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132 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Linus Torvalds
|
617a814f14 |
ALong with the usual shower of singleton patches, notable patch series in
this pull request are:
"Align kvrealloc() with krealloc()" from Danilo Krummrich. Adds
consistency to the APIs and behaviour of these two core allocation
functions. This also simplifies/enables Rustification.
"Some cleanups for shmem" from Baolin Wang. No functional changes - mode
code reuse, better function naming, logic simplifications.
"mm: some small page fault cleanups" from Josef Bacik. No functional
changes - code cleanups only.
"Various memory tiering fixes" from Zi Yan. A small fix and a little
cleanup.
"mm/swap: remove boilerplate" from Yu Zhao. Code cleanups and
simplifications and .text shrinkage.
"Kernel stack usage histogram" from Pasha Tatashin and Shakeel Butt. This
is a feature, it adds new feilds to /proc/vmstat such as
$ grep kstack /proc/vmstat
kstack_1k 3
kstack_2k 188
kstack_4k 11391
kstack_8k 243
kstack_16k 0
which tells us that 11391 processes used 4k of stack while none at all
used 16k. Useful for some system tuning things, but partivularly useful
for "the dynamic kernel stack project".
"kmemleak: support for percpu memory leak detect" from Pavel Tikhomirov.
Teaches kmemleak to detect leaksage of percpu memory.
"mm: memcg: page counters optimizations" from Roman Gushchin. "3
independent small optimizations of page counters".
"mm: split PTE/PMD PT table Kconfig cleanups+clarifications" from David
Hildenbrand. Improves PTE/PMD splitlock detection, makes powerpc/8xx work
correctly by design rather than by accident.
"mm: remove arch_make_page_accessible()" from David Hildenbrand. Some
folio conversions which make arch_make_page_accessible() unneeded.
"mm, memcg: cg2 memory{.swap,}.peak write handlers" fro David Finkel.
Cleans up and fixes our handling of the resetting of the cgroup/process
peak-memory-use detector.
"Make core VMA operations internal and testable" from Lorenzo Stoakes.
Rationalizaion and encapsulation of the VMA manipulation APIs. With a
view to better enable testing of the VMA functions, even from a
userspace-only harness.
"mm: zswap: fixes for global shrinker" from Takero Funaki. Fix issues in
the zswap global shrinker, resulting in improved performance.
"mm: print the promo watermark in zoneinfo" from Kaiyang Zhao. Fill in
some missing info in /proc/zoneinfo.
"mm: replace follow_page() by folio_walk" from David Hildenbrand. Code
cleanups and rationalizations (conversion to folio_walk()) resulting in
the removal of follow_page().
"improving dynamic zswap shrinker protection scheme" from Nhat Pham. Some
tuning to improve zswap's dynamic shrinker. Significant reductions in
swapin and improvements in performance are shown.
"mm: Fix several issues with unaccepted memory" from Kirill Shutemov.
Improvements to the new unaccepted memory feature,
"mm/mprotect: Fix dax puds" from Peter Xu. Implements mprotect on DAX
PUDs. This was missing, although nobody seems to have notied yet.
"Introduce a store type enum for the Maple tree" from Sidhartha Kumar.
Cleanups and modest performance improvements for the maple tree library
code.
"memcg: further decouple v1 code from v2" from Shakeel Butt. Move more
cgroup v1 remnants away from the v2 memcg code.
"memcg: initiate deprecation of v1 features" from Shakeel Butt. Adds
various warnings telling users that memcg v1 features are deprecated.
"mm: swap: mTHP swap allocator base on swap cluster order" from Chris Li.
Greatly improves the success rate of the mTHP swap allocation.
"mm: introduce numa_memblks" from Mike Rapoport. Moves various disparate
per-arch implementations of numa_memblk code into generic code.
"mm: batch free swaps for zap_pte_range()" from Barry Song. Greatly
improves the performance of munmap() of swap-filled ptes.
"support large folio swap-out and swap-in for shmem" from Baolin Wang.
With this series we no longer split shmem large folios into simgle-page
folios when swapping out shmem.
"mm/hugetlb: alloc/free gigantic folios" from Yu Zhao. Nice performance
improvements and code reductions for gigantic folios.
"support shmem mTHP collapse" from Baolin Wang. Adds support for
khugepaged's collapsing of shmem mTHP folios.
"mm: Optimize mseal checks" from Pedro Falcato. Fixes an mprotect()
performance regression due to the addition of mseal().
"Increase the number of bits available in page_type" from Matthew Wilcox.
Increases the number of bits available in page_type!
"Simplify the page flags a little" from Matthew Wilcox. Many legacy page
flags are now folio flags, so the page-based flags and their
accessors/mutators can be removed.
"mm: store zero pages to be swapped out in a bitmap" from Usama Arif. An
optimization which permits us to avoid writing/reading zero-filled zswap
pages to backing store.
"Avoid MAP_FIXED gap exposure" from Liam Howlett. Fixes a race window
which occurs when a MAP_FIXED operqtion is occurring during an unrelated
vma tree walk.
"mm: remove vma_merge()" from Lorenzo Stoakes. Major rotorooting of the
vma_merge() functionality, making ot cleaner, more testable and better
tested.
"misc fixups for DAMON {self,kunit} tests" from SeongJae Park. Minor
fixups of DAMON selftests and kunit tests.
"mm: memory_hotplug: improve do_migrate_range()" from Kefeng Wang. Code
cleanups and folio conversions.
"Shmem mTHP controls and stats improvements" from Ryan Roberts. Cleanups
for shmem controls and stats.
"mm: count the number of anonymous THPs per size" from Barry Song. Expose
additional anon THP stats to userspace for improved tuning.
"mm: finish isolate/putback_lru_page()" from Kefeng Wang: more folio
conversions and removal of now-unused page-based APIs.
"replace per-quota region priorities histogram buffer with per-context
one" from SeongJae Park. DAMON histogram rationalization.
"Docs/damon: update GitHub repo URLs and maintainer-profile" from SeongJae
Park. DAMON documentation updates.
"mm/vdpa: correct misuse of non-direct-reclaim __GFP_NOFAIL and improve
related doc and warn" from Jason Wang: fixes usage of page allocator
__GFP_NOFAIL and GFP_ATOMIC flags.
"mm: split underused THPs" from Yu Zhao. Improve THP=always policy - this
was overprovisioning THPs in sparsely accessed memory areas.
"zram: introduce custom comp backends API" frm Sergey Senozhatsky. Add
support for zram run-time compression algorithm tuning.
"mm: Care about shadow stack guard gap when getting an unmapped area" from
Mark Brown. Fix up the various arch_get_unmapped_area() implementations
to better respect guard areas.
"Improve mem_cgroup_iter()" from Kinsey Ho. Improve the reliability of
mem_cgroup_iter() and various code cleanups.
"mm: Support huge pfnmaps" from Peter Xu. Extends the usage of huge
pfnmap support.
"resource: Fix region_intersects() vs add_memory_driver_managed()" from
Huang Ying. Fix a bug in region_intersects() for systems with CXL memory.
"mm: hwpoison: two more poison recovery" from Kefeng Wang. Teaches a
couple more code paths to correctly recover from the encountering of
poisoned memry.
"mm: enable large folios swap-in support" from Barry Song. Support the
swapin of mTHP memory into appropriately-sized folios, rather than into
single-page folios.
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Merge tag 'mm-stable-2024-09-20-02-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
"Along with the usual shower of singleton patches, notable patch series
in this pull request are:
- "Align kvrealloc() with krealloc()" from Danilo Krummrich. Adds
consistency to the APIs and behaviour of these two core allocation
functions. This also simplifies/enables Rustification.
- "Some cleanups for shmem" from Baolin Wang. No functional changes -
mode code reuse, better function naming, logic simplifications.
- "mm: some small page fault cleanups" from Josef Bacik. No
functional changes - code cleanups only.
- "Various memory tiering fixes" from Zi Yan. A small fix and a
little cleanup.
- "mm/swap: remove boilerplate" from Yu Zhao. Code cleanups and
simplifications and .text shrinkage.
- "Kernel stack usage histogram" from Pasha Tatashin and Shakeel
Butt. This is a feature, it adds new feilds to /proc/vmstat such as
$ grep kstack /proc/vmstat
kstack_1k 3
kstack_2k 188
kstack_4k 11391
kstack_8k 243
kstack_16k 0
which tells us that 11391 processes used 4k of stack while none at
all used 16k. Useful for some system tuning things, but
partivularly useful for "the dynamic kernel stack project".
- "kmemleak: support for percpu memory leak detect" from Pavel
Tikhomirov. Teaches kmemleak to detect leaksage of percpu memory.
- "mm: memcg: page counters optimizations" from Roman Gushchin. "3
independent small optimizations of page counters".
- "mm: split PTE/PMD PT table Kconfig cleanups+clarifications" from
David Hildenbrand. Improves PTE/PMD splitlock detection, makes
powerpc/8xx work correctly by design rather than by accident.
- "mm: remove arch_make_page_accessible()" from David Hildenbrand.
Some folio conversions which make arch_make_page_accessible()
unneeded.
- "mm, memcg: cg2 memory{.swap,}.peak write handlers" fro David
Finkel. Cleans up and fixes our handling of the resetting of the
cgroup/process peak-memory-use detector.
