes has done some maintanance work on the
   get_user_pages() interface

 - Liam Howlett continues with cleanups and maintenance work to the
   maple tree code. Peng Zhang also does some work on maple tree

 - Johannes Weiner has done some cleanup work on the compaction code

 - David Hildenbrand has contributed additional selftests for
   get_user_pages()

 - Thomas Gleixner has contributed some maintenance and optimization
   work for the vmalloc code

 - Baolin Wang has provided some compaction cleanups,

 - SeongJae Park continues maintenance work on the DAMON code

 - Huang Ying has done some maintenance on the swap code's usage of
   device refcounting

 - Christoph Hellwig has some cleanups for the filemap/directio code

 - Ryan Roberts provides two patch series which yield some
   rationalization of the kernel's access to pte entries - use the
   provided APIs rather than open-coding accesses

 - Lorenzo Stoakes has some fixes to the interaction between pagecache
   and directio access to file mappings

 - John Hubbard has a series of fixes to the MM selftesting code

 - ZhangPeng continues the folio conversion campaign

 - Hugh Dickins has been working on the pagetable handling code, mainly
   with a view to reducing the load on the mmap_lock

 - Catalin Marinas has reduced the arm64 kmalloc() minimum alignment
   from 128 to 8

 - Domenico Cerasuolo has improved the zswap reclaim mechanism by
   reorganizing the LRU management

 - Matthew Wilcox provides some fixups to make gfs2 work better with the
   buffer_head code

 - Vishal Moola also has done some folio conversion work

 - Matthew Wilcox has removed the remnants of the pagevec code - their
   functionality is migrated over to struct folio_batch

* tag 'mm-stable-2023-06-24-19-15' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (380 commits)
  mm/hugetlb: remove hugetlb_set_page_subpool()
  mm: nommu: correct the range of mmap_sem_read_lock in task_mem()
  hugetlb: revert use of page_cache_next_miss()
  Revert "page cache: fix page_cache_next/prev_miss off by one"
  mm/vmscan: fix root proactive reclaim unthrottling unbalanced node
  mm: memcg: rename and document global_reclaim()
  mm: kill [add|del]_page_to_lru_list()
  mm: compaction: convert to use a folio in isolate_migratepages_block()
  mm: zswap: fix double invalidate with exclusive loads
  mm: remove unnecessary pagevec includes
  mm: remove references to pagevec
  mm: rename invalidate_mapping_pagevec to mapping_try_invalidate
  mm: remove struct pagevec
  net: convert sunrpc from pagevec to folio_batch
  i915: convert i915_gpu_error to use a folio_batch
  pagevec: rename fbatch_count()
  mm: remove check_move_unevictable_pages()
  drm: convert drm_gem_put_pages() to use a folio_batch
  i915: convert shmem_sg_free_table() to use a folio_batch
  scatterlist: add sg_set_folio()
  ...
2023-06-28 10:28:11 -07:00
Linus Torvalds
d416a46c95 execve updates for v6.5-rc1
- Fix a few comments for correctness and typos (Baruch Siach)
 
 - Small simplifications for binfmt (Christophe JAILLET)
 
 - Set p_align to 4 for PT_NOTE in core dump (Fangrui Song)
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Merge tag 'execve-v6.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull execve updates from Kees Cook:

 - Fix a few comments for correctness and typos (Baruch Siach)

 - Small simplifications for binfmt (Christophe JAILLET)

 - Set p_align to 4 for PT_NOTE in core dump (Fangrui Song)

* tag 'execve-v6.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  binfmt_elf: fix comment typo s/reset/regset/
  elf: correct note name comment
  binfmt: Slightly simplify elf_fdpic_map_file()
  binfmt: Use struct_size()
  coredump, vmcore: Set p_align to 4 for PT_NOTE
2023-06-27 21:12:41 -07:00
Linus Torvalds
2c96136a3f - Add support for unaccepted memory as specified in the UEFI spec v2.9.
The gist of it all is that Intel TDX and AMD SEV-SNP confidential
   computing guests define the notion of accepting memory before using it
   and thus preventing a whole set of attacks against such guests like
   memory replay and the like.
 
   There are a couple of strategies of how memory should be accepted
   - the current implementation does an on-demand way of accepting.
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Merge tag 'x86_cc_for_v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 confidential computing update from Borislav Petkov:

 - Add support for unaccepted memory as specified in the UEFI spec v2.9.

   The gist of it all is that Intel TDX and AMD SEV-SNP confidential
   computing guests define the notion of accepting memory before using
   it and thus preventing a whole set of attacks against such guests
   like memory replay and the like.

   There are a couple of strategies of how memory should be accepted -
   the current implementation does an on-demand way of accepting.

* tag 'x86_cc_for_v6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  virt: sevguest: Add CONFIG_CRYPTO dependency
  x86/efi: Safely enable unaccepted memory in UEFI
  x86/sev: Add SNP-specific unaccepted memory support
  x86/sev: Use large PSC requests if applicable
  x86/sev: Allow for use of the early boot GHCB for PSC requests
  x86/sev: Put PSC struct on the stack in prep for unaccepted memory support
  x86/sev: Fix calculation of end address based on number of pages
  x86/tdx: Add unaccepted memory support
  x86/tdx: Refactor try_accept_one()
  x86/tdx: Make _tdx_hypercall() and __tdx_module_call() available in boot stub
  efi/unaccepted: Avoid load_unaligned_zeropad() stepping into unaccepted memory
  efi: Add unaccepted memory support
  x86/boot/compressed: Handle unaccepted memory
  efi/libstub: Implement support for unaccepted memory
  efi/x86: Get full memory map in allocate_e820()
  mm: Add support for unaccepted memory
2023-06-26 15:32:39 -07:00
lipeifeng
341d51c886 mm: nommu: correct the range of mmap_sem_read_lock in task_mem()
During the seq_printf,the mmap_sem_read_lock protection is not
required.

Link: https://lkml.kernel.org/r/20230622040152.1173-1-lipeifeng@oppo.com
Signed-off-by: lipeifeng <lipeifeng@oppo.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-23 16:59:32 -07:00
Ryan Roberts
c33c794828 mm: ptep_get() conversion
Convert all instances of direct pte_t* dereferencing to instead use
ptep_get() helper.  This means that by default, the accesses change from a
C dereference to a READ_ONCE().  This is technically the correct thing to
do since where pgtables are modified by HW (for access/dirty) they are
volatile and therefore we should always ensure READ_ONCE() semantics.

But more importantly, by always using the helper, it can be overridden by
the architecture to fully encapsulate the contents of the pte.  Arch code
is deliberately not converted, as the arch code knows best.  It is
intended that arch code (arm64) will override the default with its own
implementation that can (e.g.) hide certain bits from the core code, or
determine young/dirty status by mixing in state from another source.

Conversion was done using Coccinelle:

----

// $ make coccicheck \
//          COCCI=ptepget.cocci \
//          SPFLAGS="--include-headers" \
//          MODE=patch

virtual patch

@ depends on patch @
pte_t *v;
@@

- *v
+ ptep_get(v)

----

Then reviewed and hand-edited to avoid multiple unnecessary calls to
ptep_get(), instead opting to store the result of a single call in a
variable, where it is correct to do so.  This aims to negate any cost of
READ_ONCE() and will benefit arch-overrides that may be more complex.

Included is a fix for an issue in an earlier version of this patch that
was pointed out by kernel test robot.  The issue arose because config
MMU=n elides definition of the ptep helper functions, including
ptep_get().  HUGETLB_PAGE=n configs still define a simple
huge_ptep_clear_flush() for linking purposes, which dereferences the ptep.
So when both configs are disabled, this caused a build error because
ptep_get() is not defined.  Fix by continuing to do a direct dereference
when MMU=n.  This is safe because for this config the arch code cannot be
trying to virtualize the ptes because none of the ptep helpers are
defined.

Link: https://lkml.kernel.org/r/20230612151545.3317766-4-ryan.roberts@arm.com
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/oe-kbuild-all/202305120142.yXsNEo6H-lkp@intel.com/
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Dave Airlie <airlied@gmail.com>
Cc: Dimitri Sivanich <dimitri.sivanich@hpe.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: SeongJae Park <sj@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-19 16:19:25 -07:00
Hugh Dickins
7780d04046 mm/pagewalkers: ACTION_AGAIN if pte_offset_map_lock() fails
Simple walk_page_range() users should set ACTION_AGAIN to retry when
pte_offset_map_lock() fails.

No need to check pmd_trans_unstable(): that was precisely to avoid the
possiblity of calling pte_offset_map() on a racily removed or inserted THP
entry, but such cases are now safely handled inside it.  Likewise there is
no need to check pmd_none() or pmd_bad() before calling it.

Link: https://lkml.kernel.org/r/c77d9d10-3aad-e3ce-4896-99e91c7947f3@google.com
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: SeongJae Park <sj@kernel.org> for mm/damon part
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Song Liu <song@kernel.org>
Cc: Steven Price <steven.price@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Zack Rusin <zackr@vmware.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-19 16:19:13 -07:00
Joel Granados
2f2665c13a sysctl: replace child with an enumeration
This is part of the effort to remove the empty element at the end of
ctl_table structs. "child" was a deprecated elem in this struct and was
being used to differentiate between two types of ctl_tables: "normal"
and "permanently emtpy".

