Commit Graph

2603 Commits

Author SHA1 Message Date
Thomas Weißschuh
559d4c6a9d sysctl: avoid spurious permanent empty tables
The test if a table is a permanently empty one, inspects the address of
the registered ctl_table argument.
However as sysctl_mount_point is an empty array and does not occupy and
space it can end up sharing an address with another object in memory.
If that other object itself is a "struct ctl_table" then registering
that table will fail as it's incorrectly recognized as permanently empty.

Avoid this issue by adding a dummy element to the array so that is not
empty anymore.
Explicitly register the table with zero elements as otherwise the dummy
element would be recognized as a sentinel element which would lead to a
runtime warning from the sysctl core.

While the issue seems not being encountered at this time, this seems
mostly to be due to luck.
Also a future change, constifying sysctl_mount_point and root_table, can
reliably trigger this issue on clang 18.

Given that empty arrays are non-standard in the first place it seems
prudent to avoid them if possible.

Fixes: 4a7b29f650 ("sysctl: move sysctl type to ctl_table_header")
Fixes: a35dd3a786 ("sysctl: drop now unnecessary out-of-bounds check")
Cc: stable@vger.kernel.org
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Closes: https://lore.kernel.org/oe-lkp/202408051453.f638857e-lkp@intel.com
Signed-off-by: Joel Granados <j.granados@samsung.com>
2024-09-02 10:37:37 +02:00
Andrii Nakryiko
00bd8ec2f7 fs/procfs: remove build ID-related code duplication in PROCMAP_QUERY
A piece of build ID handling code in PROCMAP_QUERY ioctl() was
accidentally duplicated.  It wasn't meant to be part of ed5d583a88
("fs/procfs: implement efficient VMA querying API for /proc/<pid>/maps")
commit, which is what introduced duplication.

It has no correctness implications, but we unnecessarily perform the same
work twice, if build ID parsing is requested.  Drop the duplication.

Link: https://lkml.kernel.org/r/20240729174044.4008399-1-andrii@kernel.org
Fixes: ed5d583a88 ("fs/procfs: implement efficient VMA querying API for /proc/<pid>/maps")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reported-by: Jann Horn <jannh@google.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:43:30 -07:00
Matthew Wilcox (Oracle)
09022bc196 mm: remove PG_error
The PG_error bit is now unused; delete it and free up a bit in
page->flags.

Link: https://lkml.kernel.org/r/20240807193528.1865100-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:26:05 -07:00
Christian Brauner
641bb4394f fs: move FMODE_UNSIGNED_OFFSET to fop_flags
This is another flag that is statically set and doesn't need to use up
an FMODE_* bit. Move it to ->fop_flags and free up another FMODE_* bit.

(1) mem_open() used from proc_mem_operations
(2) adi_open() used from adi_fops
(3) drm_open_helper():
    (3.1) accel_open() used from DRM_ACCEL_FOPS
    (3.2) drm_open() used from
    (3.2.1) amdgpu_driver_kms_fops
    (3.2.2) psb_gem_fops
    (3.2.3) i915_driver_fops
    (3.2.4) nouveau_driver_fops
    (3.2.5) panthor_drm_driver_fops
    (3.2.6) radeon_driver_kms_fops
    (3.2.7) tegra_drm_fops
    (3.2.8) vmwgfx_driver_fops
    (3.2.9) xe_driver_fops
    (3.2.10) DRM_GEM_FOPS
    (3.2.11) DEFINE_DRM_GEM_DMA_FOPS
(4) struct memdev sets fmode flags based on type of device opened. For
    devices using struct mem_fops unsigned offset is used.

Mark all these file operations as FOP_UNSIGNED_OFFSET and add asserts
into the open helper to ensure that the flag is always set.

Link: https://lore.kernel.org/r/20240809-work-fop_unsigned-v1-1-658e054d893e@kernel.org
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-08-30 08:22:36 +02:00
Christian Brauner
d80b065bb1
Merge patch series "proc: restrict overmounting of ephemeral entities"
Christian Brauner <brauner@kernel.org> says:

It is currently possible to mount on top of various ephemeral entities
in procfs. This specifically includes magic links. To recap, magic links
are links of the form /proc/<pid>/fd/<nr>. They serve as references to
a target file and during path lookup they cause a jump to the target
path. Such magic links disappear if the corresponding file descriptor is
closed.

Currently it is possible to overmount such magic links:

int fd = open("/mnt/foo", O_RDONLY);
sprintf(path, "/proc/%d/fd/%d", getpid(), fd);
int fd2 = openat(AT_FDCWD, path, O_PATH | O_NOFOLLOW);
mount("/mnt/bar", path, "", MS_BIND, 0);

Arguably, this is nonsensical and is mostly interesting for an attacker
that wants to somehow trick a process into e.g., reopening something
that they didn't intend to reopen or to hide a malicious file
descriptor.

But also it risks leaking mounts for long-running processes. When
overmounting a magic link like above, the mount will not be detached
when the file descriptor is closed. Only the target mountpoint will
disappear. Which has the consequence of making it impossible to unmount
that mount afterwards. So the mount will stick around until the process
exits and the /proc/<pid>/ directory is cleaned up during
proc_flush_pid() when the dentries are pruned and invalidated.

That in turn means it's possible for a program to accidentally leak
mounts and it's also possible to make a task leak mounts without it's
knowledge if the attacker just keeps overmounting things under
/proc/<pid>/fd/<nr>.

I think it's wrong to try and fix this by us starting to play games with
close() or somewhere else to undo these mounts when the file descriptor
is closed. The fact that we allow overmounting of such magic links is
simply a bug and one that we need to fix.

Similar things can be said about entries under fdinfo/ and map_files/ so
those are restricted as well.

I have a further more aggressive patch that gets out the big hammer and
makes everything under /proc/<pid>/*, as well as immediate symlinks such
as /proc/self, /proc/thread-self, /proc/mounts, /proc/net that point
into /proc/<pid>/ not overmountable. Imho, all of this should be blocked
if we can get away with it. It's only useful to hide exploits such as in [1].

And again, overmounting of any global procfs files remains unaffected
and is an existing and supported use-case.

Link: https://righteousit.com/2024/07/24/hiding-linux-processes-with-bind-mounts [1]

// Note that repro uses the traditional way of just mounting over
// /proc/<pid>/fd/<nr>. This could also all be achieved just based on
// file descriptors using move_mount(). So /proc/<pid>/fd/<nr> isn't the
// only entry vector here. It's also possible to e.g., mount directly
// onto /proc/<pid>/map_files/* without going over /proc/<pid>/fd/<nr>.
int main(int argc, char *argv[])
{
        char path[PATH_MAX];

        creat("/mnt/foo", 0777);
        creat("/mnt/bar", 0777);

        /*
         * For illustration use a bunch of file descriptors in the upper
         * range that are unused.
         */
        for (int i = 10000; i >= 256; i--) {
                printf("I'm: /proc/%d/\n", getpid());

                int fd2 = open("/mnt/foo", O_RDONLY);
                if (fd2 < 0) {
                        printf("%m - Failed to open\n");
                        _exit(1);
                }

                int newfd = dup2(fd2, i);
                if (newfd < 0) {
                        printf("%m - Failed to dup\n");
                        _exit(1);
                }
                close(fd2);

                sprintf(path, "/proc/%d/fd/%d", getpid(), newfd);
                int fd = openat(AT_FDCWD, path, O_PATH | O_NOFOLLOW);
                if (fd < 0) {
                        printf("%m - Failed to open\n");
                        _exit(3);
                }

                sprintf(path, "/proc/%d/fd/%d", getpid(), fd);
                printf("Mounting on top of %s\n", path);
                if (mount("/mnt/bar", path, "", MS_BIND, 0)) {
                        printf("%m - Failed to mount\n");
                        _exit(4);
                }

                close(newfd);
                close(fd2);
        }

        /*
         * Give some time to look at things. The mounts now linger until
         * the process exits.
         */
        sleep(10000);
        _exit(0);
}

* patches from https://lore.kernel.org/r/20240806-work-procfs-v1-0-fb04e1d09f0c@kernel.org:
  proc: block mounting on top of /proc/<pid>/fdinfo/*
  proc: block mounting on top of /proc/<pid>/fd/*
  proc: block mounting on top of /proc/<pid>/map_files/*
  proc: add proc_splice_unmountable()
  proc: proc_readfdinfo() -> proc_fdinfo_iterate()
  proc: proc_readfd() -> proc_fd_iterate()

Link: https://lore.kernel.org/r/20240806-work-procfs-v1-0-fb04e1d09f0c@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-08-30 08:22:13 +02:00
Christian Brauner
cf71eaa1ad
proc: block mounting on top of /proc/<pid>/fdinfo/*
Entries under /proc/<pid>/fdinfo/* are ephemeral and may go away before
the process dies. As such allowing them to be used as mount points
creates the ability to leak mounts that linger until the process dies
with no ability to unmount them until then. Don't allow using them as
mountpoints.

Link: https://lore.kernel.org/r/20240806-work-procfs-v1-6-fb04e1d09f0c@kernel.org
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-08-30 08:22:13 +02:00
Christian Brauner
74ce208089
proc: block mounting on top of /proc/<pid>/fd/*
Entries under /proc/<pid>/fd/* are ephemeral and may go away before the
process dies. As such allowing them to be used as mount points creates
the ability to leak mounts that linger until the process dies with no
ability to unmount them until then. Don't allow using them as
mountpoints.

Link: https://lore.kernel.org/r/20240806-work-procfs-v1-5-fb04e1d09f0c@kernel.org
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-08-30 08:22:13 +02:00
Christian Brauner
3836b31c3e
proc: block mounting on top of /proc/<pid>/map_files/*
Entries under /proc/<pid>/map_files/* are ephemeral and may go away
before the process dies. As such allowing them to be used as mount
points creates the ability to leak mounts that linger until the process
dies with no ability to unmount them until then. Don't allow using them
as mountpoints.

Link: https://lore.kernel.org/r/20240806-work-procfs-v1-4-fb04e1d09f0c@kernel.org
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-08-30 08:22:12 +02:00
Christian Brauner
32a0a965b8
proc: add proc_splice_unmountable()
Add a tiny procfs helper to splice a dentry that cannot be mounted upon.

Link: https://lore.kernel.org/r/20240806-work-procfs-v1-3-fb04e1d09f0c@kernel.org
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-08-30 08:22:12 +02:00
Christian Brauner
55d4860db2
proc: proc_readfdinfo() -> proc_fdinfo_iterate()
Give the method to iterate through the fdinfo directory a better name.

Link: https://lore.kernel.org/r/20240806-work-procfs-v1-2-fb04e1d09f0c@kernel.org
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-08-30 08:22:05 +02:00
Christian Brauner
b69181b871
proc: proc_readfd() -> proc_fd_iterate()
Give the method to iterate through the fd directory a better name.

Link: https://lore.kernel.org/r/20240806-work-procfs-v1-1-fb04e1d09f0c@kernel.org
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-08-30 08:21:34 +02:00
Adrian Ratiu
41e8149c88
proc: add config & param to block forcing mem writes
This adds a Kconfig option and boot param to allow removing
the FOLL_FORCE flag from /proc/pid/mem write calls because
it can be abused.

The traditional forcing behavior is kept as default because
it can break GDB and some other use cases.

Previously we tried a more sophisticated approach allowing
distributions to fine-tune /proc/pid/mem behavior, however
that got NAK-ed by Linus [1], who prefers this simpler
approach with semantics also easier to understand for users.

Link: https://lore.kernel.org/lkml/CAHk-=wiGWLChxYmUA5HrT5aopZrB7_2VTa0NLZcxORgkUe5tEQ@mail.gmail.com/ [1]
Cc: Doug Anderson <dianders@chromium.org>
Cc: Jeff Xu <jeffxu@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Adrian Ratiu <adrian.ratiu@collabora.com>
Link: https://lore.kernel.org/r/20240802080225.89408-1-adrian.ratiu@collabora.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-08-30 08:19:43 +02:00
Felix Moessbauer
ed4fb6d7ef hrtimer: Use and report correct timerslack values for realtime tasks
The timerslack_ns setting is used to specify how much the hardware
timers should be delayed, to potentially dispatch multiple timers in a
single interrupt. This is a performance optimization. Timers of
realtime tasks (having a realtime scheduling policy) should not be
delayed.

This logic was inconsitently applied to the hrtimers, leading to delays
of realtime tasks which used timed waits for events (e.g. condition
variables). Due to the downstream override of the slack for rt tasks,
the procfs reported incorrect (non-zero) timerslack_ns values.

This is changed by setting the timer_slack_ns task attribute to 0 for
all tasks with a rt policy. By that, downstream users do not need to
specially handle rt tasks (w.r.t. the slack), and the procfs entry
shows the correct value of "0". Setting non-zero slack values (either
via procfs or PR_SET_TIMERSLACK) on tasks with a rt policy is ignored,
as stated in "man 2 PR_SET_TIMERSLACK":

  Timer slack is not applied to threads that are scheduled under a
  real-time scheduling policy (see sched_setscheduler(2)).

The special handling of timerslack on rt tasks in downstream users
is removed as well.

Signed-off-by: Felix Moessbauer <felix.moessbauer@siemens.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20240814121032.368444-2-felix.moessbauer@siemens.com
2024-08-23 20:13:02 +02:00
Thomas Gleixner
52dea0a15c posix-timers: Convert timer list to hlist
No requirement for a real list. Spare a few bytes.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2024-07-29 21:57:35 +02:00
Linus Torvalds
7a3fad30fd Random number generator updates for Linux 6.11-rc1.
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Merge tag 'random-6.11-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random

Pull random number generator updates from Jason Donenfeld:
 "This adds getrandom() support to the vDSO.

  First, it adds a new kind of mapping to mmap(2), MAP_DROPPABLE, which
  lets the kernel zero out pages anytime under memory pressure, which
  enables allocating memory that never gets swapped to disk but also
  doesn't count as being mlocked.

