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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs fixes from Christian Brauner:
- writeback:
- Update dirtied_when instead of dirtied_time_when when a wb switch
puts an inode at the newest end of the target b_dirty list. The
list was left out of order so move_expired_inodes() could stop
before older inodes, and the lazytime expiration timestamp was
reset
- Clear the old wb's dirty-I/O state and bandwidth contribution when
a batch of inode switches leaves its dirty lists empty. An empty
wb stayed scheduled for periodic writeback and inflated
bdi->tot_write_bandwidth
- Take wb_switch_rwsem across the inode scan of
cleanup_offline_cgwb(). The v7.3-rc5 fix that rotates scanned
inodes let a scan racing a sync()'s queue_io() move lazytime
inodes past the sync's cutoff, so sync() returned without
persisting their timestamps
- Don't kick writeback for an IOCB_DONTCACHE write on an inode that
has no wb yet. With cgroup writeback an O_DIRECT RWF_DONTCACHE
write to a block device dereferenced NULL
- statmount/listmount/listns:
- Refuse statmount() string requests with a buffer that isn't larger
than struct statmount
- Don't wrap around with a U64_MAX cursor in listmount() and
listns()
- Don't end listns() at an inactive namespace
- Only add init_ipc_ns and init_net to the namespace trees if
CONFIG_IPC_NS and CONFIG_NET_NS are enabled
- iomap:
- Only mark blocks uptodate in __iomap_write_begin() after reading
them and let __iomap_write_end() mark the zeroed blocks uptodate
once the copy from userspace succeeded
- Check a chunk against max_integrity_io_size() on its own before
the bio size check
- Only enforce block alignment for direct I/O into holes and
unwritten extents if IOMAP_DIO_FSBLOCK_ALIGNED is set
- backing-file:
- Check S_APPEND and S_IMMUTABLE on the backing inode. FUSE
passthrough opens the backing file with vfs_open() which skips
may_open(), so anyone who may open the FUSE file for writing could
overwrite an append-only backing file anywhere or write to an
immutable one. Open, mmap and writes now check the backing inode
the way may_open() and do_mmap() do
- Always call kiocb_end_write() for a queued write
- Let backing files inherit FMODE_NONOTIFY from the user file. The
event fds fanotify creates for permission events on a stacked
filesystem raised FS_OPEN_PERM on the real path from inside the
listener's read() and deadlocked listeners with marks on both
layers
- pidfs:
- Look the task up before checking for exit information in
PIDFD_GET_INFO and start over if the task no longer owns the pid
once all fields have been read. A caller racing release_task() got
neither PIDFD_INFO_PID nor PIDFD_INFO_EXIT or ESRCH although the
exit information was available, and a caller racing a sub-thread's
exec reported that thread's tid as the pid
- Clear the mask bits of fields that lie beyond the struct size the
caller passed. The uapi header promises that the mask names no
such field but a caller passing PIDFD_INFO_SIZE_VER0 got the
coredump and supported mask bits set for fields that were never
written
- aio:
- Give the aio ring a ->read_folio that fails with EIO so a fault on
a ring whose file was truncated gets SIGBUS instead of jumping to
NULL
- Check nr_events against the ring size before doubling it in
ioctx_alloc()
- splice:
- Only write back an implicit file position in do_splice() when the
splice helper succeeded. splice doesn't take f_pos_lock so a
failed splice restored a stale snapshot over a position that a
concurrent getdents() had moved. On ext2 the next readdir then
trusted an offset inside a directory entry
- Retry tee() when the input pipe was emptied or the output pipe
filled between the prep steps and link_pipe() instead of returning
0 while the input pipe still has writers, as splice_pipe_to_pipe()
does
- ucount:
- Take the reference that pins a ucounts level on the 0 -> 1
transition before checking the rlimit
- Read the parent ucounts before dropping the rlimit count in
do_dec_rlimit_put_ucounts()
- inode:
- Rotate inodes whose page cache couldn't be dropped to the tail of
the LRU
- Skip inodes that another LRU walker is isolating
- setns:
- Set nsset->flags before anything in prepare_nsset() can fail so
the error path drops the cred prepared for CLONE_NEWUSER. A
failing setns() with CLONE_NEWUSER and CLONE_NEWNS leaked it
together with its user namespace
- Refuse setns(CLONE_NEWNS) for a task that shares its fs_struct
again when more namespaces are requested
- minix:
- Restore uptodate on the pinned bitmap buffers before redirtying
them after a failed writeback instead of tripping the warning in
mark_buffer_dirty(), as ext2 and ext4 do for their superblock
buffers
- Reject rmdir() of a directory with a corrupted link count with
EFSCORRUPTED instead of hitting the drop_nlink() warning
- userns: Keep the exec securebits and their locks when creating or
joining a user namespace. set_cred_user_ns() reset all securebits to
SECUREBITS_DEFAULT so anyone who may create a user namespace could
shed SECBIT_EXEC_RESTRICT_FILE and SECBIT_EXEC_DENY_INTERACTIVE with
a single unshare(CLONE_NEWUSER)
- fs: Honor FOP_UNSIGNED_OFFSET in sys_llseek() and in the pread64(),
pwrite64(), preadv() and pwritev() wrappers
- proc/kcore: Advance the vmalloc retry in read_kcore_iter() by the
last vread_iter() copy instead of the running total
- eventpoll: Return the error when the wakeup source for EPOLLWAKEUP
can't be created in EPOLL_CTL_MOD instead of reporting success
without suspend protection
- coredump: Mark do_coredump() noinline_for_stack
- nsfs: Check the trailing bytes of a namespace file handle in bytes
instead of words
- netfs: Restore the per-level and per-point decoding of the debug mask
- exportfs: Release the directory file get_name() opened with
__fput_sync(). From nfsd's kernel threads the deferred fputs arrived
faster than delayed_fput retired them and each pinned the directory's
readdir state, growing unreclaimable slab by about 90 MB per second
under a parallel tree walk
- fs: Call ramfs_kill_sb() for a ramfs rootfs. Since rootfs can be
unmounted as of v7.0 its struct ramfs_fs_info was leaked
- signal: Check the blocked mask for every entry
dequeue_synchronous_signal() looks at. The scan could select a
blocked synchronous signal and deliver it while blocked
- super: Convert the superblock device table from an rhltable to a
plain hashtable under a spinlock. This fixes a bug from v7.3 where
fs_bdev_freeze() froze a btrfs filesystem through a stale member that
open_ctree() had already released while the freeze was waiting for
SB_BORN
- fork: Leave rcu_users at zero until copy_process() can't fail
anymore. bpf_task_acquire() handed out trusted references to the new
task from the task_alloc LSM hook and sched_ext's ops.init_task() and
a failing fork freed the task behind them
- xattr: Always run cap_convert_nscap() for a security.capability
write. A zero-length setxattr() skipped it and let an unprivileged
caller without CAP_SETFCAP or write permission on the file plant an
empty security.capability xattr that made every execve() of the
binary fail with EINVAL
- namei: Skip the S_ISDIR assertion in
- proc: Refuse to mount on entries below /proc/<pid>/net like fd/,
fdinfo/ and map_files/. proc_net_d_revalidate() always fails so the
first lookup by anyone with search permission ran d_invalidate() on
the dentry and detached every mount on it, locked mounts included
- libfs: Hold one mount reference for all pins instead of one per pin.
The pin count is what keeps the mount alive, so the per-pin reference
only cost a mntget() and a mntput() through
mntput_no_expire_slowpath() for every debugfs, tracefs, securityfs or
configfs file that comes and goes
- iov_iter: Return 0 from iov_iter_alignment() for an empty iterator of
any type
- watch_queue: Give info_id its own storage instead of overlaying it
with rcu_head
- filelock: Take an active superblock reference while waiting for a
delegation break. After a lazy umount closing the delegation holder
could shut down the superblock under the waiter whose final iput()
then ran shmem_evict_inode() on freed state
- fs: Skip the copy_file_range() write limit checks when there is no
data to copy
- bpf: Allow bpf_d_path() from fentry on filp_close_sync(). Since
close_range() became synchronous this cycle close(), close_range()
and the closes on exec and exit no longer go through filp_close().
fexit stays rejected since the file may be gone by then
- fs_pin: Dequeue the wait entry unconditionally in pin_kill(). A
spuriously woken waiter kept its on-stack entry queued, took that as
proof that the pin was alive and used the freed acct structure when
umount() of the accounting file raced acct(2)
- dcache: Don't fail __d_obtain_alias() for an inode without links and
aliases. The ESTALE check added this cycle broke open_by_handle_at()
and nfsd file handle decoding on NFS and FUSE where i_nlink is just
what the server last reported and the handle may well still be valid
- selftests/ovl: Fix the mountinfo expectations of the detached layer
test which has failed since it was added
* tag 'vfs-7.4-rc1.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (60 commits)
fs: don't fail __d_obtain_alias() for unlinked inodes
ns: don't add init_ipc_ns and init_net without namespace support
aio: avoid request count overflow in ioctx_alloc()
selftests/ovl: fix detached layer mountinfo expectations
bpf: Allow bpf_d_path() from filp_close_sync()
fs: skip copy_file_range write limits when there is no data
minix: reject rmdir of a directory with a corrupted link count
fs_pin: do not trust the pin after a spurious wakeup in pin_kill()
ucount: read the parent ucounts before dropping the rlimit count
splice: retry tee() instead of returning 0 when it races
selftests/pidfd: test that fields beyond the struct size are not reported
pidfs: do not report fields that do not fit into the caller's struct
fs: let backing files inherit FMODE_NONOTIFY from the user file
splice: avoid stale f_pos writeback on error
backing-file: always end a queued write
filelock: keep superblock active through delegation wait
watch_queue: keep info_id separate from rcu_head
iomap: only follow dio alignment requirement if specified
iov_iter: fix NULL deref in iov_iter_alignment()
backing-file: enforce append-only and immutable backing inodes
...
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proc_net_d_revalidate() always returns 0 so that a dentry below
/proc/<pid>/net is never reused after setns(). So lookup_fast() will end
up calling d_invalidate(), which unhashes the dentry and detaches every
mount on it, in every mount namespace; including locked mounts.
Then lookup_slow() creates a new dentry for the same entry. So a mount
on /proc/<pid>/net/dev succeeds and goes away with the first lookup of
the name by anybody with search permission on the directory. Given it's
0555 that's everyone's grandma. A mask on such a name hides nothing as
the repro below shows.
Treat those entries like I did fd/, fdinfo/ and map_files/ and refuse to
mount on them in the first place. It's nonsensical theater otherwise:
procnet net/dev stat
// SPDX-License-Identifier: GPL-2.0
/*
* procnet: cover an entry of /proc/<pid>/ with a bind mount, lock the mount,
* then look the name up.
*
* The first task stays alive, <pid> is its pid. The "container" task has its
* own mount namespace. There it binds a mask on /proc/<pid>/<name>. It drops to
* uid 1000 and enters a new user namespace with a new mount namespace, so that
* the mask is locked. Then one task looks the name up:
*
* stat the container calls stat() on the name
* umount the container calls umount2(MNT_DETACH) on the name
* nobody a task with uid 65534 in the first namespaces calls stat()
*
* The container lists its mounts before and after (that does not look the
* name up) and then reads the name. MASK is fine. Anything else means that
* the lookup uncovered the entry.
*
* usage: procnet <name> stat|umount|nobody
* name "status" is the control, "net/dev" is a file below net, "net/stat" is
* a directory below net
*/
#define _GNU_SOURCE
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <sched.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <sys/mount.h>
#include <sys/prctl.h>
#include <sys/stat.h>
#include <sys/wait.h>
#define WORK "/run/pn"
static char target[128];
static void die(const char *what)
{
fprintf(stderr, "FATAL %s: %s\n", what, strerror(errno));
exit(2);
}
static void write_str(const char *path, const char *s, int flags)
{
int fd = open(path, O_WRONLY | flags, 0644);
if (fd < 0 || write(fd, s, strlen(s)) < 0)
die(path);
close(fd);
}
/* list the mounts below /proc without a lookup of the target */
static void mounts(const char *when)
{
char line[512];
FILE *f = fopen("/proc/self/mountinfo", "r");
int n = 0;
if (!f)
die("mountinfo");
while (fgets(line, sizeof(line), f)) {
if (!strstr(line, " /proc/"))
continue;
printf("container: %s: mount: %s", when, line);
n++;
}
fclose(f);
if (!n)
printf("container: %s: nothing is mounted below /proc\n", when);
}
static void show(const char *when, int isdir)
{
char buf[48] = "";
int fd;
if (isdir) {
struct dirent *de;
DIR *d = opendir(target);
int hit = 0;
if (!d) {
printf("container: %s: opendir(%s) = %s\n", when, target, strerror(errno));
return;
}
printf("container: %s: readdir(%s) =", when, target);
while ((de = readdir(d))) {
if (de->d_name[0] == '.')