- "Make core VMA operations internal and testable" from Lorenzo
Stoakes. Rationalizaion and encapsulation of the VMA manipulation
APIs. With a view to better enable testing of the VMA functions,
even from a userspace-only harness.
- "mm: zswap: fixes for global shrinker" from Takero Funaki. Fix
issues in the zswap global shrinker, resulting in improved
performance.
- "mm: print the promo watermark in zoneinfo" from Kaiyang Zhao. Fill
in some missing info in /proc/zoneinfo.
- "mm: replace follow_page() by folio_walk" from David Hildenbrand.
Code cleanups and rationalizations (conversion to folio_walk())
resulting in the removal of follow_page().
- "improving dynamic zswap shrinker protection scheme" from Nhat
Pham. Some tuning to improve zswap's dynamic shrinker. Significant
reductions in swapin and improvements in performance are shown.
- "mm: Fix several issues with unaccepted memory" from Kirill
Shutemov. Improvements to the new unaccepted memory feature,
- "mm/mprotect: Fix dax puds" from Peter Xu. Implements mprotect on
DAX PUDs. This was missing, although nobody seems to have notied
yet.
- "Introduce a store type enum for the Maple tree" from Sidhartha
Kumar. Cleanups and modest performance improvements for the maple
tree library code.
- "memcg: further decouple v1 code from v2" from Shakeel Butt. Move
more cgroup v1 remnants away from the v2 memcg code.
- "memcg: initiate deprecation of v1 features" from Shakeel Butt.
Adds various warnings telling users that memcg v1 features are
deprecated.
- "mm: swap: mTHP swap allocator base on swap cluster order" from
Chris Li. Greatly improves the success rate of the mTHP swap
allocation.
- "mm: introduce numa_memblks" from Mike Rapoport. Moves various
disparate per-arch implementations of numa_memblk code into generic
code.
- "mm: batch free swaps for zap_pte_range()" from Barry Song. Greatly
improves the performance of munmap() of swap-filled ptes.
- "support large folio swap-out and swap-in for shmem" from Baolin
Wang. With this series we no longer split shmem large folios into
simgle-page folios when swapping out shmem.
- "mm/hugetlb: alloc/free gigantic folios" from Yu Zhao. Nice
performance improvements and code reductions for gigantic folios.
- "support shmem mTHP collapse" from Baolin Wang. Adds support for
khugepaged's collapsing of shmem mTHP folios.
- "mm: Optimize mseal checks" from Pedro Falcato. Fixes an mprotect()
performance regression due to the addition of mseal().
- "Increase the number of bits available in page_type" from Matthew
Wilcox. Increases the number of bits available in page_type!
- "Simplify the page flags a little" from Matthew Wilcox. Many legacy
page flags are now folio flags, so the page-based flags and their
accessors/mutators can be removed.
- "mm: store zero pages to be swapped out in a bitmap" from Usama
Arif. An optimization which permits us to avoid writing/reading
zero-filled zswap pages to backing store.
- "Avoid MAP_FIXED gap exposure" from Liam Howlett. Fixes a race
window which occurs when a MAP_FIXED operqtion is occurring during
an unrelated vma tree walk.
- "mm: remove vma_merge()" from Lorenzo Stoakes. Major rotorooting of
the vma_merge() functionality, making ot cleaner, more testable and
better tested.
- "misc fixups for DAMON {self,kunit} tests" from SeongJae Park.
Minor fixups of DAMON selftests and kunit tests.
- "mm: memory_hotplug: improve do_migrate_range()" from Kefeng Wang.
Code cleanups and folio conversions.
- "Shmem mTHP controls and stats improvements" from Ryan Roberts.
Cleanups for shmem controls and stats.
- "mm: count the number of anonymous THPs per size" from Barry Song.
Expose additional anon THP stats to userspace for improved tuning.
- "mm: finish isolate/putback_lru_page()" from Kefeng Wang: more
folio conversions and removal of now-unused page-based APIs.
- "replace per-quota region priorities histogram buffer with
per-context one" from SeongJae Park. DAMON histogram
rationalization.
- "Docs/damon: update GitHub repo URLs and maintainer-profile" from
SeongJae Park. DAMON documentation updates.
- "mm/vdpa: correct misuse of non-direct-reclaim __GFP_NOFAIL and
improve related doc and warn" from Jason Wang: fixes usage of page
allocator __GFP_NOFAIL and GFP_ATOMIC flags.
- "mm: split underused THPs" from Yu Zhao. Improve THP=always policy.
This was overprovisioning THPs in sparsely accessed memory areas.
- "zram: introduce custom comp backends API" frm Sergey Senozhatsky.
Add support for zram run-time compression algorithm tuning.
- "mm: Care about shadow stack guard gap when getting an unmapped
area" from Mark Brown. Fix up the various arch_get_unmapped_area()
implementations to better respect guard areas.
- "Improve mem_cgroup_iter()" from Kinsey Ho. Improve the reliability
of mem_cgroup_iter() and various code cleanups.
- "mm: Support huge pfnmaps" from Peter Xu. Extends the usage of huge
pfnmap support.
- "resource: Fix region_intersects() vs add_memory_driver_managed()"
from Huang Ying. Fix a bug in region_intersects() for systems with
CXL memory.
- "mm: hwpoison: two more poison recovery" from Kefeng Wang. Teaches
a couple more code paths to correctly recover from the encountering
of poisoned memry.
- "mm: enable large folios swap-in support" from Barry Song. Support
the swapin of mTHP memory into appropriately-sized folios, rather
than into single-page folios"
* tag 'mm-stable-2024-09-20-02-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (416 commits)
zram: free secondary algorithms names
uprobes: turn xol_area->pages[2] into xol_area->page
uprobes: introduce the global struct vm_special_mapping xol_mapping
Revert "uprobes: use vm_special_mapping close() functionality"
mm: support large folios swap-in for sync io devices
mm: add nr argument in mem_cgroup_swapin_uncharge_swap() helper to support large folios
mm: fix swap_read_folio_zeromap() for large folios with partial zeromap
mm/debug_vm_pgtable: Use pxdp_get() for accessing page table entries
set_memory: add __must_check to generic stubs
mm/vma: return the exact errno in vms_gather_munmap_vmas()
memcg: cleanup with !CONFIG_MEMCG_V1
mm/show_mem.c: report alloc tags in human readable units
mm: support poison recovery from copy_present_page()
mm: support poison recovery from do_cow_fault()
resource, kunit: add test case for region_intersects()
resource: make alloc_free_mem_region() works for iomem_resource
mm: z3fold: deprecate CONFIG_Z3FOLD
vfio/pci: implement huge_fault support
mm/arm64: support large pfn mappings
mm/x86: support large pfn mappings
...
|
||
Rik van Riel
|
e1e4cfd01a |
mm,tmpfs: consider end of file write in shmem_is_huge
Take the end of a file write into consideration when deciding whether or not to use huge pages for tmpfs files when the tmpfs filesystem is mounted with huge=within_size This allows large writes that append to the end of a file to automatically use large pages. Doing 4MB sequential writes without fallocate to a 16GB tmpfs file with fio. The numbers without THP or with huge=always stay the same, but the performance with huge=within_size now matches that of huge=always. huge before after 4kB pages 1560 MB/s 1560 MB/s within_size 1560 MB/s 4720 MB/s always: 4720 MB/s 4720 MB/s [akpm@linux-foundation.org: coding-style cleanups] Link: https://lkml.kernel.org/r/20240903111928.7171e60c@imladris.surriel.com Signed-off-by: Rik van Riel <riel@surriel.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Tested-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Darrick J. Wong <djwong@kernel.org> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
Lorenzo Stoakes
|
a17c7d8fd2 |
userfaultfd: move core VMA manipulation logic to mm/userfaultfd.c
Patch series "Make core VMA operations internal and testable", v4. There are a number of "core" VMA manipulation functions implemented in mm/mmap.c, notably those concerning VMA merging, splitting, modifying, expanding and shrinking, which logically don't belong there. More importantly this functionality represents an internal implementation detail of memory management and should not be exposed outside of mm/ itself. This patch series isolates core VMA manipulation functionality into its own file, mm/vma.c, and provides an API to the rest of the mm code in mm/vma.h. Importantly, it also carefully implements mm/vma_internal.h, which specifies which headers need to be imported by vma.c, leading to the very useful property that vma.c depends only on mm/vma.h and mm/vma_internal.h. This means we can then re-implement vma_internal.h in userland, adding shims for kernel mechanisms as required, allowing us to unit test internal VMA functionality. This testing is useful as opposed to an e.g. kunit implementation as this way we can avoid all external kernel side-effects while testing, run tests VERY quickly, and iterate on and debug problems quickly. Excitingly this opens the door to, in the future, recreating precise problems observed in production in userland and very quickly debugging problems that might otherwise be very difficult to reproduce. This patch series takes advantage of existing shim logic and full userland maple tree support contained in tools/testing/radix-tree/ and tools/include/linux/, separating out shared components of the radix tree implementation to provide this testing. Kernel functionality is stubbed and shimmed as needed in tools/testing/vma/ which contains a fully functional userland vma_internal.h file and which imports mm/vma.c and mm/vma.h to be directly tested from userland. A simple, skeleton testing implementation is provided in tools/testing/vma/vma.c as a proof-of-concept, asserting that simple VMA merge, modify (testing split), expand and shrink functionality work correctly. This patch (of 4): This patch forms part of a patch series intending to separate out VMA logic and render it testable from userspace, which requires that core manipulation functions be exposed in an mm/-internal header file. In order to do this, we must abstract APIs we wish to test, in this instance functions which ultimately invoke vma_modify(). This patch therefore moves all logic which ultimately invokes vma_modify() to mm/userfaultfd.c, trying to transfer code at a functional granularity where possible. [lorenzo.stoakes@oracle.com: fix user-after-free in userfaultfd_clear_vma()] Link: https://lkml.kernel.org/r/3c947ddc-b804-49b7-8fe9-3ea3ca13def5@lucifer.local Link: https://lkml.kernel.org/r/cover.1722251717.git.lorenzo.stoakes@oracle.com Link: https://lkml.kernel.org/r/50c3ed995fd81c45876c86304c8a00bf3e396cfd.1722251717.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Brendan Higgins <brendanhiggins@google.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Gow <davidgow@google.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Jan Kara <jack@suse.cz> Cc: Kees Cook <kees@kernel.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Rae Moar <rmoar@google.com> Cc: SeongJae Park <sj@kernel.org> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Pengfei Xu <pengfei.xu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
Jann Horn
|
4828d207dc |
userfaultfd: don't BUG_ON() if khugepaged yanks our page table
Since khugepaged was changed to allow retracting page tables in file
mappings without holding the mmap lock, these BUG_ON()s are wrong - get
rid of them.