  Then, the vDSO implementation of getrandom() is introduced in a
  generic manner and hooked into random.c.

  Next, this is implemented on x86. (Also, though it's not ready for
  this pull, somebody has begun an arm64 implementation already)

  Finally, two vDSO selftests are added.

  There are also two housekeeping cleanup commits"

* tag 'random-6.11-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random:
  MAINTAINERS: add random.h headers to RNG subsection
  random: note that RNDGETPOOL was removed in 2.6.9-rc2
  selftests/vDSO: add tests for vgetrandom
  x86: vdso: Wire up getrandom() vDSO implementation
  random: introduce generic vDSO getrandom() implementation
  mm: add MAP_DROPPABLE for designating always lazily freeable mappings
2024-07-24 10:29:50 -07:00
Linus Torvalds
fbc90c042c - 875fa64577da ("mm/hugetlb_vmemmap: fix race with speculative PFN
walkers") is known to cause a performance regression
   (https://lore.kernel.org/all/3acefad9-96e5-4681-8014-827d6be71c7a@linux.ibm.com/T/#mfa809800a7862fb5bdf834c6f71a3a5113eb83ff).
   Yu has a fix which I'll send along later via the hotfixes branch.
 
 - In the series "mm: Avoid possible overflows in dirty throttling" Jan
   Kara addresses a couple of issues in the writeback throttling code.
   These fixes are also targetted at -stable kernels.
 
 - Ryusuke Konishi's series "nilfs2: fix potential issues related to
   reserved inodes" does that.  This should actually be in the
   mm-nonmm-stable tree, along with the many other nilfs2 patches.  My bad.
 
 - More folio conversions from Kefeng Wang in the series "mm: convert to
   folio_alloc_mpol()"
 
 - Kemeng Shi has sent some cleanups to the writeback code in the series
   "Add helper functions to remove repeated code and improve readability of
   cgroup writeback"
 
 - Kairui Song has made the swap code a little smaller and a little
   faster in the series "mm/swap: clean up and optimize swap cache index".
 
 - In the series "mm/memory: cleanly support zeropage in
   vm_insert_page*(), vm_map_pages*() and vmf_insert_mixed()" David
   Hildenbrand has reworked the rather sketchy handling of the use of the
   zeropage in MAP_SHARED mappings.  I don't see any runtime effects here -
   more a cleanup/understandability/maintainablity thing.
 
 - Dev Jain has improved selftests/mm/va_high_addr_switch.c's handling of
   higher addresses, for aarch64.  The (poorly named) series is
   "Restructure va_high_addr_switch".
 
 - The core TLB handling code gets some cleanups and possible slight
   optimizations in Bang Li's series "Add update_mmu_tlb_range() to
   simplify code".
 
 - Jane Chu has improved the handling of our
   fake-an-unrecoverable-memory-error testing feature MADV_HWPOISON in the
   series "Enhance soft hwpoison handling and injection".
 
 - Jeff Johnson has sent a billion patches everywhere to add
   MODULE_DESCRIPTION() to everything.  Some landed in this pull.
 
 - In the series "mm: cleanup MIGRATE_SYNC_NO_COPY mode", Kefeng Wang has
   simplified migration's use of hardware-offload memory copying.
 
 - Yosry Ahmed performs more folio API conversions in his series "mm:
   zswap: trivial folio conversions".
 
 - In the series "large folios swap-in: handle refault cases first",
   Chuanhua Han inches us forward in the handling of large pages in the
   swap code.  This is a cleanup and optimization, working toward the end
   objective of full support of large folio swapin/out.
 
 - In the series "mm,swap: cleanup VMA based swap readahead window
   calculation", Huang Ying has contributed some cleanups and a possible
   fixlet to his VMA based swap readahead code.
 
 - In the series "add mTHP support for anonymous shmem" Baolin Wang has
   taught anonymous shmem mappings to use multisize THP.  By default this
   is a no-op - users must opt in vis sysfs controls.  Dramatic
   improvements in pagefault latency are realized.
 
 - David Hildenbrand has some cleanups to our remaining use of
   page_mapcount() in the series "fs/proc: move page_mapcount() to
   fs/proc/internal.h".
 
 - David also has some highmem accounting cleanups in the series
   "mm/highmem: don't track highmem pages manually".
 
 - Build-time fixes and cleanups from John Hubbard in the series
   "cleanups, fixes, and progress towards avoiding "make headers"".
 
 - Cleanups and consolidation of the core pagemap handling from Barry
   Song in the series "mm: introduce pmd|pte_needs_soft_dirty_wp helpers
   and utilize them".
 
 - Lance Yang's series "Reclaim lazyfree THP without splitting" has
   reduced the latency of the reclaim of pmd-mapped THPs under fairly
   common circumstances.  A 10x speedup is seen in a microbenchmark.
 
   It does this by punting to aother CPU but I guess that's a win unless
   all CPUs are pegged.
 
 - hugetlb_cgroup cleanups from Xiu Jianfeng in the series
   "mm/hugetlb_cgroup: rework on cftypes".
 
 - Miaohe Lin's series "Some cleanups for memory-failure" does just that
   thing.
 
 - Is anyone reading this stuff?  If so, email me!
 
 - Someone other than SeongJae has developed a DAMON feature in Honggyu
   Kim's series "DAMON based tiered memory management for CXL memory".
   This adds DAMON features which may be used to help determine the
   efficiency of our placement of CXL/PCIe attached DRAM.
 
 - DAMON user API centralization and simplificatio work in SeongJae
   Park's series "mm/damon: introduce DAMON parameters online commit
   function".
 
 - In the series "mm: page_type, zsmalloc and page_mapcount_reset()"
   David Hildenbrand does some maintenance work on zsmalloc - partially
   modernizing its use of pageframe fields.
 
 - Kefeng Wang provides more folio conversions in the series "mm: remove
   page_maybe_dma_pinned() and page_mkclean()".
 
 - More cleanup from David Hildenbrand, this time in the series
   "mm/memory_hotplug: use PageOffline() instead of PageReserved() for
   !ZONE_DEVICE".  It "enlightens memory hotplug more about PageOffline()
   pages" and permits the removal of some virtio-mem hacks.
 
 - Barry Song's series "mm: clarify folio_add_new_anon_rmap() and
   __folio_add_anon_rmap()" is a cleanup to the anon folio handling in
   preparation for mTHP (multisize THP) swapin.
 
 - Kefeng Wang's series "mm: improve clear and copy user folio"
   implements more folio conversions, this time in the area of large folio
   userspace copying.
 
 - The series "Docs/mm/damon/maintaier-profile: document a mailing tool
   and community meetup series" tells people how to get better involved
   with other DAMON developers.  From SeongJae Park.
 
 - A large series ("kmsan: Enable on s390") from Ilya Leoshkevich does
   that.
 
 - David Hildenbrand sends along more cleanups, this time against the
   migration code.  The series is "mm/migrate: move NUMA hinting fault
   folio isolation + checks under PTL".
 
 - Jan Kara has found quite a lot of strangenesses and minor errors in
   the readahead code.  He addresses this in the series "mm: Fix various
   readahead quirks".
 
 - SeongJae Park's series "selftests/damon: test DAMOS tried regions and
   {min,max}_nr_regions" adds features and addresses errors in DAMON's self
   testing code.
 
 - Gavin Shan has found a userspace-triggerable WARN in the pagecache
   code.  The series "mm/filemap: Limit page cache size to that supported
   by xarray" addresses this.  The series is marked cc:stable.
 
 - Chengming Zhou's series "mm/ksm: cmp_and_merge_page() optimizations
   and cleanup" cleans up and slightly optimizes KSM.
 
 - Roman Gushchin has separated the memcg-v1 and memcg-v2 code - lots of
   code motion.  The series (which also makes the memcg-v1 code
   Kconfigurable) are
 
   "mm: memcg: separate legacy cgroup v1 code and put under config
   option" and
   "mm: memcg: put cgroup v1-specific memcg data under CONFIG_MEMCG_V1"
 
 - Dan Schatzberg's series "Add swappiness argument to memory.reclaim"
   adds an additional feature to this cgroup-v2 control file.
 
 - The series "Userspace controls soft-offline pages" from Jiaqi Yan
   permits userspace to stop the kernel's automatic treatment of excessive
   correctable memory errors.  In order to permit userspace to monitor and
   handle this situation.
 
 - Kefeng Wang's series "mm: migrate: support poison recover from migrate
   folio" teaches the kernel to appropriately handle migration from
   poisoned source folios rather than simply panicing.
 
 - SeongJae Park's series "Docs/damon: minor fixups and improvements"
   does those things.
 
 - In the series "mm/zsmalloc: change back to per-size_class lock"
   Chengming Zhou improves zsmalloc's scalability and memory utilization.
 
 - Vivek Kasireddy's series "mm/gup: Introduce memfd_pin_folios() for
   pinning memfd folios" makes the GUP code use FOLL_PIN rather than bare
   refcount increments.  So these paes can first be moved aside if they
   reside in the movable zone or a CMA block.
 
 - Andrii Nakryiko has added a binary ioctl()-based API to /proc/pid/maps
   for much faster reading of vma information.  The series is "query VMAs
   from /proc/<pid>/maps".
 
 - In the series "mm: introduce per-order mTHP split counters" Lance Yang
   improves the kernel's presentation of developer information related to
   multisize THP splitting.
 
 - Michael Ellerman has developed the series "Reimplement huge pages
   without hugepd on powerpc (8xx, e500, book3s/64)".  This permits
   userspace to use all available huge page sizes.
 
 - In the series "revert unconditional slab and page allocator fault
   injection calls" Vlastimil Babka removes a performance-affecting and not
   very useful feature from slab fault injection.
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Merge tag 'mm-stable-2024-07-21-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - In the series "mm: Avoid possible overflows in dirty throttling" Jan
   Kara addresses a couple of issues in the writeback throttling code.
   These fixes are also targetted at -stable kernels.

 - Ryusuke Konishi's series "nilfs2: fix potential issues related to
   reserved inodes" does that. This should actually be in the
   mm-nonmm-stable tree, along with the many other nilfs2 patches. My
   bad.

 - More folio conversions from Kefeng Wang in the series "mm: convert to
   folio_alloc_mpol()"

 - Kemeng Shi has sent some cleanups to the writeback code in the series
   "Add helper functions to remove repeated code and improve readability
   of cgroup writeback"

 - Kairui Song has made the swap code a little smaller and a little
   faster in the series "mm/swap: clean up and optimize swap cache
   index".

 - In the series "mm/memory: cleanly support zeropage in
   vm_insert_page*(), vm_map_pages*() and vmf_insert_mixed()" David
   Hildenbrand has reworked the rather sketchy handling of the use of
   the zeropage in MAP_SHARED mappings. I don't see any runtime effects
   here - more a cleanup/understandability/maintainablity thing.

 - Dev Jain has improved selftests/mm/va_high_addr_switch.c's handling
   of higher addresses, for aarch64. The (poorly named) series is
   "Restructure va_high_addr_switch".

 - The core TLB handling code gets some cleanups and possible slight
   optimizations in Bang Li's series "Add update_mmu_tlb_range() to
   simplify code".

 - Jane Chu has improved the handling of our
   fake-an-unrecoverable-memory-error testing feature MADV_HWPOISON in
   the series "Enhance soft hwpoison handling and injection".

 - Jeff Johnson has sent a billion patches everywhere to add
   MODULE_DESCRIPTION() to everything. Some landed in this pull.

 - In the series "mm: cleanup MIGRATE_SYNC_NO_COPY mode", Kefeng Wang
   has simplified migration's use of hardware-offload memory copying.

 - Yosry Ahmed performs more folio API conversions in his series "mm:
   zswap: trivial folio conversions".

 - In the series "large folios swap-in: handle refault cases first",
   Chuanhua Han inches us forward in the handling of large pages in the
   swap code. This is a cleanup and optimization, working toward the end
   objective of full support of large folio swapin/out.

 - In the series "mm,swap: cleanup VMA based swap readahead window
   calculation", Huang Ying has contributed some cleanups and a possible
   fixlet to his VMA based swap readahead code.

 - In the series "add mTHP support for anonymous shmem" Baolin Wang has
   taught anonymous shmem mappings to use multisize THP. By default this
   is a no-op - users must opt in vis sysfs controls. Dramatic
   improvements in pagefault latency are realized.

 - David Hildenbrand has some cleanups to our remaining use of
   page_mapcount() in the series "fs/proc: move page_mapcount() to
   fs/proc/internal.h".

 - David also has some highmem accounting cleanups in the series
   "mm/highmem: don't track highmem pages manually".

 - Build-time fixes and cleanups from John Hubbard in the series
   "cleanups, fixes, and progress towards avoiding "make headers"".

 - Cleanups and consolidation of the core pagemap handling from Barry
   Song in the series "mm: introduce pmd|pte_needs_soft_dirty_wp helpers
   and utilize them".

 - Lance Yang's series "Reclaim lazyfree THP without splitting" has
   reduced the latency of the reclaim of pmd-mapped THPs under fairly
   common circumstances. A 10x speedup is seen in a microbenchmark.

   It does this by punting to aother CPU but I guess that's a win unless
   all CPUs are pegged.

 - hugetlb_cgroup cleanups from Xiu Jianfeng in the series
   "mm/hugetlb_cgroup: rework on cftypes".

 - Miaohe Lin's series "Some cleanups for memory-failure" does just that
   thing.

 - Someone other than SeongJae has developed a DAMON feature in Honggyu
   Kim's series "DAMON based tiered memory management for CXL memory".
   This adds DAMON features which may be used to help determine the
   efficiency of our placement of CXL/PCIe attached DRAM.

 - DAMON user API centralization and simplificatio work in SeongJae
   Park's series "mm/damon: introduce DAMON parameters online commit
   function".