continue;
printf(" %s", de->d_name);
hit |= strcmp(de->d_name, "MASK");
}
closedir(d);
printf("%s\n", hit ? " <-- HIT" : "");
return;
}
fd = open(target, O_RDONLY);
if (fd < 0) {
printf("container: %s: open(%s) = %s\n", when, target, strerror(errno));
return;
}
if (read(fd, buf, sizeof(buf) - 1) < 0)
die("read");
close(fd);
if (strchr(buf, '\n'))
*strchr(buf, '\n') = 0;
printf("container: %s: read(%s) = \"%s\"%s\n", when, target, buf,
strncmp(buf, "MASK", 4) ? " <-- HIT" : "");
}
int main(int argc, char **argv)
{
const char *name = argc > 1 ? argv[1] : "net/dev";
const char *op = argc > 2 ? argv[2] : "stat";
int isdir = !strcmp(name, "net/stat");
int to_host[2], to_cont[2];
struct stat st;
pid_t pid;
char c;
setvbuf(stdout, NULL, _IOLBF, 0);
snprintf(target, sizeof(target), "/proc/%d/%s", getpid(), name);
if (unshare(CLONE_NEWNS) || mount(NULL, "/", NULL, MS_REC | MS_PRIVATE, NULL))
die("unshare");
mkdir(WORK, 0755);
if (mount("W", WORK, "tmpfs", 0, NULL))
die("mount W");
write_str(WORK "/mask", "MASK", O_CREAT);
mkdir(WORK "/maskdir", 0755);
write_str(WORK "/maskdir/MASK", "MASK", O_CREAT);
if (pipe(to_host) || pipe(to_cont))
die("pipe");
pid = fork();
if (pid < 0)
die("fork");
if (!pid) {
if (unshare(CLONE_NEWNS))
die("container unshare");
if (mount(isdir ? WORK "/maskdir" : WORK "/mask", target, NULL, MS_BIND, NULL)) {
printf("container: bind the mask on %s: %s\n", target, strerror(errno));
exit(0);
}
printf("container: bind the mask on %s: ok\n", target);
if (setgid(1000) || setuid(1000) || prctl(PR_SET_DUMPABLE, 1))
die("setuid");
/* lock the mount: a new user namespace with a copy of the tree */
if (unshare(CLONE_NEWUSER | CLONE_NEWNS))
die("container userns");
write_str("/proc/self/setgroups", "deny", 0);
write_str("/proc/self/uid_map", "0 1000 1", 0);
write_str("/proc/self/gid_map", "0 1000 1", 0);
mounts("before");
errno = 0;
if (!strcmp(op, "stat")) {
stat(target, &st);
printf("container: stat(%s): %s\n", target, strerror(errno));
} else if (!strcmp(op, "umount")) {
umount2(target, MNT_DETACH);
printf("container: umount2(%s, MNT_DETACH): %s\n", target, strerror(errno));
} else if (write(to_host[1], "g", 1) != 1 || read(to_cont[0], &c, 1) != 1) {
die("sync");
}
mounts("after");
show("after", isdir);
exit(0);
}
close(to_host[1]);
if (read(to_host[0], &c, 1) == 1) {
pid_t p2 = fork();
if (!p2) {
if (setgid(65534) || setuid(65534))
die("setuid");
errno = 0;
stat(target, &st);
printf("nobody: uid %u: stat(%s): %s\n", getuid(), target, strerror(errno));
exit(0);
}
waitpid(p2, NULL, 0);
if (write(to_cont[1], "g", 1) != 1)
die("sync");
}
waitpid(pid, NULL, 0);
return 0;
}
Fixes: 1fde6f21d90f ("proc: fix /proc/net/* after setns(2)")
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20261024-work-procfs-fixes-v1-1-46b03c3a8fac@kernel.org
Acked-by: Jan Kara <jack@suse.cz>
Reviewed-by: Aleksa Sarai <aleksa@amutable.com>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull more MM updates from Andrew Morton:
- "mm: make VMA flag semantics explicit, eliminate VM_SPECIAL" (Lorenzo
Stoakes):
Replace VM_SPECIAL with helpers describing mapping ownership and
behavior. Enforce the mmap flag rules and convert affected drivers,
removing ambiguous tests shared by driver mappings and ordinary
memory.
- "support kselftest on nommu platform" (Hajime Tazaki):
Add opt-in mmap and mremap tests for NOMMU systems. Teach the runner
to avoid its fork-dependent timeout command and document the build
and runtime requirements.
- "mm/collapse: separate a collapse from its callers" (Kiryl
Shutsemau):
Separate huge-page collapse from caller policy. Replace khugepaged
identity checks with explicit permissions, and separate scanning from
collapse with the mmap_lock drop in one place.
- "mm: implement and use vma_has_anon_rmap(), silence KCSAN" (Lorenzo
Stoakes):
Provide a common helper for testing whether a VMA has anonymous
reverse mappings. Document the locking rules, annotate intentional
concurrent reads for KCSAN, and convert the core MM callers.
- "mm/sparse: remove SECTION_MARKED_PRESENT and further cleanups"
(David Hildenbrand):
Remove SECTION_MARKED_PRESENT in favor of the early-section flag.
Simplify sparse memory initialization, section metadata handling and
related PFN validity checks.
- "sh: remove NUMA and SPARSEMEM support" (Mike Rapoport):
Remove SuperH NUMA and SPARSEMEM support. The extra memory banks have
been unusable since the NO_BOOTMEM conversion, leaving only the code
and data overhead.
- "mm: Unify device DAX and HugeTLB vmemmap population paths" (Muchun
Song):
Unify the generic device DAX and HugeTLB vmemmap population paths and
shared tail-page handling. Remove the duplicate DAX machinery while
retaining the powerpc radix implementation.
- "kselftest: mm: fix some failure of split_huge_page_test" (Yeoreum
Yun):
Fix huge-page split tests racing with khugepaged recollapse. Use
pagemap and page flags instead of VMA-boundary assumptions which fail
when glibc has already enabled THP.
- "memcg: move memcgid refcount to objcg to unpin dying memcgs"
(Bingfang Guo):
Let dying memcgs be freed while swapped-out shmem still holds their
IDs. Move ID references to reparentable objcgs, with the necessary
swap accounting and RCU lifetime changes.
- "mm/truncate: fix data loss when truncating straddling large folios"
(Zhang Yi):
Preserve out-of-range data when truncating straddling large folios.
Fix a lookup race and split-failure handling, and handle minimum
folio orders for the forthcoming ext4 iomap buffered I/O path.
- "mm/damon: introduce damos quota goal target metric complement flag"
(SJ Park):
Let DAMOS quota goals use a metric's complement, so utilization can
also express free-memory goals without adding separate metrics. Add
the sysfs interface, documentation and tests.
- "arm64/mm: Standardize printing for pgtable entries" (Anshuman
Khandual):
Use the generic formatter for arm64 page-table entries, ready for
future wider entries. Move the safe-PTE-update check out of the
header to avoid an include cycle.
- "mm: kmsan: fix iounmap metadata teardown" (Dima Koziuk):
Fix KMSAN metadata leaks on iounmap and failed ioremap allocations.
Free backing pages before removing their mappings, and share the
teardown with partial-allocation cleanup.
- "mm/damon/core: preserve quota state when constructing schemes" (Karl
Mehltretter):
Preserve running DAMOS quota state while validating parameter
updates. Even rejected updates could reset accounting and exceed the
quota window; add tests for both accepted and rejected updates.
- "mm/vmalloc: fix vmalloc_dump_obj VA lookup" (Ye Liu):
Fix vmalloc_dump_obj() lookups for last-page addresses and
allocations spanning vmap zones. These allocations were being missed
in diagnostic output.
- "mm: various (urgent?) fixes" (David Hildenbrand):
Fix mmap charge leaks and hugetlb use-after-free, wrong-address
unmapping, stuck locks and endless faults. Also preserve reservations
on failed mremap and handle stale userfaultfd bits.
- "maple_tree: fix maple_range_64 crashes in RCU mode" (Dimitris
Charisis):
Fix pointer and metadata confusion during RCU destruction of
maple_range_64 nodes, avoiding double frees and invalid accesses. Add
a regression test; no in-tree user currently uses this combination.
- "mm: fix hugetlb NR_HUGETLB accounting on folio migration" (Hongfu
Li):
Fix hugetlb migration and preallocation accounting so /proc/vmstat
retains the correct count and memory.numa_stat follows the folio to
its new node.
- "mm/damon: fix a minor bug, clean code, and add a test" (SJ Park):
Fix 32-bit DAMON age overflow which made old regions look young.
Share hugetlb folio acquisition code and add a regression test for
the previously fixed last-region skipping bug.
- "mm/damon/core: cleanup code, reduce stack usage, and add kunit" (SJ
Park):
Reduce kdamond stack usage and remove unused enums. Add deterministic
PSI quota-goal tests which do not depend on the machine's current
memory pressure.
- "mm/damon: fix the temporal goal tuner's size quota conversion"
(Donggeun Yoo):
Bound the temporal tuner's quota conversion to prevent overflow and
zero effective quotas, which could stop schemes making progress. Add
boundary tests.
- "Don't use GFP_DMA when calling dma_alloc_coherent" (Baoquan He):
Remove redundant GFP_DMA flags from coherent DMA allocation calls.
The DMA API already selects the zone from device limits and ignores
the caller's flag.
- "kselftest: mm: fix intermittent failure khugepaged test" (Yeoreum
Yun):
Propagate child-process failures in the khugepaged tests and prevent
background collapse from racing their checks. This removes false
passes and intermittent failures.
- "MAINTAINERS: cover all hugetlb headers under HUGETLB SUBSYSTEM"
(Enze Li):
Cover all hugetlb headers in MAINTAINERS so get_maintainer.pl finds
the right maintainers. Also label the closing hugetlb_cgroup.h
include guard.
Summary of the 65 singletons in this merge:
The singletons include a few worthwhile performance fixes. Avoiding
unnecessary reverse-map tree updates gave a reported 15.9% improvement
in UnixBench's execl test on a 192-core x86 system. A reclaim retry
fix stops defrag_mode from spinning under memory.low protection; a
reported file-creation stress test ran 5.7 times faster, with far less
memory pressure. Narrower hugetlb invalidations also spare KVM guests
needless refaults: the reported Redis-in-VM P99 QPS penalty while
punching holes fell from 7.09% to 1.45%.
Several fixes prevent lost data or corrupted memory. Lazyfree
huge-page races with mremap()/munmap() could lose data or access freed
memory, and MADV_COLD could lose a concurrent write's dirty bit.
Another fix prevents stale migration entries from outliving large
folios. On filesystems with blocks smaller than a page, extending a
file by 4 GiB or more could expose bytes written past the old EOF
through mmap instead of zeroes. That is fixed, along with
use-after-free races in PAGEMAP_SCAN during process exit and in
memory-cgroup accounting on PREEMPT_RT kernels.
Other fixes stop UFFDIO_MOVE spinning forever on pinned large folios,
which could wedge other memory operations, and stop mremap() leaking
commit charges until allocations fail under strict overcommit. A
further fix keeps userfaultfd tracking intact on neighboring mappings.
NUMA binding no longer prevents long-term pins when the chosen node
has only movable memory, fixing QEMU/VFIO startup and io_uring buffer
registration failures. MGLRU also gets a fix for early-boot crashes
with memory cgroups disabled at boot, notably in small crash kernels.
* tag 'mm-stable-2026-10-25-19-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (213 commits)
mm: multi-gen LRU: fix NULL lruvec->pgdat deref with memcg disabled on cmdline
mm/page_counter: use WRITE_ONCE() for emin/elow when parent is the root
mm/memcontrol: publish null pointer before dropping css reference
test_maple_tree: test maple_range_64 node in RCU mode
maple_tree: fix maple_range_64 crashes in RCU mode
mm/vma: avoid broken uffd merge on mremap
tools/testing/shared: catch a failed posix_memalign()
mm/damon/core: remove unreachable damos charge_{target,addr}_from
mm/shrinker: allocate shrinker_info_unit from a dedicated kmem_cache
riscv: mm: exclude invalid THP PMDs from page table check
mm/damon/core: filter out damos address filter-split failed region
fs/proc/task_mmu: pin mm_users in do_pagemap_scan()
mm/mempolicy: apply bind policies against the scoped allocation zone
mm/vmscan: reclaim every zone in per-node proactive reclaim
mm/mremap: correctly uncharge accountable VMAs in error path
mm/mremap: populate calculated fields in vrm state correctly
MAINTAINERS: add an entry for MEMORY MANAGEMENT - MEMORY MAP
mm: bdi: reset min_ratio after the sysfs attributes are gone
mm/page_vma_mapped: continue past nonmatching huge PMDs
selftests/mm: skip hugetlb cgroup v2 tests without the needed controllers
...
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull non-MM updates from Andrew Morton:
- "ocfs2: exit recovery thread on mount error path" (Joseph Qi):
Stop OCFS2 recovery before freeing failed-mount state and replay
slots, closing use-after-free and double-free races. Defer
suballocator reclaim to break a transaction-lock deadlock with
dismount.
- "ocfs2: validate suballoc slot and bit of metadata blocks" (Joseph
Qi):
Validate OCFS2 metadata suballocator slots, bits and directory index
block locations. Reject corrupt metadata with filesystem errors
instead of BUGs or out-of-bounds accesses.
- "ocfs2: deal with legacy signed name hash values" (Joseph Qi):
Restore OCFS2 lookups for non-ASCII names stored with legacy signed
hashes. Use stored xattr hashes during bucket splits to avoid
duplicate entries and spurious ENOSPC failures.
- "ocfs2: stabilize dentry names in file and setattr traces" (Cen
Zhang):
Snapshot OCFS2 names during file and setattr tracing to prevent
rename races using freed storage or mismatched names and lengths.
Preserve trace formats and the locked release open-count sample.
- "panic: fix panic_force_cpu= redirect races and NMI bypass" (Bradley
Morgan):
Fix panic_force_cpu races and NMI redirection so crash-kernel CPU
selection is honored. Preserve variable arguments on failed redirects
and use a static message buffer.
- "fat: allocate multiple clusters in fallocate" (Matheus Alves de
Almeida):
Allocate FAT clusters in batches for FALLOC_FL_KEEP_SIZE and batch
FAT updates. This removes repeated single-cluster allocation
overhead, particularly on synchronous mounts.