What changed?:
* Replace "child" with an enumeration that will have two values: the
  default (0) and the permanently empty (1). The latter is left at zero
  so when struct ctl_table is created with kzalloc or in a local
  context, it will have the zero value by default. We document the
  new enum with kdoc.
* Remove the "empty child" check from sysctl_check_table
* Remove count_subheaders function as there is no longer a need to
  calculate how many headers there are for every child
* Remove the recursive call to unregister_sysctl_table as there is no
  need to traverse down the child tree any longer
* Add a new SYSCTL_PERM_EMPTY_DIR binary flag
* Remove the last remanence of child from partport/procfs.c

Signed-off-by: Joel Granados <j.granados@samsung.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-06-18 02:32:54 -07:00
Joel Granados
94a6490518 sysctl: Remove debugging dump_stack
Remove unneeded dump_stack in __register_sysctl_table

Signed-off-by: Joel Granados <j.granados@samsung.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-06-18 02:32:54 -07:00
Azeem Shaikh
9e627588bf procfs: replace all non-returning strlcpy with strscpy
strlcpy() reads the entire source buffer first.  This read may exceed the
destination size limit.  This is both inefficient and can lead to linear
read overflows if a source string is not NUL-terminated [1].  In an effort
to remove strlcpy() completely [2], replace strlcpy() here with strscpy().
No return values were used, so direct replacement is safe.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
[2] https://github.com/KSPP/linux/issues/89

Link: https://lkml.kernel.org/r/20230510212457.3491385-1-azeemshaikh38@gmail.com
Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Liu Shixin <liushixin2@huawei.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-09 17:44:13 -07:00
Yuanchu Xie
7bab8dfb12 mm: pagemap: restrict pagewalk to the requested range
The pagewalk in pagemap_read reads one PTE past the end of the requested
range, and stops when the buffer runs out of space. While it produces
the right result, the extra read is unnecessary and less performant.

I timed the following command before and after this patch:
	dd count=100000 if=/proc/self/pagemap of=/dev/null
The results are consistently within 0.001s across 5 runs.

Before:
100000+0 records in
100000+0 records out
51200000 bytes (51 MB) copied, 0.0763159 s, 671 MB/s

real    0m0.078s
user    0m0.012s
sys     0m0.065s

After:
100000+0 records in
100000+0 records out
51200000 bytes (51 MB) copied, 0.0487928 s, 1.0 GB/s

real    0m0.050s
user    0m0.011s
sys     0m0.039s

Link: https://lkml.kernel.org/r/20230515172608.3558391-1-yuanchu@google.com
Signed-off-by: Yuanchu Xie <yuanchu@google.com>
Acked-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Zach O'Keefe <zokeefe@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-09 16:25:20 -07:00
Kirill A. Shutemov
dcdfdd40fa mm: Add support for unaccepted memory
UEFI Specification version 2.9 introduces the concept of memory
acceptance. Some Virtual Machine platforms, such as Intel TDX or AMD
SEV-SNP, require memory to be accepted before it can be used by the
guest. Accepting happens via a protocol specific to the Virtual Machine
platform.

There are several ways the kernel can deal with unaccepted memory:

 1. Accept all the memory during boot. It is easy to implement and it
    doesn't have runtime cost once the system is booted. The downside is
    very long boot time.

    Accept can be parallelized to multiple CPUs to keep it manageable
    (i.e. via DEFERRED_STRUCT_PAGE_INIT), but it tends to saturate
    memory bandwidth and does not scale beyond the point.

 2. Accept a block of memory on the first use. It requires more
    infrastructure and changes in page allocator to make it work, but
    it provides good boot time.

    On-demand memory accept means latency spikes every time kernel steps
    onto a new memory block. The spikes will go away once workload data
    set size gets stabilized or all memory gets accepted.

 3. Accept all memory in background. Introduce a thread (or multiple)
    that gets memory accepted proactively. It will minimize time the
    system experience latency spikes on memory allocation while keeping
    low boot time.

    This approach cannot function on its own. It is an extension of #2:
    background memory acceptance requires functional scheduler, but the
    page allocator may need to tap into unaccepted memory before that.

    The downside of the approach is that these threads also steal CPU
    cycles and memory bandwidth from the user's workload and may hurt
    user experience.

Implement #1 and #2 for now. #2 is the default. Some workloads may want
to use #1 with accept_memory=eager in kernel command line. #3 can be
implemented later based on user's demands.

Support of unaccepted memory requires a few changes in core-mm code:

  - memblock accepts memory on allocation. It serves early boot memory
    allocations and doesn't limit them to pre-accepted pool of memory.

  - page allocator accepts memory on the first allocation of the page.
    When kernel runs out of accepted memory, it accepts memory until the
    high watermark is reached. It helps to minimize fragmentation.

EFI code will provide two helpers if the platform supports unaccepted
memory:

 - accept_memory() makes a range of physical addresses accepted.

 - range_contains_unaccepted_memory() checks anything within the range
   of physical addresses requires acceptance.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>	# memblock
Link: https://lore.kernel.org/r/20230606142637.5171-2-kirill.shutemov@linux.intel.com
2023-06-06 16:38:22 +02:00
Linus Walleij
9b2d38b4e4 fs/proc/kcore.c: Pass a pointer to virt_addr_valid()
The virt_addr_valid() should be passed a pointer, the current
code passing a long unsigned int is just exploiting the
unintentional polymorphism of these calls being implemented
as preprocessor macros.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2023-05-29 11:27:07 +02:00
David Howells
b0072734ff tty, proc, kernfs, random: Use copy_splice_read()
Use copy_splice_read() for tty, procfs, kernfs and random files rather
than going through generic_file_splice_read() as they just copy the file
into the output buffer and don't splice pages.  This avoids the need for
them to have a ->read_folio() to satisfy filemap_splice_read().

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cc: Christoph Hellwig <hch@lst.de>
cc: Jens Axboe <axboe@kernel.dk>
cc: Al Viro <viro@zeniv.linux.org.uk>
cc: John Hubbard <jhubbard@nvidia.com>
cc: David Hildenbrand <david@redhat.com>
cc: Matthew Wilcox <willy@infradead.org>
cc: Miklos Szeredi <miklos@szeredi.hu>
cc: Arnd Bergmann <arnd@arndb.de>
cc: linux-block@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
Link: https://lore.kernel.org/r/20230522135018.2742245-13-dhowells@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-05-24 08:42:16 -06:00
Joel Granados
b8cbc0855a sysctl: Remove register_sysctl_table
This is part of the general push to deprecate register_sysctl_paths and
register_sysctl_table. After removing all the calling functions, we
remove both the register_sysctl_table function and the documentation
check that appeared in check-sysctl-docs awk script.

We save 595 bytes with this change:

./scripts/bloat-o-meter vmlinux.1.refactor-base-paths vmlinux.2.remove-sysctl-table
add/remove: 2/8 grow/shrink: 1/0 up/down: 1154/-1749 (-595)
Function                                     old     new   delta
count_subheaders                               -     983    +983
unregister_sysctl_table                       29     184    +155
__pfx_count_subheaders                         -      16     +16
__pfx_unregister_sysctl_table.part            16       -     -16
__pfx_register_leaf_sysctl_tables.constprop   16       -     -16
__pfx_count_subheaders.part                   16       -     -16
__pfx___register_sysctl_base                  16       -     -16
unregister_sysctl_table.part                 136       -    -136
__register_sysctl_base                       478       -    -478
register_leaf_sysctl_tables.constprop        524       -    -524
count_subheaders.part                        547       -    -547
Total: Before=21257652, After=21257057, chg -0.00%

[mcgrof: remove register_leaf_sysctl_tables and append_path too and
 add bloat-o-meter stats]

Signed-off-by: Joel Granados <j.granados@samsung.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Acked-by: Christian Brauner <brauner@kernel.org>
2023-05-23 21:43:26 -07:00
Joel Granados
19c4e618a1 sysctl: stop exporting register_sysctl_table
We make register_sysctl_table static because the only function calling
it is in fs/proc/proc_sysctl.c (__register_sysctl_base). We remove it
from the sysctl.h header and modify the documentation in both the header
and proc_sysctl.c files to mention "register_sysctl" instead of
"register_sysctl_table".

This plus the commits that remove register_sysctl_table from parport
save 217 bytes:

./scripts/bloat-o-meter .bsysctl/vmlinux.old .bsysctl/vmlinux.new
add/remove: 0/1 grow/shrink: 5/1 up/down: 458/-675 (-217)
Function                                     old     new   delta
__register_sysctl_base                         8     286    +278
parport_proc_register                        268     379    +111
parport_device_proc_register                 195     247     +52
kzalloc.constprop                            598     608     +10
parport_default_proc_register                 62      69      +7
register_sysctl_table                        291       -    -291
parport_sysctl_template                     1288     904    -384
Total: Before=8603076, After=8602859, chg -0.00%

Signed-off-by: Joel Granados <j.granados@samsung.com>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-05-23 21:43:26 -07:00
Fangrui Song
60592fb6b6 coredump, vmcore: Set p_align to 4 for PT_NOTE
Tools like readelf/llvm-readelf use p_align to parse a PT_NOTE program
header as an array of 4-byte entries or 8-byte entries. Currently, there
are workarounds[1] in place for Linux to treat p_align==0 as 4. However,
it would be more appropriate to set the correct alignment so that tools
do not have to rely on guesswork. FreeBSD coredumps set p_align to 4 as
well.

[1]: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=82ed9683ec099d8205dc499ac84febc975235af6
[2]: https://reviews.llvm.org/D150022

Signed-off-by: Fangrui Song <maskray@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230512022528.3430327-1-maskray@google.com
2023-05-16 14:32:00 -07:00
Luis Chamberlain
0199849acd sysctl: remove register_sysctl_paths()
The deprecation for register_sysctl_paths() is over. We can rejoice as
we nuke register_sysctl_paths(). The routine register_sysctl_table()
was the only user left of register_sysctl_paths(), so we can now just
open code and move the implementation over to what used to be
to __register_sysctl_paths().

The old dynamic struct ctl_table_set *set is now the point to
sysctl_table_root.default_set.