 - In the series "mm: page_type, zsmalloc and page_mapcount_reset()"
   David Hildenbrand does some maintenance work on zsmalloc - partially
   modernizing its use of pageframe fields.

 - Kefeng Wang provides more folio conversions in the series "mm: remove
   page_maybe_dma_pinned() and page_mkclean()".

 - More cleanup from David Hildenbrand, this time in the series
   "mm/memory_hotplug: use PageOffline() instead of PageReserved() for
   !ZONE_DEVICE". It "enlightens memory hotplug more about PageOffline()
   pages" and permits the removal of some virtio-mem hacks.

 - Barry Song's series "mm: clarify folio_add_new_anon_rmap() and
   __folio_add_anon_rmap()" is a cleanup to the anon folio handling in
   preparation for mTHP (multisize THP) swapin.

 - Kefeng Wang's series "mm: improve clear and copy user folio"
   implements more folio conversions, this time in the area of large
   folio userspace copying.

 - The series "Docs/mm/damon/maintaier-profile: document a mailing tool
   and community meetup series" tells people how to get better involved
   with other DAMON developers. From SeongJae Park.

 - A large series ("kmsan: Enable on s390") from Ilya Leoshkevich does
   that.

 - David Hildenbrand sends along more cleanups, this time against the
   migration code. The series is "mm/migrate: move NUMA hinting fault
   folio isolation + checks under PTL".

 - Jan Kara has found quite a lot of strangenesses and minor errors in
   the readahead code. He addresses this in the series "mm: Fix various
   readahead quirks".

 - SeongJae Park's series "selftests/damon: test DAMOS tried regions and
   {min,max}_nr_regions" adds features and addresses errors in DAMON's
   self testing code.

 - Gavin Shan has found a userspace-triggerable WARN in the pagecache
   code. The series "mm/filemap: Limit page cache size to that supported
   by xarray" addresses this. The series is marked cc:stable.

 - Chengming Zhou's series "mm/ksm: cmp_and_merge_page() optimizations
   and cleanup" cleans up and slightly optimizes KSM.

 - Roman Gushchin has separated the memcg-v1 and memcg-v2 code - lots of
   code motion. The series (which also makes the memcg-v1 code
   Kconfigurable) are "mm: memcg: separate legacy cgroup v1 code and put
   under config option" and "mm: memcg: put cgroup v1-specific memcg
   data under CONFIG_MEMCG_V1"

 - Dan Schatzberg's series "Add swappiness argument to memory.reclaim"
   adds an additional feature to this cgroup-v2 control file.

 - The series "Userspace controls soft-offline pages" from Jiaqi Yan
   permits userspace to stop the kernel's automatic treatment of
   excessive correctable memory errors. In order to permit userspace to
   monitor and handle this situation.

 - Kefeng Wang's series "mm: migrate: support poison recover from
   migrate folio" teaches the kernel to appropriately handle migration
   from poisoned source folios rather than simply panicing.

 - SeongJae Park's series "Docs/damon: minor fixups and improvements"
   does those things.

 - In the series "mm/zsmalloc: change back to per-size_class lock"
   Chengming Zhou improves zsmalloc's scalability and memory
   utilization.

 - Vivek Kasireddy's series "mm/gup: Introduce memfd_pin_folios() for
   pinning memfd folios" makes the GUP code use FOLL_PIN rather than
   bare refcount increments. So these paes can first be moved aside if
   they reside in the movable zone or a CMA block.

 - Andrii Nakryiko has added a binary ioctl()-based API to
   /proc/pid/maps for much faster reading of vma information. The series
   is "query VMAs from /proc/<pid>/maps".

 - In the series "mm: introduce per-order mTHP split counters" Lance
   Yang improves the kernel's presentation of developer information
   related to multisize THP splitting.

 - Michael Ellerman has developed the series "Reimplement huge pages
   without hugepd on powerpc (8xx, e500, book3s/64)". This permits
   userspace to use all available huge page sizes.

 - In the series "revert unconditional slab and page allocator fault
   injection calls" Vlastimil Babka removes a performance-affecting and
   not very useful feature from slab fault injection.

* tag 'mm-stable-2024-07-21-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (411 commits)
  mm/mglru: fix ineffective protection calculation
  mm/zswap: fix a white space issue
  mm/hugetlb: fix kernel NULL pointer dereference when migrating hugetlb folio
  mm/hugetlb: fix possible recursive locking detected warning
  mm/gup: clear the LRU flag of a page before adding to LRU batch
  mm/numa_balancing: teach mpol_to_str about the balancing mode
  mm: memcg1: convert charge move flags to unsigned long long
  alloc_tag: fix page_ext_get/page_ext_put sequence during page splitting
  lib: reuse page_ext_data() to obtain codetag_ref
  lib: add missing newline character in the warning message
  mm/mglru: fix overshooting shrinker memory
  mm/mglru: fix div-by-zero in vmpressure_calc_level()
  mm/kmemleak: replace strncpy() with strscpy()
  mm, page_alloc: put should_fail_alloc_page() back behing CONFIG_FAIL_PAGE_ALLOC
  mm, slab: put should_failslab() back behind CONFIG_SHOULD_FAILSLAB
  mm: ignore data-race in __swap_writepage
  hugetlbfs: ensure generic_hugetlb_get_unmapped_area() returns higher address than mmap_min_addr
  mm: shmem: rename mTHP shmem counters
  mm: swap_state: use folio_alloc_mpol() in __read_swap_cache_async()
  mm/migrate: putback split folios when numa hint migration fails
  ...
2024-07-21 17:15:46 -07:00
Jason A. Donenfeld
9651fcedf7 mm: add MAP_DROPPABLE for designating always lazily freeable mappings
The vDSO getrandom() implementation works with a buffer allocated with a
new system call that has certain requirements:

- It shouldn't be written to core dumps.
  * Easy: VM_DONTDUMP.
- It should be zeroed on fork.
  * Easy: VM_WIPEONFORK.

- It shouldn't be written to swap.
  * Uh-oh: mlock is rlimited.
  * Uh-oh: mlock isn't inherited by forks.

- It shouldn't reserve actual memory, but it also shouldn't crash when
  page faulting in memory if none is available
  * Uh-oh: VM_NORESERVE means segfaults.

It turns out that the vDSO getrandom() function has three really nice
characteristics that we can exploit to solve this problem:

1) Due to being wiped during fork(), the vDSO code is already robust to
   having the contents of the pages it reads zeroed out midway through
   the function's execution.

2) In the absolute worst case of whatever contingency we're coding for,
   we have the option to fallback to the getrandom() syscall, and
   everything is fine.

3) The buffers the function uses are only ever useful for a maximum of
   60 seconds -- a sort of cache, rather than a long term allocation.

These characteristics mean that we can introduce VM_DROPPABLE, which
has the following semantics:

a) It never is written out to swap.
b) Under memory pressure, mm can just drop the pages (so that they're
   zero when read back again).
c) It is inherited by fork.
d) It doesn't count against the mlock budget, since nothing is locked.
e) If there's not enough memory to service a page fault, it's not fatal,
   and no signal is sent.

This way, allocations used by vDSO getrandom() can use:

    VM_DROPPABLE | VM_DONTDUMP | VM_WIPEONFORK | VM_NORESERVE

And there will be no problem with OOMing, crashing on overcommitment,
using memory when not in use, not wiping on fork(), coredumps, or
writing out to swap.

In order to let vDSO getrandom() use this, expose these via mmap(2) as
MAP_DROPPABLE.

Note that this involves removing the MADV_FREE special case from
sort_folio(), which according to Yu Zhao is unnecessary and will simply
result in an extra call to shrink_folio_list() in the worst case. The
chunk removed reenables the swapbacked flag, which we don't want for
VM_DROPPABLE, and we can't conditionalize it here because there isn't a
vma reference available.

Finally, the provided self test ensures that this is working as desired.

Cc: linux-mm@kvack.org
Acked-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2024-07-19 20:22:12 +02:00
Linus Torvalds
f8a8b94d06 sysctl changes for 6.11-rc1
Summary
 
 * Remove "->procname == NULL" check when iterating through sysctl table arrays
 
     Removing sentinels in ctl_table arrays reduces the build time size and
     runtime memory consumed by ~64 bytes per array. With all ctl_table
     sentinels gone, the additional check for ->procname == NULL that worked in
     tandem with the ARRAY_SIZE to calculate the size of the ctl_table arrays is
     no longer needed and has been removed. The sysctl register functions now
     returns an error if a sentinel is used.
 
 * Preparation patches for sysctl constification
 
     Constifying ctl_table structs prevents the modification of proc_handler
     function pointers as they would reside in .rodata. The ctl_table arguments
     in sysctl utility functions are const qualified in preparation for a future
     treewide proc_handler argument constification commit.
 
 * Misc fixes
 
     Increase robustness of set_ownership by providing sane default ownership
     values in case the callee doesn't set them. Bound check proc_dou8vec_minmax
     to avoid loading buggy modules and give sysctl testing module a name to
     avoid compiler complaints.
 
 Testing
 
   * This got push to linux-next in v6.10-rc2, so it has had more than a month
     of testing
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Merge tag 'sysctl-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl

Pull sysctl updates from Joel Granados:

 - Remove "->procname == NULL" check when iterating through sysctl table
   arrays

   Removing sentinels in ctl_table arrays reduces the build time size
   and runtime memory consumed by ~64 bytes per array. With all
   ctl_table sentinels gone, the additional check for ->procname == NULL
   that worked in tandem with the ARRAY_SIZE to calculate the size of
   the ctl_table arrays is no longer needed and has been removed. The
   sysctl register functions now returns an error if a sentinel is used.

 - Preparation patches for sysctl constification

   Constifying ctl_table structs prevents the modification of
   proc_handler function pointers as they would reside in .rodata. The
   ctl_table arguments in sysctl utility functions are const qualified
   in preparation for a future treewide proc_handler argument
   constification commit.

 - Misc fixes

   Increase robustness of set_ownership by providing sane default
   ownership values in case the callee doesn't set them. Bound check
   proc_dou8vec_minmax to avoid loading buggy modules and give sysctl
   testing module a name to avoid compiler complaints.

* tag 'sysctl-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl:
  sysctl: Warn on an empty procname element
  sysctl: Remove ctl_table sentinel code comments
  sysctl: Remove "child" sysctl code comments
  sysctl: Remove superfluous empty allocations from sysctl internals
  sysctl: Replace nr_entries with ctl_table_size in new_links
  sysctl: Remove check for sentinel element in ctl_table arrays
  mm profiling: Remove superfluous sentinel element from ctl_table
  locking: Remove superfluous sentinel element from kern_lockdep_table
  sysctl: Add module description to sysctl-testing
  sysctl: constify ctl_table arguments of utility function
  utsname: constify ctl_table arguments of utility function
  sysctl: move the extra1/2 boundary check of u8 to sysctl_check_table_array
  sysctl: always initialize i_uid/i_gid
2024-07-16 14:24:29 -07:00
Linus Torvalds
b051320d6a vfs-6.11.misc
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Merge tag 'vfs-6.11.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull misc vfs updates from Christian Brauner:
 "Features:

   - Support passing NULL along AT_EMPTY_PATH for statx().

     NULL paths with any flag value other than AT_EMPTY_PATH go the
     usual route and end up with -EFAULT to retain compatibility (Rust
     is abusing calls of the sort to detect availability of statx)

     This avoids path lookup code, lockref management, memory allocation
     and in case of NULL path userspace memory access (which can be
     quite expensive with SMAP on x86_64)

   - Don't block i_writecount during exec. Remove the
     deny_write_access() mechanism for executables

   - Relax open_by_handle_at() permissions in specific cases where we
     can prove that the caller had sufficient privileges to open a file

   - Switch timespec64 fields in struct inode to discrete integers
     freeing up 4 bytes

  Fixes:

   - Fix false positive circular locking warning in hfsplus

   - Initialize hfs_inode_info after hfs_alloc_inode() in hfs

   - Avoid accidental overflows in vfs_fallocate()

   - Don't interrupt fallocate with EINTR in tmpfs to avoid constantly
     restarting shmem_fallocate()

   - Add missing quote in comment in fs/readdir

  Cleanups:

   - Don't assign and test in an if statement in mqueue. Move the
     assignment out of the if statement

   - Reflow the logic in may_create_in_sticky()

   - Remove the usage of the deprecated ida_simple_xx() API from procfs

   - Reject FSCONFIG_CMD_CREATE_EXCL requets that depend on the new
     mount api early

   - Rename variables in copy_tree() to make it easier to understand

   - Replace WARN(down_read_trylock, ...) abuse with proper asserts in
     various places in the VFS

   - Get rid of user_path_at_empty() and drop the empty argument from
     getname_flags()

   - Check for error while copying and no path in one branch in
     getname_flags()

   - Avoid redundant smp_mb() for THP handling in do_dentry_open()

   - Rename parent_ino to d_parent_ino and make it use RCU

   - Remove unused header include in fs/readdir

   - Export in_group_capable() helper and switch f2fs and fuse over to
     it instead of open-coding the logic in both places"

* tag 'vfs-6.11.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (27 commits)
  ipc: mqueue: remove assignment from IS_ERR argument
  vfs: rename parent_ino to d_parent_ino and make it use RCU
  vfs: support statx(..., NULL, AT_EMPTY_PATH, ...)
  stat: use vfs_empty_path() helper
  fs: new helper vfs_empty_path()
  fs: reflow may_create_in_sticky()
  vfs: remove redundant smp_mb for thp handling in do_dentry_open
  fuse: Use in_group_or_capable() helper
  f2fs: Use in_group_or_capable() helper
  fs: Export in_group_or_capable()
  vfs: reorder checks in may_create_in_sticky
  hfs: fix to initialize fields of hfs_inode_info after hfs_alloc_inode()
  proc: Remove usage of the deprecated ida_simple_xx() API
  hfsplus: fix to avoid false alarm of circular locking
  Improve readability of copy_tree
  vfs: shave a branch in getname_flags
  vfs: retire user_path_at_empty and drop empty arg from getname_flags
  vfs: stop using user_path_at_empty in do_readlinkat
  tmpfs: don't interrupt fallocate with EINTR
  fs: don't block i_writecount during exec
  ...
2024-07-15 10:52:51 -07:00
Ran Xiaokai
4c8763e84a kpageflags: detect isolated KPF_THP folios
When folio is isolated, the PG_lru bit is cleared.  So the PG_lru check in
stable_page_flags() will miss this kind of isolated folios.  Use
folio_test_large_rmappable() instead to also include isolated folios.