- "scripts/gdb: fix radix tree lookup and stack depot diagnostic"
(Ting-Han Hou):
Fix GDB radix-tree lookup and its handling of XArray sibling, retry
and zero entries. Also repair the stack-depot diagnostic for an
out-of-range pool index.
- "hung_task: Improve warning budget handling and task reporting"
(Aaron Tomlin):
Reset the hung-task warning budget after recovery so later hangs
remain visible. Keep the configured limit intact and emit one summary
per scan when detailed reports exhaust the budget.
- "bootconfig: Reject unexpected data after null character and
cleanups" (Masami Hiramatsu):
Reject bootconfig data after an embedded null while accepting
trailing padding. Validate the full input in the userspace tool, and
retain internal tree sanity checks there rather than in the kernel.
- "kbuild: GCOV cleanups following the prefer-atomic fix" (Konstantin
Khorenko):
Use the actual GCOV build flags in the prefer-atomic compiler probe.
Move flag setup into scripts/Makefile.gcov and skip the probe when
GCOV is disabled.
- "ocfs2: xattr bucket validation fixes" (Joseph Qi):
Accept valid OCFS2 xattr buckets spanning 512-byte blocks, avoiding
false read-only remounts. Reject misaligned buckets and return errors
instead of panicking on corrupt defrag metadata.
- "ocfs2: fix metadata reservation for xattr value trees" (Joseph Qi):
Reserve enough OCFS2 metadata for new and relocated xattr value
trees. Fix shortfalls which could cause ENOSPC, dropped entries and
leaked clusters on fragmented filesystems; remove duplicate
reservations.
- "Introduce arch_do_panic" (Mete Durlu):
Add arch_do_panic() and move s390 and sparc handling out of generic
panic code. The architecture-specific actions now follow the
end-of-panic marker.
- "checkpatch: userspace improvements" (Petr Vorel):
Improve checkpatch's userspace detection and suppress kernel-only
checks. Recognize standard inttypes macros and add explicit
--userspace and --no-userspace overrides.
- "ocfs2: validate dr_fs_generation of dir index root blocks" (Joseph
Qi):
Check OCFS2 directory index generations and leaf block numbers.
Reject stale or misplaced blocks instead of using metadata left by a
previously formatted filesystem.
- "selftests/membarrier: Skip an unregistered memory barrier test on
Musl" (Chris Gellermann):
Skip the unregistered membarrier test when libc has already
registered the command. Musl does this during thread creation,
causing false failures in the multithreaded test.
- "init: fix array boundary bugs in boot parameter parsing"
(Wilson Felipe Pereira):
Fix boot argument boundary cases which leave stale arguments in
init's command line or panic when replacing the final environment
variable. Clear the last slot and check duplicates before the limit.
Summary of the 87 singletons in this merge:
The OCFS2 singletons fix deadlocks between xattr updates and inline
truncation, and during inode reclaim. Corrupt quota and extent
metadata could also crash the kernel or corrupt memory; these paths
now check the layout before using it. Other fixes close use-after-free
and publication races around cluster reconfiguration, node failure,
quota remount errors and shared refcount trees. New files now retain
security labels from all stacked LSMs instead of silently dropping all
but one. Valid xattr insertions also stop tripping FORTIFY on builds
with counted arrays.
Elsewhere, a lost wakeup could leave hardware-monitoring reads stuck
in unkillable sleep and block further I2C traffic. That is fixed, as
are kernel memory leaks in POSIX message-queue notifications and tmpfs
casefold setup which could grow until memory is exhausted. A driver
removal race which could crash the kernel is fixed too. The
hibernation command through reboot() also stops taking the same mutex
twice, avoiding a deadlock before suspension.
On the boot side, bzip2 decoding now accepts valid full blocks emitted
by lbzip2, fixing failures to boot those compressed kernels. Malformed
bzip2 streams can no longer overflow the decode buffer, and LZ4
initrds are checked before the decoder can read past their end. FAT
rejects geometry which overflows the data-area calculation on 32-bit
systems, and rolls back entries when inode setup fails, preventing
failed creations from reappearing after remount. The x86 XOR and RAID6
AVX paths also avoid imposing a slowdown on subsequent SSE code.
* tag 'mm-nonmm-stable-2026-10-25-14-57' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (134 commits)
scripts/gdb: fix stack depot out-of-bounds diagnostic
scripts/gdb: fix radix tree lookup pointer handling
ocfs2/cluster: remove zero-address nodes from IP tree on teardown
ocfs2: snapshot the dentry name while tracing file release
ocfs2: snapshot dentry names in file and setattr traces
ocfs2/dlm: drain join handlers before releasing module text
MAINTAINERS: update Markus's e-mail address
mailmap: add entries for Andrew Jones
stackdepot: stop preallocating after the final pool
ocfs2: drain quorum work before removing the cluster
watchdog: force console verbose when reporting lockups
profiling: fix sampling step on 64-bit big-endian systems
kernel/reboot: avoid potential deadlocks during suspension
compat: avoid double rounding in times()
ocfs2: pin owning modules for open debugfs files
ocfs2/cluster: initialize heartbeat regions before publishing them
selftests/proc: proc-pid-vm: fix unused variable warning on non-x86
ocfs2: pin refcount trees before dropping the lookup lock
ocfs2: validate the xattr tree root of an indexed xattr block
ocfs2/dlm: hold the lookup reference across convert AST enqueue
...
|
|
The PAGEMAP_SCAN ioctl takes mmap_read_lock() on an mm obtained from
/proc/<pid>/pagemap without holding a reference to mm_users.
proc_mem_open() deliberately grabs only mm_count, so a consumer that
touches the address space has to call mmget_not_zero() first. Every other
consumer in this file does -- m_start(), do_procmap_query(),
show_smaps_rollup() and pagemap_read() -- but do_pagemap_scan() does not.
Without that reference the target can reach exit_mmap() concurrently, and
exit_mmap() calls unmap_vmas() while holding mmap_lock only for reading,
which does not exclude the scanner. For ordinary VMAs this is harmless,
as free_pgtables() and remove_vma() run afterwards under mmap_write_lock.
A shared hugetlb VMA is different: __hugetlb_zap_end() frees the VMA's
hugetlb_vma_lock inside the read-locked phase.
walk_hugetlb_range() can therefore load vma->vm_private_data, have the
lock freed underneath it, and then down_read() a freed rw_semaphore. The
load happens before the freeing side clears the pointer, so this is a
use-after-free and not a NULL dereference. Any unprivileged user can
reach it with no huge pages configured, as hugetlb_reserve_pages()
allocates the lock before the VM_NORESERVE early return.
Pin mm_users across the scan, the way the other consumers do. mmput()
from the exiting task can then no longer reach exit_mmap() while a walk is
in progress.
[akpm@linux-foundation.org: remove unneeded & undesirable test for !mm]
Link: https://lore.kernel.org/20261014095540.3261469-1-ngocquy0700@gmail.com
Fixes: 52526ca7fdb9 ("fs/proc/task_mmu: implement IOCTL to get and optionally clear info about PTEs")
Signed-off-by: Ngoc Quy <ngocquy0700@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Assisted-by: Claude:claude-opus-5
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Muhammad Usama Anjum <usama.anjum@arm.com>
Cc: <stable@vger.kernel.org>
|
|
The is_vm_hugetlb_page() predicate is badly named - the mapping can span
more than a page and it is inconsistent with other VMA predicates that
typically are prefixed by vma_.
Rename to vma_is_hugetlb() for consistency, and while we're here update
some VM_BUG_ON_VMA() to VM_WARN_ON_ONCE_VMA() as to avoid unnecessary
oopses.
No functional change intended.
Link: https://lore.kernel.org/20261013-b4-mmap-prepare-vma-flag-sanify-v6-28-1aa3c9b139f9@kernel.org
Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Marc Zyngier <maz@kernel.org>
Acked-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Acked-by: Anup Patel <anup@brainfault.org>
Acked-by: Zi Yan <ziy@nvidia.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Stephen Smalley <stephen.smalley.work@gmail.com>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Eduard Zingerman <eddyz87@gmail.com>
Cc: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Nico Pache <nico.pache@linux.dev>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Usama Arif <usama.arif@linux.dev>
Cc: Kiryl Shutsemau <kas@kernel.org>
Cc: Doug Gilbert <dgilbert@interlog.com>
Cc: James Bottomley <james.bottomley@hansenpartnership.com>
Cc: Martin K. Petersen <mkp@kernel.org>
Cc: Simona Vetter <simona@ffwll.ch>
Cc: Helge Deller <deller@gmx.de>
Cc: Sebastian Reichel <sre@kernel.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Harry Yoo <harry@kernel.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: David Airlie <airlied@gmail.com>
Cc: Will Deacon <will@kernel.org>
Cc: Aneesh Kumar K.V <aneesh.kumar@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Oliver Upton <oupton@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Paul Walmsley <pjw@kernel.org>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Rakie Kim <rakie.kim@sk.com>
Cc: Byungchul Park <byungchul@sk.com>
Cc: Gregory Price <gourry@gourry.net>
Cc: Ying Huang <ying.huang@linux.alibaba.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Chris Li <chrisl@kernel.org>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Baoquan He <baoquan.he@linux.dev>
Cc: Youngjun Park <youngjun.park@lge.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Qi Zheng <qi.zheng@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Yuanchu Xie <yuanchu@google.com>
Cc: Wei Xu <weixugc@google.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Xu Xin <xu.xin@linux.dev>
Cc: Ihor Solodrai <ihor.solodrai@linux.dev>
Cc: Bert Karwatzki <spasswolf@web.de>
|
|
pfn_to_online_page() will only succeed on some PFNs within the same
section, not necessarily all. Let's make that clearer.
While at it, rephrase it to "Allow inspection of".
Link: https://lore.kernel.org/20260921-b4-sparsemem_cleanups-v2-12-54d81d65e125@kernel.org
Signed-off-by: David Hildenbrand (Arm) <david@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Qi Zheng <qi.zheng@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Barry Song <baohua@kernel.org>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Yuanchu Xie <yuanchu@google.com>
Cc: Wei Xu <weixugc@google.com>
Cc: Baoquan He <baoquan.he@linux.dev>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Brendan Jackman <brendan.jackman@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Kieran Bingham <kbingham@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Danilo Krummrich <dakr@kernel.org>
|
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git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl
Pull sysctl updates from Joel Granados:
- Disallow partial vector updates
Stage sysctl vector writes before updating. Removes the chance of
leaving a sysctl vector partially updated due to erroneous input.
This is not an atomic write; a concurrent reader can still see a
partially updated vector.
- Remove redundant sysctl config guards
Remove locations where (CONFIG_SYSCTL && CONFIG_PROC_FS) was checked.
They are superfluous as CONFIG_SYSCTL now depends directly on
CONFIG_PROC_FS.
- Rewrite selftests using KTAP helpers
Each test now reports its own KTAP result and runs in a subshell.
Test suite continues after failure.
- Misc
Fix a use-after-free in the selftests test_sysctl module. Quiet an
unused variable warning in fs/proc/proc_sysctl.c:init_header(). Add
tests for partial vector updates and the int jiffies converters.
* tag 'sysctl-7.04-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl:
selftests: sysctl: Check the sign of a negative jiffies read
sysctl: Add jiffies converter entries to the test module
sysctl: quiet unused variable warning in fs/proc/proc_sysctl.c:init_header()
sysctl: unregister tables before freeing bitmap
sysctl: Rewrite selftests on top of KTAP helpers
sysctl: remove redundant CONFIG_PROC_FS checks
sysctl: consolidate CONFIG_SYSCTL into a single block in kernel/sysctl.c
sysctl: collapse redundant CONFIG_SYSCTL nesting in kernel/sysctl.c
sysctl: Add 0013 to test partially updated vectors
sysctl: Disallow partial updates for erroneous sysctl vectors
sysctl: Reject uint arrays before calling the general proc_vec
sysctl: Split data conversion and file position handling
|
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
- "selftests/mm: improve khugepaged coverage" (Kiryl Shutsemau):
Give khugepaged a proper workout. Extend the tests to all supported
mTHP orders, check exactly which windows collapsed, and make scan
completion deterministic. Race collapse against faults, pinning, fork
and remap; verify that the contents survive.
Add coverage for whole-page-table zaps and memory pressure too.
- "selftests/mm: separate GUP microbenchmarking from functional testing"
(Sarthak Sharma):
Untangle GUP benchmarking from correctness testing. Move the
benchmark into tools/mm, add a standalone harness-based GUP selftest,
and move shared helpers into tools/lib/mm. Give each tool one job
instead of mixing timing measurements with correctness checks.
Cover the mapping, pinning and batch-size combinations explicitly.
- "mm: Switch device DAX to section-based vmemmap optimization" (Muchun
Song):
Apply section-based vmemmap optimization to device DAX. Rework the
backing metadata layout to save memory while preserving the handling
of device memory hotplug and its different alignment and lifetime
requirements.
- "mm: Introduce section-based vmemmap optimization for HugeTLB"
(Muchun Song):
Cut the memory consumed by HugeTLB's struct page array with
section-based vmemmap optimization. Arrange the metadata so large
huge pages need fewer backing pages, while keeping initialization,
teardown and the various hugepage configurations straight.
- "mm/huge_memory: clean up and decouple the anon and file split
helpers" (Kairui Song):
Separate anonymous and file-backed folio splitting, which have rather
different locking and bookkeeping requirements. Move the work into
separate helpers, drop dead checks and tidy swap-cache handling. Fix
error paths, including one that could leave a folio frozen.
Keep the swap cache cases separate from file-cache splitting.