The old dynamic const struct ctl_path *path was being used in the
routine register_sysctl_paths() with a static:

static const struct ctl_path null_path[] = { {} };

Since this is a null path we can now just simplfy the old routine
and remove its use as its always empty.

This saves us a total of 230 bytes.

$ ./scripts/bloat-o-meter vmlinux.old vmlinux
add/remove: 2/7 grow/shrink: 1/1 up/down: 1015/-1245 (-230)
Function                                     old     new   delta
register_leaf_sysctl_tables.constprop          -     524    +524
register_sysctl_table                         22     497    +475
__pfx_register_leaf_sysctl_tables.constprop       -      16     +16
null_path                                      8       -      -8
__pfx_register_sysctl_paths                   16       -     -16
__pfx_register_leaf_sysctl_tables             16       -     -16
__pfx___register_sysctl_paths                 16       -     -16
__register_sysctl_base                        29      12     -17
register_sysctl_paths                         18       -     -18
register_leaf_sysctl_tables                  534       -    -534
__register_sysctl_paths                      620       -    -620
Total: Before=21259666, After=21259436, chg -0.00%

Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-05-02 19:24:16 -07:00
Linus Torvalds
22b8cc3e78 Add support for new Linear Address Masking CPU feature. This is similar
to ARM's Top Byte Ignore and allows userspace to store metadata in some
 bits of pointers without masking it out before use.
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Merge tag 'x86_mm_for_6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 LAM (Linear Address Masking) support from Dave Hansen:
 "Add support for the new Linear Address Masking CPU feature.

  This is similar to ARM's Top Byte Ignore and allows userspace to store
  metadata in some bits of pointers without masking it out before use"

* tag 'x86_mm_for_6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm/iommu/sva: Do not allow to set FORCE_TAGGED_SVA bit from outside
  x86/mm/iommu/sva: Fix error code for LAM enabling failure due to SVA
  selftests/x86/lam: Add test cases for LAM vs thread creation
  selftests/x86/lam: Add ARCH_FORCE_TAGGED_SVA test cases for linear-address masking
  selftests/x86/lam: Add inherit test cases for linear-address masking
  selftests/x86/lam: Add io_uring test cases for linear-address masking
  selftests/x86/lam: Add mmap and SYSCALL test cases for linear-address masking
  selftests/x86/lam: Add malloc and tag-bits test cases for linear-address masking
  x86/mm/iommu/sva: Make LAM and SVA mutually exclusive
  iommu/sva: Replace pasid_valid() helper with mm_valid_pasid()
  mm: Expose untagging mask in /proc/$PID/status
  x86/mm: Provide arch_prctl() interface for LAM
  x86/mm: Reduce untagged_addr() overhead for systems without LAM
  x86/uaccess: Provide untagged_addr() and remove tags before address check
  mm: Introduce untagged_addr_remote()
  x86/mm: Handle LAM on context switch
  x86: CPUID and CR3/CR4 flags for Linear Address Masking
  x86: Allow atomic MM_CONTEXT flags setting
  x86/mm: Rework address range check in get_user() and put_user()
2023-04-28 09:43:49 -07:00
Linus Torvalds
33afd4b763 Mainly singleton patches all over the place. Series of note are:
- updates to scripts/gdb from Glenn Washburn
 
 - kexec cleanups from Bjorn Helgaas
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Merge tag 'mm-nonmm-stable-2023-04-27-16-01' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull non-MM updates from Andrew Morton:
 "Mainly singleton patches all over the place.

  Series of note are:

   - updates to scripts/gdb from Glenn Washburn

   - kexec cleanups from Bjorn Helgaas"

* tag 'mm-nonmm-stable-2023-04-27-16-01' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (50 commits)
  mailmap: add entries for Paul Mackerras
  libgcc: add forward declarations for generic library routines
  mailmap: add entry for Oleksandr
  ocfs2: reduce ioctl stack usage
  fs/proc: add Kthread flag to /proc/$pid/status
  ia64: fix an addr to taddr in huge_pte_offset()
  checkpatch: introduce proper bindings license check
  epoll: rename global epmutex
  scripts/gdb: add GDB convenience functions $lx_dentry_name() and $lx_i_dentry()
  scripts/gdb: create linux/vfs.py for VFS related GDB helpers
  uapi/linux/const.h: prefer ISO-friendly __typeof__
  delayacct: track delays from IRQ/SOFTIRQ
  scripts/gdb: timerlist: convert int chunks to str
  scripts/gdb: print interrupts
  scripts/gdb: raise error with reduced debugging information
  scripts/gdb: add a Radix Tree Parser
  lib/rbtree: use '+' instead of '|' for setting color.
  proc/stat: remove arch_idle_time()
  checkpatch: check for misuse of the link tags
  checkpatch: allow Closes tags with links
  ...
2023-04-27 19:57:00 -07:00
Linus Torvalds
7fa8a8ee94 - Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of
switching from a user process to a kernel thread.
 
 - More folio conversions from Kefeng Wang, Zhang Peng and Pankaj Raghav.
 
 - zsmalloc performance improvements from Sergey Senozhatsky.
 
 - Yue Zhao has found and fixed some data race issues around the
   alteration of memcg userspace tunables.
 
 - VFS rationalizations from Christoph Hellwig:
 
   - removal of most of the callers of write_one_page().
 
   - make __filemap_get_folio()'s return value more useful
 
 - Luis Chamberlain has changed tmpfs so it no longer requires swap
   backing.  Use `mount -o noswap'.
 
 - Qi Zheng has made the slab shrinkers operate locklessly, providing
   some scalability benefits.
 
 - Keith Busch has improved dmapool's performance, making part of its
   operations O(1) rather than O(n).
 
 - Peter Xu adds the UFFD_FEATURE_WP_UNPOPULATED feature to userfaultd,
   permitting userspace to wr-protect anon memory unpopulated ptes.
 
 - Kirill Shutemov has changed MAX_ORDER's meaning to be inclusive rather
   than exclusive, and has fixed a bunch of errors which were caused by its
   unintuitive meaning.
 
 - Axel Rasmussen give userfaultfd the UFFDIO_CONTINUE_MODE_WP feature,
   which causes minor faults to install a write-protected pte.
 
 - Vlastimil Babka has done some maintenance work on vma_merge():
   cleanups to the kernel code and improvements to our userspace test
   harness.
 
 - Cleanups to do_fault_around() by Lorenzo Stoakes.
 
 - Mike Rapoport has moved a lot of initialization code out of various
   mm/ files and into mm/mm_init.c.
 
 - Lorenzo Stoakes removd vmf_insert_mixed_prot(), which was added for
   DRM, but DRM doesn't use it any more.
 
 - Lorenzo has also coverted read_kcore() and vread() to use iterators
   and has thereby removed the use of bounce buffers in some cases.
 
 - Lorenzo has also contributed further cleanups of vma_merge().
 
 - Chaitanya Prakash provides some fixes to the mmap selftesting code.
 
 - Matthew Wilcox changes xfs and afs so they no longer take sleeping
   locks in ->map_page(), a step towards RCUification of pagefaults.
 
 - Suren Baghdasaryan has improved mmap_lock scalability by switching to
   per-VMA locking.
 
 - Frederic Weisbecker has reworked the percpu cache draining so that it
   no longer causes latency glitches on cpu isolated workloads.
 
 - Mike Rapoport cleans up and corrects the ARCH_FORCE_MAX_ORDER Kconfig
   logic.
 
 - Liu Shixin has changed zswap's initialization so we no longer waste a
   chunk of memory if zswap is not being used.
 
 - Yosry Ahmed has improved the performance of memcg statistics flushing.
 
 - David Stevens has fixed several issues involving khugepaged,
   userfaultfd and shmem.
 
 - Christoph Hellwig has provided some cleanup work to zram's IO-related
   code paths.
 
 - David Hildenbrand has fixed up some issues in the selftest code's
   testing of our pte state changing.
 
 - Pankaj Raghav has made page_endio() unneeded and has removed it.
 
 - Peter Xu contributed some rationalizations of the userfaultfd
   selftests.
 
 - Yosry Ahmed has fixed an issue around memcg's page recalim accounting.
 
 - Chaitanya Prakash has fixed some arm-related issues in the
   selftests/mm code.
 
 - Longlong Xia has improved the way in which KSM handles hwpoisoned
   pages.
 
 - Peter Xu fixes a few issues with uffd-wp at fork() time.
 
 - Stefan Roesch has changed KSM so that it may now be used on a
   per-process and per-cgroup basis.
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Merge tag 'mm-stable-2023-04-27-15-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of
   switching from a user process to a kernel thread.

 - More folio conversions from Kefeng Wang, Zhang Peng and Pankaj
   Raghav.

 - zsmalloc performance improvements from Sergey Senozhatsky.

 - Yue Zhao has found and fixed some data race issues around the
   alteration of memcg userspace tunables.

 - VFS rationalizations from Christoph Hellwig:
     - removal of most of the callers of write_one_page()
     - make __filemap_get_folio()'s return value more useful

 - Luis Chamberlain has changed tmpfs so it no longer requires swap
   backing. Use `mount -o noswap'.

 - Qi Zheng has made the slab shrinkers operate locklessly, providing
   some scalability benefits.

 - Keith Busch has improved dmapool's performance, making part of its
   operations O(1) rather than O(n).

 - Peter Xu adds the UFFD_FEATURE_WP_UNPOPULATED feature to userfaultd,
   permitting userspace to wr-protect anon memory unpopulated ptes.

 - Kirill Shutemov has changed MAX_ORDER's meaning to be inclusive
   rather than exclusive, and has fixed a bunch of errors which were
   caused by its unintuitive meaning.

 - Axel Rasmussen give userfaultfd the UFFDIO_CONTINUE_MODE_WP feature,
   which causes minor faults to install a write-protected pte.

 - Vlastimil Babka has done some maintenance work on vma_merge():
   cleanups to the kernel code and improvements to our userspace test
   harness.