Since pagecache supports large folios and the introduction of mTHP, the
semantics of KPF_THP have been expanded, now it indicates not only
PMD-sized THP.  Update related documentation to clearly state that KPF_THP
indicates multiple order THPs.

[ran.xiaokai@zte.com.cn: directly use is_zero_folio(), per David]
  Link: https://lkml.kernel.org/r/20240708062601.165215-1-ranxiaokai627@163.com
Link: https://lkml.kernel.org/r/20240705104343.112680-1-ranxiaokai627@163.com
Signed-off-by: Ran Xiaokai <ran.xiaokai@zte.com.cn>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Andrei Vagin <avagin@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Svetly Todorov <svetly.todorov@memverge.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-12 15:52:21 -07:00
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>
2024-07-12 15:52:15 -07:00
Andrii Nakryiko
bfc69fd05e fs/procfs: add build ID fetching to PROCMAP_QUERY API
The need to get ELF build ID reliably is an important aspect when dealing
with profiling and stack trace symbolization, and /proc/<pid>/maps textual
representation doesn't help with this.

To get backing file's ELF build ID, application has to first resolve VMA,
then use it's start/end address range to follow a special
/proc/<pid>/map_files/<start>-<end> symlink to open the ELF file (this is
necessary because backing file might have been removed from the disk or
was already replaced with another binary in the same file path.

Such approach, beyond just adding complexity of having to do a bunch of
extra work, has extra security implications.  Because application opens
underlying ELF file and needs read access to its entire contents (as far
as kernel is concerned), kernel puts additional capable() checks on
following /proc/<pid>/map_files/<start>-<end> symlink.  And that makes
sense in general.

But in the case of build ID, profiler/symbolizer doesn't need the contents
of ELF file, per se.  It's only build ID that is of interest, and ELF
build ID itself doesn't provide any sensitive information.

So this patch adds a way to request backing file's ELF build ID along the
rest of VMA information in the same API.  User has control over whether
this piece of information is requested or not by either setting
build_id_size field to zero or non-zero maximum buffer size they provided
through build_id_addr field (which encodes user pointer as __u64 field). 
This is a completely optional piece of information, and so has no
performance implications for user cases that don't care about build ID,
while improving performance and simplifying the setup for those
application that do need it.

Kernel already implements build ID fetching, which is used from BPF
subsystem.  We are reusing this code here, but plan a follow up changes to
make it work better under more relaxed assumption (compared to what
existing code assumes) of being called from user process context, in which
page faults are allowed.  BPF-specific implementation currently bails out
if necessary part of ELF file is not paged in, all due to extra
BPF-specific restrictions (like the need to fetch build ID in restrictive
contexts such as NMI handler).

[andrii@kernel.org: fix integer to pointer cast warning in do_procmap_query()]
  Link: https://lkml.kernel.org/r/20240701174805.1897344-1-andrii@kernel.org
Link: https://lkml.kernel.org/r/20240627170900.1672542-4-andrii@kernel.org
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-12 15:52:12 -07:00
Andrii Nakryiko
ed5d583a88 fs/procfs: implement efficient VMA querying API for /proc/<pid>/maps
/proc/<pid>/maps file is extremely useful in practice for various tasks
involving figuring out process memory layout, what files are backing any
given memory range, etc.  One important class of applications that
absolutely rely on this are profilers/stack symbolizers (perf tool being
one of them).  Patterns of use differ, but they generally would fall into
two categories.

In on-demand pattern, a profiler/symbolizer would normally capture stack
trace containing absolute memory addresses of some functions, and would
then use /proc/<pid>/maps file to find corresponding backing ELF files
(normally, only executable VMAs are of interest), file offsets within
them, and then continue from there to get yet more information (ELF
symbols, DWARF information) to get human-readable symbolic information. 
This pattern is used by Meta's fleet-wide profiler, as one example.

In preprocessing pattern, application doesn't know the set of addresses of
interest, so it has to fetch all relevant VMAs (again, probably only
executable ones), store or cache them, then proceed with profiling and
stack trace capture.  Once done, it would do symbolization based on stored
VMA information.  This can happen at much later point in time.  This
patterns is used by perf tool, as an example.

In either case, there are both performance and correctness requirement
involved.  This address to VMA information translation has to be done as
efficiently as possible, but also not miss any VMA (especially in the case
of loading/unloading shared libraries).  In practice, correctness can't be
guaranteed (due to process dying before VMA data can be captured, or
shared library being unloaded, etc), but any effort to maximize the chance
of finding the VMA is appreciated.

Unfortunately, for all the /proc/<pid>/maps file universality and
usefulness, it doesn't fit the above use cases 100%.

First, it's main purpose is to emit all VMAs sequentially, but in practice
captured addresses would fall only into a smaller subset of all process'
VMAs, mainly containing executable text.  Yet, library would need to parse
most or all of the contents to find needed VMAs, as there is no way to
skip VMAs that are of no use.  Efficient library can do the linear pass
and it is still relatively efficient, but it's definitely an overhead that
can be avoided, if there was a way to do more targeted querying of the
relevant VMA information.

Second, it's a text based interface, which makes its programmatic use from
applications and libraries more cumbersome and inefficient due to the need
to handle text parsing to get necessary pieces of information.  The
overhead is actually payed both by kernel, formatting originally binary
VMA data into text, and then by user space application, parsing it back
into binary data for further use.

For the on-demand pattern of usage, described above, another problem when
writing generic stack trace symbolization library is an unfortunate
performance-vs-correctness tradeoff that needs to be made.  Library has to
make a decision to either cache parsed contents of /proc/<pid>/maps (after
initial processing) to service future requests (if application requests to
symbolize another set of addresses (for the same process), captured at
some later time, which is typical for periodic/continuous profiling cases)
to avoid higher costs of re-parsing this file.  Or it has to choose to
cache the contents in memory to speed up future requests.  In the former
case, more memory is used for the cache and there is a risk of getting
stale data if application loads or unloads shared libraries, or otherwise
changed its set of VMAs somehow, e.g., through additional mmap() calls. 
In the latter case, it's the performance hit that comes from re-opening
the file and re-parsing its contents all over again.

This patch aims to solve this problem by providing a new API built on top
of /proc/<pid>/maps.  It's meant to address both non-selectiveness and
text nature of /proc/<pid>/maps, by giving user more control of what sort
of VMA(s) needs to be queried, and being binary-based interface eliminates
the overhead of text formatting (on kernel side) and parsing (on user
space side).

It's also designed to be extensible and forward/backward compatible by
including required struct size field, which user has to provide.  We use
established copy_struct_from_user() approach to handle extensibility.

User has a choice to pick either getting VMA that covers provided address
or -ENOENT if none is found (exact, least surprising, case).  Or, with an
extra query flag (PROCMAP_QUERY_COVERING_OR_NEXT_VMA), they can get either
VMA that covers the address (if there is one), or the closest next VMA
(i.e., VMA with the smallest vm_start > addr).  The latter allows more
efficient use, but, given it could be a surprising behavior, requires an
explicit opt-in.

There is another query flag that is useful for some use cases. 
PROCMAP_QUERY_FILE_BACKED_VMA instructs this API to only return
file-backed VMAs.  Combining this with PROCMAP_QUERY_COVERING_OR_NEXT_VMA
makes it possible to efficiently iterate only file-backed VMAs of the
process, which is what profilers/symbolizers are normally interested in.

All the above querying flags can be combined with (also optional) set of
desired VMA permissions flags.  This allows to, for example, iterate only
an executable subset of VMAs, which is what preprocessing pattern, used by
perf tool, would benefit from, as the assumption is that captured stack
traces would have addresses of executable code.  This saves time by
skipping non-executable VMAs altogether efficienty.

All these querying flags (modifiers) are orthogonal and can be combined in
a semantically meaningful and natural way.

Basing this ioctl()-based API on top of /proc/<pid>/maps's FD makes sense
given it's querying the same set of VMA data.  It's also benefitial
because permission checks for /proc/<pid>/maps is performed at open time
once, and the actual data read of text contents of /proc/<pid>/maps is
done without further permission checks.  We piggyback on this pattern with
ioctl()-based API as well, as that's a desired property.  Both for
performance reasons, but also for security and flexibility reasons.

Allowing application to open an FD for /proc/self/maps without any extra
capabilities, and then passing it to some sort of profiling agent through
Unix-domain socket, would allow such profiling agent to not require some
of the capabilities that are otherwise expected when opening
/proc/<pid>/maps file for *another* process.  This is a desirable property
for some more restricted setups.

This new ioctl-based implementation doesn't interfere with seq_file-based
implementation of /proc/<pid>/maps textual interface, and so could be used
together or independently without paying any price for that.

Note also, that fetching VMA name (e.g., backing file path, or special
hard-coded or user-provided names) is optional just like build ID.  If
user sets vma_name_size to zero, kernel code won't attempt to retrieve it,
saving resources.

Earlier versions of this patch set were adding per-VMA locking, which is
why we have a code structure that is ready for abstracting mmap_lock vs
vm_lock differences (query_vma_setup(), query_vma_teardown(), and
query_vma_find_by_addr()), but given anon_vma_name() is not yet compatible
with per-VMA locking, initial implementation sticks to using only
mmap_lock for now.  It will be easy to add back per-VMA locking once all
the pieces are ready later on.  Which is why we keep existing code
structure with setup/teardown/query helper functions.

[andrii@kernel.org: improve PROCMAP_QUERY's compat mode handling]
  Link: https://lkml.kernel.org/r/20240701174805.1897344-2-andrii@kernel.org
Link: https://lkml.kernel.org/r/20240627170900.1672542-3-andrii@kernel.org
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-12 15:52:11 -07:00
Andrii Nakryiko
acd4b2ecf3 fs/procfs: extract logic for getting VMA name constituents
Patch series "ioctl()-based API to query VMAs from /proc/<pid>/maps", v6.

Implement binary ioctl()-based interface to /proc/<pid>/maps file to allow
applications to query VMA information more efficiently than reading *all*
VMAs nonselectively through text-based interface of /proc/<pid>/maps file.

Patch #2 goes into a lot of details and background on some common patterns
of using /proc/<pid>/maps in the area of performance profiling and
subsequent symbolization of captured stack traces.  As mentioned in that
patch, patterns of VMA querying can differ depending on specific use case,
but can generally be grouped into two main categories: the need to query a
small subset of VMAs covering a given batch of addresses, or
reading/storing/caching all (typically, executable) VMAs upfront for later
processing.

The new PROCMAP_QUERY ioctl() API added in this patch set was motivated by
the former pattern of usage.  Earlier revisions had a patch adding a tool
that faithfully reproduces an efficient VMA matching pass of a symbolizer,
collecting a subset of covering VMAs for a given set of addresses as
efficiently as possible.  This tool served both as a testing ground, as
well as a benchmarking tool.  It implements everything both for currently
existing text-based /proc/<pid>/maps interface, as well as for newly-added
PROCMAP_QUERY ioctl().  This revision dropped the tool from the patch set
and, once the API lands upstream, this tool might be added separately on
Github as an example.

Based on discussion on earlier revisions of this patch set, it turned out
that this ioctl() API is competitive with highly-optimized text-based
pre-processing pattern that perf tool is using.  Based on perf discussion,
this revision adds more flexibility in specifying a subset of VMAs that
are of interest.  Now it's possible to specify desired permissions of VMAs
(e.g., request only executable ones) and/or restrict to only a subset of
VMAs that have file backing.  This further improves the efficiency when
using this new API thanks to more selective (executable VMAs only)
querying.

In addition to a custom benchmarking tool, and experimental perf
integration (available at [0]), Daniel Mueller has since also implemented
an experimental integration into blazesym (see [1]), a library used for
stack trace symbolization by our server fleet-wide profiler and another
on-device profiler agent that runs on weaker ARM devices.  The latter
ARM-based device profiler is especially sensitive to performance, and so
we benchmarked and compared text-based /proc/<pid>/maps solution to the
equivalent one using PROCMAP_QUERY ioctl().

Results are very encouraging, giving us 5x improvement for end-to-end
so-called "address normalization" pass, which is the part of the
symbolization process that happens locally on ARM device, before being
sent out for further heavier-weight processing on more powerful remote
server.  Note that this is not an artificial microbenchmark.  It's a full
end-to-end API call being measured with real-world data on real-world
device.

  TEXT-BASED
  ==========
  Benchmarking main/normalize_process_no_build_ids_uncached_maps
  main/normalize_process_no_build_ids_uncached_maps
	  time:   [49.777 µs 49.982 µs 50.250 µs]

  IOCTL-BASED
  ===========
  Benchmarking main/normalize_process_no_build_ids_uncached_maps
  main/normalize_process_no_build_ids_uncached_maps
	  time:   [10.328 µs 10.391 µs 10.457 µs]
	  change: [−79.453% −79.304% −79.166%] (p = 0.00 < 0.02)
	  Performance has improved.

You can see above that we see the drop from 50µs down to 10µs for
exactly the same amount of work, with the same data and target process.

With the aforementioned custom tool, we see about ~40x improvement (it
might vary a bit, depending on a specific captured set of addresses).  And
even for perf-based benchmark it's on par or slightly ahead when using
permission-based filtering (fetching only executable VMAs).