We could also remove the preceding "if (unlikely(...))" block, but then we
could reach pte_offset_map_lock() with transhuge pages not just for file
mappings but also for anonymous mappings - which would probably be fine
but I think is not necessarily expected.
Link: https://lkml.kernel.org/r/20240813-uffd-thp-flip-fix-v2-2-5efa61078a41@google.com
Fixes:
|
||
|
Jann Horn
|
71c186efc1 |
userfaultfd: fix checks for huge PMDs
Patch series "userfaultfd: fix races around pmd_trans_huge() check", v2.
The pmd_trans_huge() code in mfill_atomic() is wrong in three different
ways depending on kernel version:
1. The pmd_trans_huge() check is racy and can lead to a BUG_ON() (if you hit
the right two race windows) - I've tested this in a kernel build with
some extra mdelay() calls. See the commit message for a description
of the race scenario.
On older kernels (before 6.5), I think the same bug can even
theoretically lead to accessing transhuge page contents as a page table
if you hit the right 5 narrow race windows (I haven't tested this case).
2. As pointed out by Qi Zheng, pmd_trans_huge() is not sufficient for
detecting PMDs that don't point to page tables.
On older kernels (before 6.5), you'd just have to win a single fairly
wide race to hit this.
I've tested this on 6.1 stable by racing migration (with a mdelay()
patched into try_to_migrate()) against UFFDIO_ZEROPAGE - on my x86
VM, that causes a kernel oops in ptlock_ptr().
3. On newer kernels (>=6.5), for shmem mappings, khugepaged is allowed
to yank page tables out from under us (though I haven't tested that),
so I think the BUG_ON() checks in mfill_atomic() are just wrong.
I decided to write two separate fixes for these (one fix for bugs 1+2, one
fix for bug 3), so that the first fix can be backported to kernels
affected by bugs 1+2.
This patch (of 2):
This fixes two issues.
I discovered that the following race can occur:
mfill_atomic other thread
============ ============
<zap PMD>
pmdp_get_lockless() [reads none pmd]
<bail if trans_huge>
<if none:>
<pagefault creates transhuge zeropage>
__pte_alloc [no-op]
<zap PMD>
<bail if pmd_trans_huge(*dst_pmd)>
BUG_ON(pmd_none(*dst_pmd))
I have experimentally verified this in a kernel with extra mdelay() calls;
the BUG_ON(pmd_none(*dst_pmd)) triggers.
On kernels newer than commit
|
||
Christophe Leroy
|
e6c0c03245 |
mm: provide mm_struct and address to huge_ptep_get()
On powerpc 8xx huge_ptep_get() will need to know whether the given ptep is a PTE entry or a PMD entry. This cannot be known with the PMD entry itself because there is no easy way to know it from the content of the entry. So huge_ptep_get() will need to know either the size of the page or get the pmd. In order to be consistent with huge_ptep_get_and_clear(), give mm and address to huge_ptep_get(). Link: https://lkml.kernel.org/r/cc00c70dd384298796a4e1b25d6c4eb306d3af85.1719928057.git.christophe.leroy@csgroup.eu Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
Barry Song
|
15bde4abab |
mm: extend rmap flags arguments for folio_add_new_anon_rmap
Patch series "mm: clarify folio_add_new_anon_rmap() and __folio_add_anon_rmap()", v2. This patchset is preparatory work for mTHP swapin. folio_add_new_anon_rmap() assumes that new anon rmaps are always exclusive. However, this assumption doesn’t hold true for cases like do_swap_page(), where a new anon might be added to the swapcache and is not necessarily exclusive. The patchset extends the rmap flags to allow folio_add_new_anon_rmap() to handle both exclusive and non-exclusive new anon folios. The do_swap_page() function is updated to use this extended API with rmap flags. Consequently, all new anon folios now consistently use folio_add_new_anon_rmap(). The special case for !folio_test_anon() in __folio_add_anon_rmap() can be safely removed. In conclusion, new anon folios always use folio_add_new_anon_rmap(), regardless of exclusivity. Old anon folios continue to use __folio_add_anon_rmap() via folio_add_anon_rmap_pmd() and folio_add_anon_rmap_ptes(). This patch (of 3): In the case of a swap-in, a new anonymous folio is not necessarily exclusive. This patch updates the rmap flags to allow a new anonymous folio to be treated as either exclusive or non-exclusive. To maintain the existing behavior, we always use EXCLUSIVE as the default setting. [akpm@linux-foundation.org: cleanup and constifications per David and akpm] [v-songbaohua@oppo.com: fix missing doc for flags of folio_add_new_anon_rmap()] Link: https://lkml.kernel.org/r/20240619210641.62542-1-21cnbao@gmail.com [v-songbaohua@oppo.com: enhance doc for extend rmap flags arguments for folio_add_new_anon_rmap] Link: https://lkml.kernel.org/r/20240622030256.43775-1-21cnbao@gmail.com Link: https://lkml.kernel.org/r/20240617231137.80726-1-21cnbao@gmail.com Link: https://lkml.kernel.org/r/20240617231137.80726-2-21cnbao@gmail.com Signed-off-by: Barry Song <v-songbaohua@oppo.com> Suggested-by: David Hildenbrand <david@redhat.com> Tested-by: Shuai Yuan <yuanshuai@oppo.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Chris Li <chrisl@kernel.org> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Yosry Ahmed <yosryahmed@google.com> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
Jiapeng Chong
|
37a4b34ac9 |
mm: userfaultfd: use swap() in double_pt_lock()
Use existing swap() function rather than duplicating its implementation. ./mm/userfaultfd.c:1006:13-14: WARNING opportunity for swap() Link: https://lkml.kernel.org/r/20240531091643.67778-1-jiapeng.chong@linux.alibaba.com Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com> Reported-by: Abaci Robot <abaci@linux.alibaba.com> Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=9266 Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Linus Torvalds
|
61307b7be4 |
The usual shower of singleton fixes and minor series all over MM,
documented (hopefully adequately) in the respective changelogs. Notable
series include:
- Lucas Stach has provided some page-mapping
cleanup/consolidation/maintainability work in the series "mm/treewide:
Remove pXd_huge() API".
- In the series "Allow migrate on protnone reference with
MPOL_PREFERRED_MANY policy", Donet Tom has optimized mempolicy's
MPOL_PREFERRED_MANY mode, yielding almost doubled performance in one
test.
- In their series "Memory allocation profiling" Kent Overstreet and
Suren Baghdasaryan have contributed a means of determining (via
/proc/allocinfo) whereabouts in the kernel memory is being allocated:
number of calls and amount of memory.
- Matthew Wilcox has provided the series "Various significant MM
patches" which does a number of rather unrelated things, but in largely
similar code sites.
- In his series "mm: page_alloc: freelist migratetype hygiene" Johannes
Weiner has fixed the page allocator's handling of migratetype requests,
with resulting improvements in compaction efficiency.
- In the series "make the hugetlb migration strategy consistent" Baolin
Wang has fixed a hugetlb migration issue, which should improve hugetlb
allocation reliability.
- Liu Shixin has hit an I/O meltdown caused by readahead in a
memory-tight memcg. Addressed in the series "Fix I/O high when memory
almost met memcg limit".
- In the series "mm/filemap: optimize folio adding and splitting" Kairui
Song has optimized pagecache insertion, yielding ~10% performance
improvement in one test.
- Baoquan He has cleaned up and consolidated the early zone
initialization code in the series "mm/mm_init.c: refactor
free_area_init_core()".
- Baoquan has also redone some MM initializatio code in the series
"mm/init: minor clean up and improvement".
- MM helper cleanups from Christoph Hellwig in his series "remove
follow_pfn".
- More cleanups from Matthew Wilcox in the series "Various page->flags
cleanups".
- Vlastimil Babka has contributed maintainability improvements in the
series "memcg_kmem hooks refactoring".