 - Cleanups to do_fault_around() by Lorenzo Stoakes.

 - Mike Rapoport has moved a lot of initialization code out of various
   mm/ files and into mm/mm_init.c.

 - Lorenzo Stoakes removd vmf_insert_mixed_prot(), which was added for
   DRM, but DRM doesn't use it any more.

 - Lorenzo has also coverted read_kcore() and vread() to use iterators
   and has thereby removed the use of bounce buffers in some cases.

 - Lorenzo has also contributed further cleanups of vma_merge().

 - Chaitanya Prakash provides some fixes to the mmap selftesting code.

 - Matthew Wilcox changes xfs and afs so they no longer take sleeping
   locks in ->map_page(), a step towards RCUification of pagefaults.

 - Suren Baghdasaryan has improved mmap_lock scalability by switching to
   per-VMA locking.

 - Frederic Weisbecker has reworked the percpu cache draining so that it
   no longer causes latency glitches on cpu isolated workloads.

 - Mike Rapoport cleans up and corrects the ARCH_FORCE_MAX_ORDER Kconfig
   logic.

 - Liu Shixin has changed zswap's initialization so we no longer waste a
   chunk of memory if zswap is not being used.

 - Yosry Ahmed has improved the performance of memcg statistics
   flushing.

 - David Stevens has fixed several issues involving khugepaged,
   userfaultfd and shmem.

 - Christoph Hellwig has provided some cleanup work to zram's IO-related
   code paths.

 - David Hildenbrand has fixed up some issues in the selftest code's
   testing of our pte state changing.

 - Pankaj Raghav has made page_endio() unneeded and has removed it.

 - Peter Xu contributed some rationalizations of the userfaultfd
   selftests.

 - Yosry Ahmed has fixed an issue around memcg's page recalim
   accounting.

 - Chaitanya Prakash has fixed some arm-related issues in the
   selftests/mm code.

 - Longlong Xia has improved the way in which KSM handles hwpoisoned
   pages.

 - Peter Xu fixes a few issues with uffd-wp at fork() time.

 - Stefan Roesch has changed KSM so that it may now be used on a
   per-process and per-cgroup basis.

* tag 'mm-stable-2023-04-27-15-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (369 commits)
  mm,unmap: avoid flushing TLB in batch if PTE is inaccessible
  shmem: restrict noswap option to initial user namespace
  mm/khugepaged: fix conflicting mods to collapse_file()
  sparse: remove unnecessary 0 values from rc
  mm: move 'mmap_min_addr' logic from callers into vm_unmapped_area()
  hugetlb: pte_alloc_huge() to replace huge pte_alloc_map()
  maple_tree: fix allocation in mas_sparse_area()
  mm: do not increment pgfault stats when page fault handler retries
  zsmalloc: allow only one active pool compaction context
  selftests/mm: add new selftests for KSM
  mm: add new KSM process and sysfs knobs
  mm: add new api to enable ksm per process
  mm: shrinkers: fix debugfs file permissions
  mm: don't check VMA write permissions if the PTE/PMD indicates write permissions
  migrate_pages_batch: fix statistics for longterm pin retry
  userfaultfd: use helper function range_in_vma()
  lib/show_mem.c: use for_each_populated_zone() simplify code
  mm: correct arg in reclaim_pages()/reclaim_clean_pages_from_list()
  fs/buffer: convert create_page_buffers to folio_create_buffers
  fs/buffer: add folio_create_empty_buffers helper
  ...
2023-04-27 19:42:02 -07:00
Linus Torvalds
888d3c9f7f sysctl-6.4-rc1
This pull request goes with only a few sysctl moves from the
 kernel/sysctl.c file, the rest of the work has been put towards
 deprecating two API calls which incur recursion and prevent us
 from simplifying the registration process / saving memory per
 move. Most of the changes have been soaking on linux-next since
 v6.3-rc3.
 
 I've slowed down the kernel/sysctl.c moves due to Matthew Wilcox's
 feedback that we should see if we could *save* memory with these
 moves instead of incurring more memory. We currently incur more
 memory since when we move a syctl from kernel/sysclt.c out to its
 own file we end up having to add a new empty sysctl used to register
 it. To achieve saving memory we want to allow syctls to be passed
 without requiring the end element being empty, and just have our
 registration process rely on ARRAY_SIZE(). Without this, supporting
 both styles of sysctls would make the sysctl registration pretty
 brittle, hard to read and maintain as can be seen from Meng Tang's
 efforts to do just this [0]. Fortunately, in order to use ARRAY_SIZE()
 for all sysctl registrations also implies doing the work to deprecate
 two API calls which use recursion in order to support sysctl
 declarations with subdirectories.
 
 And so during this development cycle quite a bit of effort went into
 this deprecation effort. I've annotated the following two APIs are
 deprecated and in few kernel releases we should be good to remove them:
 
   * register_sysctl_table()
   * register_sysctl_paths()
 
 During this merge window we should be able to deprecate and unexport
 register_sysctl_paths(), we can probably do that towards the end
 of this merge window.
 
 Deprecating register_sysctl_table() will take a bit more time but
 this pull request goes with a few example of how to do this.
 
 As it turns out each of the conversions to move away from either of
 these two API calls *also* saves memory. And so long term, all these
 changes *will* prove to have saved a bit of memory on boot.
 
 The way I see it then is if remove a user of one deprecated call, it
 gives us enough savings to move one kernel/sysctl.c out from the
 generic arrays as we end up with about the same amount of bytes.
 
 Since deprecating register_sysctl_table() and register_sysctl_paths()
 does not require maintainer coordination except the final unexport
 you'll see quite a bit of these changes from other pull requests, I've
 just kept the stragglers after rc3.
 
 Most of these changes have been soaking on linux-next since around rc3.
 
 [0] https://lkml.kernel.org/r/ZAD+cpbrqlc5vmry@bombadil.infradead.org
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Merge tag 'sysctl-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux

Pull sysctl updates from Luis Chamberlain:
 "This only does a few sysctl moves from the kernel/sysctl.c file, the
  rest of the work has been put towards deprecating two API calls which
  incur recursion and prevent us from simplifying the registration
  process / saving memory per move. Most of the changes have been
  soaking on linux-next since v6.3-rc3.

  I've slowed down the kernel/sysctl.c moves due to Matthew Wilcox's
  feedback that we should see if we could *save* memory with these moves
  instead of incurring more memory. We currently incur more memory since
  when we move a syctl from kernel/sysclt.c out to its own file we end
  up having to add a new empty sysctl used to register it. To achieve
  saving memory we want to allow syctls to be passed without requiring
  the end element being empty, and just have our registration process
  rely on ARRAY_SIZE(). Without this, supporting both styles of sysctls
  would make the sysctl registration pretty brittle, hard to read and
  maintain as can be seen from Meng Tang's efforts to do just this [0].
  Fortunately, in order to use ARRAY_SIZE() for all sysctl registrations
  also implies doing the work to deprecate two API calls which use
  recursion in order to support sysctl declarations with subdirectories.

  And so during this development cycle quite a bit of effort went into
  this deprecation effort. I've annotated the following two APIs are
  deprecated and in few kernel releases we should be good to remove
  them:

   - register_sysctl_table()
   - register_sysctl_paths()

  During this merge window we should be able to deprecate and unexport
  register_sysctl_paths(), we can probably do that towards the end of
  this merge window.

  Deprecating register_sysctl_table() will take a bit more time but this
  pull request goes with a few example of how to do this.

  As it turns out each of the conversions to move away from either of
  these two API calls *also* saves memory. And so long term, all these
  changes *will* prove to have saved a bit of memory on boot.

  The way I see it then is if remove a user of one deprecated call, it
  gives us enough savings to move one kernel/sysctl.c out from the
  generic arrays as we end up with about the same amount of bytes.

  Since deprecating register_sysctl_table() and register_sysctl_paths()
  does not require maintainer coordination except the final unexport
  you'll see quite a bit of these changes from other pull requests, I've
  just kept the stragglers after rc3"

Link: https://lkml.kernel.org/r/ZAD+cpbrqlc5vmry@bombadil.infradead.org [0]

* tag 'sysctl-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux: (29 commits)
  fs: fix sysctls.c built
  mm: compaction: remove incorrect #ifdef checks
  mm: compaction: move compaction sysctl to its own file
  mm: memory-failure: Move memory failure sysctls to its own file
  arm: simplify two-level sysctl registration for ctl_isa_vars
  ia64: simplify one-level sysctl registration for kdump_ctl_table
  utsname: simplify one-level sysctl registration for uts_kern_table
  ntfs: simplfy one-level sysctl registration for ntfs_sysctls
  coda: simplify one-level sysctl registration for coda_table
  fs/cachefiles: simplify one-level sysctl registration for cachefiles_sysctls
  xfs: simplify two-level sysctl registration for xfs_table
  nfs: simplify two-level sysctl registration for nfs_cb_sysctls
  nfs: simplify two-level sysctl registration for nfs4_cb_sysctls
  lockd: simplify two-level sysctl registration for nlm_sysctls
  proc_sysctl: enhance documentation
  xen: simplify sysctl registration for balloon
  md: simplify sysctl registration
  hv: simplify sysctl registration
  scsi: simplify sysctl registration with register_sysctl()
  csky: simplify alignment sysctl registration
  ...
2023-04-27 16:52:33 -07:00
Chunguang Wu
522dc4e5f5 fs/proc: add Kthread flag to /proc/$pid/status
The command `ps -ef ` and `top -c` mark kernel thread by '[' and ']', but
sometimes the result is not correct.  The task->flags in /proc/$pid/stat
is good, but we need remember the value of PF_KTHREAD is 0x00200000 and
convert dec to hex.  If we have no binary program and shell script which
read /proc/$pid/stat, we can know it directly by `cat /proc/$pid/status`.