Earlier revisions attempted to use per-VMA locking, if kernel was compiled
with CONFIG_PER_VMA_LOCK=y, but it turned out that anon_vma_name() is not
yet compatible with per-VMA locking and assumes mmap_lock to be taken,
which makes the use of per-VMA locking for this API premature.  It was
agreed ([2]) to continue for now with just mmap_lock, but the code
structure is such that it should be easy to add per-VMA locking support
once all the pieces are ready.

One thing that did not change was basing this new API as an ioctl()
command on /proc/<pid>/maps file.  An ioctl-based API on top of pidfd was
considered, but has its own downsides.  Implementing ioctl() directly on
pidfd will cause access permission checks on every single ioctl(), which
leads to performance concerns and potential spam of capable() audit
messages.  It also prevents a nice pattern, possible with
/proc/<pid>/maps, in which application opens /proc/self/maps FD (requiring
no additional capabilities) and passed this FD to profiling agent for
querying.  To achieve similar pattern, a new file would have to be created
from pidf just for VMA querying, which is considered to be inferior to
just querying /proc/<pid>/maps FD as proposed in current approach.  These
aspects were discussed in the hallway track at recent LSF/MM/BPF 2024 and
sticking to procfs ioctl() was the final agreement we arrived at.

  [0] https://github.com/anakryiko/linux/commits/procfs-proc-maps-ioctl-v2/
  [1] https://github.com/libbpf/blazesym/pull/675
  [2] https://lore.kernel.org/bpf/7rm3izyq2vjp5evdjc7c6z4crdd3oerpiknumdnmmemwyiwx7t@hleldw7iozi3/


This patch (of 6):

Extract generic logic to fetch relevant pieces of data to describe VMA
name.  This could be just some string (either special constant or
user-provided), or a string with some formatted wrapping text (e.g.,
"[anon_shmem:<something>]"), or, commonly, file path.  seq_file-based
logic has different methods to handle all three cases, but they are
currently mixed in with extracting underlying sources of data.

This patch splits this into data fetching and data formatting, so that
data fetching can be reused later on.

There should be no functional changes.

Link: https://lkml.kernel.org/r/20240627170900.1672542-1-andrii@kernel.org
Link: https://lkml.kernel.org/r/20240627170900.1672542-2-andrii@kernel.org
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-12 15:52:11 -07:00
Kefeng Wang
aca08acce7 fs/proc/task_mmu: use folio API in pte_is_pinned()
Patch series "mm: remove page_maybe_dma_pinned() and page_mkclean()".

Most page_maybe_dma_pinned() and page_mkclean() callers have been
converted to the folio equivalents, after two more convertsions,
remove them and update the comment and documention.


This patch (of 4):

Convert to use vm_normal_folio() and folio_maybe_dma_pinned() API, which
helps to remove page_maybe_dma_pinned() in the subsequent change.

Link: https://lkml.kernel.org/r/20240604114822.2089819-1-wangkefeng.wang@huawei.com
Link: https://lkml.kernel.org/r/20240604114822.2089819-2-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Helge Deller <deller@gmx.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03 19:30:17 -07:00
David Hildenbrand
cdd9a571b7 fs/proc: move page_mapcount() to fs/proc/internal.h
...  and rename it to folio_precise_page_mapcount().  fs/proc is the last
remaining user, and that should stay that way.

While at it, cleanup kpagecount_read() a bit: there are still some legacy
leftovers -- when the interface was introduced it returned the page
refcount, but was changed briefly afterwards to return the page mapcount. 
Further, some simple folio conversion.

Once we stop using the per-page mapcounts of large folios, all
folio_precise_page_mapcount() users will have to implement an alternative
way to achieve what they are trying to achieve, possibly in a less precise
way.

[dan.carpenter@linaro.org: fix uninitialized variable in pagemap_pmd_range()]
  Link: https://lkml.kernel.org/r/9d6eaba7-92f8-4a70-8765-38a519680a87@moroto.mountain
Link: https://lkml.kernel.org/r/20240607122357.115423-6-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: Oscar Salvador <osalvador@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03 19:30:06 -07:00
David Hildenbrand
3689c3ebdd fs/proc/task_mmu: account non-present entries as "maybe shared, but no idea how often"
We currently rely on mapcount information for pages referenced by
non-present entries to calculate the USS (shared vs.  private) and the
PSS.

However, relying on mapcounts for non-present entries doesn't make any
sense.  We have to treat such entries as "maybe shared, but no idea how
often", implying that they will *not* get accounted towards the USS, and
will get fully accounted to the PSS (no idea how often shared).

There is one exception: device exclusive entries essentially behave like
present entries (e.g., mapcount incremented).

In smaps_pmd_entry(), use is_pfn_swap_entry() instead of
is_migration_entry(), which should not make a real difference but makes
the code look more similar to the PTE variant.

While at it, adjust the comments in smaps_account().

Link: https://lkml.kernel.org/r/20240607122357.115423-5-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: Oscar Salvador <osalvador@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03 19:30:06 -07:00
David Hildenbrand
2c1f057e5b fs/proc/task_mmu: properly detect PM_MMAP_EXCLUSIVE per page of PMD-mapped THPs
We added PM_MMAP_EXCLUSIVE in 2015 via commit 77bb499bb6 ("pagemap: add
mmap-exclusive bit for marking pages mapped only here"), when THPs could
not be partially mapped and page_mapcount() returned something that was
true for all pages of the THP.

In 2016, we added support for partially mapping THPs via commit
53f9263bab ("mm: rework mapcount accounting to enable 4k mapping of
THPs") but missed to determine PM_MMAP_EXCLUSIVE as well per page.

Checking page_mapcount() on the head page does not tell the whole story.

We should check each individual page.  In a future without per-page
mapcounts it will be different, but we'll change that to be consistent
with PTE-mapped THPs once we deal with that.

Link: https://lkml.kernel.org/r/20240607122357.115423-4-david@redhat.com
Fixes: 53f9263bab ("mm: rework mapcount accounting to enable 4k mapping of THPs")
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Lance Yang <ioworker0@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03 19:30:05 -07:00
David Hildenbrand
da7f31ed0f fs/proc/task_mmu: don't indicate PM_MMAP_EXCLUSIVE without PM_PRESENT
Relying on the mapcount for non-present PTEs that reference pages doesn't
make any sense: they are not accounted in the mapcount, so page_mapcount()
== 1 won't return the result we actually want to know.

While we don't check the mapcount for migration entries already, we could
end up checking it for swap, hwpoison, device exclusive, ...  entries,
which we really shouldn't.

There is one exception: device private entries, which we consider
fake-present (e.g., incremented the mapcount).  But we won't care about
that for now for PM_MMAP_EXCLUSIVE, because indicating PM_SWAP for them
although they are fake-present already sounds suspiciously wrong.

Let's never indicate PM_MMAP_EXCLUSIVE without PM_PRESENT.

Link: https://lkml.kernel.org/r/20240607122357.115423-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Lance Yang <ioworker0@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03 19:30:05 -07:00
David Hildenbrand
3f9f022e97 fs/proc/task_mmu: indicate PM_FILE for PMD-mapped file THP
Patch series "fs/proc: move page_mapcount() to fs/proc/internal.h".

With all other page_mapcount() users in the tree gone, move
page_mapcount() to fs/proc/internal.h, rename it and extend the
documentation to prevent future (ab)use.

... of course, I find some issues while working on that code that I sort
first ;)

We'll now only end up calling page_mapcount() [now
folio_precise_page_mapcount()] on pages mapped via present page table
entries.  Except for /proc/kpagecount, that still does questionable
things, but we'll leave that legacy interface as is for now.

Did a quick sanity check.  Likely we would want some better selfestest for
/proc/$/pagemap + smaps.  I'll see if I can find some time to write some
more.


This patch (of 6):

Looks like we never taught pagemap_pmd_range() about the existence of
PMD-mapped file THPs.  Seems to date back to the times when we first added
support for non-anon THPs in the form of shmem THP.

Link: https://lkml.kernel.org/r/20240607122357.115423-1-david@redhat.com
Link: https://lkml.kernel.org/r/20240607122357.115423-2-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Fixes: 800d8c63b2 ("shmem: add huge pages support")
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Lance Yang <ioworker0@gmail.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03 19:30:05 -07:00
Christophe JAILLET
7f07ee5a23
proc: Remove usage of the deprecated ida_simple_xx() API
ida_alloc() and ida_free() should be preferred to the deprecated
ida_simple_get() and ida_simple_remove().

Note that the upper limit of ida_simple_get() is exclusive, but the one of
ida_alloc_max() is inclusive. So a -1 has been added when needed.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/ae10003feb87d240163d0854de95f09e1f00be7d.1717855701.git.christophe.jaillet@wanadoo.fr
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-06-25 11:15:47 +02:00
Jeff Xu
399ab86ea5 /proc/pid/smaps: add mseal info for vma
Add sl in /proc/pid/smaps to indicate vma is sealed

Link: https://lkml.kernel.org/r/20240614232014.806352-2-jeffxu@google.com
Fixes: 8be7258aad ("mseal: add mseal syscall")
Signed-off-by: Jeff Xu <jeffxu@chromium.org>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Cc: Jann Horn <jannh@google.com>
Cc: Jorge Lucangeli Obes <jorgelo@chromium.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Stephen Röttger <sroettger@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-06-24 20:52:09 -07:00
Joel Granados
acc154691f sysctl: Warn on an empty procname element
Add a pr_err warning in case a ctl_table is registered with a sentinel
element containing a NULL procname.

Signed-off-by: Joel Granados <j.granados@samsung.com>
2024-06-13 10:50:52 +02:00
Joel Granados
3717540377 sysctl: Remove ctl_table sentinel code comments
Remove the mention of a "zero terminated entry" from the
__register_sysctl_table function doc.

Signed-off-by: Joel Granados <j.granados@samsung.com>
2024-06-13 10:50:52 +02:00
Joel Granados
a02fe70de4 sysctl: Remove "child" sysctl code comments
Erase the code comments mentioning "child" that were forgotten when the
child element was removed in commit 2f2665c13a ("sysctl: replace
child with an enumeration").

Signed-off-by: Joel Granados <j.granados@samsung.com>
2024-06-13 10:50:52 +02:00
Joel Granados
aef9d25e7f sysctl: Remove superfluous empty allocations from sysctl internals
Now that the sentinels have been removed from ctl_table arrays, there is
no need to artificially append empty ctl_table elements at ctl_table
registration. Remove superfluous empty allocation from new_dir and
new_links.

Signed-off-by: Joel Granados <j.granados@samsung.com>
2024-06-13 10:50:52 +02:00
Joel Granados
55bb7eb62d sysctl: Replace nr_entries with ctl_table_size in new_links
The number of ctl_table entries (nr_entries) calculation was previously
based on the ctl_table_size and the sentinel element. Since the
sentinels have been removed, we remove the calculation and just use the
ctl_table_size from the ctl_table_header.

Signed-off-by: Joel Granados <j.granados@samsung.com>
2024-06-13 10:50:52 +02:00
Joel Granados
d7a76ec871 sysctl: Remove check for sentinel element in ctl_table arrays
Use ARRAY_SIZE exclusively by removing the check to ->procname in the
stopping criteria of the loops traversing ctl_table arrays. This commit
finalizes the removal of the sentinel elements at the end of ctl_table
arrays which reduces the build time size and run time memory bloat by
~64 bytes per sentinel (further information Link :
https://lore.kernel.org/all/ZO5Yx5JFogGi%2FcBo@bombadil.infradead.org/)

Remove the entry->procname evaluation from the for loop stopping
criteria in sysctl and sysctl_net.

Signed-off-by: Joel Granados <j.granados@samsung.com>
2024-06-13 10:50:52 +02:00
Chengming Zhou
c2dc78b86e mm/ksm: fix ksm_zero_pages accounting
We normally ksm_zero_pages++ in ksmd when page is merged with zero page,
but ksm_zero_pages-- is done from page tables side, where there is no any
accessing protection of ksm_zero_pages.

So we can read very exceptional value of ksm_zero_pages in rare cases,
such as -1, which is very confusing to users.

Fix it by changing to use atomic_long_t, and the same case with the
mm->ksm_zero_pages.

Link: https://lkml.kernel.org/r/20240528-b4-ksm-counters-v3-2-34bb358fdc13@linux.dev
Fixes: e2942062e0 ("ksm: count all zero pages placed by KSM")
Fixes: 6080d19f07 ("ksm: add ksm zero pages for each process")
Signed-off-by: Chengming Zhou <chengming.zhou@linux.dev>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ran Xiaokai <ran.xiaokai@zte.com.cn>
Cc: Stefan Roesch <shr@devkernel.io>
Cc: xu xin <xu.xin16@zte.com.cn>
Cc: Yang Yang <yang.yang29@zte.com.cn>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-06-05 19:19:26 -07:00
Wen Yang
b5ffbd1396 sysctl: move the extra1/2 boundary check of u8 to sysctl_check_table_array
Move boundary checking for proc_dou8ved_minmax into module loading, thereby
reporting errors in advance. And add a kunit test case ensuring the
boundary check is done correctly.

The boundary check in proc_dou8vec_minmax done to the extra elements in
the ctl_table struct is currently performed at runtime. This allows buggy
kernel modules to be loaded normally without any errors only to fail
when used.