- More folio conversions and cleanups in Matthew Wilcox's series
"Convert huge_zero_page to huge_zero_folio"
"khugepaged folio conversions"
"Remove page_idle and page_young wrappers"
"Use folio APIs in procfs"
"Clean up __folio_put()"
"Some cleanups for memory-failure"
"Remove page_mapping()"
"More folio compat code removal"
- David Hildenbrand chipped in with "fs/proc/task_mmu: convert hugetlb
functions to work on folis".
- Code consolidation and cleanup work related to GUP's handling of
hugetlbs in Peter Xu's series "mm/gup: Unify hugetlb, part 2".
- Rick Edgecombe has developed some fixes to stack guard gaps in the
series "Cover a guard gap corner case".
- Jinjiang Tu has fixed KSM's behaviour after a fork+exec in the series
"mm/ksm: fix ksm exec support for prctl".
- Baolin Wang has implemented NUMA balancing for multi-size THPs. This
is a simple first-cut implementation for now. The series is "support
multi-size THP numa balancing".
- Cleanups to vma handling helper functions from Matthew Wilcox in the
series "Unify vma_address and vma_pgoff_address".
- Some selftests maintenance work from Dev Jain in the series
"selftests/mm: mremap_test: Optimizations and style fixes".
- Improvements to the swapping of multi-size THPs from Ryan Roberts in
the series "Swap-out mTHP without splitting".
- Kefeng Wang has significantly optimized the handling of arm64's
permission page faults in the series
"arch/mm/fault: accelerate pagefault when badaccess"
"mm: remove arch's private VM_FAULT_BADMAP/BADACCESS"
- GUP cleanups from David Hildenbrand in "mm/gup: consistently call it
GUP-fast".
- hugetlb fault code cleanups from Vishal Moola in "Hugetlb fault path to
use struct vm_fault".
- selftests build fixes from John Hubbard in the series "Fix
selftests/mm build without requiring "make headers"".
- Memory tiering fixes/improvements from Ho-Ren (Jack) Chuang in the
series "Improved Memory Tier Creation for CPUless NUMA Nodes". Fixes
the initialization code so that migration between different memory types
works as intended.
- David Hildenbrand has improved follow_pte() and fixed an errant driver
in the series "mm: follow_pte() improvements and acrn follow_pte()
fixes".
- David also did some cleanup work on large folio mapcounts in his
series "mm: mapcount for large folios + page_mapcount() cleanups".
- Folio conversions in KSM in Alex Shi's series "transfer page to folio
in KSM".
- Barry Song has added some sysfs stats for monitoring multi-size THP's
in the series "mm: add per-order mTHP alloc and swpout counters".
- Some zswap cleanups from Yosry Ahmed in the series "zswap same-filled
and limit checking cleanups".
- Matthew Wilcox has been looking at buffer_head code and found the
documentation to be lacking. The series is "Improve buffer head
documentation".
- Multi-size THPs get more work, this time from Lance Yang. His series
"mm/madvise: enhance lazyfreeing with mTHP in madvise_free" optimizes
the freeing of these things.
- Kemeng Shi has added more userspace-visible writeback instrumentation
in the series "Improve visibility of writeback".
- Kemeng Shi then sent some maintenance work on top in the series "Fix
and cleanups to page-writeback".
- Matthew Wilcox reduces mmap_lock traffic in the anon vma code in the
series "Improve anon_vma scalability for anon VMAs". Intel's test bot
reported an improbable 3x improvement in one test.
- SeongJae Park adds some DAMON feature work in the series
"mm/damon: add a DAMOS filter type for page granularity access recheck"
"selftests/damon: add DAMOS quota goal test"
- Also some maintenance work in the series
"mm/damon/paddr: simplify page level access re-check for pageout"
"mm/damon: misc fixes and improvements"
- David Hildenbrand has disabled some known-to-fail selftests ni the
series "selftests: mm: cow: flag vmsplice() hugetlb tests as XFAIL".
- memcg metadata storage optimizations from Shakeel Butt in "memcg:
reduce memory consumption by memcg stats".
- DAX fixes and maintenance work from Vishal Verma in the series
"dax/bus.c: Fixups for dax-bus locking".
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Merge tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull mm updates from Andrew Morton:
"The usual shower of singleton fixes and minor series all over MM,
documented (hopefully adequately) in the respective changelogs.
Notable series include:
- Lucas Stach has provided some page-mapping cleanup/consolidation/
maintainability work in the series "mm/treewide: Remove pXd_huge()
API".
- In the series "Allow migrate on protnone reference with
MPOL_PREFERRED_MANY policy", Donet Tom has optimized mempolicy's
MPOL_PREFERRED_MANY mode, yielding almost doubled performance in
one test.
- In their series "Memory allocation profiling" Kent Overstreet and
Suren Baghdasaryan have contributed a means of determining (via
/proc/allocinfo) whereabouts in the kernel memory is being
allocated: number of calls and amount of memory.
- Matthew Wilcox has provided the series "Various significant MM
patches" which does a number of rather unrelated things, but in
largely similar code sites.
- In his series "mm: page_alloc: freelist migratetype hygiene"
Johannes Weiner has fixed the page allocator's handling of
migratetype requests, with resulting improvements in compaction
efficiency.
- In the series "make the hugetlb migration strategy consistent"
Baolin Wang has fixed a hugetlb migration issue, which should
improve hugetlb allocation reliability.
- Liu Shixin has hit an I/O meltdown caused by readahead in a
memory-tight memcg. Addressed in the series "Fix I/O high when
memory almost met memcg limit".
- In the series "mm/filemap: optimize folio adding and splitting"
Kairui Song has optimized pagecache insertion, yielding ~10%
performance improvement in one test.
- Baoquan He has cleaned up and consolidated the early zone
initialization code in the series "mm/mm_init.c: refactor
free_area_init_core()".
- Baoquan has also redone some MM initializatio code in the series
"mm/init: minor clean up and improvement".
- MM helper cleanups from Christoph Hellwig in his series "remove
follow_pfn".
- More cleanups from Matthew Wilcox in the series "Various
page->flags cleanups".
- Vlastimil Babka has contributed maintainability improvements in the
series "memcg_kmem hooks refactoring".
- More folio conversions and cleanups in Matthew Wilcox's series:
"Convert huge_zero_page to huge_zero_folio"
"khugepaged folio conversions"
"Remove page_idle and page_young wrappers"
"Use folio APIs in procfs"
"Clean up __folio_put()"
"Some cleanups for memory-failure"
"Remove page_mapping()"
"More folio compat code removal"
- David Hildenbrand chipped in with "fs/proc/task_mmu: convert
hugetlb functions to work on folis".
- Code consolidation and cleanup work related to GUP's handling of
hugetlbs in Peter Xu's series "mm/gup: Unify hugetlb, part 2".
- Rick Edgecombe has developed some fixes to stack guard gaps in the
series "Cover a guard gap corner case".
- Jinjiang Tu has fixed KSM's behaviour after a fork+exec in the
series "mm/ksm: fix ksm exec support for prctl".
- Baolin Wang has implemented NUMA balancing for multi-size THPs.
This is a simple first-cut implementation for now. The series is
"support multi-size THP numa balancing".
- Cleanups to vma handling helper functions from Matthew Wilcox in
the series "Unify vma_address and vma_pgoff_address".
- Some selftests maintenance work from Dev Jain in the series
"selftests/mm: mremap_test: Optimizations and style fixes".
- Improvements to the swapping of multi-size THPs from Ryan Roberts
in the series "Swap-out mTHP without splitting".
- Kefeng Wang has significantly optimized the handling of arm64's
permission page faults in the series
"arch/mm/fault: accelerate pagefault when badaccess"
"mm: remove arch's private VM_FAULT_BADMAP/BADACCESS"
- GUP cleanups from David Hildenbrand in "mm/gup: consistently call
it GUP-fast".
- hugetlb fault code cleanups from Vishal Moola in "Hugetlb fault
path to use struct vm_fault".
- selftests build fixes from John Hubbard in the series "Fix
selftests/mm build without requiring "make headers"".
- Memory tiering fixes/improvements from Ho-Ren (Jack) Chuang in the
series "Improved Memory Tier Creation for CPUless NUMA Nodes".
Fixes the initialization code so that migration between different
memory types works as intended.
- David Hildenbrand has improved follow_pte() and fixed an errant
driver in the series "mm: follow_pte() improvements and acrn
follow_pte() fixes".
- David also did some cleanup work on large folio mapcounts in his
series "mm: mapcount for large folios + page_mapcount() cleanups".
- Folio conversions in KSM in Alex Shi's series "transfer page to
folio in KSM".
- Barry Song has added some sysfs stats for monitoring multi-size
THP's in the series "mm: add per-order mTHP alloc and swpout
counters".
- Some zswap cleanups from Yosry Ahmed in the series "zswap
same-filled and limit checking cleanups".
- Matthew Wilcox has been looking at buffer_head code and found the
documentation to be lacking. The series is "Improve buffer head
documentation".
- Multi-size THPs get more work, this time from Lance Yang. His
series "mm/madvise: enhance lazyfreeing with mTHP in madvise_free"
optimizes the freeing of these things.
- Kemeng Shi has added more userspace-visible writeback
instrumentation in the series "Improve visibility of writeback".