Link: https://lkml.kernel.org/r/20230416052404.2920-1-fullspring2018@gmail.com
Signed-off-by: Chunguang Wu <fullspring2018@gmail.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-21 14:54:34 -07:00
Stefan Roesch
d21077fbc2 mm: add new KSM process and sysfs knobs
This adds the general_profit KSM sysfs knob and the process profit metric
knobs to ksm_stat.

1) expose general_profit metric

   The documentation mentions a general profit metric, however this
   metric is not calculated.  In addition the formula depends on the size
   of internal structures, which makes it more difficult for an
   administrator to make the calculation.  Adding the metric for a better
   user experience.

2) document general_profit sysfs knob

3) calculate ksm process profit metric

   The ksm documentation mentions the process profit metric and how to
   calculate it.  This adds the calculation of the metric.

4) mm: expose ksm process profit metric in ksm_stat

   This exposes the ksm process profit metric in /proc/<pid>/ksm_stat.
   The documentation mentions the formula for the ksm process profit
   metric, however it does not calculate it.  In addition the formula
   depends on the size of internal structures.  So it makes sense to
   expose it.

5) document new procfs ksm knobs

Link: https://lkml.kernel.org/r/20230418051342.1919757-3-shr@devkernel.io
Signed-off-by: Stefan Roesch <shr@devkernel.io>
Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Rik van Riel <riel@surriel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-21 14:52:03 -07:00
Heiko Carstens
1be2edb25c proc/stat: remove arch_idle_time()
The last (only) architecture specific arch_idle_time() implementation was
removed with commit be76ea6144 ("s390/idle: remove arch_cpu_idle_time()
and corresponding code").

Therefore remove the now dead code in fs/proc/stat.c as well.

Link: https://lkml.kernel.org/r/20230405143452.2677172-1-hca@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18 16:39:33 -07:00
Steven Price
b4aca54792 smaps: fix defined but not used smaps_shmem_walk_ops
When !CONFIG_SHMEM smaps_shmem_walk_ops is defined but not used,
triggering a compiler warning.  To avoid the warning remove the #ifdef
around the usage.  This has no effect because shmem_mapping() is a stub
returning false when !CONFIG_SHMEM so the code will be compiled out,
however we now need to also provide a stub for shmem_swap_usage().

Link: https://lkml.kernel.org/r/20230405103819.151246-1-steven.price@arm.com
Fixes: 7b86ac3371 ("pagewalk: separate function pointers from iterator data")
Signed-off-by: Steven Price <steven.price@arm.com>
Reported-by: kernel test robot <lkp@intel.com>
  Link: https://lore.kernel.org/oe-kbuild-all/202304031749.UiyJpxzF-lkp@intel.com/
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-18 16:29:54 -07:00
Luis Chamberlain
1dc8689e4c proc_sysctl: enhance documentation
Expand documentation to clarify:

  o that paths don't need to exist for the new API callers
  o clarify that we *require* callers to keep the memory of
    the table around during the lifetime of the sysctls
  o annotate routines we are trying to deprecate and later remove

Cc: stable@vger.kernel.org # v5.17
Cc: Christian Brauner <brauner@kernel.org>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-04-13 11:49:22 -07:00
Luis Chamberlain
228b09de93 sysctl: clarify register_sysctl_init() base directory order
Relatively new docs which I added which hinted the base directories needed
to be created before is wrong, remove that incorrect comment. This has been
hinted before by Eric twice already [0] [1], I had just not verified that
until now. Now that I've verified that updates the docs to relax the context
described.

[0] https://lkml.kernel.org/r/875ys0azt8.fsf@email.froward.int.ebiederm.org
[1] https://lkml.kernel.org/r/87ftbiud6s.fsf@x220.int.ebiederm.org

Cc: stable@vger.kernel.org # v5.17
Cc: Christian Brauner <brauner@kernel.org>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Suggested-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-04-13 11:49:04 -07:00
Luis Chamberlain
b2f56e5574 proc_sysctl: move helper which creates required subdirectories
Move the code which creates the subdirectories for a ctl table
into a helper routine so to make it easier to review. Document
the goal.

This creates no functional changes.

Reviewed-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-04-13 11:49:00 -07:00
Luis Chamberlain
67ff32289a proc_sysctl: update docs for __register_sysctl_table()
Update the docs for __register_sysctl_table() to make it clear no child
entries can be passed. When the child is true these are non-leaf entries
on the ctl table and sysctl treats these as directories. The point to
__register_sysctl_table() is to deal only with directories not part of
the ctl table where thay may riside, to be simple and avoid recursion.

While at it, hint towards using long on extra1 and extra2 later.

Cc: stable@vger.kernel.org # v5.17
Cc: Christian Brauner <brauner@kernel.org>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-04-13 11:47:47 -07:00
Alexey Dobriyan
70e79866ab ELF: fix all "Elf" typos
ELF is acronym and therefore should be spelled in all caps.

I left one exception at Documentation/arm/nwfpe/nwfpe.rst which looks like
being written in the first person.

Link: https://lkml.kernel.org/r/Y/3wGWQviIOkyLJW@p183
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-08 13:45:37 -07:00
Chao Yu
b99b258899 proc: remove mark_inode_dirty() in .setattr()
procfs' .setattr() has updated i_uid, i_gid and i_mode into proc dirent,
we don't need to call mark_inode_dirty() for delayed update, remove it.

Link: https://lkml.kernel.org/r/20230131150840.34726-1-chao@kernel.org
Signed-off-by: Chao Yu <chao@kernel.org>
Reviewed-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-08 13:45:36 -07:00
Lorenzo Stoakes
4c91c07c93 mm: vmalloc: convert vread() to vread_iter()
Having previously laid the foundation for converting vread() to an
iterator function, pull the trigger and do so.

This patch attempts to provide minimal refactoring and to reflect the
existing logic as best we can, for example we continue to zero portions of
memory not read, as before.

Overall, there should be no functional difference other than a performance
improvement in /proc/kcore access to vmalloc regions.

Now we have eliminated the need for a bounce buffer in read_kcore_iter(),
we dispense with it, and try to write to user memory optimistically but
with faults disabled via copy_page_to_iter_nofault().  We already have
preemption disabled by holding a spin lock.  We continue faulting in until
the operation is complete.

Additionally, we must account for the fact that at any point a copy may
fail (most likely due to a fault not being able to occur), we exit
indicating fewer bytes retrieved than expected.

[sfr@canb.auug.org.au: fix sparc64 warning]
  Link: https://lkml.kernel.org/r/20230320144721.663280c3@canb.auug.org.au
[lstoakes@gmail.com: redo Stephen's sparc build fix]
  Link: https://lkml.kernel.org/r/8506cbc667c39205e65a323f750ff9c11a463798.1679566220.git.lstoakes@gmail.com
[akpm@linux-foundation.org: unbreak uio.h includes]
Link: https://lkml.kernel.org/r/941f88bc5ab928e6656e1e2593b91bf0f8c81e1b.1679511146.git.lstoakes@gmail.com
Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reviewed-by: Baoquan He <bhe@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Liu Shixin <liushixin2@huawei.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-05 19:42:57 -07:00
Lorenzo Stoakes
46c0d6d090 fs/proc/kcore: convert read_kcore() to read_kcore_iter()
For the time being we still use a bounce buffer for vread(), however in
the next patch we will convert this to interact directly with the iterator
and eliminate the bounce buffer altogether.

Link: https://lkml.kernel.org/r/ebe12c8d70eebd71f487d80095605f3ad0d1489c.1679511146.git.lstoakes@gmail.com
Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Baoquan He <bhe@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Liu Shixin <liushixin2@huawei.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-05 19:42:56 -07:00
Lorenzo Stoakes
2e1c017077 fs/proc/kcore: avoid bounce buffer for ktext data
Patch series "convert read_kcore(), vread() to use iterators", v8.

While reviewing Baoquan's recent changes to permit vread() access to
vm_map_ram regions of vmalloc allocations, Willy pointed out [1] that it
would be nice to refactor vread() as a whole, since its only user is
read_kcore() and the existing form of vread() necessitates the use of a
bounce buffer.

This patch series does exactly that, as well as adjusting how we read the
kernel text section to avoid the use of a bounce buffer in this case as
well.

This has been tested against the test case which motivated Baoquan's
changes in the first place [2] which continues to function correctly, as
do the vmalloc self tests.


This patch (of 4):

Commit df04abfd18 ("fs/proc/kcore.c: Add bounce buffer for ktext data")
introduced the use of a bounce buffer to retrieve kernel text data for
/proc/kcore in order to avoid failures arising from hardened user copies
enabled by CONFIG_HARDENED_USERCOPY in check_kernel_text_object().

We can avoid doing this if instead of copy_to_user() we use
_copy_to_user() which bypasses the hardening check.  This is more
efficient than using a bounce buffer and simplifies the code.

We do so as part an overall effort to eliminate bounce buffer usage in the
function with an eye to converting it an iterator read.

Link: https://lkml.kernel.org/r/cover.1679566220.git.lstoakes@gmail.com
Link: https://lore.kernel.org/all/Y8WfDSRkc%2FOHP3oD@casper.infradead.org/ [1]
Link: https://lore.kernel.org/all/87ilk6gos2.fsf@oracle.com/T/#u [2]
Link: https://lkml.kernel.org/r/fd39b0bfa7edc76d360def7d034baaee71d90158.1679511146.git.lstoakes@gmail.com
Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Baoquan He <bhe@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Liu Shixin <liushixin2@huawei.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-05 19:42:56 -07:00
Tomas Mudrunka
bd23024b97 mm/memtest: add results of early memtest to /proc/meminfo
Currently the memtest results were only presented in dmesg.