- "mm: Unconditional per-VMA locks and cleanups" (Dave Hansen):
Make per-VMA locking unconditional and clean up the old conditional
code around it. This removes configuration-dependent plumbing and
lets callers depend on one locking model rather than carrying both
cases along.
- "memcg: remove the v1 soft limit" (Shakeel Butt):
Remove the old cgroup v1 memory soft-limit machinery. This has long
since been superseded by the newer memory-control interfaces; hauling
around a separate reclaim scheme for it no longer buys us much.
- "read proc/pid/smaps_rollup under per-vma lock" (Suren Baghdasaryan):
Read /proc/PID/smaps_rollup using per-VMA locks where possible,
rather than holding mmap_lock across the entire walk. Retain the
contention fallback and add tearing tests. This considerably reduces
latency when another thread is busy changing its mappings.
- "mm/damon: introduce data access-as-a-data attribute" (SJ Park):
Teach DAMON to expose memory access observations as data attributes,
making them available to the probe and filtering machinery. Extend
the interfaces, documentation and tests so the new information can be
used rather than merely collected.
- "Remove PG_private by using page/folio->private checks instead" (Zi
Yan):
Get rid of PG_private and use the folio's private pointer to say
whether private data is attached. Convert the filesystem users,
including erofs, f2fs and md, and clean up the old accessors and
flags. There are a few special cases, notably swapcache and hugetlb,
which need explicit care.
- "mm: make userland page table freeing RCU-safe" (Lorenzo Stoakes):
Make freeing userspace page tables safe against RCU readers. Sort out
the page-table lifetime and locking rules so walkers cannot stumble
over freed tables while mappings are being torn down.
- "make unused huge shrinker memcg aware" (Qi Zheng):
Make shmem's unused-huge-folio shrinker aware of memory cgroups, so
reclaim can find those folios under the right memcg. Wire up the
per-memcg tracking and its lifetime rules, and give the shrinklist
its own lockdep class to avoid spurious dependency reports.
- "mm: Drop pxd_ERROR()" (Anshuman Khandual):
Remove the old pxd_ERROR() page-table checks and their
architecture-specific baggage. Simplify the common page-table
interfaces and callers now that these checks no longer serve a
useful purpose.
- "memcg: group struct fields by access pattern" (Shakeel Butt):
Rearrange memcg's hot and cold fields according to how they're
actually accessed. Keep frequently updated counters and their
neighboring state from fighting over cachelines and reduce needless
cacheline traffic.
- "mm/damon/core: fix the size charged for a filter-trimmed region"
(Donggeun Yoo):
Fix DAMOS quota accounting when a filter trims a monitoring region.
Charge only the part left after filtering, not the original region,
and add KUnit coverage. Previously the excluded memory could eat into
the quota and make schemes run more slowly than requested.
- "mm/damon: add kunit and selftests for probes and probe weights" (SJ
Park):
Add more tests for DAMON probes and their weights, including
validation and the results reported to userspace. This is mostly
about catching regressions in the newer probe infrastructure before
they become harder to diagnose.
- "mm: memcontrol: constify the read side of the read side of the memcg
API" (Tal Zussman):
Mark the read-only parts of the memcg interface const, from folio and
lruvec accessors to counters and swap helpers. Most of this is
mechanical, but it makes the contracts clearer and lets the compiler
catch accidental writes.
- "mm/damon/vaddr: support {prep,apply}_probes" (SJ Park):
Support the new prepare/apply probe operations in DAMON's
virtual-address backend. This brings vaddr monitoring into line with
the probe infrastructure and makes the added probe types useful there
too.
- "mm/mglru: clean up folio counters and flag usage" (Kairui Song):
Simplify MGLRU's folio counters and flag handling. Remove redundant
accounting paths and make the state transitions easier to follow
without changing the intended reclaim policy.
- "arch, mm/execmem: resolve confusion about set_direct_map_valid_noflush()"
(Mike Rapoport (Microsoft)):
Clarify and straighten out the set_direct_map_valid_noflush()
interface across architectures and execmem. Make the requested
mapping changes and the callers' expectations agree, rather than
relying on subtly different architecture behavior.
- "mm: zswap: free cold writeback folios promptly" (Alexandre Ghiti):
Free zswap writeback folios as soon as their disk write completes.
They are cold temporary buffers, so putting them on the LRU only
makes reclaim rediscover them later. Extend swap-cache dropbehind and
let zswap keep these folios off the LRU altogether.
- "mm: gup: cleanup gup_fast call chain" (Aristeu Rozanski):
Clean up the GUP-fast call chain and simplify how the fast-path
helpers pass their arguments and results around. Keep the page-pin
behavior the same while making the call sequence easier to maintain.
- "mm: optimize zone-device memmap initialization" (Li Zhe):
Speed up initialization of zone-device struct pages. Avoid redundant
work when setting up large device-memory ranges, where touching every
descriptor can get expensive.
- "mm/zswap: shrink zswap_entry via a pool id" (Jianyue Wu):
Reduce the size of zswap_entry by storing a compact pool identifier
instead of a full pointer. Keep the pool lookup and lifetime handling
correct while saving per-entry metadata.
- "mm/damon: support access monitoring of hugetlb-backed memory"
(Krishna Iyer):
Let DAMON monitor hugetlb-backed memory too. Extend the relevant
access checks and add coverage so those mappings no longer fall
through a hole in the monitoring machinery.
- "mm/execmem: fixes and cleanups for the ROX cache" (Mike Rapoport):
Tidy execmem's read-only-executable cache and fix its handling of the
awkward allocation and release cases. The aim is to make the cache's
ownership and permission transitions more predictable.
- "zsmallc: remove old object read API" (Sergey Senozhatsky):
Drop zsmalloc's old object-read API and move its remaining users to
the supported access mechanism. This removes a duplicate interface
which we no longer need.
- "mm/mempolicy: stop copying state in the interleave paths" (Gregory
Price):
Stop copying mempolicy state in the interleave paths when a reference
to the existing policy will do. This avoids extra work and makes the
ownership rules less obscure.
- "mm/mglru: speed up inc_min_seq() and fix cold/hot inversions" (Barry
Song):
Make MGLRU's generation advancement cheaper and fix cases where cold
and hot folios end up in the wrong order. Adjust the counter and list
handling so reclaim doesn't keep passing over the better eviction
candidates.
- "mm: Fix MF_DELAYED handling on memory failure" (Lisa Wang):
Treat MF_DELAYED as a partially completed memory-failure operation,
not an outright failure. Propagate that result correctly through
shmem and the generic handler, fix the extra-reference accounting,
and add tests for the resulting SIGBUS behavior.
- "tools/mm/page_owner_sort: fix --sort, add module filter, improve
usage" (Ye Liu):
Fix page_owner_sort's --sort handling, add module-based filtering and
make the usage output more helpful. This makes the tool less
frustrating when tracking down who is holding on to pages.
- "mm/damon: move damos filter range arguments validation to core" (SJ
Park):
Move DAMOS filter range validation into the core, where all callers
can share it. Also close the sysfs read-twice races which could pass
inconsistent ranges, and add tests for invalid input.
- "mm/damon: misc cleanups" (Zenghui Yu):
Clean up a collection of small DAMON rough edges in the core,
interfaces and tests. No large behavior change here, just simpler
code and fewer opportunities for confusion.
- "mm/damon: cleanup code, add test cases, and update guidances in
docs" (SJ Park):
Clean up DAMON's core and interfaces, add missing test cases and
bring the documentation into line with the code. These changes should
make the newer facilities easier to understand and maintain.
- "mm/damon: introduce hugepage_size probe filter" (SJ Park):
Add a DAMON probe filter for hugepage size. Let users select a range
of folio sizes through sysfs, validate the range and document the new
interface, so monitoring can concentrate on memory backed by the
desired hugepage sizes.
- "selftests/mm: pagemap_ioctl test fixes and cleanups" (Zenghui Yu):
Fix some pagemap ioctl test assumptions and clean up their setup and
reporting. Make failures point to the operation that went wrong
rather than to test harness bookkeeping.
- "mm: avoid large folio splits when swap is unavailable" (Johannes
Weiner):
Avoid splitting large folios merely to attempt swap when no swap
space is available. There is little point paying for an expensive
split when reclaim cannot actually swap the resulting pages out.
- "mm: workingset: fix the shadow node budget under MGLRU" (Hui Zhu):
Fix the workingset shadow-node budget with MGLRU enabled. Keep the
shadow entries within the intended limits so refault tracking does
not quietly consume more metadata than it should.
- "selftests/mm: TAP output and global-state fixes" (Song Hu):
Fix selftests which produce misleading TAP output or fail to restore
global settings after a run. A test ought to leave the system as it
found it, particularly when a whole suite follows behind.
- "mm: remove page_swap_entry()" (Tal Zussman):
Remove page_swap_entry() and convert its remaining users to the folio
and swap-entry helpers. Lose an old page-level interface and make the
swap paths a little more consistent.
- "mm: refactor zonelist constructors and iterators" (Gregory Price):
Refactor the zonelist construction and walk helpers to reduce
duplicated logic. Keep the allocation ordering rules intact while
making it clearer how zones are selected.
- "mm: kmemleak: batch the struct page scan" (Breno Leitao):
Scan adjacent struct pages in batches instead of taking kmemleak_lock
once for every single page. This preserves scan coverage and the
lock-hold bound, while cutting overhead substantially on debug
kernels.
- "mm/damon: misc improvements in tests and documents" (Zenghui Yu):
Fix some DAMON selftests which leave kdamond running or fail under
Python safe-path mode, and improve the KUnit coverage and
documentation. Nothing especially glamorous, but these are worth
doing.
- "mm/damon: introduce probe_hits_wsum DAMOS core filter" (SJ Park):
Add a DAMOS core filter using weighted probe-hit counts. This gives
schemes another way to select regions based on what the monitoring
probes observed.
- "mm/mglru: fix ineffective memory protection for non-kswapd reclaim"
(Ridong Chen):
Fix MGLRU's memory protection handling for reclaim outside kswapd.
The protection settings weren't having the intended effect in these
paths, leaving protected memory more exposed than requested.
- "mm/damon: improve readability, clarity and test coverage" (SJ Park):
Simplify a handful of DAMON core helpers, clarify their behavior and
expand test coverage. There are no intended userspace-visible changes
in this batch.
- "mm: replace PF_KCOMPACTD/PF_KSWAPD with kthread_func()" (Kefeng
Wang):
Stop identifying reclaim and compaction workers through the PF_KSWAPD
and PF_KCOMPACTD task flags. Use their kthread functions instead and
remove the redundant flag plumbing.
- "mm/hugetlb: fix surplus accounting and availability checks during
demotion" (Longlong Xia):
Fix HugeTLB surplus accounting and availability checks when demoting
huge pages. Keep the counters and reservation decisions consistent as
one huge page turns into several smaller ones.
- "mm/damon: add kunit tests for probe_hits handling and probe params
validation" (Jason Angelov):
Add KUnit tests for DAMON probe-hit handling and invalid probe
parameters. These cover edge cases that were too easy to miss in
ordinary monitoring tests.
- "mm/damon: fix misc bugs in kunit, quota goals and sysfs refresh_ms"
(SJ Park):
Fix a few DAMON bugs in KUnit tests, quota-goal handling and the
sysfs refresh interval. Small fixes, but the incorrect results and
control behavior were real.
- "mm: zswap: optimize zswap invalidate and store" (Kefeng Wang):
Simplify zswap's invalidate and store paths to avoid avoidable
lookups and work. Keep the entry lifetime rules intact while making
those frequent operations cheaper.
- "mm: replace custom ratelimiting logic" (Pedro Falcato):
Replace hand-rolled MM rate limiting with the common kernel helpers.
There is no need to maintain another local version of the same
mechanism.
- "mm/vmalloc: minor cleanups" (Ye Liu):
Tidy some vmalloc initialization and reporting code, and pull
duplicated vmap-area insertion work into a helper. No functional
changes are intended.
- "mm/mglru: clean up isolate_folios for readability and clarity"
(Ridong Chen):
Clean up MGLRU's isolate_folios() so the decisions are easier to read
and verify. Keep reclaim behavior unchanged while removing
unnecessary twists in the control flow.
- "Catch automatic storage in IDA and Maple Tree definitions" (Yury
Norov):
Catch IDA and maple-tree definitions placed in automatic storage
where the lifetime rules are wrong or easy to get wrong. Add checks
so such mistakes are harder to slip through unnoticed.
- "mm, swap: some random fixes and cleanups" (Kemeng Shi):
Fix and simplify a few unrelated swap paths, removing redundant work
and tidying up error handling. A small collection of things which
were better fixed than left lying around.
- "mm/page_io: folio conversion cleanups" (Tal Zussman):
Finish some page-to-folio conversions in swap I/O, removing obsolete
wrappers and using folio operations consistently. The I/O behavior is
intended to remain the same.
- "mm/swap: skip empty clusters in the swapoff scan" (Youngjun Park):
Skip empty swap clusters during swapoff instead of walking slots
which have nothing to release. This avoids pointless work on sparsely
used swap devices.
- "mm: trace: decode architecture-specific VMA flags" (Meijing Zhao):
Teach the VMA trace output to decode architecture-specific flags,
rather than leaving them as unexplained bits. That should make
tracing a good deal more useful when debugging unusual mappings.
- "mm, swap: don't spin on a bad swap entry" (Breno Leitao):
Stop repeatedly retrying a swap entry which is already known to be
bad. Make the error path terminate cleanly instead of wasting CPU
chasing an entry that cannot be used.