- Kemeng Shi then sent some maintenance work on top in the series
"Fix and cleanups to page-writeback".
- Matthew Wilcox reduces mmap_lock traffic in the anon vma code in
the series "Improve anon_vma scalability for anon VMAs". Intel's
test bot reported an improbable 3x improvement in one test.
- SeongJae Park adds some DAMON feature work in the series
"mm/damon: add a DAMOS filter type for page granularity access recheck"
"selftests/damon: add DAMOS quota goal test"
- Also some maintenance work in the series
"mm/damon/paddr: simplify page level access re-check for pageout"
"mm/damon: misc fixes and improvements"
- David Hildenbrand has disabled some known-to-fail selftests ni the
series "selftests: mm: cow: flag vmsplice() hugetlb tests as
XFAIL".
- memcg metadata storage optimizations from Shakeel Butt in "memcg:
reduce memory consumption by memcg stats".
- DAX fixes and maintenance work from Vishal Verma in the series
"dax/bus.c: Fixups for dax-bus locking""
* tag 'mm-stable-2024-05-17-19-19' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (426 commits)
memcg, oom: cleanup unused memcg_oom_gfp_mask and memcg_oom_order
selftests/mm: hugetlb_madv_vs_map: avoid test skipping by querying hugepage size at runtime
mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_wp
mm/hugetlb: add missing VM_FAULT_SET_HINDEX in hugetlb_fault
selftests: cgroup: add tests to verify the zswap writeback path
mm: memcg: make alloc_mem_cgroup_per_node_info() return bool
mm/damon/core: fix return value from damos_wmark_metric_value
mm: do not update memcg stats for NR_{FILE/SHMEM}_PMDMAPPED
selftests: cgroup: remove redundant enabling of memory controller
Docs/mm/damon/maintainer-profile: allow posting patches based on damon/next tree
Docs/mm/damon/maintainer-profile: change the maintainer's timezone from PST to PT
Docs/mm/damon/design: use a list for supported filters
Docs/admin-guide/mm/damon/usage: fix wrong schemes effective quota update command
Docs/admin-guide/mm/damon/usage: fix wrong example of DAMOS filter matching sysfs file
selftests/damon: classify tests for functionalities and regressions
selftests/damon/_damon_sysfs: use 'is' instead of '==' for 'None'
selftests/damon/_damon_sysfs: find sysfs mount point from /proc/mounts
selftests/damon/_damon_sysfs: check errors from nr_schemes file reads
mm/damon/core: initialize ->esz_bp from damos_quota_init_priv()
selftests/damon: add a test for DAMOS quota goal
...
|
||
Matthew Wilcox (Oracle)
|
73b4a0cd82 |
mm: fix some minor per-VMA lock issues in userfaultfd
Rename lock_vma() to uffd_lock_vma() because it really is uffd specific. Remove comment referencing unlock_vma() which doesn't exist. Fix the comment about lock_vma_under_rcu() which I just made incorrect. Link: https://lkml.kernel.org/r/20240426144506.1290619-4-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Suren Baghdasaryan <surenb@google.com> Cc: David Hildenbrand <david@redhat.com> Cc: Jann Horn <jannh@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Matthew Wilcox (Oracle)
|
a568b4126b |
userfault; expand folio use in mfill_atomic_install_pte()
Call page_folio() a little earlier so we can use folio_mapping() instead of page_mapping(), saving a call to compound_head(). Link: https://lkml.kernel.org/r/20240423225552.4113447-6-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Eric Biggers <ebiggers@google.com> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
Suren Baghdasaryan
|
b5ba3a6427 |
userfaultfd: remove WRITE_ONCE when setting folio->index during UFFDIO_MOVE
When folio is moved with UFFDIO_MOVE it gets locked before the rmap and index are modified. Due to the folio lock being already held, WRITE_ONCE() is not needed when setting the folio index. Remove it. Link: https://lkml.kernel.org/r/20240415020821.1152951-1-surenb@google.com Reported-by: Matthew Wilcox <willy@infradead.org> Signed-off-by: Suren Baghdasaryan <surenb@google.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Peter Xu <peterx@redhat.com> Cc: Lokesh Gidra <lokeshgidra@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Matthew Wilcox (Oracle)
|
e06d03d559 |
mm: add pmd_folio()
Convert directly from a pmd to a folio without going through another representation first. For now this is just a slightly shorter way to write it, but it might end up being more efficient later. Link: https://lkml.kernel.org/r/20240326202833.523759-4-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Matthew Wilcox (Oracle)
|
5beaee54a3 |
mm: add is_huge_zero_folio()
This is the folio equivalent of is_huge_zero_page(). It doesn't add any efficiency, but it does prevent the caller from passing a tail page and getting confused when the predicate returns false. Link: https://lkml.kernel.org/r/20240326202833.523759-3-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
David Hildenbrand
|
90a7592da1 |
mm/userfaultfd: Do not place zeropages when zeropages are disallowed
s390x must disable shared zeropages for processes running VMs, because the VMs could end up making use of "storage keys" or protected virtualization, which are incompatible with shared zeropages. Yet, with userfaultfd it is possible to insert shared zeropages into such processes. Let's fallback to simply allocating a fresh zeroed anonymous folio and insert that instead. mm_forbids_zeropage() was introduced in commit |
||
Lokesh Gidra
|
30af24facf |
userfaultfd: fix deadlock warning when locking src and dst VMAs
Use down_read_nested() to avoid the warning.
Link: https://lkml.kernel.org/r/20240321235818.125118-1-lokeshgidra@google.com
Fixes:
|
||
|
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()
...
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James Houghton
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b14d1671dd |
mm: add an explicit smp_wmb() to UFFDIO_CONTINUE
Users of UFFDIO_CONTINUE may reasonably assume that a write memory barrier is included as part of UFFDIO_CONTINUE. That is, a user may believe that all writes it has done to a page that it is now UFFDIO_CONTINUE'ing are guaranteed to be visible to anyone subsequently reading the page through the newly mapped virtual memory region. Today, such a user happens to be correct. mmget_not_zero(), for example, is called as part of UFFDIO_CONTINUE (and comes before any PTE updates), and it implicitly gives us a write barrier. To be resilient against future changes, include an explicit smp_wmb(). While we're at it, optimize the smp_wmb() that is already incidentally present for the HugeTLB case. Merely making a syscall does not generally imply the memory ordering constraints that we need (including on x86). Link: https://lkml.kernel.org/r/20240307010250.3847179-1-jthoughton@google.com Signed-off-by: James Houghton <jthoughton@google.com> Reviewed-by: Peter Xu <peterx@redhat.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Qi Zheng
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d7a08838ab |
mm: userfaultfd: fix unexpected change to src_folio when UFFDIO_MOVE fails
After ptep_clear_flush(), if we find that src_folio is pinned we will fail
UFFDIO_MOVE and put src_folio back to src_pte entry, but the change to
src_folio->{mapping,index} is not restored in this process. This is not
what we expected, so fix it.
This can cause the rmap for that page to be invalid, possibly resulting
in memory corruption. At least swapout+migration would no longer work,
because we might fail to locate the mappings of that folio.
Link: https://lkml.kernel.org/r/20240222080815.46291-1-zhengqi.arch@bytedance.com
Fixes:
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Lokesh Gidra
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867a43a34f |
userfaultfd: use per-vma locks in userfaultfd operations
All userfaultfd operations, except write-protect, opportunistically use per-vma locks to lock vmas. On failure, attempt again inside mmap_lock critical section. Write-protect operation requires mmap_lock as it iterates over multiple vmas. Link: https://lkml.kernel.org/r/20240215182756.3448972-5-lokeshgidra@google.com Signed-off-by: Lokesh Gidra <lokeshgidra@google.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Brian Geffon <bgeffon@google.com> Cc: David Hildenbrand <david@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Nicolas Geoffray <ngeoffray@google.com> Cc: Peter Xu <peterx@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Tim Murray <timmurray@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Lokesh Gidra
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5e4c24a57b |
userfaultfd: protect mmap_changing with rw_sem in userfaulfd_ctx
Increments and loads to mmap_changing are always in mmap_lock critical section. This ensures that if userspace requests event notification for non-cooperative operations (e.g. mremap), userfaultfd operations don't occur concurrently. This can be achieved by using a separate read-write semaphore in userfaultfd_ctx such that increments are done in write-mode and loads in read-mode, thereby eliminating the dependency on mmap_lock for this purpose. This is a preparatory step before we replace mmap_lock usage with per-vma locks in fill/move ioctls. Link: https://lkml.kernel.org/r/20240215182756.3448972-3-lokeshgidra@google.com Signed-off-by: Lokesh Gidra <lokeshgidra@google.com> Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Brian Geffon <bgeffon@google.com> Cc: David Hildenbrand <david@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Nicolas Geoffray <ngeoffray@google.com> Cc: Peter Xu <peterx@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Tim Murray <timmurray@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
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Suren Baghdasaryan
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eb1521dad8 |
userfaultfd: handle zeropage moves by UFFDIO_MOVE
Current implementation of UFFDIO_MOVE fails to move zeropages and returns EBUSY when it encounters one. We can handle them by mapping a zeropage at the destination and clearing the mapping at the source. This is done both for ordinary and for huge zeropages. Link: https://lkml.kernel.org/r/20240131175618.2417291-1-surenb@google.com Signed-off-by: Suren Baghdasaryan <surenb@google.com> Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Closes: https://lore.kernel.org/r/202401300107.U8iMAkTl-lkp@intel.com/ Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Brian Geffon <bgeffon@google.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jann Horn <jannh@google.com> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Lokesh Gidra <lokeshgidra@google.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Nicolas Geoffray <ngeoffray@google.com> Cc: Peter Xu <peterx@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: ZhangPeng <zhangpeng362@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Kefeng Wang
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a23f517b0e |
mm: convert mm_counter() to take a folio
Now all callers of mm_counter() have a folio, convert mm_counter() to take a folio. Saves a call to compound_head() hidden inside PageAnon(). Link: https://lkml.kernel.org/r/20240111152429.3374566-10-willy@infradead.org Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Ryan Roberts
|
56ae10cf62 |
mm/userfaultfd: UFFDIO_MOVE implementation should use ptep_get()
Commit |
||
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Lokesh Gidra
|
67695f18d5 |
userfaultfd: fix mmap_changing checking in mfill_atomic_hugetlb
In mfill_atomic_hugetlb(), mmap_changing isn't being checked
again if we drop mmap_lock and reacquire it. When the lock is not held,
mmap_changing could have been incremented. This is also inconsistent
with the behavior in mfill_atomic().