When running a large fleet of devices without ECC RAM it's currently not
easy to do bulk monitoring for memory corruption.  You have to parse
dmesg, but that's a ring buffer so the error might disappear after some
time.  In general I do not consider dmesg to be a great API to query RAM
status.

In several companies I've seen such errors remain undetected and cause
issues for way too long.  So I think it makes sense to provide a
monitoring API, so that we can safely detect and act upon them.

This adds /proc/meminfo entry which can be easily used by scripts.

Link: https://lkml.kernel.org/r/20230321103430.7130-1-tomas.mudrunka@gmail.com
Signed-off-by: Tomas Mudrunka <tomas.mudrunka@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-05 19:42:55 -07:00
Vlastimil Babka
d88e2a2bd2 mm, pagemap: remove SLOB and SLQB from comments and documentation
SLOB has been removed and SLQB never merged, so remove their mentions
from comments and documentation of pagemap.

In stable_page_flags() also correct an outdated comment mentioning that
PageBuddy() means a page->_refcount of -1, and remove compound_head()
from the PageSlab() call, as that's already implicitly there thanks to
PF_NO_TAIL.

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Lorenzo Stoakes <lstoakes@gmail.com>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
2023-03-29 10:32:11 +02:00
Kirill A. Shutemov
f7d304343b mm: Expose untagging mask in /proc/$PID/status
Add a line in /proc/$PID/status to report untag_mask. It can be
used to find out LAM status of the process from the outside. It is
useful for debuggers.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Alexander Potapenko <glider@google.com>
Link: https://lore.kernel.org/all/20230312112612.31869-10-kirill.shutemov%40linux.intel.com
2023-03-16 13:08:40 -07:00
Kirill A. Shutemov
428e106ae1 mm: Introduce untagged_addr_remote()
untagged_addr() removes tags/metadata from the address and brings it to
the canonical form. The helper is implemented on arm64 and sparc. Both of
them do untagging based on global rules.

However, Linear Address Masking (LAM) on x86 introduces per-process
settings for untagging. As a result, untagged_addr() is now only
suitable for untagging addresses for the current proccess.

The new helper untagged_addr_remote() has to be used when the address
targets remote process. It requires the mmap lock for target mm to be
taken.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Alexander Potapenko <glider@google.com>
Link: https://lore.kernel.org/all/20230312112612.31869-6-kirill.shutemov%40linux.intel.com
2023-03-16 13:08:39 -07:00
Linus Torvalds
f122a08b19 capability: just use a 'u64' instead of a 'u32[2]' array
Back in 2008 we extended the capability bits from 32 to 64, and we did
it by extending the single 32-bit capability word from one word to an
array of two words.  It was then obfuscated by hiding the "2" behind two
macro expansions, with the reasoning being that maybe it gets extended
further some day.

That reasoning may have been valid at the time, but the last thing we
want to do is to extend the capability set any more.  And the array of
values not only causes source code oddities (with loops to deal with
it), but also results in worse code generation.  It's a lose-lose
situation.

So just change the 'u32[2]' into a 'u64' and be done with it.

We still have to deal with the fact that the user space interface is
designed around an array of these 32-bit values, but that was the case
before too, since the array layouts were different (ie user space
doesn't use an array of 32-bit values for individual capability masks,
but an array of 32-bit slices of multiple masks).

So that marshalling of data is actually simplified too, even if it does
remain somewhat obscure and odd.

This was all triggered by my reaction to the new "cap_isidentical()"
introduced recently.  By just using a saner data structure, it went from

	unsigned __capi;
	CAP_FOR_EACH_U32(__capi) {
		if (a.cap[__capi] != b.cap[__capi])
			return false;
	}
	return true;

to just being

	return a.val == b.val;

instead.  Which is rather more obvious both to humans and to compilers.

Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: Serge Hallyn <serge@hallyn.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Paul Moore <paul@paul-moore.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-03-01 10:01:22 -08:00
Linus Torvalds
d2980d8d82 There is no particular theme here - mainly quick hits all over the tree.
Most notable is a set of zlib changes from Mikhail Zaslonko which enhances
 and fixes zlib's use of S390 hardware support: "lib/zlib: Set of s390
 DFLTCC related patches for kernel zlib".
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Merge tag 'mm-nonmm-stable-2023-02-20-15-29' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull non-MM updates from Andrew Morton:
 "There is no particular theme here - mainly quick hits all over the
  tree.

  Most notable is a set of zlib changes from Mikhail Zaslonko which
  enhances and fixes zlib's use of S390 hardware support: 'lib/zlib: Set
  of s390 DFLTCC related patches for kernel zlib'"

* tag 'mm-nonmm-stable-2023-02-20-15-29' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (55 commits)
  Update CREDITS file entry for Jesper Juhl
  sparc: allow PM configs for sparc32 COMPILE_TEST
  hung_task: print message when hung_task_warnings gets down to zero.
  arch/Kconfig: fix indentation
  scripts/tags.sh: fix the Kconfig tags generation when using latest ctags
  nilfs2: prevent WARNING in nilfs_dat_commit_end()
  lib/zlib: remove redundation assignement of avail_in dfltcc_gdht()
  lib/Kconfig.debug: do not enable DEBUG_PREEMPT by default
  lib/zlib: DFLTCC always switch to software inflate for Z_PACKET_FLUSH option
  lib/zlib: DFLTCC support inflate with small window
  lib/zlib: Split deflate and inflate states for DFLTCC
  lib/zlib: DFLTCC not writing header bits when avail_out == 0
  lib/zlib: fix DFLTCC ignoring flush modes when avail_in == 0
  lib/zlib: fix DFLTCC not flushing EOBS when creating raw streams
  lib/zlib: implement switching between DFLTCC and software
  lib/zlib: adjust offset calculation for dfltcc_state
  nilfs2: replace WARN_ONs for invalid DAT metadata block requests
  scripts/spelling.txt: add "exsits" pattern and fix typo instances
  fs: gracefully handle ->get_block not mapping bh in __mpage_writepage
  cramfs: Kconfig: fix spelling & punctuation
  ...
2023-02-23 17:55:40 -08:00
Linus Torvalds
3822a7c409 - Daniel Verkamp has contributed a memfd series ("mm/memfd: add
F_SEAL_EXEC") which permits the setting of the memfd execute bit at
   memfd creation time, with the option of sealing the state of the X bit.
 
 - Peter Xu adds a patch series ("mm/hugetlb: Make huge_pte_offset()
   thread-safe for pmd unshare") which addresses a rare race condition
   related to PMD unsharing.
 
 - Several folioification patch serieses from Matthew Wilcox, Vishal
   Moola, Sidhartha Kumar and Lorenzo Stoakes
 
 - Johannes Weiner has a series ("mm: push down lock_page_memcg()") which
   does perform some memcg maintenance and cleanup work.
 
 - SeongJae Park has added DAMOS filtering to DAMON, with the series
   "mm/damon/core: implement damos filter".  These filters provide users
   with finer-grained control over DAMOS's actions.  SeongJae has also done
   some DAMON cleanup work.
 
 - Kairui Song adds a series ("Clean up and fixes for swap").
 
 - Vernon Yang contributed the series "Clean up and refinement for maple
   tree".
 
 - Yu Zhao has contributed the "mm: multi-gen LRU: memcg LRU" series.  It
   adds to MGLRU an LRU of memcgs, to improve the scalability of global
   reclaim.
 
 - David Hildenbrand has added some userfaultfd cleanup work in the
   series "mm: uffd-wp + change_protection() cleanups".
 
 - Christoph Hellwig has removed the generic_writepages() library
   function in the series "remove generic_writepages".
 
 - Baolin Wang has performed some maintenance on the compaction code in
   his series "Some small improvements for compaction".
 
 - Sidhartha Kumar is doing some maintenance work on struct page in his
   series "Get rid of tail page fields".
 
 - David Hildenbrand contributed some cleanup, bugfixing and
   generalization of pte management and of pte debugging in his series "mm:
   support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all architectures with swap
   PTEs".
 
 - Mel Gorman and Neil Brown have removed the __GFP_ATOMIC allocation
   flag in the series "Discard __GFP_ATOMIC".
 
 - Sergey Senozhatsky has improved zsmalloc's memory utilization with his
   series "zsmalloc: make zspage chain size configurable".
 
 - Joey Gouly has added prctl() support for prohibiting the creation of
   writeable+executable mappings.  The previous BPF-based approach had
   shortcomings.  See "mm: In-kernel support for memory-deny-write-execute
   (MDWE)".
 
 - Waiman Long did some kmemleak cleanup and bugfixing in the series
   "mm/kmemleak: Simplify kmemleak_cond_resched() & fix UAF".
 
 - T.J.  Alumbaugh has contributed some MGLRU cleanup work in his series
   "mm: multi-gen LRU: improve".
 
 - Jiaqi Yan has provided some enhancements to our memory error
   statistics reporting, mainly by presenting the statistics on a per-node
   basis.  See the series "Introduce per NUMA node memory error
   statistics".
 
 - Mel Gorman has a second and hopefully final shot at fixing a CPU-hog
   regression in compaction via his series "Fix excessive CPU usage during
   compaction".
 
 - Christoph Hellwig does some vmalloc maintenance work in the series
   "cleanup vfree and vunmap".
 
 - Christoph Hellwig has removed block_device_operations.rw_page() in ths
   series "remove ->rw_page".
 
 - We get some maple_tree improvements and cleanups in Liam Howlett's
   series "VMA tree type safety and remove __vma_adjust()".
 
 - Suren Baghdasaryan has done some work on the maintainability of our
   vm_flags handling in the series "introduce vm_flags modifier functions".
 