This is a buggy example module:
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/sysctl.h>

	static struct ctl_table_header *_table_header = NULL;
	static unsigned char _data = 0;
	struct ctl_table table[] = {
		{
			.procname       = "foo",
			.data           = &_data,
			.maxlen         = sizeof(u8),
			.mode           = 0644,
			.proc_handler   = proc_dou8vec_minmax,
			.extra1         = SYSCTL_ZERO,
			.extra2         = SYSCTL_ONE_THOUSAND,
		},
	};

	static int init_demo(void) {
		_table_header = register_sysctl("kernel", table);
		if (!_table_header)
			return -ENOMEM;

		return 0;
	}

	module_init(init_demo);
	MODULE_LICENSE("GPL");

And this is the result:
        # insmod test.ko
        # cat /proc/sys/kernel/foo
        cat: /proc/sys/kernel/foo: Invalid argument

Suggested-by: Joel Granados <j.granados@samsung.com>
Signed-off-by: Wen Yang <wen.yang@linux.dev>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Joel Granados <j.granados@samsung.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Joel Granados <j.granados@samsung.com>
Signed-off-by: Joel Granados <j.granados@samsung.com>
2024-06-03 15:14:34 +02:00
Thomas Weißschuh
98ca62ba9e sysctl: always initialize i_uid/i_gid
Always initialize i_uid/i_gid inside the sysfs core so set_ownership()
can safely skip setting them.

Commit 5ec27ec735 ("fs/proc/proc_sysctl.c: fix the default values of
i_uid/i_gid on /proc/sys inodes.") added defaults for i_uid/i_gid when
set_ownership() was not implemented. It also missed adjusting
net_ctl_set_ownership() to use the same default values in case the
computation of a better value failed.

Fixes: 5ec27ec735 ("fs/proc/proc_sysctl.c: fix the default values of i_uid/i_gid on /proc/sys inodes.")
Cc: stable@vger.kernel.org
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Joel Granados <j.granados@samsung.com>
2024-06-03 15:11:58 +02:00
Yuanyuan Zhong
6d065f507d mm: /proc/pid/smaps_rollup: avoid skipping vma after getting mmap_lock again
After switching smaps_rollup to use VMA iterator, searching for next entry
is part of the condition expression of the do-while loop.  So the current
VMA needs to be addressed before the continue statement.

Otherwise, with some VMAs skipped, userspace observed memory
consumption from /proc/pid/smaps_rollup will be smaller than the sum of
the corresponding fields from /proc/pid/smaps.

Link: https://lkml.kernel.org/r/20240523183531.2535436-1-yzhong@purestorage.com
Fixes: c4c84f0628 ("fs/proc/task_mmu: stop using linked list and highest_vm_end")
Signed-off-by: Yuanyuan Zhong <yzhong@purestorage.com>
Reviewed-by: Mohamed Khalfella <mkhalfella@purestorage.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-24 11:55:07 -07:00
Linus Torvalds
b6394d6f71 Assorted commits that had missed the last merge window...
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Merge tag 'pull-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull misc vfs updates from Al Viro:
 "Assorted commits that had missed the last merge window..."

* tag 'pull-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  remove call_{read,write}_iter() functions
  do_dentry_open(): kill inode argument
  kernel_file_open(): get rid of inode argument
  get_file_rcu(): no need to check for NULL separately
  fd_is_open(): move to fs/file.c
  close_on_exec(): pass files_struct instead of fdtable
2024-05-21 13:11:44 -07:00
Linus Torvalds
eb6a9339ef Mainly singleton patches, documented in their respective changelogs.
Notable series include:
 
 - Some maintenance and performance work for ocfs2 in Heming Zhao's
   series "improve write IO performance when fragmentation is high".
 
 - Some ocfs2 bugfixes from Su Yue in the series "ocfs2 bugs fixes
   exposed by fstests".
 
 - kfifo header rework from Andy Shevchenko in the series "kfifo: Clean
   up kfifo.h".
 
 - GDB script fixes from Florian Rommel in the series "scripts/gdb: Fixes
   for $lx_current and $lx_per_cpu".
 
 - After much discussion, a coding-style update from Barry Song
   explaining one reason why inline functions are preferred over macros.
   The series is "codingstyle: avoid unused parameters for a function-like
   macro".
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Merge tag 'mm-nonmm-stable-2024-05-19-11-56' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull non-mm updates from Andrew Morton:
 "Mainly singleton patches, documented in their respective changelogs.
  Notable series include:

   - Some maintenance and performance work for ocfs2 in Heming Zhao's
     series "improve write IO performance when fragmentation is high".

   - Some ocfs2 bugfixes from Su Yue in the series "ocfs2 bugs fixes
     exposed by fstests".

   - kfifo header rework from Andy Shevchenko in the series "kfifo:
     Clean up kfifo.h".

   - GDB script fixes from Florian Rommel in the series "scripts/gdb:
     Fixes for $lx_current and $lx_per_cpu".

   - After much discussion, a coding-style update from Barry Song
     explaining one reason why inline functions are preferred over
     macros. The series is "codingstyle: avoid unused parameters for a
     function-like macro""

* tag 'mm-nonmm-stable-2024-05-19-11-56' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (62 commits)
  fs/proc: fix softlockup in __read_vmcore
  nilfs2: convert BUG_ON() in nilfs_finish_roll_forward() to WARN_ON()
  scripts: checkpatch: check unused parameters for function-like macro
  Documentation: coding-style: ask function-like macros to evaluate parameters
  nilfs2: use __field_struct() for a bitwise field
  selftests/kcmp: remove unused open mode
  nilfs2: remove calls to folio_set_error() and folio_clear_error()
  kernel/watchdog_perf.c: tidy up kerneldoc
  watchdog: allow nmi watchdog to use raw perf event
  watchdog: handle comma separated nmi_watchdog command line
  nilfs2: make superblock data array index computation sparse friendly
  squashfs: remove calls to set the folio error flag
  squashfs: convert squashfs_symlink_read_folio to use folio APIs
  scripts/gdb: fix detection of current CPU in KGDB
  scripts/gdb: make get_thread_info accept pointers
  scripts/gdb: fix parameter handling in $lx_per_cpu
  scripts/gdb: fix failing KGDB detection during probe
  kfifo: don't use "proxy" headers
  media: stih-cec: add missing io.h
  media: rc: add missing io.h
  ...
2024-05-19 14:02:03 -07:00
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
  ...
2024-05-19 09:21:03 -07:00
Linus Torvalds
91b6163be4 sysctl changes for v6.10-rc1
Summary
 * Removed sentinel elements from ctl_table structs in kernel/*
 
   Removing sentinels in ctl_table arrays reduces the build time size and
   runtime memory consumed by ~64 bytes per array. Removals for net/, io_uring/,
   mm/, ipc/ and security/ are set to go into mainline through their respective
   subsystems making the next release the most likely place where the final
   series that removes the check for proc_name == NULL will land. This PR adds
   to removals already in arch/, drivers/ and fs/.
 
 * Adjusted ctl_table definitions and references to allow constification
 
   Adjustments:
     - Removing unused ctl_table function arguments
     - Moving non-const elements from ctl_table to ctl_table_header
     - Making ctl_table pointers const in ctl_table_root structure
 
   Making the static ctl_table structs const will increase safety by keeping the
   pointers to proc_handler functions in .rodata. Though no ctl_tables where
   made const in this PR, the ground work for making that possible has started
   with these changes sent by Thomas Weißschuh.
 
 Testing
 * These changes went into linux-next after v6.9-rc4; giving it a good month of
   testing.
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Merge tag 'sysctl-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl

Pull sysctl updates from Joel Granados:

 - Remove sentinel elements from ctl_table structs in kernel/*

   Removing sentinels in ctl_table arrays reduces the build time size
   and runtime memory consumed by ~64 bytes per array. Removals for
   net/, io_uring/, mm/, ipc/ and security/ are set to go into mainline
   through their respective subsystems making the next release the most
   likely place where the final series that removes the check for
   proc_name == NULL will land.

   This adds to removals already in arch/, drivers/ and fs/.

 - Adjust ctl_table definitions and references to allow constification
     - Remove unused ctl_table function arguments
     - Move non-const elements from ctl_table to ctl_table_header
     - Make ctl_table pointers const in ctl_table_root structure

   Making the static ctl_table structs const will increase safety by
   keeping the pointers to proc_handler functions in .rodata. Though no
   ctl_tables where made const in this PR, the ground work for making
   that possible has started with these changes sent by Thomas
   Weißschuh.

* tag 'sysctl-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl:
  sysctl: drop now unnecessary out-of-bounds check
  sysctl: move sysctl type to ctl_table_header
  sysctl: drop sysctl_is_perm_empty_ctl_table
  sysctl: treewide: constify argument ctl_table_root::permissions(table)
  sysctl: treewide: drop unused argument ctl_table_root::set_ownership(table)
  bpf: Remove the now superfluous sentinel elements from ctl_table array
  delayacct: Remove the now superfluous sentinel elements from ctl_table array
  kprobes: Remove the now superfluous sentinel elements from ctl_table array
  printk: Remove the now superfluous sentinel elements from ctl_table array
  scheduler: Remove the now superfluous sentinel elements from ctl_table array
  seccomp: Remove the now superfluous sentinel elements from ctl_table array
  timekeeping: Remove the now superfluous sentinel elements from ctl_table array
  ftrace: Remove the now superfluous sentinel elements from ctl_table array
  umh: Remove the now superfluous sentinel elements from ctl_table array
  kernel misc: Remove the now superfluous sentinel elements from ctl_table array
2024-05-17 17:31:24 -07:00
Linus Torvalds
1b0aabcc9a vfs-6.10.misc
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Merge tag 'vfs-6.10.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

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

  Features:

   - Free up FMODE_* bits. I've freed up bits 6, 7, 8, and 24. That
     means we now have six free FMODE_* bits in total (but bit #6
     already got used for FMODE_WRITE_RESTRICTED)

   - Add FOP_HUGE_PAGES flag (follow-up to FMODE_* cleanup)

   - Add fd_raw cleanup class so we can make use of automatic cleanup
     provided by CLASS(fd_raw, f)(fd) for O_PATH fds as well

   - Optimize seq_puts()

   - Simplify __seq_puts()

   - Add new anon_inode_getfile_fmode() api to allow specifying f_mode
     instead of open-coding it in multiple places

   - Annotate struct file_handle with __counted_by() and use
     struct_size()

   - Warn in get_file() whether f_count resurrection from zero is
     attempted (epoll/drm discussion)

   - Folio-sophize aio

   - Export the subvolume id in statx() for both btrfs and bcachefs

   - Relax linkat(AT_EMPTY_PATH) requirements

   - Add F_DUPFD_QUERY fcntl() allowing to compare two file descriptors
     for dup*() equality replacing kcmp()

  Cleanups:

   - Compile out swapfile inode checks when swap isn't enabled

   - Use (1 << n) notation for FMODE_* bitshifts for clarity

   - Remove redundant variable assignment in fs/direct-io

   - Cleanup uses of strncpy in orangefs

   - Speed up and cleanup writeback

   - Move fsparam_string_empty() helper into header since it's currently
     open-coded in multiple places

   - Add kernel-doc comments to proc_create_net_data_write()

   - Don't needlessly read dentry->d_flags twice

  Fixes:

   - Fix out-of-range warning in nilfs2

   - Fix ecryptfs overflow due to wrong encryption packet size
     calculation

   - Fix overly long line in xfs file_operations (follow-up to FMODE_*
     cleanup)

   - Don't raise FOP_BUFFER_{R,W}ASYNC for directories in xfs (follow-up
     to FMODE_* cleanup)

   - Don't call xfs_file_open from xfs_dir_open (follow-up to FMODE_*
     cleanup)

   - Fix stable offset api to prevent endless loops

   - Fix afs file server rotations

   - Prevent xattr node from overflowing the eraseblock in jffs2

   - Move fdinfo PTRACE_MODE_READ procfs check into the .permission()
     operation instead of .open() operation since this caused userspace
     regressions"

* tag 'vfs-6.10.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (39 commits)
  afs: Fix fileserver rotation getting stuck
  selftests: add F_DUPDFD_QUERY selftests
  fcntl: add F_DUPFD_QUERY fcntl()
  file: add fd_raw cleanup class
  fs: WARN when f_count resurrection is attempted
  seq_file: Simplify __seq_puts()
  seq_file: Optimize seq_puts()
  proc: Move fdinfo PTRACE_MODE_READ check into the inode .permission operation
  fs: Create anon_inode_getfile_fmode()
  xfs: don't call xfs_file_open from xfs_dir_open
  xfs: drop fop_flags for directories
  xfs: fix overly long line in the file_operations
  shmem: Fix shmem_rename2()
  libfs: Add simple_offset_rename() API
  libfs: Fix simple_offset_rename_exchange()
  jffs2: prevent xattr node from overflowing the eraseblock
  vfs, swap: compile out IS_SWAPFILE() on swapless configs
  vfs: relax linkat() AT_EMPTY_PATH - aka flink() - requirements
  fs/direct-io: remove redundant assignment to variable retval
  fs/dcache: Re-use value stored to dentry->d_flags instead of re-reading
  ...
2024-05-13 11:40:06 -07:00
Rik van Riel
5cbcb62ddd fs/proc: fix softlockup in __read_vmcore
While taking a kernel core dump with makedumpfile on a larger system,
softlockup messages often appear.

While softlockup warnings can be harmless, they can also interfere with
things like RCU freeing memory, which can be problematic when the kdump
kexec image is configured with as little memory as possible.

Avoid the softlockup, and give things like work items and RCU a chance to
do their thing during __read_vmcore by adding a cond_resched.

Link: https://lkml.kernel.org/r/20240507091858.36ff767f@imladris.surriel.com
Signed-off-by: Rik van Riel <riel@surriel.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-11 15:51:44 -07:00
Matthew Wilcox
e0ffb29bc5 mm: simplify thp_vma_allowable_order
Combine the three boolean arguments into one flags argument for
readability.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:53:53 -07:00
David Hildenbrand
6401a2e690 fs/proc/task_mmu: convert smaps_hugetlb_range() to work on folios
Let's get rid of another page_mapcount() check and simply use
folio_likely_mapped_shared(), which is precise for hugetlb folios.

While at it, use huge_ptep_get() + pte_page() instead of ptep_get() +
vm_normal_page(), just like we do in pagemap_hugetlb_range().

No functional change intended.