Link: https://lkml.kernel.org/r/20240117223729.1444522-1-lokeshgidra@google.com
Fixes:
|
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Suren Baghdasaryan
|
5d4747a6cc |
userfaultfd: avoid huge_zero_page in UFFDIO_MOVE
While testing UFFDIO_MOVE ioctl, syzbot triggered VM_BUG_ON_PAGE caused by
a call to PageAnonExclusive() with a huge_zero_page as a parameter.
UFFDIO_MOVE does not yet handle zeropages and returns EBUSY when one is
encountered. Add an early huge_zero_page check in the PMD move path to
avoid this situation.
Link: https://lkml.kernel.org/r/20240112013935.1474648-1-surenb@google.com
Fixes:
|
||
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Suren Baghdasaryan
|
982ae058b2 |
userfaultfd: fix move_pages_pte() splitting folio under RCU read lock
While testing the split PMD path with lockdep enabled I've got an "Invalid
wait context" error caused by split_huge_page_to_list() trying to lock
anon_vma->rwsem while inside RCU read section. The issues is due to
move_pages_pte() calling split_folio() under RCU read lock. Fix this by
unmapping the PTEs and exiting RCU read section before splitting the folio
and then retrying. The same retry pattern is used when locking the folio
or anon_vma in this function. After splitting the large folio we unlock
and release it because after the split the old folio might not be the one
that contains the src_addr.
Link: https://lkml.kernel.org/r/20240102233256.1077959-1-surenb@google.com
Fixes:
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||
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David Hildenbrand
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7123e19c3c |
mm/userfaultfd: page_add_file_rmap() -> folio_add_file_rmap_pte()
Let's convert mfill_atomic_install_pte(). Link: https://lkml.kernel.org/r/20231220224504.646757-12-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Yin Fengwei <fengwei.yin@intel.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Matthew Wilcox (Oracle)
|
2853b66b60 |
mm: remove some calls to page_add_new_anon_rmap()
We already have the folio in these functions, we just need to use it. folio_add_new_anon_rmap() didn't exist at the time they were converted to folios. Link: https://lkml.kernel.org/r/20231211162214.2146080-5-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
Andrea Arcangeli
|
adef440691 |
userfaultfd: UFFDIO_MOVE uABI
Implement the uABI of UFFDIO_MOVE ioctl. UFFDIO_COPY performs ~20% better than UFFDIO_MOVE when the application needs pages to be allocated [1]. However, with UFFDIO_MOVE, if pages are available (in userspace) for recycling, as is usually the case in heap compaction algorithms, then we can avoid the page allocation and memcpy (done by UFFDIO_COPY). Also, since the pages are recycled in the userspace, we avoid the need to release (via madvise) the pages back to the kernel [2]. We see over 40% reduction (on a Google pixel 6 device) in the compacting thread's completion time by using UFFDIO_MOVE vs. UFFDIO_COPY. This was measured using a benchmark that emulates a heap compaction implementation using userfaultfd (to allow concurrent accesses by application threads). More details of the usecase are explained in [2]. Furthermore, UFFDIO_MOVE enables moving swapped-out pages without touching them within the same vma. Today, it can only be done by mremap, however it forces splitting the vma. [1] https://lore.kernel.org/all/1425575884-2574-1-git-send-email-aarcange@redhat.com/ [2] https://lore.kernel.org/linux-mm/CA+EESO4uO84SSnBhArH4HvLNhaUQ5nZKNKXqxRCyjniNVjp0Aw@mail.gmail.com/ Update for the ioctl_userfaultfd(2) manpage: UFFDIO_MOVE (Since Linux xxx) Move a continuous memory chunk into the userfault registered range and optionally wake up the blocked thread. The source and destination addresses and the number of bytes to move are specified by the src, dst, and len fields of the uffdio_move structure pointed to by argp: struct uffdio_move { __u64 dst; /* Destination of move */ __u64 src; /* Source of move */ __u64 len; /* Number of bytes to move */ __u64 mode; /* Flags controlling behavior of move */ __s64 move; /* Number of bytes moved, or negated error */ }; The following value may be bitwise ORed in mode to change the behavior of the UFFDIO_MOVE operation: UFFDIO_MOVE_MODE_DONTWAKE Do not wake up the thread that waits for page-fault resolution UFFDIO_MOVE_MODE_ALLOW_SRC_HOLES Allow holes in the source virtual range that is being moved. When not specified, the holes will result in ENOENT error. When specified, the holes will be accounted as successfully moved memory. This is mostly useful to move hugepage aligned virtual regions without knowing if there are transparent hugepages in the regions or not, but preventing the risk of having to split the hugepage during the operation. The move field is used by the kernel to return the number of bytes that was actually moved, or an error (a negated errno- style value). If the value returned in move doesn't match the value that was specified in len, the operation fails with the error EAGAIN. The move field is output-only; it is not read by the UFFDIO_MOVE operation. The operation may fail for various reasons. Usually, remapping of pages that are not exclusive to the given process fail; once KSM might deduplicate pages or fork() COW-shares pages during fork() with child processes, they are no longer exclusive. Further, the kernel might only perform lightweight checks for detecting whether the pages are exclusive, and return -EBUSY in case that check fails. To make the operation more likely to succeed, KSM should be disabled, fork() should be avoided or MADV_DONTFORK should be configured for the source VMA before fork(). This ioctl(2) operation returns 0 on success. In this case, the entire area was moved. On error, -1 is returned and errno is set to indicate the error. Possible errors include: EAGAIN The number of bytes moved (i.e., the value returned in the move field) does not equal the value that was specified in the len field. EINVAL Either dst or len was not a multiple of the system page size, or the range specified by src and len or dst and len was invalid. EINVAL An invalid bit was specified in the mode field. ENOENT The source virtual memory range has unmapped holes and UFFDIO_MOVE_MODE_ALLOW_SRC_HOLES is not set. EEXIST The destination virtual memory range is fully or partially mapped. EBUSY The pages in the source virtual memory range are either pinned or not exclusive to the process. The kernel might only perform lightweight checks for detecting whether the pages are exclusive. To make the operation more likely to succeed, KSM should be disabled, fork() should be avoided or MADV_DONTFORK should be configured for the source virtual memory area before fork(). ENOMEM Allocating memory needed for the operation failed. ESRCH The target process has exited at the time of a UFFDIO_MOVE operation. Link: https://lkml.kernel.org/r/20231206103702.3873743-3-surenb@google.com Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Suren Baghdasaryan <surenb@google.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Brian Geffon <bgeffon@google.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jann Horn <jannh@google.com> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Lokesh Gidra <lokeshgidra@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Nicolas Geoffray <ngeoffray@google.com> Cc: Peter Xu <peterx@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: ZhangPeng <zhangpeng362@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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|
Ryan Roberts
|
afccb0804f |
mm: more ptep_get() conversion
Commit
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|
Linus Torvalds
|
df57721f9a |
Add x86 shadow stack support
Convert IBT selftest to asm to fix objtool warning -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEV76QKkVc4xCGURexaDWVMHDJkrAFAmTv1QQACgkQaDWVMHDJ krAUwhAAn6TOwHJK8BSkHeiQhON1nrlP3c5cv0AyZ2NP8RYDrZrSZvhpYBJ6wgKC Cx5CGq5nn9twYsYS3KsktLKDfR3lRdsQ7K9qtyFtYiaeaVKo+7gEKl/K+klwai8/ gninQWHk0zmSCja8Vi77q52WOMkQKapT8+vaON9EVDO8dVEi+CvhAIfPwMafuiwO Rk4X86SzoZu9FP79LcCg9XyGC/XbM2OG9eNUTSCKT40qTTKm5y4gix687NvAlaHR ko5MTsdl0Wfp6Qk0ohT74LnoA2c1g/FluvZIM33ci/2rFpkf9Hw7ip3lUXqn6CPx rKiZ+pVRc0xikVWkraMfIGMJfUd2rhelp8OyoozD7DB7UZw40Q4RW4N5tgq9Fhe9 MQs3p1v9N8xHdRKl365UcOczUxNAmv4u0nV5gY/4FMC6VjldCl2V9fmqYXyzFS4/ Ogg4FSd7c2JyGFKPs+5uXyi+RY2qOX4+nzHOoKD7SY616IYqtgKoz5usxETLwZ6s VtJOmJL0h//z0A7tBliB0zd+SQ5UQQBDC2XouQH2fNX2isJMn0UDmWJGjaHgK6Hh 8jVp6LNqf+CEQS387UxckOyj7fu438hDky1Ggaw4YqowEOhQeqLVO4++x+HITrbp AupXfbJw9h9cMN63Yc0gVxXQ9IMZ+M7UxLtZ3Cd8/PVztNy/clA= =3UUm -----END PGP SIGNATURE----- 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 ... |
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Axel Rasmussen
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8a13897fb0 |
mm: userfaultfd: support UFFDIO_POISON for hugetlbfs
The behavior here is the same as it is for anon/shmem. This is done separately because hugetlb pte marker handling is a bit different. Link: https://lkml.kernel.org/r/20230707215540.2324998-6-axelrasmussen@google.com Signed-off-by: Axel Rasmussen <axelrasmussen@google.com> Acked-by: Peter Xu <peterx@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Brian Geffon <bgeffon@google.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Gaosheng Cui <cuigaosheng1@huawei.com> Cc: Huang, Ying <ying.huang@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: James Houghton <jthoughton@google.com> Cc: Jan Alexander Steffens (heftig) <heftig@archlinux.org> Cc: Jiaqi Yan <jiaqiyan@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nadav Amit <namit@vmware.com> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Suleiman Souhlal <suleiman@google.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: T.J. Alumbaugh <talumbau@google.com> Cc: Yu Zhao <yuzhao@google.com> Cc: ZhangPeng <zhangpeng362@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Hugh Dickins
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597425df4f |
mm: userfaultfd: add new UFFDIO_POISON ioctl: fix
Smatch has observed that pte_offset_map_lock() is now allowed to fail, and then ptl should not be unlocked. Use -EAGAIN here like elsewhere. Link: https://lkml.kernel.org/r/bc7bba61-d34f-ad3a-ccf1-c191585ef851@google.com Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: Axel Rasmussen <axelrasmussen@google.com> Cc: Dan Carpenter <dan.carpenter@linaro.org> Cc: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Axel Rasmussen