 - Some pagemap cleanup and generalization work in Mike Rapoport's series
   "mm, arch: add generic implementation of pfn_valid() for FLATMEM" and
   "fixups for generic implementation of pfn_valid()"
 
 - Baoquan He has done some work to make /proc/vmallocinfo and
   /proc/kcore better represent the real state of things in his series
   "mm/vmalloc.c: allow vread() to read out vm_map_ram areas".
 
 - Jason Gunthorpe rationalized the GUP system's interface to the rest of
   the kernel in the series "Simplify the external interface for GUP".
 
 - SeongJae Park wishes to migrate people from DAMON's debugfs interface
   over to its sysfs interface.  To support this, we'll temporarily be
   printing warnings when people use the debugfs interface.  See the series
   "mm/damon: deprecate DAMON debugfs interface".
 
 - Andrey Konovalov provided the accurately named "lib/stackdepot: fixes
   and clean-ups" series.
 
 - Huang Ying has provided a dramatic reduction in migration's TLB flush
   IPI rates with the series "migrate_pages(): batch TLB flushing".
 
 - Arnd Bergmann has some objtool fixups in "objtool warning fixes".
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Merge tag 'mm-stable-2023-02-20-13-37' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - Daniel Verkamp has contributed a memfd series ("mm/memfd: add
   F_SEAL_EXEC") which permits the setting of the memfd execute bit at
   memfd creation time, with the option of sealing the state of the X
   bit.

 - Peter Xu adds a patch series ("mm/hugetlb: Make huge_pte_offset()
   thread-safe for pmd unshare") which addresses a rare race condition
   related to PMD unsharing.

 - Several folioification patch serieses from Matthew Wilcox, Vishal
   Moola, Sidhartha Kumar and Lorenzo Stoakes

 - Johannes Weiner has a series ("mm: push down lock_page_memcg()")
   which does perform some memcg maintenance and cleanup work.

 - SeongJae Park has added DAMOS filtering to DAMON, with the series
   "mm/damon/core: implement damos filter".

   These filters provide users with finer-grained control over DAMOS's
   actions. SeongJae has also done some DAMON cleanup work.

 - Kairui Song adds a series ("Clean up and fixes for swap").

 - Vernon Yang contributed the series "Clean up and refinement for maple
   tree".

 - Yu Zhao has contributed the "mm: multi-gen LRU: memcg LRU" series. It
   adds to MGLRU an LRU of memcgs, to improve the scalability of global
   reclaim.

 - David Hildenbrand has added some userfaultfd cleanup work in the
   series "mm: uffd-wp + change_protection() cleanups".

 - Christoph Hellwig has removed the generic_writepages() library
   function in the series "remove generic_writepages".

 - Baolin Wang has performed some maintenance on the compaction code in
   his series "Some small improvements for compaction".

 - Sidhartha Kumar is doing some maintenance work on struct page in his
   series "Get rid of tail page fields".

 - David Hildenbrand contributed some cleanup, bugfixing and
   generalization of pte management and of pte debugging in his series
   "mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all architectures with
   swap PTEs".

 - Mel Gorman and Neil Brown have removed the __GFP_ATOMIC allocation
   flag in the series "Discard __GFP_ATOMIC".

 - Sergey Senozhatsky has improved zsmalloc's memory utilization with
   his series "zsmalloc: make zspage chain size configurable".

 - Joey Gouly has added prctl() support for prohibiting the creation of
   writeable+executable mappings.

   The previous BPF-based approach had shortcomings. See "mm: In-kernel
   support for memory-deny-write-execute (MDWE)".

 - Waiman Long did some kmemleak cleanup and bugfixing in the series
   "mm/kmemleak: Simplify kmemleak_cond_resched() & fix UAF".

 - T.J. Alumbaugh has contributed some MGLRU cleanup work in his series
   "mm: multi-gen LRU: improve".

 - Jiaqi Yan has provided some enhancements to our memory error
   statistics reporting, mainly by presenting the statistics on a
   per-node basis. See the series "Introduce per NUMA node memory error
   statistics".

 - Mel Gorman has a second and hopefully final shot at fixing a CPU-hog
   regression in compaction via his series "Fix excessive CPU usage
   during compaction".

 - Christoph Hellwig does some vmalloc maintenance work in the series
   "cleanup vfree and vunmap".

 - Christoph Hellwig has removed block_device_operations.rw_page() in
   ths series "remove ->rw_page".

 - We get some maple_tree improvements and cleanups in Liam Howlett's
   series "VMA tree type safety and remove __vma_adjust()".

 - Suren Baghdasaryan has done some work on the maintainability of our
   vm_flags handling in the series "introduce vm_flags modifier
   functions".

 - Some pagemap cleanup and generalization work in Mike Rapoport's
   series "mm, arch: add generic implementation of pfn_valid() for
   FLATMEM" and "fixups for generic implementation of pfn_valid()"

 - Baoquan He has done some work to make /proc/vmallocinfo and
   /proc/kcore better represent the real state of things in his series
   "mm/vmalloc.c: allow vread() to read out vm_map_ram areas".

 - Jason Gunthorpe rationalized the GUP system's interface to the rest
   of the kernel in the series "Simplify the external interface for
   GUP".

 - SeongJae Park wishes to migrate people from DAMON's debugfs interface
   over to its sysfs interface. To support this, we'll temporarily be
   printing warnings when people use the debugfs interface. See the
   series "mm/damon: deprecate DAMON debugfs interface".

 - Andrey Konovalov provided the accurately named "lib/stackdepot: fixes
   and clean-ups" series.

 - Huang Ying has provided a dramatic reduction in migration's TLB flush
   IPI rates with the series "migrate_pages(): batch TLB flushing".

 - Arnd Bergmann has some objtool fixups in "objtool warning fixes".

* tag 'mm-stable-2023-02-20-13-37' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (505 commits)
  include/linux/migrate.h: remove unneeded externs
  mm/memory_hotplug: cleanup return value handing in do_migrate_range()
  mm/uffd: fix comment in handling pte markers
  mm: change to return bool for isolate_movable_page()
  mm: hugetlb: change to return bool for isolate_hugetlb()
  mm: change to return bool for isolate_lru_page()
  mm: change to return bool for folio_isolate_lru()
  objtool: add UACCESS exceptions for __tsan_volatile_read/write
  kmsan: disable ftrace in kmsan core code
  kasan: mark addr_has_metadata __always_inline
  mm: memcontrol: rename memcg_kmem_enabled()
  sh: initialize max_mapnr
  m68k/nommu: add missing definition of ARCH_PFN_OFFSET
  mm: percpu: fix incorrect size in pcpu_obj_full_size()
  maple_tree: reduce stack usage with gcc-9 and earlier
  mm: page_alloc: call panic() when memoryless node allocation fails
  mm: multi-gen LRU: avoid futile retries
  migrate_pages: move THP/hugetlb migration support check to simplify code
  migrate_pages: batch flushing TLB
  migrate_pages: share more code between _unmap and _move
  ...
2023-02-23 17:09:35 -08:00
Ondrej Mosnacek
f1aa2eb5ea sysctl: fix proc_dobool() usability
Currently proc_dobool expects a (bool *) in table->data, but sizeof(int)
in table->maxsize, because it uses do_proc_dointvec() directly.

This is unsafe for at least two reasons:
1. A sysctl table definition may use { .data = &variable, .maxsize =
   sizeof(variable) }, not realizing that this makes the sysctl unusable
   (see the Fixes: tag) and that they need to use the completely
   counterintuitive sizeof(int) instead.
2. proc_dobool() will currently try to parse an array of values if given
   .maxsize >= 2*sizeof(int), but will try to write values of type bool
   by offsets of sizeof(int), so it will not work correctly with neither
   an (int *) nor a (bool *). There is no .maxsize validation to prevent
   this.

Fix this by:
1. Constraining proc_dobool() to allow only one value and .maxsize ==
   sizeof(bool).
2. Wrapping the original struct ctl_table in a temporary one with .data
   pointing to a local int variable and .maxsize set to sizeof(int) and
   passing this one to proc_dointvec(), converting the value to/from
   bool as needed (using proc_dou8vec_minmax() as an example).
3. Extending sysctl_check_table() to enforce proc_dobool() expectations.
4. Fixing the proc_dobool() docstring (it was just copy-pasted from
   proc_douintvec, apparently...).
5. Converting all existing proc_dobool() users to set .maxsize to
   sizeof(bool) instead of sizeof(int).

Fixes: 83efeeeb3d ("tty: Allow TIOCSTI to be disabled")
Fixes: a2071573d6 ("sysctl: introduce new proc handler proc_dobool")
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-02-21 13:34:07 -08:00
Linus Torvalds
05e6295f7b fs.idmapped.v6.3
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Merge tag 'fs.idmapped.v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping

Pull vfs idmapping updates from Christian Brauner:

 - Last cycle we introduced the dedicated struct mnt_idmap type for
   mount idmapping and the required infrastucture in 256c8aed2b ("fs:
   introduce dedicated idmap type for mounts"). As promised in last
   cycle's pull request message this converts everything to rely on
   struct mnt_idmap.

   Currently we still pass around the plain namespace that was attached
   to a mount. This is in general pretty convenient but it makes it easy
   to conflate namespaces that are relevant on the filesystem with
   namespaces that are relevant on the mount level. Especially for
   non-vfs developers without detailed knowledge in this area this was a
   potential source for bugs.

   This finishes the conversion. Instead of passing the plain namespace
   around this updates all places that currently take a pointer to a
   mnt_userns with a pointer to struct mnt_idmap.

   Now that the conversion is done all helpers down to the really
   low-level helpers only accept a struct mnt_idmap argument instead of
   two namespace arguments.

   Conflating mount and other idmappings will now cause the compiler to
   complain loudly thus eliminating the possibility of any bugs. This
   makes it impossible for filesystem developers to mix up mount and
   filesystem idmappings as they are two distinct types and require
   distinct helpers that cannot be used interchangeably.