Link: https://lkml.kernel.org/r/20240417092313.753919-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:53:41 -07:00
David Hildenbrand
88e4e47c12 fs/proc/task_mmu: convert pagemap_hugetlb_range() to work on folios
Patch series "fs/proc/task_mmu: convert hugetlb functions to work on folis".

Let's convert two more functions, getting rid of two more page_mapcount()
calls.


This patch (of 2):

Let's get rid of another page_mapcount() check and simply use
folio_likely_mapped_shared(), which is precise for hugetlb folios.

While at it, also check for PMD table sharing, like we do in
smaps_hugetlb_range().

No functional change intended, except that we would now detect hugetlb
folios shared via PMD table sharing correctly.

Link: https://lkml.kernel.org/r/20240417092313.753919-1-david@redhat.com
Link: https://lkml.kernel.org/r/20240417092313.753919-2-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:53:41 -07:00
Ryan Roberts
2c7ad9a590 fs/proc/task_mmu: fix uffd-wp confusion in pagemap_scan_pmd_entry()
pagemap_scan_pmd_entry() checks if uffd-wp is set on each pte to avoid
unnecessary if set.  However it was previously checking with
`pte_uffd_wp(ptep_get(pte))` without first confirming that the pte was
present.  It is only valid to call pte_uffd_wp() for present ptes.  For
swap ptes, pte_swp_uffd_wp() must be called because the uffd-wp bit may be
kept in a different position, depending on the arch.

This was leading to test failures in the pagemap_ioctl mm selftest, when
bringing up uffd-wp support on arm64 due to incorrectly interpretting the
uffd-wp status of migration entries.

Let's fix this by using the correct check based on pte_present().  While
we are at it, let's pass the pte to make_uffd_wp_pte() to avoid the
pointless extra ptep_get() which can't be optimized out due to READ_ONCE()
on many arches.

Link: https://lkml.kernel.org/r/20240429114104.182890-1-ryan.roberts@arm.com
Fixes: 12f6b01a0b ("fs/proc/task_mmu: add fast paths to get/clear PAGE_IS_WRITTEN flag")
Closes: https://lore.kernel.org/linux-arm-kernel/ZiuyGXt0XWwRgFh9@x1n/
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Tested-by: Muhammad Usama Anjum <usama.anjum@collabora.com> 
Cc: Peter Xu <peterx@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:28:07 -07:00
Ryan Roberts
c70dce4982 fs/proc/task_mmu: fix loss of young/dirty bits during pagemap scan
make_uffd_wp_pte() was previously doing:

  pte = ptep_get(ptep);
  ptep_modify_prot_start(ptep);
  pte = pte_mkuffd_wp(pte);
  ptep_modify_prot_commit(ptep, pte);

But if another thread accessed or dirtied the pte between the first 2
calls, this could lead to loss of that information.  Since
ptep_modify_prot_start() gets and clears atomically, the following is the
correct pattern and prevents any possible race.  Any access after the
first call would see an invalid pte and cause a fault:

  pte = ptep_modify_prot_start(ptep);
  pte = pte_mkuffd_wp(pte);
  ptep_modify_prot_commit(ptep, pte);

Link: https://lkml.kernel.org/r/20240429114017.182570-1-ryan.roberts@arm.com
Fixes: 52526ca7fd ("fs/proc/task_mmu: implement IOCTL to get and optionally clear info about PTEs")
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-05 17:28:06 -07:00
Tyler Hicks (Microsoft)
0a960ba498
proc: Move fdinfo PTRACE_MODE_READ check into the inode .permission operation
The following commits loosened the permissions of /proc/<PID>/fdinfo/
directory, as well as the files within it, from 0500 to 0555 while also
introducing a PTRACE_MODE_READ check between the current task and
<PID>'s task:

 - commit 7bc3fa0172 ("procfs: allow reading fdinfo with PTRACE_MODE_READ")
 - commit 1927e498ae ("procfs: prevent unprivileged processes accessing fdinfo dir")

Before those changes, inode based system calls like inotify_add_watch(2)
would fail when the current task didn't have sufficient read permissions:

 [...]
 lstat("/proc/1/task/1/fdinfo", {st_mode=S_IFDIR|0500, st_size=0, ...}) = 0
 inotify_add_watch(64, "/proc/1/task/1/fdinfo",
		   IN_MODIFY|IN_ATTRIB|IN_MOVED_FROM|IN_MOVED_TO|IN_CREATE|IN_DELETE|
		   IN_ONLYDIR|IN_DONT_FOLLOW|IN_EXCL_UNLINK) = -1 EACCES (Permission denied)
 [...]

This matches the documented behavior in the inotify_add_watch(2) man
page:

 ERRORS
       EACCES Read access to the given file is not permitted.

After those changes, inotify_add_watch(2) started succeeding despite the
current task not having PTRACE_MODE_READ privileges on the target task:

 [...]
 lstat("/proc/1/task/1/fdinfo", {st_mode=S_IFDIR|0555, st_size=0, ...}) = 0
 inotify_add_watch(64, "/proc/1/task/1/fdinfo",
		   IN_MODIFY|IN_ATTRIB|IN_MOVED_FROM|IN_MOVED_TO|IN_CREATE|IN_DELETE|
		   IN_ONLYDIR|IN_DONT_FOLLOW|IN_EXCL_UNLINK) = 1757
 openat(AT_FDCWD, "/proc/1/task/1/fdinfo",
	O_RDONLY|O_NONBLOCK|O_CLOEXEC|O_DIRECTORY) = -1 EACCES (Permission denied)
 [...]

This change in behavior broke .NET prior to v7. See the github link
below for the v7 commit that inadvertently/quietly (?) fixed .NET after
the kernel changes mentioned above.

Return to the old behavior by moving the PTRACE_MODE_READ check out of
the file .open operation and into the inode .permission operation:

 [...]
 lstat("/proc/1/task/1/fdinfo", {st_mode=S_IFDIR|0555, st_size=0, ...}) = 0
 inotify_add_watch(64, "/proc/1/task/1/fdinfo",
		   IN_MODIFY|IN_ATTRIB|IN_MOVED_FROM|IN_MOVED_TO|IN_CREATE|IN_DELETE|
		   IN_ONLYDIR|IN_DONT_FOLLOW|IN_EXCL_UNLINK) = -1 EACCES (Permission denied)
 [...]

Reported-by: Kevin Parsons (Microsoft) <parsonskev@gmail.com>
Link: 89e5469ac5
Link: https://stackoverflow.com/questions/75379065/start-self-contained-net6-build-exe-as-service-on-raspbian-system-unauthorizeda
Fixes: 7bc3fa0172 ("procfs: allow reading fdinfo with PTRACE_MODE_READ")
Cc: stable@vger.kernel.org
Cc: Christian Brauner <brauner@kernel.org>
Cc: Christian König <christian.koenig@amd.com>
Cc: Jann Horn <jannh@google.com>
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: Hardik Garg <hargar@linux.microsoft.com>
Cc: Allen Pais <apais@linux.microsoft.com>
Signed-off-by: Tyler Hicks (Microsoft) <code@tyhicks.com>
Link: https://lore.kernel.org/r/20240501005646.745089-1-code@tyhicks.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-05-02 11:42:04 +02:00
Justin Stitt
ad5f0eb540 vmcore: replace strncpy with strscpy_pad
strncpy() is in the process of being replaced as it is deprecated [1].
We should move towards safer and less ambiguous string interfaces.

Looking at vmcoredd_header's definition:
|	struct vmcoredd_header {
|		__u32 n_namesz; /* Name size */
|		__u32 n_descsz; /* Content size */
|		__u32 n_type;   /* NT_VMCOREDD */
|		__u8 name[8];   /* LINUX\0\0\0 */
|		__u8 dump_name[VMCOREDD_MAX_NAME_BYTES]; /* Device dump's name */
|	};
.. we see that @name wants to be NUL-padded.

We're copying data->dump_name which is defined as:
|	char dump_name[VMCOREDD_MAX_NAME_BYTES]; /* Unique name of the dump */
.. which shares the same size as vdd_hdr->dump_name. Let's make sure we
NUL-pad this as well.

Use strscpy_pad() which NUL-terminates and NUL-pads its destination
buffers. Specifically, use the new 2-argument version of strscpy_pad
introduced in Commit e6584c3964 ("string: Allow 2-argument
strscpy()").

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://github.com/KSPP/linux/issues/90
Link: https://lkml.kernel.org/r/20240401-strncpy-fs-proc-vmcore-c-v2-1-dd0a73f42635@google.com
Signed-off-by: Justin Stitt <justinstitt@google.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 21:07:06 -07:00
Matthew Wilcox (Oracle)
039d26d10d proc: convert smaps_pmd_entry to use a folio
Replace two calls to compound_head() with one.

Link: https://lkml.kernel.org/r/20240403171456.1445117-5-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Christian Brauner <brauner@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:56:36 -07:00
Matthew Wilcox (Oracle)
27bb0a70e5 proc: pass a folio to smaps_page_accumulate()
Both callers already have a folio; pass it in instead of doing the
conversion each time.

Link: https://lkml.kernel.org/r/20240403171456.1445117-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Christian Brauner <brauner@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:56:36 -07:00
Matthew Wilcox (Oracle)
cfc96da432 proc: convert smaps_page_accumulate to use a folio
Replaces three calls to compound_head() with one.  Shrinks the function
from 2614 bytes to 1112 bytes in an allmodconfig build.

Link: https://lkml.kernel.org/r/20240403171456.1445117-3-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Christian Brauner <brauner@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:56:35 -07:00
Matthew Wilcox (Oracle)
f1dc623fa0 proc: convert gather_stats to use a folio
Patch series "Use folio APIs in procfs".

We're down to very few users of the PageFoo macros, with proc being a
major user.

After this patchset and another patchset I have for khugepaged, we can get
rid of PageActive, PageReadahead and PageSwapBacked.  This patchset has
the usual advantages in its own right of removing hidden calls to
compound_head().  We have the page table lock, so the mapcount & refcount
are stable and there can't be any races with folios suddenly becoming tail
pages.


This patch (of 4):

Replaces six calls to compound_head() with one.  Shrinks the function from
5054 bytes to 1756 bytes in an allmodconfig build.

Link: https://lkml.kernel.org/r/20240403171456.1445117-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20240403171456.1445117-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Christian Brauner <brauner@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:56:35 -07:00
Matthew Wilcox (Oracle)
6c977f36dc proc: convert smaps_account() to use a folio
Replace seven calls to compound_head() with one.

Link: https://lkml.kernel.org/r/20240402201252.917342-3-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>
2024-04-25 20:56:34 -07:00
Matthew Wilcox (Oracle)
03aa577f3b proc: convert clear_refs_pte_range to use a folio
Patch series "Remove page_idle and page_young wrappers".

There are only a couple of places left using the page wrappers for idle &
young tracking.  Convert the two users in proc and then we can remove the
wrappers.  That enables the further simplification of autogenerating the
definitions when CONFIG_PAGE_IDLE_FLAG is disabled.  


This patch (of 4):

Replaces four calls to compound_head() with two.

Link: https://lkml.kernel.org/r/20240402201252.917342-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20240402201252.917342-2-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>
2024-04-25 20:56:34 -07:00
Rick Edgecombe
529ce23a76 mm: switch mm->get_unmapped_area() to a flag
The mm_struct contains a function pointer *get_unmapped_area(), which is
set to either arch_get_unmapped_area() or arch_get_unmapped_area_topdown()
during the initialization of the mm.

Since the function pointer only ever points to two functions that are
named the same across all arch's, a function pointer is not really
required.  In addition future changes will want to add versions of the
functions that take additional arguments.  So to save a pointers worth of
bytes in mm_struct, and prevent adding additional function pointers to
mm_struct in future changes, remove it and keep the information about
which get_unmapped_area() to use in a flag.

Add the new flag to MMF_INIT_MASK so it doesn't get clobbered on fork by
mmf_init_flags().  Most MM flags get clobbered on fork.  In the
pre-existing behavior mm->get_unmapped_area() would get copied to the new
mm in dup_mm(), so not clobbering the flag preserves the existing behavior
around inheriting the topdown-ness.

Introduce a helper, mm_get_unmapped_area(), to easily convert code that
refers to the old function pointer to instead select and call either
arch_get_unmapped_area() or arch_get_unmapped_area_topdown() based on the
flag.  Then drop the mm->get_unmapped_area() function pointer.  Leave the
get_unmapped_area() pointer in struct file_operations alone.  The main
purpose of this change is to reorganize in preparation for future changes,
but it also converts the calls of mm->get_unmapped_area() from indirect
branches into a direct ones.

The stress-ng bigheap benchmark calls realloc a lot, which calls through
get_unmapped_area() in the kernel.  On x86, the change yielded a ~1%
improvement there on a retpoline config.

In testing a few x86 configs, removing the pointer unfortunately didn't
result in any actual size reductions in the compiled layout of mm_struct. 
But depending on compiler or arch alignment requirements, the change could
shrink the size of mm_struct.

Link: https://lkml.kernel.org/r/20240326021656.202649-3-rick.p.edgecombe@intel.com
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Aneesh Kumar K.V <aneesh.kumar@kernel.org>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Deepak Gupta <debug@rivosinc.com>
Cc: Guo Ren <guoren@kernel.org>
Cc: Helge Deller <deller@gmx.de>
Cc: H. Peter Anvin (Intel) <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Naveen N. Rao <naveen.n.rao@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:56:25 -07:00
Rick Edgecombe
5def1e0f47 proc: refactor pde_get_unmapped_area as prep
Patch series "Cover a guard gap corner case", v4.

In working on x86’s shadow stack feature, I came across some limitations
around the kernel’s handling of guard gaps.  AFAICT these limitations
are not too important for the traditional stack usage of guard gaps, but
have bigger impact on shadow stack’s usage.  And now in addition to x86,
we have two other architectures implementing shadow stack like features
that plan to use guard gaps.  I wanted to see about addressing them, but I
have not worked on mmap() placement related code before, so would greatly
appreciate if people could take a look and point me in the right
direction.