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fc71884a5f |
mm: userfaultfd: add new UFFDIO_POISON ioctl
The basic idea here is to "simulate" memory poisoning for VMs. A VM running on some host might encounter a memory error, after which some page(s) are poisoned (i.e., future accesses SIGBUS). They expect that once poisoned, pages can never become "un-poisoned". So, when we live migrate the VM, we need to preserve the poisoned status of these pages. When live migrating, we try to get the guest running on its new host as quickly as possible. So, we start it running before all memory has been copied, and before we're certain which pages should be poisoned or not. So the basic way to use this new feature is: - On the new host, the guest's memory is registered with userfaultfd, in either MISSING or MINOR mode (doesn't really matter for this purpose). - On any first access, we get a userfaultfd event. At this point we can communicate with the old host to find out if the page was poisoned. - If so, we can respond with a UFFDIO_POISON - this places a swap marker so any future accesses will SIGBUS. Because the pte is now "present", future accesses won't generate more userfaultfd events, they'll just SIGBUS directly. UFFDIO_POISON does not handle unmapping previously-present PTEs. This isn't needed, because during live migration we want to intercept all accesses with userfaultfd (not just writes, so WP mode isn't useful for this). So whether minor or missing mode is being used (or both), the PTE won't be present in any case, so handling that case isn't needed. Similarly, UFFDIO_POISON won't replace existing PTE markers. This might be okay to do, but it seems to be safer to just refuse to overwrite any existing entry (like a UFFD_WP PTE marker). Link: https://lkml.kernel.org/r/20230707215540.2324998-5-axelrasmussen@google.com Signed-off-by: Axel Rasmussen <axelrasmussen@google.com> Acked-by: Peter Xu <peterx@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Brian Geffon <bgeffon@google.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Gaosheng Cui <cuigaosheng1@huawei.com> Cc: Huang, Ying <ying.huang@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: James Houghton <jthoughton@google.com> Cc: Jan Alexander Steffens (heftig) <heftig@archlinux.org> Cc: Jiaqi Yan <jiaqiyan@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nadav Amit <namit@vmware.com> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Suleiman Souhlal <suleiman@google.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: T.J. Alumbaugh <talumbau@google.com> Cc: Yu Zhao <yuzhao@google.com> Cc: ZhangPeng <zhangpeng362@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Axel Rasmussen
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435cdb41a7 |
mm: userfaultfd: extract file size check out into a helper
This code is already duplicated twice, and UFFDIO_POISON will do the same check a third time. So, it's worth extracting into a helper to save repetitive lines of code. Link: https://lkml.kernel.org/r/20230707215540.2324998-4-axelrasmussen@google.com Signed-off-by: Axel Rasmussen <axelrasmussen@google.com> Reviewed-by: Peter Xu <peterx@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Brian Geffon <bgeffon@google.com> Cc: Christian Brauner <brauner@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Gaosheng Cui <cuigaosheng1@huawei.com> Cc: Huang, Ying <ying.huang@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: James Houghton <jthoughton@google.com> Cc: Jan Alexander Steffens (heftig) <heftig@archlinux.org> Cc: Jiaqi Yan <jiaqiyan@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nadav Amit <namit@vmware.com> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Suleiman Souhlal <suleiman@google.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: T.J. Alumbaugh <talumbau@google.com> Cc: Yu Zhao <yuzhao@google.com> Cc: ZhangPeng <zhangpeng362@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Rick Edgecombe
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161e393c0f |
mm: Make pte_mkwrite() take a VMA
The x86 Shadow stack feature includes a new type of memory called shadow stack. This shadow stack memory has some unusual properties, which requires some core mm changes to function properly. One of these unusual properties is that shadow stack memory is writable, but only in limited ways. These limits are applied via a specific PTE bit combination. Nevertheless, the memory is writable, and core mm code will need to apply the writable permissions in the typical paths that call pte_mkwrite(). Future patches will make pte_mkwrite() take a VMA, so that the x86 implementation of it can know whether to create regular writable or shadow stack mappings. But there are a couple of challenges to this. Modifying the signatures of each arch pte_mkwrite() implementation would be error prone because some are generated with macros and would need to be re-implemented. Also, some pte_mkwrite() callers operate on kernel memory without a VMA. So this can be done in a three step process. First pte_mkwrite() can be renamed to pte_mkwrite_novma() in each arch, with a generic pte_mkwrite() added that just calls pte_mkwrite_novma(). Next callers without a VMA can be moved to pte_mkwrite_novma(). And lastly, pte_mkwrite() and all callers can be changed to take/pass a VMA. Previous work pte_mkwrite() renamed pte_mkwrite_novma() and converted callers that don't have a VMA were to use pte_mkwrite_novma(). So now change pte_mkwrite() to take a VMA and change the remaining callers to pass a VMA. Apply the same changes for pmd_mkwrite(). No functional change. Suggested-by: David Hildenbrand <david@redhat.com> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org> Acked-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/all/20230613001108.3040476-4-rick.p.edgecombe%40intel.com |
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Ryan Roberts
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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> |
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Hugh Dickins
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3622d3cde3 |
mm/userfaultfd: allow pte_offset_map_lock() to fail
mfill_atomic_install_pte() and mfill_atomic_pte_zeropage() treat failed pte_offset_map_lock() as -EAGAIN, which mfill_atomic() already returns to user for a similar race. Link: https://lkml.kernel.org/r/50cf3930-1bfa-4de9-a079-3da47b7ce17b@google.com Signed-off-by: Hugh Dickins <hughd@google.com> 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: SeongJae Park <sj@kernel.org> 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> |
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ZhangPeng
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686ea6e61d |
userfaultfd: use helper function range_in_vma()
We can use range_in_vma() to check if dst_start, dst_start + len are within the dst_vma range. Minor readability improvement. Link: https://lkml.kernel.org/r/20230417003919.930515-1-zhangpeng362@huawei.com Signed-off-by: ZhangPeng <zhangpeng362@huawei.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Nanyong Sun <sunnanyong@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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ZhangPeng
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d7be6d7eee |
userfaultfd: convert mfill_atomic() to use a folio
Convert mfill_atomic_pte_copy(), shmem_mfill_atomic_pte() and mfill_atomic_pte() to take in a folio pointer. Convert mfill_atomic() to use a folio. Convert page_kaddr to kaddr in mfill_atomic(). Link: https://lkml.kernel.org/r/20230410133932.32288-7-zhangpeng362@huawei.com Signed-off-by: ZhangPeng <zhangpeng362@huawei.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nanyong Sun <sunnanyong@huawei.com> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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ZhangPeng
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0169fd518a |
userfaultfd: convert mfill_atomic_hugetlb() to use a folio
Convert hugetlb_mfill_atomic_pte() to take in a folio pointer instead of a page pointer. Convert mfill_atomic_hugetlb() to use a folio. Link: https://lkml.kernel.org/r/20230410133932.32288-5-zhangpeng362@huawei.com Signed-off-by: ZhangPeng <zhangpeng362@huawei.com> Reviewed-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nanyong Sun <sunnanyong@huawei.com> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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ZhangPeng
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e87340ca5c |
userfaultfd: convert copy_huge_page_from_user() to copy_folio_from_user()
Replace copy_huge_page_from_user() with copy_folio_from_user(). copy_folio_from_user() does the same as copy_huge_page_from_user(), but takes in a folio instead of a page. Convert page_kaddr to kaddr in copy_folio_from_user() to do indenting cleanup. Link: https://lkml.kernel.org/r/20230410133932.32288-4-zhangpeng362@huawei.com Signed-off-by: ZhangPeng <zhangpeng362@huawei.com> Reviewed-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nanyong Sun <sunnanyong@huawei.com> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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ZhangPeng
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07e6d4095c |
userfaultfd: convert mfill_atomic_pte_copy() to use a folio
Patch series "userfaultfd: convert userfaultfd functions to use folios", v6. This patch series converts several userfaultfd functions to use folios. This patch (of 6): Call vma_alloc_folio() directly instead of alloc_page_vma() and convert page_kaddr to kaddr in mfill_atomic_pte_copy(). Removes several calls to compound_head(). Link: https://lkml.kernel.org/r/20230410133932.32288-1-zhangpeng362@huawei.com Link: https://lkml.kernel.org/r/20230410133932.32288-2-zhangpeng362@huawei.com Signed-off-by: ZhangPeng <zhangpeng362@huawei.com> Reviewed-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nanyong Sun <sunnanyong@huawei.com> Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Axel Rasmussen
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0289184476 |
mm: userfaultfd: add UFFDIO_CONTINUE_MODE_WP to install WP PTEs
UFFDIO_COPY already has UFFDIO_COPY_MODE_WP, so when installing a new PTE
to resolve a missing fault, one can install a write-protected one. This
is useful when using UFFDIO_REGISTER_MODE_{MISSING,WP} in combination.