   Everything associated with struct mnt_idmap is moved into a single
   separate file. With that change no code can poke around in struct
   mnt_idmap. It can only be interacted with through dedicated helpers.
   That means all filesystems are and all of the vfs is completely
   oblivious to the actual implementation of idmappings.

   We are now also able to extend struct mnt_idmap as we see fit. For
   example, we can decouple it completely from namespaces for users that
   don't require or don't want to use them at all. We can also extend
   the concept of idmappings so we can cover filesystem specific
   requirements.

   In combination with the vfs{g,u}id_t work we finished in v6.2 this
   makes this feature substantially more robust and thus difficult to
   implement wrong by a given filesystem and also protects the vfs.

 - Enable idmapped mounts for tmpfs and fulfill a longstanding request.

   A long-standing request from users had been to make it possible to
   create idmapped mounts for tmpfs. For example, to share the host's
   tmpfs mount between multiple sandboxes. This is a prerequisite for
   some advanced Kubernetes cases. Systemd also has a range of use-cases
   to increase service isolation. And there are more users of this.

   However, with all of the other work going on this was way down on the
   priority list but luckily someone other than ourselves picked this
   up.

   As usual the patch is tiny as all the infrastructure work had been
   done multiple kernel releases ago. In addition to all the tests that
   we already have I requested that Rodrigo add a dedicated tmpfs
   testsuite for idmapped mounts to xfstests. It is to be included into
   xfstests during the v6.3 development cycle. This should add a slew of
   additional tests.

* tag 'fs.idmapped.v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping: (26 commits)
  shmem: support idmapped mounts for tmpfs
  fs: move mnt_idmap
  fs: port vfs{g,u}id helpers to mnt_idmap
  fs: port fs{g,u}id helpers to mnt_idmap
  fs: port i_{g,u}id_into_vfs{g,u}id() to mnt_idmap
  fs: port i_{g,u}id_{needs_}update() to mnt_idmap
  quota: port to mnt_idmap
  fs: port privilege checking helpers to mnt_idmap
  fs: port inode_owner_or_capable() to mnt_idmap
  fs: port inode_init_owner() to mnt_idmap
  fs: port acl to mnt_idmap
  fs: port xattr to mnt_idmap
  fs: port ->permission() to pass mnt_idmap
  fs: port ->fileattr_set() to pass mnt_idmap
  fs: port ->set_acl() to pass mnt_idmap
  fs: port ->get_acl() to pass mnt_idmap
  fs: port ->tmpfile() to pass mnt_idmap
  fs: port ->rename() to pass mnt_idmap
  fs: port ->mknod() to pass mnt_idmap
  fs: port ->mkdir() to pass mnt_idmap
  ...
2023-02-20 11:53:11 -08:00
Linus Torvalds
575a7e0f81 File locking changes for v6.3
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Merge tag 'locks-v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux

Pull file locking updates from Jeff Layton:
 "The main change here is that I've broken out most of the file locking
  definitions into a new header file. I also went ahead and completed
  the removal of locks_inode function"

* tag 'locks-v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux:
  fs: remove locks_inode
  filelock: move file locking definitions to separate header file
2023-02-20 11:10:38 -08:00
Suren Baghdasaryan
1c71222e5f mm: replace vma->vm_flags direct modifications with modifier calls
Replace direct modifications to vma->vm_flags with calls to modifier
functions to be able to track flag changes and to keep vma locking
correctness.

[akpm@linux-foundation.org: fix drivers/misc/open-dice.c, per Hyeonggon Yoo]
Link: https://lkml.kernel.org/r/20230126193752.297968-5-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjun Roy <arjunroy@google.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: David Rientjes <rientjes@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Laurent Dufour <ldufour@linux.ibm.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Minchan Kim <minchan@google.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Peter Oskolkov <posk@google.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Punit Agrawal <punit.agrawal@bytedance.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Soheil Hassas Yeganeh <soheil@google.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-09 16:51:39 -08:00
Liam R. Howlett
250cb40f0a task_mmu: convert to vma iterator
Use the vma iterator so that the iterator can be invalidated or updated to
avoid each caller doing so.

Update the comments to how the vma iterator works.  The vma iterator will
keep track of the last vm_end and start the search from vm_end + 1.

Link: https://lkml.kernel.org/r/20230120162650.984577-22-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-09 16:51:34 -08:00
Alexey Dobriyan
a61c01e8f4 proc: mark /proc/cmdline as permanent
/proc/cmdline is never removed, mark is as permanent for slightly faster
open and close.

Link: https://lkml.kernel.org/r/Y66xAveh2yUsP7m9@p183
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-02 22:50:02 -08:00
Alistair Popple
7d4a8be0c4 mm/mmu_notifier: remove unused mmu_notifier_range_update_to_read_only export
mmu_notifier_range_update_to_read_only() was originally introduced in
commit c6d23413f8 ("mm/mmu_notifier:
mmu_notifier_range_update_to_read_only() helper") as an optimisation for
device drivers that know a range has only been mapped read-only.  However
there are no users of this feature so remove it.  As it is the only user
of the struct mmu_notifier_range.vma field remove that also.

Link: https://lkml.kernel.org/r/20230110025722.600912-1-apopple@nvidia.com
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-02 22:32:54 -08:00
Andrew Morton
5ab0fc155d Sync mm-stable with mm-hotfixes-stable to pick up dependent patches
Merge branch 'mm-hotfixes-stable' into mm-stable
2023-01-31 17:25:17 -08:00
Mike Kravetz
3489dbb696 mm: hugetlb: proc: check for hugetlb shared PMD in /proc/PID/smaps
Patch series "Fixes for hugetlb mapcount at most 1 for shared PMDs".

This issue of mapcount in hugetlb pages referenced by shared PMDs was
discussed in [1].  The following two patches address user visible behavior
caused by this issue.

[1] https://lore.kernel.org/linux-mm/Y9BF+OCdWnCSilEu@monkey/


This patch (of 2):

A hugetlb page will have a mapcount of 1 if mapped by multiple processes
via a shared PMD.  This is because only the first process increases the
map count, and subsequent processes just add the shared PMD page to their
page table.

page_mapcount is being used to decide if a hugetlb page is shared or
private in /proc/PID/smaps.  Pages referenced via a shared PMD were
incorrectly being counted as private.

To fix, check for a shared PMD if mapcount is 1.  If a shared PMD is found
count the hugetlb page as shared.  A new helper to check for a shared PMD
is added.

[akpm@linux-foundation.org: simplification, per David]
[akpm@linux-foundation.org: hugetlb.h: include page_ref.h for page_count()]
Link: https://lkml.kernel.org/r/20230126222721.222195-2-mike.kravetz@oracle.com
Fixes: 25ee01a2fc ("mm: hugetlb: proc: add hugetlb-related fields to /proc/PID/smaps")
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Acked-by: Peter Xu <peterx@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: James Houghton <jthoughton@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-31 16:44:09 -08:00
Christian Brauner
4609e1f18e
fs: port ->permission() to pass mnt_idmap
Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-19 09:24:28 +01:00
Christian Brauner
b74d24f7a7
fs: port ->getattr() to pass mnt_idmap
Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-19 09:24:25 +01:00
Christian Brauner
c1632a0f11
fs: port ->setattr() to pass mnt_idmap
Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-19 09:24:02 +01:00
David Hildenbrand
fc4f4be9b5 mm/nommu: factor out check for NOMMU shared mappings into is_nommu_shared_mapping()
Patch series "mm/nommu: don't use VM_MAYSHARE for MAP_PRIVATE mappings".

Trying to reduce the confusion around VM_SHARED and VM_MAYSHARE first
requires !CONFIG_MMU to stop using VM_MAYSHARE for MAP_PRIVATE mappings. 
CONFIG_MMU only sets VM_MAYSHARE for MAP_SHARED mappings.

This paves the way for further VM_MAYSHARE and VM_SHARED cleanups: for
example, renaming VM_MAYSHARED to VM_MAP_SHARED to make it cleaner what is
actually means.

Let's first get the weird case out of the way and not use VM_MAYSHARE in
MAP_PRIVATE mappings, using a new VM_MAYOVERLAY flag instead.


This patch (of 3):

We want to stop using VM_MAYSHARE in private mappings to pave the way for
clarifying the semantics of VM_MAYSHARE vs.  VM_SHARED and reduce the
confusion.  While CONFIG_MMU uses VM_MAYSHARE to represent MAP_SHARED,
!CONFIG_MMU also sets VM_MAYSHARE for selected R/O private file mappings
that are an effective overlay of a file mapping.

Let's factor out all relevant VM_MAYSHARE checks in !CONFIG_MMU code into
is_nommu_shared_mapping() first.

Note that whenever VM_SHARED is set, VM_MAYSHARE must be set as well
(unless there is a serious BUG).  So there is not need to test for
VM_SHARED manually.

No functional change intended.

Link: https://lkml.kernel.org/r/20230102160856.500584-1-david@redhat.com
Link: https://lkml.kernel.org/r/20230102160856.500584-2-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Nicolas Pitre <nico@fluxnic.net>
Cc: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-18 17:12:56 -08:00
Jeff Layton
5970e15dbc filelock: move file locking definitions to separate header file
The file locking definitions have lived in fs.h since the dawn of time,
but they are only used by a small subset of the source files that
include it.

Move the file locking definitions to a new header file, and add the
appropriate #include directives to the source files that need them. By
doing this we trim down fs.h a bit and limit the amount of rebuilding
that has to be done when we make changes to the file locking APIs.

Reviewed-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Howells <dhowells@redhat.com>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Acked-by: Chuck Lever <chuck.lever@oracle.com>
Acked-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: Steve French <stfrench@microsoft.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
2023-01-11 06:52:32 -05:00