- "mm/page_isolation: fix UBSAN shift-out-of-bounds in
isolate_single_pageblock" (Qi Xi):
Fix an out-of-range shift in isolate_single_pageblock() and tighten
its associated boundary handling. UBSAN found the issue; the result
should be more robust pageblock isolation.
- "mm: khugepaged: fix tracepoint UAF" (Vernon Yang):
Fix a use-after-free in khugepaged tracepoint handling. Make sure the
information recorded by tracing stays valid for as long as the trace
event needs it.
- "mm/damon: fix DAMOS bugs in core, paddr and vaddr" (SJ Park):
Fix several DAMOS problems across the core and physical- and
virtual-address backends. The changes close error cases and bring the
implementations back into agreement.
- "mm/hugetlb_cgroup: move the per-node usage along with the folio"
(Hongfu Li):
Move HugeTLB per-node usage accounting when folios migrate between
nodes or are reparented to another cgroup. Otherwise numa_stat can
retain stale charges and even underflow when the folio is freed.
- "docs/core-api: memory-allocation: add k[mz]alloc_obj() and clarify
kmalloc" (Mike Rapoport):
Document the typed k[mz]alloc_obj() allocation helpers and clear up
some kmalloc guidance. Make it easier for callers to choose the right
interface.
- "selftests/mm: Validate selections and scope memfd_secret setup"
(Tianyi Chen):
Check selftest selections before running and confine memfd_secret
setup to the cases that actually need it. Avoid confusing failures
caused by the test harness itself.
- "mm/damon: move zero damos quota target_value handling to the core
layer" (SJ Park):
Handle a zero DAMOS quota goal target in the core rather than making
each user of the interface invent its own rule. Keep quota decisions
consistent across callers.
- "mm/damon: Introduce a huge page collapsing mechanism using auto
tuning" (Asier Gutierrez):
Add an auto-tuned DAMON mechanism for collapsing huge pages. Use
monitoring feedback to decide when collapse is worthwhile rather than
forcing one fixed policy onto every workload.
- "kmemleak: fix stale documentation and raise the verbose default"
(Breno Leitao):
Bring the kmemleak documentation up to date and require a third
confirming scan before verbose kernels print a suspected leak. The
extra scan helps suppress transient false positives in noisy debug
builds.
- "mm/memory: improve insert_pages() error handling" (Avi Weiss):
Tighten insert_pages() error handling so partial failures are
reported and cleaned up consistently. The caller should not have to
guess how far the operation got.
- "mm/damon: allow NULL or unstarted damon_ctx parameter for
damon_call()" (SJ Park):
Make damon_call() handle NULL and not-yet-started contexts safely.
Simplify the rules for callers and avoid an indefinite wait on an
invalid state.
- "mm/damon: introduce pgidle_set probe filter type" (SJ Park):
Add a pgidle_set DAMON probe filter, giving monitoring users another
way to select pages by their idle-tracking state. Wire it through the
filter interfaces and tests.
- "mm/damon/core: remove unused helper functions" (Cheng-Han Wu):
Remove DAMON core helpers which no longer have callers. Keep the API
surface smaller rather than retaining dead code just in case.
- "mm: stop calling pmd_folio() on special PMDs" (Gregory Price):
Avoid calling pmd_folio() on special PMD mappings that have no struct
page. The old assumption could fault in procfs walkers; use the
normal-folio checks and handle those mappings properly.
- "mm: remove three unused helpers from mm.h" (Tal Zussman):
Remove three unused helpers from mm.h. Fewer obsolete interfaces for
the next person to stumble over.
- "mm/damon: improvements in efficiency, error handling, documents"
(Liew Rui Yan):
Skip needless DAMOS quota work once the quota is full, propagate a
missing sysfs error and tidy a couple of comments. The ignored error
could make a monitoring-start request appear successful when it
wasn't.
- "docs/mm/damon/design: add explanation of nr_snapshots" (Liew Rui
Yan):
Explain DAMON's nr_snapshots accounting in the design documentation
and straighten out the associated terminology. Make it clearer what
users should expect from that counter.
- "selftests/cgroup: fixes for test_zswap on single core VM" (Wilson
Felipe Pereira):
Fix two test_zswap failures on single-CPU VMs. Wait for the exiting
child's cgroup to become unpopulated before reconfiguring it, and
avoid another test assumption which breaks under constrained
scheduling.
- "docs/ksm: fix advisor documentation and comment" (Jinjiang Tu):
Correct the KSM advisor documentation and a misleading code comment.
Keep the description aligned with how the advisor actually works.
- "Fix bugs in HugeTLB allocation when mem_cgroup_charge_hugetlb()
fails" (Ackerley Tng):
Fix HugeTLB allocation cleanup when the memcg charge fails. Make sure
failure exits undo what was allocated rather than leaving stale
accounting or resources behind.
- "mm, memcg: fix memory.peak reset clobbering other fds' watermark"
(Ridong Chen):
Fix memory.peak reset handling so resetting one file descriptor
doesn't overwrite the watermark kept for another. Keep those per-open
measurements independent as intended.
- "mm: reject zone device folios in more folio walkers" (Gregory
Price):
Reject zone-device folios in page walkers that cannot safely handle
them. Extend the existing checks rather than assuming every folio has
ordinary system-memory backing.
- "percpu: remove code with no effect" (Sang-Heon Jeon):
Remove a few pieces of percpu code which no longer do anything. There
is no reason to keep maintaining dead paths.
* tag 'mm-stable-2026-10-19-21-33' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (539 commits)
mm: shmem: assign a lock class to the unused huge shrinklist
mm: vmscan: put rotation-missed folios at the LRU tail
mm: kmemleak: scan the struct page array in MAX_SCAN_SIZE batches
mm: kmemleak: move the struct page scan into a helper
mm/damon: document that a zero sample_interval is accepted
mm/damon: fix typos in comments
mm/damon/sysfs: propagate damon_call() error in turn_damon_on
mm/damon/core: skip quota score setup when the quota is full
mm/damon/tests/core-kunit: test the size charged for a filter-trimmed region
mm/damon/core: charge only the part of a region the filter left
mm: disallow raw PFN mappings of huge/shared zeropage
selftests/mm: zap whole PTE tables in the khugepaged race harness
selftests/mm: add memory-pressure threads to the khugepaged race harness
selftests/mm: race the collapse of windows with holes
selftests/mm: add khugepaged race harness
selftests/mm: check that one khugepaged pass collapses one window
selftests/mm: run every supported collapse order by default
selftests/mm: cover a shared-source collapse write race
selftests/mm: parameterize the mixed-source collapse case by source order
selftests/mm: add order-parameterized khugepaged collapse cases
...
|
|
A readv() or preadv() of /proc/kcore fails with EFAULT, although every
byte of the destination is writable, when the page of a later iovec is
not present at the moment the copy of a KCORE_VMALLOC chunk is retried:
swapped out, migrated by compaction or NUMA balancing, write-protected
by KSM, or unmapped by MADV_DONTNEED from another thread. Only root can
read /proc/kcore, and the read must use more than one iovec. On an
x86_64 defconfig kernel (v7.3-rc7) a preadv() of one vmalloc page into
two 2 KiB iovecs on separate pages, with a second thread repeatedly
unmapping the second page, failed 77701 of 200000 calls with EFAULT;
with the fix all 200000 succeed. Affected since v6.4.
read_kcore_iter() copies a KCORE_VMALLOC chunk with vread_iter(), which
writes to the user buffer with page faults disabled and stops at the
first iovec whose page is absent, after the earlier iovecs were
written; the loop then faults the rest of the buffer in and calls
vread_iter() again for what is left. It keeps the running total in
`read` and advances the source address and the remaining length by that
total:
read += vread_iter(iter, src, left);
if (read == tsz)
break;
src += read;
left -= read;
In the reproducer the first call copies the 2048 bytes of the first
iovec and stops at the second: read is 2048, and src and left move by
2048, which is right. The page that fault_in_iov_iter_writeable() then
faults in is unmapped again before the second call, which copies 0
bytes: read is still 2048, but src moves by another 2048 to the end of
the chunk and left drops to 0. The third call has nothing to copy, src
moves by 2048 once more, left wraps around, and
fault_in_iov_iter_writeable() fails on that length, so the read returns
-EFAULT. When both short copies are non-zero (three or more iovecs) the
extra call also copies bytes from the wrong offset of the page into the
buffer before the failure. A single iovec is not affected: its nofault
copy is all or nothing, so a short copy is always empty and the advance
by the total is still the advance by the last copy.
Keep the return value of each vread_iter() call and advance src and
left by that; `read` stays the running total compared with tsz.
Found while formally verifying vread_iter() against the kernel binary.
Fixes: 4c91c07c93bb ("mm: vmalloc: convert vread() to vread_iter()")
Signed-off-by: Nickolai Zeldovich <nickolai@csail.mit.edu>
Link: https://patch.msgid.link/20261017034739.793431-1-nickolai@csail.mit.edu
Reviewed-by: Omar Sandoval <osandov@osandov.com>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
"Kconfig updates:
- Simplify PREEMPT_DYNAMIC (Mark Rutland)
Fair scheduler updates:
- Remove redundant RUN_TO_PARITY check (Elif Topuz)
- Declare augmented callbacks per field, fix
rb_add_augmented_cached() descent (Yiwei Lin, Peter Zijlstra)
- Restart fair hrtick after same-task repicks (Shubhang Kaushik)
- Improve the scheduling latency of short slice tasks (Vincent
Guittot)
Deadline/RT scheduler updates:
- Check start_dl_timer expiry with ktime_before() (Liang Hao)
- irq_work: CPU-hotplug improvements on PREEMPT_RT (Sebastian Andrzej
Siewior)
Energy-aware scheduling updates:
- Implement the steal_governor, introduce preferred CPUs and
steal-driven vCPU backoff (Shrikanth Hegde)
Multi-processor load-balancing updates:
- Enable preferred SMT siblings on NVIDIA Olympus (Andrea Righi)
- Randomize equally shallow idle CPU picks (Christian Loehle)
- Remove redundant core_sched_seq (Hui Su)
Cache-aware scheduling updates:
- Avoid publishing partial LLC utilization (Jemmy Wong)
NUMA-balancing updates:
- Reset NUMA fault locality after scan period update (Eric Kim)
Proxy execution updates:
- Ongoing work to implement sleeping owner handling for proxy
execution (John Stultz, Vasily Gorbik)
- Preparatory steps to make sched_ext compatible with proxy execution
(Andrea Righi)
Scheduler infrastructure updates & fixes:
- Remove the RCU wait from PSI trigger destruction (Shakeel Butt)
- Avoid modifying wait-entry on failed priority registration
(Hui Su)
- Use the new static key API for sched_feat (Hongyan Xia)
- Convert paravirt_steal to new static key APIs (Hongyan Xia)
- cputime: Don't account idle time twice after dyntick-idle
(Stian Halseth)
Scheduler debugging updates:
- Set TIF_NEED_RESCHED before calling __trace_set_need_resched()
(Sechang Lim)
- Fix context analysis errors in non-preferred CPU push (Shrikanth
Hegde)
Misc cleanups and fixes by Christian Loehle, Shubhang Kaushik,
Thomas Huth and Vladimir Zapolskiy"
* tag 'sched-core-2026-10-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (64 commits)
sched: Replace nr_iowait_cpu() with a bool accessor
Revert "sched/fair: Remove dead code on enqueue_task_fair()"
sched/cache: Avoid publishing partial LLC utilization
sched/cputime: Don't account idle time twice after dyntick-idle
sched/psi: Remove the RCU wait from trigger destruction
sched/eevdf: Remove redundant RUN_TO_PARITY check
sched/wait: Avoid modifying entry on failed priority registration
rbtree_test: Use rb_add_augmented_cached() for the cached augmented test
rbtree: Update augmented data on the way down in rb_add_augmented_cached()
rbtree: Declare augmented callbacks per field with RB_AUG()
rbtree_test: Use rb_add() and rb_add_cached() for the basic tests
smpboot: Don't park the thread if work is pending
irq_work: Flush lazy work CPU down on PREEMPT_RT
irq_work: Update a comment regarding CPU hotplug invocation
sched/topology: Add asymmetric SMT packing override
sched/fair: Honor asymmetric SMT priority in idle selection
sched: Set TIF_NEED_RESCHED before calling __trace_set_need_resched()
sched/core: Fix context analysis errors in non-preferred CPU push
virt/steal_governor: Enable the driver
virt/steal_governor: Implement steal_governor policy loop
...
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|
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull misc vfs updates from Christian Brauner:
"Fixes:
- aio: a keyed poll completion on an epoll instance could recurse
into the same epoll waitqueue lock when the result eventfd is
watched by that very instance. An unprivileged process could make a
CPU spin on the recursive lock. eventfd-backed poll completions are
always deferred now.
- fsnotify_inoderemove() is only called once the inode is really
dead, no nlink and no aliases, and open_by_handle_at() can't add an
alias to a dead inode anymore. The race could crash fsnotify or
lose inode mark notifications.
- devtmpfs: the conversion of the public instance to ->get_tree()
broke reconfiguring the shared superblock's options on later mounts
which made the boot time defaults permanent. A reconfigure context
is kept in fc->fs_private so the parse ops can forward options to
the underlying filesystem.
- ufs truncated the 64-bit directory size to an unsigned int in
ufs_last_byte(). A crafted image with a 4 GiB directory produced an
out-of-folio read in ufs_find_entry() and, with
CONFIG_UFS_FS_WRITE, a write into an adjacent page.
- devpts rejects max=0 instead of silently lifting the per-instance
pty limit. The value wrapped into ida_alloc_max() and became
unlimited.
- fs_pin publishes pins with the rcu list helpers so the kill paths
reading the lists under rcu see the initialization.