This was motivated by testing HugeTLB HGM [1], and in particular its
interaction with userfaultfd features. Existing userfaultfd code supports
using WP and MINOR modes together (i.e. you can register an area with
both enabled), but without this CONTINUE flag the combination is in
practice unusable.
So, add an analogous UFFDIO_CONTINUE_MODE_WP, which does the same thing as
UFFDIO_COPY_MODE_WP, but for *minor* faults.
Update the selftest to do some very basic exercising of the new flag.
Update Documentation/ to describe how these flags are used (neither the
COPY nor the new CONTINUE versions of this mode flag were described there
before).
[1]: https://patchwork.kernel.org/project/linux-mm/cover/20230218002819.1486479-1-jthoughton@google.com/
Link: https://lkml.kernel.org/r/20230314221250.682452-5-axelrasmussen@google.com
Signed-off-by: Axel Rasmussen <axelrasmussen@google.com>
Acked-by: Peter Xu <peterx@redhat.com>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nadav Amit <namit@vmware.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Axel Rasmussen
|
d971293703 |
mm: userfaultfd: combine 'mode' and 'wp_copy' arguments
Many userfaultfd ioctl functions take both a 'mode' and a 'wp_copy'
argument. In future commits we plan to plumb the flags through to more
places, so we'd be proliferating the very long argument list even further.
Let's take the time to simplify the argument list. Combine the two
arguments into one - and generalize, so when we add more flags in the
future, it doesn't imply more function arguments.
Since the modes (copy, zeropage, continue) are mutually exclusive, store
them as an integer value (0, 1, 2) in the low bits. Place combine-able
flag bits in the high bits.
This is quite similar to an earlier patch proposed by Nadav Amit
("userfaultfd: introduce uffd_flags" [1]). The main difference is that
patch only handled flags, whereas this patch *also* combines the "mode"
argument into the same type to shorten the argument list.
[1]: https://lore.kernel.org/all/20220619233449.181323-2-namit@vmware.com/
Link: https://lkml.kernel.org/r/20230314221250.682452-4-axelrasmussen@google.com
Signed-off-by: Axel Rasmussen <axelrasmussen@google.com>
Acked-by: James Houghton <jthoughton@google.com>
Acked-by: Peter Xu <peterx@redhat.com>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
||
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Axel Rasmussen
|
61c5004022 |
mm: userfaultfd: don't pass around both mm and vma
Quite a few userfaultfd functions took both mm and vma pointers as arguments. Since the mm is trivially accessible via vma->vm_mm, there's no reason to pass both; it just needlessly extends the already long argument list. Get rid of the mm pointer, where possible, to shorten the argument list. Link: https://lkml.kernel.org/r/20230314221250.682452-3-axelrasmussen@google.com Signed-off-by: Axel Rasmussen <axelrasmussen@google.com> Acked-by: Peter Xu <peterx@redhat.com> Acked-by: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Hugh Dickins <hughd@google.com> Cc: James Houghton <jthoughton@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nadav Amit <namit@vmware.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Axel Rasmussen
|
a734991cca |
mm: userfaultfd: rename functions for clarity + consistency
Patch series "mm: userfaultfd: refactor and add UFFDIO_CONTINUE_MODE_WP",
v5.
- Commits 1-3 refactor userfaultfd ioctl code without behavior changes, with the
main goal of improving consistency and reducing the number of function args.
- Commit 4 adds UFFDIO_CONTINUE_MODE_WP.
This patch (of 4):
The basic problem is, over time we've added new userfaultfd ioctls, and
we've refactored the code so functions which used to handle only one case
are now re-used to deal with several cases. While this happened, we
didn't bother to rename the functions.
Similarly, as we added new functions, we cargo-culted pieces of the
now-inconsistent naming scheme, so those functions too ended up with names
that don't make a lot of sense.
A key point here is, "copy" in most userfaultfd code refers specifically
to UFFDIO_COPY, where we allocate a new page and copy its contents from
userspace. There are many functions with "copy" in the name that don't
actually do this (at least in some cases).
So, rename things into a consistent scheme. The high level idea is that
the call stack for userfaultfd ioctls becomes:
userfaultfd_ioctl
-> userfaultfd_(particular ioctl)
-> mfill_atomic_(particular kind of fill operation)
-> mfill_atomic /* loops over pages in range */
-> mfill_atomic_pte /* deals with single pages */
-> mfill_atomic_pte_(particular kind of fill operation)
-> mfill_atomic_install_pte
There are of course some special cases (shmem, hugetlb), but this is the
general structure which all function names now adhere to.
Link: https://lkml.kernel.org/r/20230314221250.682452-1-axelrasmussen@google.com
Link: https://lkml.kernel.org/r/20230314221250.682452-2-axelrasmussen@google.com
Signed-off-by: Axel Rasmussen <axelrasmussen@google.com>
Acked-by: Peter Xu <peterx@redhat.com>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Hugh Dickins <hughd@google.com>
Cc: James Houghton <jthoughton@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nadav Amit <namit@vmware.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
||
Muhammad Usama Anjum
|
a1b92a3f14 |
mm/userfaultfd: support WP on multiple VMAs
mwriteprotect_range() errors out if [start, end) doesn't fall in one VMA. We are facing a use case where multiple VMAs are present in one range of interest. For example, the following pseudocode reproduces the error which we are trying to fix: - Allocate memory of size 16 pages with PROT_NONE with mmap - Register userfaultfd - Change protection of the first half (1 to 8 pages) of memory to PROT_READ | PROT_WRITE. This breaks the memory area in two VMAs. - Now UFFDIO_WRITEPROTECT_MODE_WP on the whole memory of 16 pages errors out. This is a simple use case where user may or may not know if the memory area has been divided into multiple VMAs. We need an implementation which doesn't disrupt the already present users. So keeping things simple, stop going over all the VMAs if any one of the VMA hasn't been registered in WP mode. While at it, remove the un-needed error check as well. [akpm@linux-foundation.org: s/VM_WARN_ON_ONCE/VM_WARN_ONCE/ to fix build] Link: https://lkml.kernel.org/r/20230217105558.832710-1-usama.anjum@collabora.com Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com> Acked-by: Peter Xu <peterx@redhat.com> Acked-by: David Hildenbrand <david@redhat.com> Reported-by: Paul Gofman <pgofman@codeweavers.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
Peter Xu
|
d1751118c8 |
mm/uffd: detect pgtable allocation failures
Before this patch, when there's any pgtable allocation issues happened
during change_protection(), the error will be ignored from the syscall.
For shmem, there will be an error dumped into the host dmesg. Two issues
with that:
(1) Doing a trace dump when allocation fails is not anything close to
grace.
(2) The user should be notified with any kind of such error, so the user
can trap it and decide what to do next, either by retrying, or stop
the process properly, or anything else.
For userfault users, this will change the API of UFFDIO_WRITEPROTECT when
pgtable allocation failure happened. It should not normally break anyone,
though. If it breaks, then in good ways.
One man-page update will be on the way to introduce the new -ENOMEM for
UFFDIO_WRITEPROTECT. Not marking stable so we keep the old behavior on
the 5.19-till-now kernels.
[akpm@linux-foundation.org: coding-style cleanups]
Link: https://lkml.kernel.org/r/20230104225207.1066932-4-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Reported-by: James Houghton <jthoughton@google.com>
Acked-by: James Houghton <jthoughton@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|