The nature of the limitations of concern is as follows. In order to ensure 
guard gaps between mappings, mmap() would need to consider two things:
 1. That the new mapping isn’t placed in an any existing mapping’s guard
    gap.
 2. That the new mapping isn’t placed such that any existing mappings are
    not in *its* guard gaps
Currently mmap never considers (2), and (1) is not considered in some 
situations.

When not passing an address hint, or passing one without
MAP_FIXED_NOREPLACE, (1) is enforced.  With MAP_FIXED_NOREPLACE, (1) is
not enforced.  With MAP_FIXED, (1) is not considered, but this seems to be
expected since MAP_FIXED can already clobber existing mappings.  For
MAP_FIXED_NOREPLACE I would have guessed it should respect the guard gaps
of existing mappings, but it is probably a little ambiguous.

In this series I just tried to add enforcement of (2) for the normal (no
address hint) case and only for the newer shadow stack memory (not
stacks).  The reason is that with the no-address-hint situation, landing
next to a guard gap could come up naturally and so be more influencable by
attackers such that two shadow stacks could be adjacent without a guard
gap.  Where as the address-hint scenarios would require more control -
being able to call mmap() with specific arguments.  As for why not just
fix the other corner cases anyway, I thought it might have some greater
possibility of affecting existing apps.


This patch (of 14):

Future changes will perform a treewide change to remove the indirect
branch that is involved in calling mm->get_unmapped_area().  After doing
this, the function will no longer be able to be handled as a function
pointer.  To make the treewide change diff cleaner and easier to review,
refactor pde_get_unmapped_area() such that mm->get_unmapped_area() is
called without being stored in a local function pointer.  With this in
refactoring, follow on changes will be able to simply replace the call
site with a future function that calls it directly.

Link: https://lkml.kernel.org/r/20240326021656.202649-1-rick.p.edgecombe@intel.com
Link: https://lkml.kernel.org/r/20240326021656.202649-2-rick.p.edgecombe@intel.com
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Deepak Gupta <debug@rivosinc.com>
Cc: H. Peter Anvin (Intel) <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Aneesh Kumar K.V <aneesh.kumar@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Guo Ren <guoren@kernel.org>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Naveen N. Rao <naveen.n.rao@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:56:25 -07:00
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>
2024-04-25 20:56:18 -07:00
Matthew Wilcox (Oracle)
dee3d0bef2 proc: rewrite stable_page_flags()
Reduce the usage of PageFlag tests and reduce the number of
compound_head() calls.

For multi-page folios, we'll now show all pages as having the flags that
apply to them, e.g.  if it's dirty, all pages will have the dirty flag set
instead of just the head page.  The mapped flag is still per page, as is
the hwpoison flag.

[willy@infradead.org: fix up some bits vs masks]
  Link: https://lkml.kernel.org/r/20240403173112.1450721-1-willy@infradead.org
[willy@infradead.org: fix warnings]
  Link: https://lkml.kernel.org/r/ZhBPtCYfSuFuUMEz@casper.infradead.org
Link: https://lkml.kernel.org/r/20240326171045.410737-11-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Svetly Todorov <svetly.todorov@memverge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:56:15 -07:00
Johannes Weiner
91cdcd8d62 mm: zswap: optimize zswap pool size tracking
Profiling the munmap() of a zswapped memory region shows 60% of the total
cycles currently going into updating the zswap_pool_total_size.

There are three consumers of this counter:
- store, to enforce the globally configured pool limit
- meminfo & debugfs, to report the size to the user
- shrink, to determine the batch size for each cycle

Instead of aggregating everytime an entry enters or exits the zswap
pool, aggregate the value from the zpools on-demand:

- Stores aggregate the counter anyway upon success. Aggregating to
  check the limit instead is the same amount of work.

- Meminfo & debugfs might benefit somewhat from a pre-aggregated
  counter, but aren't exactly hotpaths.

- Shrinking can aggregate once for every cycle instead of doing it for
  every freed entry. As the shrinker might work on tens or hundreds of
  objects per scan cycle, this is a large reduction in aggregations.

The paths that benefit dramatically are swapin, swapoff, and unmaps. 
There could be millions of pages being processed until somebody asks for
the pool size again.  This eliminates the pool size updates from those
paths entirely.

Top profile entries for a 24G range munmap(), before:

    38.54%  zswap-unmap  [kernel.kallsyms]  [k] zs_zpool_total_size
    12.51%  zswap-unmap  [kernel.kallsyms]  [k] zpool_get_total_size
     9.10%  zswap-unmap  [kernel.kallsyms]  [k] zswap_update_total_size
     2.95%  zswap-unmap  [kernel.kallsyms]  [k] obj_cgroup_uncharge_zswap
     2.88%  zswap-unmap  [kernel.kallsyms]  [k] __slab_free
     2.86%  zswap-unmap  [kernel.kallsyms]  [k] xas_store

and after:

     7.70%  zswap-unmap  [kernel.kallsyms]  [k] __slab_free
     7.16%  zswap-unmap  [kernel.kallsyms]  [k] obj_cgroup_uncharge_zswap
     6.74%  zswap-unmap  [kernel.kallsyms]  [k] xas_store

It was also briefly considered to move to a single atomic in zswap
that is updated by the backends, since zswap only cares about the sum
of all pools anyway. However, zram directly needs per-pool information
out of zsmalloc. To keep the backend from having to update two atomics
every time, I opted for the lazy aggregation instead for now.

Link: https://lkml.kernel.org/r/20240312153901.3441-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Yosry Ahmed <yosryahmed@google.com>
Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev>
Reviewed-by: Nhat Pham <nphamcs@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:55:47 -07:00
Matthew Wilcox (Oracle)
fd1a745ce0 mm: support page_mapcount() on page_has_type() pages
Return 0 for pages which can't be mapped.  This matches how page_mapped()
works.  It is more convenient for users to not have to filter out these
pages.

Link: https://lkml.kernel.org/r/20240321142448.1645400-5-willy@infradead.org
Fixes: 9c5ccf2db0 ("mm: remove HUGETLB_PAGE_DTOR")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-24 19:34:26 -07:00
Thomas Weißschuh
a35dd3a786 sysctl: drop now unnecessary out-of-bounds check
Remove the now unneeded check for ctl_table_size; it is safe
to do so as sysctl_set_perm_empty_ctl_header() does not access the
ctl_table member anymore.

This also makes the element of sysctl_mount_point unnecessary, so drop
it at the same time.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Joel Granados <j.granados@samsung.com>
2024-04-24 09:43:54 +02:00
Thomas Weißschuh
4a7b29f650 sysctl: move sysctl type to ctl_table_header
Move the SYSCTL_TABLE_TYPE_{DEFAULT,PERMANENTLY_EMPTY} enums from
ctl_table to ctl_table_header.
Removing the mutable member is necessary to constify static instances
of struct ctl_table.

Move the initialization of the sysctl_mount_point type into
init_header() where all the other header fields are also initialized.

As a side-effect the memory usage of the sysctl core is reduced.
Each ctl_table_header instance can manage multiple ctl_table instances
and is only allocated when the table is actually registered.
This saves 8 bytes of memory per ctl_table on 64bit, 4 due to the enum
field itself and 4 due to padding.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Joel Granados <j.granados@samsung.com>
2024-04-24 09:43:54 +02:00
Thomas Weißschuh
eb32d3adef sysctl: drop sysctl_is_perm_empty_ctl_table
It is used only twice and those callers are simpler with
sysctl_is_perm_empty_ctl_header().
So use this sibling function.

This is part of an effort to constify definition of struct ctl_table.
For this effort the mutable member 'type' is moved from
struct ctl_table to struct ctl_table_header.
Unifying the macros sysctl_is_perm_empty_ctl_* makes this easier.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Joel Granados <j.granados@samsung.com>
2024-04-24 09:43:54 +02:00
Thomas Weißschuh
520713a93d sysctl: treewide: drop unused argument ctl_table_root::set_ownership(table)
Remove the 'table' argument from set_ownership as it is never used. This
change is a step towards putting "struct ctl_table" into .rodata and
eventually having sysctl core only use "const struct ctl_table".

The patch was created with the following coccinelle script:

  @@
  identifier func, head, table, uid, gid;
  @@

  void func(
    struct ctl_table_header *head,
  - struct ctl_table *table,
    kuid_t *uid, kgid_t *gid)
  { ... }

No additional occurrences of 'set_ownership' were found after doing a
tree-wide search.

Reviewed-by: Joel Granados <j.granados@samsung.com>
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Joel Granados <j.granados@samsung.com>
2024-04-24 09:43:54 +02:00
Al Viro
f60d374d2c close_on_exec(): pass files_struct instead of fdtable
both callers are happier that way...

Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-04-15 16:03:24 -04:00
Masami Hiramatsu
c722cea208 fs/proc: Skip bootloader comment if no embedded kernel parameters
If the "bootconfig" kernel command-line argument was specified or if
the kernel was built with CONFIG_BOOT_CONFIG_FORCE, but if there are
no embedded kernel parameter, omit the "# Parameters from bootloader:"
comment from the /proc/bootconfig file.  This will cause automation
to fall back to the /proc/cmdline file, which will be identical to the
comment in this no-embedded-kernel-parameters case.

Link: https://lore.kernel.org/all/20240409044358.1156477-2-paulmck@kernel.org/

Fixes: 8b8ce6c75430 ("fs/proc: remove redundant comments from /proc/bootconfig")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: stable@vger.kernel.org
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-04-09 23:36:18 +09:00
Zhenhua Huang
fbbdc255fb fs/proc: remove redundant comments from /proc/bootconfig
commit 717c7c894d ("fs/proc: Add boot loader arguments as comment to
/proc/bootconfig") adds bootloader argument comments into /proc/bootconfig.

/proc/bootconfig shows boot_command_line[] multiple times following
every xbc key value pair, that's duplicated and not necessary.
Remove redundant ones.

Output before and after the fix is like:
key1 = value1
*bootloader argument comments*
key2 = value2
*bootloader argument comments*
key3 = value3
*bootloader argument comments*
...

key1 = value1
key2 = value2
key3 = value3
*bootloader argument comments*
...

Link: https://lore.kernel.org/all/20240409044358.1156477-1-paulmck@kernel.org/

Fixes: 717c7c894d ("fs/proc: Add boot loader arguments as comment to /proc/bootconfig")
Signed-off-by: Zhenhua Huang <quic_zhenhuah@quicinc.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: <linux-trace-kernel@vger.kernel.org>
Cc: <linux-fsdevel@vger.kernel.org>
Cc: stable@vger.kernel.org
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-04-09 23:31:54 +09:00
Arnd Bergmann
c40845e319 kbuild: make -Woverride-init warnings more consistent
The -Woverride-init warn about code that may be intentional or not,
but the inintentional ones tend to be real bugs, so there is a bit of
disagreement on whether this warning option should be enabled by default
and we have multiple settings in scripts/Makefile.extrawarn as well as
individual subsystems.

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

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

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

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

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

Pull MM updates from Andrew Morton:

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

 - More folio conversions from Matthew Wilcox in the series

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

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

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

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

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

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

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

 - More DAMON work from SeongJae Park in the series

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

 - Some zsmalloc maintenance work from Chengming Zhou in the series

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  Features:

   - Support idmapped mounts for hugetlbfs.

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

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

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

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

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

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

  Cleanups:

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

   - Use the dedicated file_mnt_idmap helper in ntfs3.

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

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

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

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

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

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

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

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

   - Use inode_set_ctime_to_ts() in inode_set_ctime_current()

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

   - Various smaller cleanups for eventfds.

  Fixes:

   - Fix various comments and typos, and unneeded initializations.

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

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

   - Fix build errors in various selftests.

   - Avoid wrap-around instrumentation in various places.

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

   - Fix sysv sb_read() call.

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

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

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

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

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

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

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

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

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

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

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

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

And add config item CRASH_RESERVE to control its enabling.

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

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

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

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

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

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

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

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

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


This patch (of 3):

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  Let us recap the purpose of this work:

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

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

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

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

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

Pull security module updates from Paul Moore:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  Features:

   - Add Jan Kara as VFS reviewer

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

  Cleanups:

   - Remove a redundant might_sleep() from wait_on_inode()

   - Initialize pointer with NULL, not 0

   - Clarify comment on access_override_creds()

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

   - Process aio completions in batches to avoid needless wakeups

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

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

   - Simplify fput() for files that were never opened

   - Get rid of various pointless file helpers

   - Rename various file helpers

   - Rename struct file members after SLAB_TYPESAFE_BY_RCU switch from
     last cycle

   - Make relatime_need_update() return bool

   - Use GFP_KERNEL instead of GFP_USER when allocating superblocks

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

  Fixes:

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

   - s/Retuns/Returns/g in various places

   - Add missing parameter documentation on can_move_mount_beneath()

   - Rename i_mapping->private_data to i_mapping->i_private_data

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

   - Improve __fget_files_rcu() code generation to improve performance

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

   - Fix some kernel docs in hfsplus

   - s/passs/pass/g in various places

   - Fix kernel docs in ntfs

   - Fix kcalloc() arguments order reported by gcc 14

   - Fix uninitialized value in reiserfs"

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

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

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

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

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

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

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

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

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

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

[ryan.roberts@arm.com: fix build warning when CONFIG_SYSFS is disabled]
  Link: https://lkml.kernel.org/r/20231211125320.3997543-1-ryan.roberts@arm.com
Link: https://lkml.kernel.org/r/20231207161211.2374093-4-ryan.roberts@arm.com
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: Barry Song <v-songbaohua@oppo.com>
Tested-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Tested-by: John Hubbard <jhubbard@nvidia.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Rientjes <rientjes@google.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Itaru Kitayama <itaru.kitayama@gmail.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yin Fengwei <fengwei.yin@intel.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-20 14:48:12 -08:00