- dentry_kill() reports a Tasks-RCU quiescent state. Its
cond_resched() is the only reschedule point on the dentry teardown
path and cond_resched() isn't a quiescent state for Tasks-RCU, so
Meta kept seeing rcu_tasks stalls in btrfs subvolume deletion.
- writeback sizes foreign flushes by the target wb's dirty pages
instead of the memcg-wide count which over or undersized a single
bdi flush.
- nfsd READ emitted two fsnotify access events on the iterator path
since vfs_iocb_iter_read() already sends one. A READ on a krb5i or
krb5p mount showed up twice in inotify.
- pipe and splice pass a poll key when waking readers and writers so
epoll, poll() and select() waiters only wake for the event they
asked for.
- the iso8859-14 Unicode to charset tables had page01 duplicated as
page1e so 29 code points mapped to the wrong bytes and 22 that
aren't in the charset were accepted.
- orangefs doesn't wait for an unmount service operation that never
returns on system shutdown and uses ssize_t for strscpy() errors.
- __register_chrdev() checks the kobject_set_name() return value.
- selftest fixes: the openat2 tests hardcoded O_LARGEFILE to 0x8000
which is O_NOFOLLOW on powerpc, resolve_test makes /tmp a
mountpoint so RESOLVE_NO_XDEV has a boundary to trip over,
file_stressor moves into its own directory with a 30 minute
timeout, the kernfs listxattr test skips when SELinux exposes
security.selinux, the namespaces active reference tests wait for
the thread via a PIDFD_THREAD pidfd since pthread_join() returns
before exit_nsproxy_namespaces(), the idmapped_tmpfile test chowns
its directory into the mapped range, the clone3 CLONE_CLEAR_SIGHAND
test adds CLONE_VM so it fails for the intended reason, the pidfd
PPID error message prints the values it compares and fscontext_ns
gets a .gitignore.
Cleanups:
- vmcore prints the release of the crashed kernel from the VMCOREINFO
note so a kdump that dies before the dump lands still says which
kernel it was for.
- initramfs allocates hardlink hash entries with the validated cpio
name length instead of PATH_MAX, which put every entry in
kmalloc-8k.
- the unused dax_layout_busy_page() is removed,
dax_layout_busy_page_range() becomes static and dax_folio_init()
drops a redundant list initialization.
- vfs_empty_path() is removed, it has had no callers since
getname_maybe_null().
- comment and documentation fixes in aio, bpf_fs_kfuncs,
fs-writeback, inode, read_write, squashfs and the vfs.rst copy of
struct file_system_type"
* tag 'vfs-7.4-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (38 commits)
selftests/filesystems: Fix idmapped_tmpfile layer dir ownership
selftests/namespaces: Wait for thread exit via pidfd in active-ref tests
writeback: size foreign flushes by target wb dirty pages
initramfs: Reduce hardlink hash allocation sizes
fs: remove unused vfs_empty_path()
dcache: report a Tasks-RCU quiescent state in dentry_kill()
vmcore: report the release of the crashed kernel
splice: pass a poll key when waking pipe readers and writers
pipe: pass a poll key when waking writers after a resize
orangefs: use ssize_t instead of size_t for error codes...
orangefs_super: don't wait on service operation on system shutdown.
docs/vfs: Fix the struct file_system_type copy
nls: fix the Unicode to charset tables of iso8859-14
selftests/filesystems/openat2: make /tmp a mountpoint inside private namespace
selftests/filesystems/openat2: fix O_LARGEFILE definitions for non-arm64 architectures
fs: fix misleading comments in read_write.c
squashfs: fix inode number description in documentation
fs: fix typos in comments
fs/dax: Make dax_layout_busy_page_range() static
fs/dax: Remove unused dax_layout_busy_page()
...
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|
proc/pid/smaps_rollup can be read using the combination of RCU and VMA
read locks, similar to proc/pid/{maps|smaps|numa_maps}. RCU is required
to safely traverse the VMA tree and VMA lock stabilizes the VMA being
processed and the pagetable walk. Note that we have to keep the logic to
drop mmap_lock on contention because even when using per-VMA locks we
might have to fall back to holding the mmap_lock.
Running Paul's contention benchmark [1] shows considerable improvement
both in median and in the worst case latencies:
Execution command: run-proc-vs-map.sh --nsamples 20 --rawdata -- \
--busyduration 2 --procfile smaps_rollup
Baseline:
Median Minimum Maximum
0.174 0.161 2.553
0.174 0.164 2.663
0.174 0.165 2.664
0.174 0.166 2.679
0.174 0.167 2.691
0.174 0.168 2.704
0.174 0.169 2.729
0.174 0.172 2.741
0.174 0.174 2.745
0.174 0.174 2.755
0.174 0.175 2.790
0.174 0.177 2.809
0.174 0.179 3.096
0.174 0.183 3.144
0.174 0.184 3.158
0.174 0.185 3.175
0.174 0.185 4.568
0.174 0.198 4.821
0.174 0.214 5.143
0.174 0.251 5.220
Patched:
Median Minimum Maximum
0.007 0.007 1.952
0.007 0.007 1.955
0.007 0.007 1.955
0.007 0.007 1.955
0.007 0.007 1.957
0.007 0.007 1.969
0.007 0.007 2.065
0.007 0.007 2.075
0.007 0.007 2.146
0.007 0.007 2.195
0.007 0.007 2.223
0.007 0.007 2.259
0.007 0.007 2.488
0.007 0.007 2.562
0.007 0.007 2.599
0.007 0.007 2.697
0.007 0.007 3.030
0.007 0.007 3.075
0.007 0.007 3.145
0.007 0.007 3.225
Remove now unused lock_ctx_mm() and move unlock_ctx_vma() next to
unlock_ctx_mm() as they are logically related.
Remove a long comment about 4 cases that we handle when dropping the mmap
lock in the middle of VMA walk due to contention. The first 3 cases
explained there are handled naturally and only case 4 needs to be handled
in a special way, which is done in smap_gather_stats() by gathering stats
from the portion of the VMA that has not yet been processed. For
posterity, moving this comment here:
After dropping the lock, there are four cases to consider. See the
following example for explanation.
+------+------+-----------+
| VMA1 | VMA2 | VMA3 |
+------+------+-----------+
| | | |
4k 8k 16k 400k
Suppose we drop the lock after reading VMA2 due to
contention, then we get:
last_vma_end = 16k
1) VMA2 is freed, but VMA3 exists:
vma_next(vmi) will return VMA3.
In this case, just continue from VMA3.
2) VMA2 still exists:
vma_next(vmi) will return VMA3.
In this case, just continue from VMA3.
3) No more VMAs can be found:
vma_next(vmi) will return NULL.
No more things to do, just break.
4) (last_vma_end - 1) is the middle of a vma (VMA'):
vma_next(vmi) will return VMA' whose range
contains last_vma_end.
Iterate VMA' from last_vma_end.
Link: https://lore.kernel.org/20260918153318.758387-7-surenb@google.com
Link: https://github.com/paulmckrcu/proc-mmap_sem-test [1]
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Cc: David Hildenbrand (Arm) <david@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Liam R. Howlett (Oracle) <liam@infradead.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: "Paul E . McKenney" <paulmck@kernel.org>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Usama Arif <usama.arif@linux.dev>
Cc: Vlastimil Babka <vbabka@kernel.org>
|
|
proc_get_vma() returning gate VMA at the end is desirable for the its
current m_start/m_next callers, as they need to report a gate VMA at the
end of the address space. This behavior is very specific to these callers
and makes proc_get_vma() hard to use for other purposes.
Move this usage-specific behavior into the callers themselves so that
proc_get_vma() returns either a valid VMA, an error or a NULL when no more
VMAs are available. This makes it more generic, simpler and usable in the
later patches.
Link: https://lore.kernel.org/20260918153318.758387-6-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Liam R. Howlett (Oracle) <liam@infradead.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: "Paul E . McKenney" <paulmck@kernel.org>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Usama Arif <usama.arif@linux.dev>
Cc: Vlastimil Babka <vbabka@kernel.org>
|
|
smap_gather_stats() interprets its start parameter to mean vma->vm_start
when it's set to 0. Eliminate this special interpretation and provide two
separate functions for a partial and complete VMA walk.
Since smap_gather_stats() operates within a single VMA, we can replace
walk_page_vma()/walk_page_range() calls with walk_page_range_vma() which
is simpler and also can be called while holding per-VMA lock.
No functional change intended.
Link: https://lore.kernel.org/20260918153318.758387-5-surenb@google.com
Suggested-by: Lorenzo Stoakes <ljs@kernel.org>
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Liam R. Howlett (Oracle) <liam@infradead.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: "Paul E . McKenney" <paulmck@kernel.org>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Usama Arif <usama.arif@linux.dev>
Cc: Vlastimil Babka <vbabka@kernel.org>
|
|
smap_gather_stats() optimizes stats gathering by skipping the walk for
shmem mappings in certain conditions. Update the comment to clarify these
conditions and use vma_is_cow_mapping() for CoW identification instead of
open-coding it.
No functional change intended.
Link: https://lore.kernel.org/20260918153318.758387-4-surenb@google.com
Suggested-by: David Hildenbrand (Arm) <david@kernel.org>
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Liam R. Howlett (Oracle) <liam@infradead.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: "Paul E . McKenney" <paulmck@kernel.org>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Usama Arif <usama.arif@linux.dev>
Cc: Vlastimil Babka <vbabka@kernel.org>
|
|
It was pointed out in the previous reviews of this code that many
functions are specified as inline, which is unnecessary as the compiler
can make that decision by itself. Cleanup these definitions.
No change in the resulting binary file size with gcc v15.2.0. No
functional change intended.
[akpm@linux-foundation.org: fix CONFIG_NUMA=y && CONFIG_PROC_PAGE_MONITOR=n]
Link: https://lore.kernel.org/20260918153318.758387-3-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Liam R. Howlett (Oracle) <liam@infradead.org>
Reviewed-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Acked-by: Usama Arif <usama.arif@linux.dev>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: "Paul E . McKenney" <paulmck@kernel.org>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Vlastimil Babka <vbabka@kernel.org>
|
|
Patch series "read proc/pid/smaps_rollup under per-vma lock", v5.
proc/pid/smaps_rollup can be read using the combination of RCU and VMA
read locks, similar to proc/pid/{maps|smaps|numa_maps}. RCU is required
to safely traverse the VMA tree and VMA lock stabilizes the VMA being
processed and the pagetable walk. Note that we have to keep the logic to
drop mmap_lock on contention because even when using per-VMA locks we
might have to fall back to holding the mmap_lock.
The first 5 patches are cleanups making later change simpler. The main
change is in patch 6. Patch 7 extends existing proc-maps-race tearing
test to verify smaps_rollup content.
This patch (of 7):
When per-vma locks were behind a config option, a number of helper
functions were needed to simplify the locking code. Now that these locks
are universally available, we can do a little cleanup. Remove
lock_vma_range(), unlock_vma_range(), query_vma_setup(),
query_vma_teardown() helpers.
No functional change intended.
Link: https://lore.kernel.org/20260918153318.758387-1-surenb@google.com
Link: https://lore.kernel.org/20260918153318.758387-2-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Liam R. Howlett (Oracle) <liam@infradead.org>
Reviewed-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Acked-by: Usama Arif <usama.arif@linux.dev>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: "Paul E . McKenney" <paulmck@kernel.org>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Vlastimil Babka <vbabka@kernel.org>
|
|
Use a folio for the page cache page the s390 fault handler reads the old
kernel's memory into. This removes four compound_head() calls and one of
the last callers of find_or_create_page().
The vmcore mapping only has order-0 folios, so the logic is unchanged.
Compile tested for s390.
Link: https://lore.kernel.org/20260915-vmcore-fault-folio-v1-1-a0cb6278670f@columbia.edu
Signed-off-by: Tal Zussman <tz2294@columbia.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Pratyush Yadav <pratyush@kernel.org>
Cc: Baoquan He <baoquan.he@linux.dev>
Cc: Dave Young <ruirui.yang@linux.dev>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
|
|
mshv_vtl_low can install a special PMD from a PFN supplied in the mmap file
offset. That PFN need not have a memmap entry. Reading /proc/PID/pagemap
or writing /proc/PID/clear_refs for such a mapping oopses the kernel.
With a test driver mapping the PFN at the 1 TiB mark:
echo 1 > /proc/self/clear_refs
BUG: unable to handle page fault for address: fffffb5b80000008
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
RIP: 0010:clear_refs_pte_range+0xb1/0x1e0
Call Trace:
walk_pgd_range+0x50a/0xad0
__walk_page_range+0x6a/0x1d0
walk_page_range_mm_unsafe+0x193/0x230
clear_refs_write+0x18e/0x3f0
pread(pagemap_fd, buf, 512 * 8, addr / PAGE_SIZE * 8)
BUG: unable to handle page fault for address: fffff57840000008
RIP: 0010:pagemap_pmd_range+0x3cf/0x6b0
Call Trace:
walk_pgd_range+0x50a/0xad0
__walk_page_range+0x6a/0x1d0
walk_page_range_mm_unsafe+0x193/0x230
pagemap_read+0x1dc/0x350
clear_refs_pte_range() passes the PMD to pmd_folio(), while
pagemap_pmd_range_thp() uses pmd_page() followed by page_folio().
Both paths assume the PFN has a struct page and dereference bad address.
Use vm_normal_folio_pmd() and vm_normal_page_pmd() so clear_refs skips
folio operations and pagemap skips folio-derived flags for special PMDs.
This matches the PTE paths, which already use vm_normal_folio() and
vm_normal_page().
User-facing notes:
- Pagemap still reports PM_PRESENT and the PFN to a CAP_SYS_ADMIN reader.
- For a special PMD backed by a valid memmap entry and for the huge
zero PMD, PM_FILE changes from set to clear.
- PM_MMAP_EXCLUSIVE is already clear in both cases.
- The output for an anonymous THP is unchanged.
Tested in QEMU with the test driver on broken and fixed kernels. Both proc
operations oops before the fix and return 0 after it.
This is technically reachable via mshv_vtl_low, so I tagged it stable.
Link: https://lore.kernel.org/20260912122822.3348978-1-gourry@gourry.net
Fixes: 3c8e44c9b369 ("mm: mark special bits for huge pfn mappings when inject")
Signed-off-by: Gregory Price <gourry@gourry.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reported-by: sashiko-bot <sashiko-bot@kernel.org>
Closes: https://sashiko.dev/#/patchset/20260912034833.2952750-1-gourry%40gourry.net
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Assisted-by: LLM
Cc: Jann Horn <jannh@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: <stable@vger.kernel.org> # v6.19+
|
|
After the changes of the prior commits, page/folio->private != NULL is now
equivalent to checking PG_private.
Stop checking PG_private on pages and folios and use page/folio->private
instead, except swapcache and hugetlb folios, because the former uses a
field (swp_entry_t swap) overlapping with ->private and the latter sets
its flags in ->private. Exclude swapcache and hugetlb when the code is
meant to check PG_private only. PG_swapcache and folio->swap.val cannot
be set/clear as a whole, so excluding swapcache with
folio_test_swapcache() is not reliable. Instead, use
folio_test_swapbacked(), since PG_swapbacked is stable when a folio is
added to/removed from swapcache. Add a helper,
folio_has_attached_private(), for this check.
folio_test_private() and PagePrivate() now read folio/page->private
plainly instead of an atomic read of PG_private bit, so KCSAN complains
about possible data races. Annotate them with data_race().
folio_expected_ref_count() can be called without the folio lock, so
annotate folio->mapping with data_race() while at it.
folio_set/clear_private() and Set/ClearPagePrivate() become no-ops.
PG_private is no longer checked at page free time. They will be removed in
an upcoming commit.
Remove KPF_PRIVATE since PG_private is no longer used.
Link: https://lore.kernel.org/20260920-remove-pg_private-v5-10-bb68b6a21869@nvidia.com
Signed-off-by: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Assisted-by: LLM
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Liam R. Howlett" <liam@infradead.org>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Nico Pache <nico.pache@linux.dev>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Usama Arif <usama.arif@linux.dev>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Rakie Kim <rakie.kim@sk.com>
Cc: Byungchul Park <byungchul@sk.com>
Cc: Gregory Price <gourry@gourry.net>
Cc: Ying Huang <ying.huang@linux.alibaba.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Qi Zheng <qi.zheng@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Kairui Song <kasong@tencent.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Yuanchu Xie <yuanchu@google.com>
Cc: Wei Xu <weixugc@google.com>
|
|
When a posix timer is created targeting a specific thread (using
SIGEV_SIGNAL | SIGEV_THREAD_ID), it takes a reference to the target struct
pid in timer->it_pid. If the target thread subsequently terminates, its
numeric tid is freed and can be recycled for an unrelated task. However,
the timer holds its reference to the original struct pid.
show_timer() in /proc/[pid]/timers previously called pid_nr_ns() directly
on timer->it_pid without checking whether any task remained attached to
that struct pid. As a result:
1. It reported the stale tid, which could mistakenly refer to a recycled
pid.
2. In the kernel, expired signals for dead target threads are dropped by
posixtimer_send_sigqueue() because posixtimer_get_target() returns
NULL, so the timer functionally acts as SIGEV_NONE.
3. Checkpoint/restore tools (CRIU) parsing /proc/[pid]/timers would try
to restore a timer with SIGEV_SIGNAL | SIGEV_THREAD_ID targeting a
non-existent or unrelated thread.
Check pid_has_task(timer->it_pid, timer->it_pid_type) in show_timer(). If
the target task has died, override notify to SIGEV_NONE and report PID 0
(e.g., 'notify: none/pid.0').
Link: https://lore.kernel.org/20260816161216.984580-1-avagin@google.com
Fixes: 57b8015e07a7 ("posix-timers: Show sigevent info in proc file")
Signed-off-by: Andrei Vagin <avagin@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
|
|
Patch series "mm: Unconditional per-VMA locks and cleanups", v7.
tl;dr: Make per-VMA locks available in all configs. Simplify some of the
per-VMA lock users now that they can rely on them being always available.
Binder and networking folks: Your code is the target of the cleanups. I'm
cc'ing you now on v2 because there's emerging consensus on the mm side
that the approach here is sane. I'm not quite sure how this pile would
get merged, but ack/review tags would be appreciated if this looks good to
you.
Longer version:
When working on some x86 shadow stack code, it was a real pain to avoid
causing recursive locking problems with mmap_lock. One way to avoid those
was to avoid mmap_lock and use per-VMA locks instead. They are great, but
they are not available in all configs which makes them unusable in generic
code, or if you want to completely avoid mmap_lock.
Make per-VMA locks available in all configs. Right now, they are only
available on select architectures when SMP and MMU are enabled. But all
of the primitives that per-VMA locks are built on (RCU, maple trees,
refcounts) work just fine without SMP or MMU.
The only real downside is that making VMAs a wee bit bigger on !MMU and
!SMP builds.
The upside is much cleaner code, lower complexity and less #ifdeffery.
Clean up a binder VMA locking site now that it can rely on per-VMA locks.
Building on top of universally-available per-VMA locks, introduce a new
helper. Since the new API does not require callers to have a fallback to
mmap_lock, it's much easier to use. Callers can potentially replace this
very common kernel idiom:
mmap_read_lock(mm);
vma = vma_lookup()
// fiddle with vma
mmap_read_unlock(mm);
with:
vma = vma_start_read_unlocked(mm, address);
// fiddle with vma
vma_end_read(vma);
Which avoids mmap_lock entirely in the fast path.
Use that new API for another binder site and one in the TCP code.
This patch (of 7):
The per-VMA locks have been around for several years. They've had some
bugs worked out of them and have seen quite wide use. However, they are
still only available when architectures explicitly enable them. Remove
the conditional compilation around the per-VMA locks, making them
available on all architectures and configs.
The approach up to now seemed to be to add ARCH_SUPPORTS_PER_VMA_LOCK when
the architecture started using per-VMA locks in the fault handler. But,
contrary to the naming, the Kconfig option does not really indicate
whether the architecture supports per-VMA locks or not. It is more of a
marker for whether the architecture is likely to benefit from per-VMA
locks.
To me, the most important thing side-effect of universal availability is
letting per-VMA locks be used in SMP=n configs. This lets us use
per-VMA locking in all x86 code without fallbacks.
Overall, this just generally makes the kernel simpler. Just look at the
diffstat. It also opens the door to users that want to use the per-VMA
locks in common code. Doing *that* brings additional simplifications.
The downside of this is adding some fields to vm_area_struct and
mm_struct. There are likely ways to optimize this, especially for things
like SMP=n configs. For now, do the simplest thing: use the same
implementation everywhere.
== Considerations for NOMMU config ==
NOMMU systems do not write-lock VMAs, therefore read-locking a VMA would
always succeed unless VMA is detached. Therefore for NOMMU config we make
vma_mark_attached() a NOOP, which keeps VMAs always in detached state.
This causes VMA read-locking to always fail and the caller falls back to
locking mmap_lock.
The following functions will have a different implementation in NOMMU
config:
- vma_mark_attached(), vma_mark_detached() are made NOOPs, keeping VMAs
always in a detached state and preventing assertions and refcount
underflows;
- vma_start_write(), vma_start_write_killable() are made NOOPs to avoid
warnings in __vma_start_write() due to VMAs being detached. These
functions are not used in NOMMU code but __vma_start_write() is an
exported function, therefore might be used by drivers.
- vma_assert_attached() is made NOOP because it's reachable from NOMMU
code via split_vma()->vma_iter_store_new()->vma_iter_store_overwrite();
- vma_assert_write_locked() is asserting vma->vm_mm is write-locked, as
was done before this change;
- vma_assert_locked() is asserting vma->vm_mm is locked, as was done
before this change;
The following functions work for both MMU and NOMMU configs:
- vma_lock_init() performs the same initialization as for MMU config;
- mm_lock_seqcount_init(), mm_lock_seqcount_begin(),
mm_lock_seqcount_end() are called from mmap_write_{lock|unlock} and
update mm_lock_seq correctly.
- mmap_lock_speculate_try_begin(), mmap_lock_speculate_retry() work as
is because mm_lock_seq is updated correctly;
- vma_start_read(), vma_start_read_locked() will always fail because
VMAs are always detached;
- vma_end_read() will never be called because vma_start_read() never
succeeds;
- vma_is_attached() always return false because VMAs are always
detached;
- vma_assert_detached() will never trigger because VMAs are never
attached;
- vma_start_read_locked() always return false because VMAs are always
detached;
- lock_vma_under_rcu() will be safe as the attempted read lock will bail;
Changes in the following files are not affecting NOMMU config:
task_mmu.c - not compiled when CONFIG_MMU=n;
pagewalk.c - not compiled when CONFIG_MMU=n;
userfaultfd.c - not compiled when CONFIG_MMU=n (CONFIG_USERFAULTFD depends
on CONFIG_MMU);
The following changes in the BPF code are made to keep NOMMU config
working like before:
stack_map_lock_vma() - keeps mmap_lock in NOMMU config;
bpf_iter_task_vma_new() - bails out in NOMMU config;
Link: https://lore.kernel.org/20260831203056.838265-1-surenb@google.com
Link: https://lore.kernel.org/20260831203056.838265-2-surenb@google.com
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Todd Kjos <tkjos@android.com>
Cc: Christian Brauner <christian@brauner.io>
Cc: Carlos Llamas <cmllamas@google.com>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: David Ahern <dsahern@kernel.org>
Cc: Arve Hjønnevåg <arve@android.com>
|
|
In oom_badness() and proc_oom_score(), the oom_score_adj normalization
uses a hardcoded 1000, which is the value of OOM_SCORE_ADJ_MAX defined in
include/uapi/linux/oom.h. Other code in the kernel (e.g. fs/proc/base.c
oom_adj handling) already uses OOM_SCORE_ADJ_MAX for the same purpose.
Replace the magic number with the macro for consistency and readability.
No functional change.
Link: https://lore.kernel.org/20260811033609.3992348-1-ye.liu@linux.dev
Signed-off-by: Ye Liu <liuye@kylinos.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Song Hu <husong@kylinos.cn>
|
|
Provide a new helper function which sums up a given type of cpustat
over a specified cpumask.
This allows the caller's code to be simpler and avoids duplication.
For example, subsequent patch in the steal governor use this exact
same pattern when calculating steal time.
Number of cpus can be derived from cpumask_weight() where necessary.
Suggested-by: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Yury Norov <ynorov@nvidia.com>
Reviewed-by: Mete Durlu <meted@linux.ibm.com>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://patch.msgid.link/20260928053728.797539-2-sshegde@linux.ibm.com
|
|
kdump runs in a very small environment and cut-down set of drivers, and
it can die before the dump lands: it runs out of memory, a device hangs
on reset, or a watchdog fires while the dump is still being written out.
This happens about a single high digit percentage on most of big scale
datacenters.
When that happens the only evidence left is what the capture kernel
printed to the console, and that does not say which kernel crashed.
A fleet typically pins one kdump image and boots it after crashes from
many different production kernels, and it is useful to understand what
are the combination of crashed kernel panic and succesful kdump
collection.
Whether the dump completes at all tends to depend on the kernel that
died: memory pinned, devices in flight, dump size.
The release is already recorded. crash_save_vmcoreinfo_init() puts
OSRELEASE= in the VMCOREINFO note, and by the time vmcore_init() has run
parse_crash_elf_headers() that note sits in elfnotes_buf. Walk the notes
for it and print:
vmcore: dump is from kernel 7.3.0-rc3-next-20260917
Given this is cheap and useful, I think it is worth adding to vmcore, to
improve kdump monitoring.
Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20260921-kdump_print-v1-1-e445fec3177c@debian.org
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
|
|
The init_header() function uses list_for_each_table_entry() without
using the entry argument. This causes a warning when building with W=1.
Since the code is correct, mark the associated variable as
__maybe_unused.
Signed-off-by: Ethan Nelson-Moore <enelsonmoore@gmail.com>
Signed-off-by: Joel Granados <joel.granados@kernel.org>
|
|
Convert to const struct mnt_idmap.
A mount's idmapping is immutable. The only thing that is allowed to be
modified afterwards is the reference count and that is hidden behind
mnt_idmap_get() and mnt_idmap_put(). Everything else only ever reads
from the idmapping. This is the same model that struct cred uses and the
idmapping is also rather sensitive.
So make the idmap argument const wherever we can. The conversion is done
from the bottom up so callers can continue to pass a non-const pointer
to a const parameter until the conversion is finished.
No functional changes.
Link: https://patch.msgid.link/20260901-work-idmap-const-v1-24-54ccd48e100b@kernel.org
Acked-by: Paul Moore <paul@paul-moore.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Seth Forshee <sforshee@kernel.org>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
|
|
Convert to const struct mnt_idmap.
A mount's idmapping is immutable. The only thing that is allowed to be
modified afterwards is the reference count and that is hidden behind
mnt_idmap_get() and mnt_idmap_put(). Everything else only ever reads
from the idmapping. This is the same model that struct cred uses and the
idmapping is also rather sensitive.
So make the idmap argument const wherever we can. The conversion is done
from the bottom up so callers can continue to pass a non-const pointer
to a const parameter until the conversion is finished.
No functional changes.
Link: https://patch.msgid.link/20260901-work-idmap-const-v1-23-54ccd48e100b@kernel.org
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Seth Forshee <sforshee@kernel.org>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
|
|
Convert to const struct mnt_idmap.
A mount's idmapping is immutable. The only thing that is allowed to be
modified afterwards is the reference count and that is hidden behind
mnt_idmap_get() and mnt_idmap_put(). Everything else only ever reads
from the idmapping. This is the same model that struct cred uses and the
idmapping is also rather sensitive.
So make the idmap argument const wherever we can. The conversion is done
from the bottom up so callers can continue to pass a non-const pointer
to a const parameter until the conversion is finished.
No functional changes.
Link: https://patch.msgid.link/20260901-work-idmap-const-v1-12-54ccd48e100b@kernel.org
Acked-by: Paul Moore <paul@paul-moore.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Seth Forshee <sforshee@kernel.org>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull more MM updates from Andrew Morton:
- "mm/rmap: index MAP_PRIVATE file-backed folios by anonymous pgoff"
(Lorenzo Stoakes)
Index MAP_PRIVATE file-backed folios by their anonymous page offset
to resolve confusion around reverse mapping for zeroed and CoW'd
file-backed memory.
Use this new VMA anonymous page offset tracking to eliminate index
conflicts and lay the foundation for scalable CoW performance
improvements.
- "promote mapped executable folios after first usage for MGLRU"
(Baolin Wang)
Make MGLRU's protection of mapped executable file folios more
reliable. Follow the classical LRU's logic, promoting mapped
executable file folios after their first usage to give executable
code a better chance to stay in memory and improve workload
performance.
- "mm: vmscan: fix node reclaim ignoring swappiness parameter" (Ridong
Chen)
Fix per-node proactive reclaim interface's ignoring the swappiness
parameter when CONFIG_MEMCG is disabled by consolidating
sc_swappiness() into a single function that checks
proactive_swappiness regardless of kernel configuration.
- "mm/vmscan: reduce lru_lock contention via vmstat-derived
scan-balance cost" (Usama Arif)
Reduce lru_lock contention in the reclaim path by deriving
scan-balance costs from vmstat counters rather than lock-acquired
producer updates.
Read and decay these cost signals on the reclaim side under a
dedicated per-lruvec lock, reducing total LRU lock wait time by over
60% without impacting scan throughput.
- "zram: fix zram issues reported by sashiko" (Sergey Senozhatsky)
Fix two low-risk zram bugs which Sashiko spotted in drive-by review.
- "Honor XA_FLAGS_ACCOUNT in xas_split_alloc() and charge to folio's
memcg" (Zi Yan)
Fix xas_split_alloc() by enabling target folio memcg charging during
splits and adding the missing __GFP_ACCOUNT flag for proper XArray
node memory accounting.
- "selftests/mm: use pattern matching in .gitignore" (Pratyush Mallick)
Replace hardcoded binary names in selftests/mm/.gitignore with a
generic pattern-matching rule to automatically ignore generated test
files and avoid manual updates when adding new tests.
- "mm/page_ext: remove pgdat_page_ext_init()" (Sang-Heon Jeon)
Make the incompatibility between FLATMEM and NUMA explicit in
mm/Kconfig and remove the unused pgdat_page_ext_init() function.
- "zram: fix zstd error paths and add parameter validation" (Haoqin
Huang)
Clean up zram compression backends by removing redundant error
cleanup, adding parameter and dictionary validation, auto-prefixing
algorithm error logs, and resetting parameters prior to
reinitialization.
- "zram: fix stale scan bounds after reinitialization" (Longlong Xia)
Prevent out-of-bounds slot accesses during concurrent zram resets by
moving table scan bound calculations under dev_lock in
writeback_store() and read_block_state().
- "add anon mTHP collapse test cases" (Baolin Wang)
Extend selftests helper functions to support arbitrary page orders
and add new test cases and options for mTHP collapse in khugepaged.
- "selftests/mm: Handle unsupported and transient test conditions"
(Muhammad Usama Anjum)
Update MM selftests to report a SKIP status instead of a failure when
required kernel or filesystem features are unsupported, while adding
retry logic for transient page migration errors.
- "mm/zswap: Fixes and improves the zswap shrink" (Hao Jia)
Fix the missing zswap global shrinker when CONFIG_MEMCG is disabled
and extend shrink_memcg() to support batch writeback for improved
writeback efficiency.
- "alloc_tag: introduce IOCTL-based filtering for MAP" (Suren
Baghdasaryan)
Introduce an IOCTL-based binary interface for memory allocation
profiling that enables kernel-side filtering before per-CPU counter
aggregation.
This eliminates the text-parsing overhead of /proc/allocinfo and
provides up to a 20x speedup by transferring only filtered allocation
data to userspace.
- "better block swap batching and a different take on swap_ops v5"
(Christoph Hellwig)
Refactor block swap I/O to use swap_iocb for batching instead of
single-bio requests and rebase the swap_ops interface, achieving
faster swap throughput during kernel builds.
- "mm: kmemleak: reduce transient false positives by confirming leaks"
(Catalin Marinas)
Reduce false-positive kmemleak reports by combining two kmemleak
enhancements that add a second confirmation scan and a configurable
minimum unreferenced scan count module parameter.
- "mm: kmemleak: default min_unref_scans to 2 for verbose kernels"
(Breno Leitao)
Auto-scanning kernels can generate false-positive memory leak reports
on single scans, so this patch defaults min_unref_scans to 2 when
CONFIG_DEBUG_KMEMLEAK_VERBOSE is enabled to require a second
confirming scan.
- "swap_ops updates" (Christoph Hellwig)
Batching I/O for synchronous swap devices causes performance
regressions and filesystem-based swap suffers from double-indirection
overhead. This series resolves both issues by reintroducing per-folio
writes for synchronous swap and allowing filesystems to directly
export their own swap_ops.
- "mm/khugepaged: several cleanups" (Nico Pache)
khugepaged accumulated redundant state-checking patterns and outdated
comments following mTHP integration. Introduce dedicated helpers for
PTE validation and event counting while refreshing the internal
documentation.
- "maple_tree: lock checking and clean ups" (Liam Howlett)
Syzbot reports incorrectly blame memory management exit paths for
locking bugs, maple tree erase operations risk allocation failures
without gfp flags and internal documentation lacks clarity.
Improve lock error detection, update docs, fix race and allocation
edge cases and optimize erase allocations using a fallback to
GFP_KERNEL | GFP_NOFAIL.
* tag 'mm-stable-2026-08-26-15-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (172 commits)
selftests/proc: make proc-maps-race work with READ_IMPLIES_EXEC
memcg: move LRU size accounting on reparenting instead of copying it
mm/vmscan: fix comment logic in balance_pgdat
maple_tree: add helper mas_make_walkable()
maple_tree: avoid extra gap calculation
maple_tree: fix argument name in header
maple_tree: change two GFP flags in tests
maple_tree: document erase and allocations better
maple_tree: avoid mas_erase() and mtree_erase() failures
maple_tree: document that erase may use GFP_KERNEL for allocations
maple_tree: catch race in mas_alloc_cyclic()
maple_tree: add bulk parent set helper
maple_tree: micro optimisation of mas_wr_store_type()
maple_tree: optimise mas_wr_node_store() when not in rcu mode
maple_tree: use prefetched value in mas_wr_store_type()
maple_tree: clarify comments on mas_nomem()
maple_tree: drop MAPLE_ALLOC_SLOTS
maple_tree: drop dead code from mas_extend_spanning_null()
maple_tree: documentation fix
maple_tree: add write lock checking with lockdep sequence numbers
...
|
|
All remaining callers of is_cow_mapping() are invoking it in the form of
is_cow_mapping(vma->vm_flags) or an indirected version of this.
Therefore, provide a helper - vma_is_cow_mapping() to directly test the
VMA.
Additionally provide a new helper vma_flags_is_cow_mapping() which
performs the check using the new vma_flags_t type, and share this logic
between vma_is_cow_mapping() and vma_desc_is_cow_mapping().
With these changes, no callers of is_cow_mapping() remain, so remove it.
Also update the userland VMA tests to reflect the change.
No functional change intended.
[akpm@linux-foundation.org: fix kerneldoc comment typo, per Lorenzo]
Link: https://lore.kernel.org/aob1goSSPH6sTN9y@gremlin
Link: https://lore.kernel.org/20260813-b4-scalable-cow-virt-pgoff-v5-2-c21581c0c3c8@kernel.org
Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Deucher <alexander.deucher@amd.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Baoquan He <baoquan.he@linux.dev>
Cc: Barry Song <baohua@kernel.org>
Cc: Boris Brezillon <boris.brezillon@collabora.com>
Cc: Byungchul Park <byungchul@sk.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Chris Li <chrisl@kernel.org>
Cc: Christan König <christian.koenig@amd.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Dave Airlie <airlied@gmail.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Gregory Price (Meta) <gourry@gourry.net>
Cc: Harry Yoo <harry@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Huang Ray <Ray.Huang@amd.com>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Marc Rutland <mark.rutland@arm.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Namhyung kim <namhyung@kernel.org>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Nico Pache <npache@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rakie Kim <rakie.kim@sk.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Steven Price <steven.price@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Thomas Zimemrmann <tzimmermann@suse.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: xu xin <xu.xin16@zte.com.cn>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
- "mm: drop "sub" prefix from various places" (Dev Jain)
page->folio conversion and a naming cleanup
- "mm/kasan: remove redundant initialization for kasan_flag_write_only"
(Igor Putko)
KASAN cleanup work
- "mm/filemap: reduce unnecessary xarray lookups" (Chi Zhiling)
Small speedup in the pagecaache read code
- "mm/percpu: Fix possible NOFS/NOIO reclaim recursion" (Kaitao Cheng)
Improve the vmalloc code - mainly the avoidance of GFP_KERNEL
allocations when the caller asked for GFP_NOFS or GFP_NOIO
- "mm/kmemleak: avoid soft lockup when scanning task stacks" (Breno
Leitao)
Avoid a soft lockup watchdog trigger from the kmemleak scanning code
in extreme situations
- "mm/page_owner: misc cleanups" (Ye Liu)
Cleanups to the page_owner code. For some reason lots of people have
been working on the page_owner code this cycle.
- "mm: convert to walk_page_range_vma() to eliminate find_vma()"
(Kefeng Wang)
Simplify and accelerate the page walking library function
- "mm/migrate: preparatory cleanups for batch copy and offload"
(Shivank Garg)
Cleanups in the migration code
- "mm/page_owner: add per-fd filter infrastructure for print_mode and
NUMA filtering" (Zhen Ni)
Per-fd filtering to page_owner in order to reduce the sometimes vast
amount of output it can produce
- "mm: Refactor bootmem gigantic hugepage allocation" (Muchun Song)
Fixes and preparatory cleanups around bootmem HugeTLB handling,
sparse initialization ordering, and related vmemmap setup
- "mm/zsmalloc: reduce lock contention in zs_free()" (Wenchao Hao)
Reduce lock contention in zs_free(), which dominates the unmap path
under memory pressure on Android (LMK kills) and on x86 servers
running zswap-heavy workloads.
Up to 1.83x improvement in microbenchmarking.
- "move alloc_tag.c file under mm/" (Suren Baghdasaryan)
- "samples/damon: handle damon_{start,stop}() failures" (SJ Park)
Fix improper handling of damon_start(), damon_stop(), and
damon_call() failures across DAMON sample modules to prevent
potential memory leaks, operation disruptions and use-after-free
bugs
- "mm/damon/sysfs: kobject_del() directories that users can
create/remove" (SJ Park)
Fix delayed sysfs directory removal under DEBUG_KOBJECT_RELEASE
causeing creation failures due to duplicate directory names by adding
missing kobject_del() calls before creating new directories
- "mm: cleanup clear_not_present_full_ptes()" (David Hildenbrand)
Clean up the core pte handling code
- "selftests/damon: misc fixes for test bugs" (Kunwu Chan)
Fix several bugs in the DAMON selftests
- "selftests/damon: fix memcg_path staging handling" (Cheng Nie)
Fix a bug in _damon_sysfs.py for damos_filter memcg_path setup, and
add a test case for it in sysfs.py.
- "selftests/damon: test kdamond refresh_ms" (Ruslan Valiyev)
Selftest coverage for DAMON's refresh_ms sysfs feature by updating
the test control module and verifying that scheme stats update
automatically without manual intervention
- "mm/damon: five misc fixups" (Akinobu Mita)
Miscellaneous DAMON fixups.
- "mm/damon/core: detect internal variation above max_nr_regions/2"
(Jiayuan Chen)
Fix DAMON's region splitting behavior when region counts exceed half
the maximum budget by dynamically scaling down the split fraction as
the limit approaches, preventing large regions from staying un-split,
and add corresponding KUnit test coverage
- "mm: preparatory patches for PMD level swap entries" (Usama Arif)
Refactor and clean up PMD softleaf helpers, call sites, and
architecture flags to lay the groundwork for a follow-up series that
introduces PMD page table swap entries
- "mm/damon: update, optimize, and clean up doc, tests, and code" (SJ
Park)
Update DAMON design and ABI documentation, expands unit and selftest
coverage, optimize damon_commit_target_regions(), and clean up
recently added sysfs interface code for better readability
- "mm/vmpressure: reduce CPU, memory and code overhead on cgroup v2"
(Usama Arif)
Optimize vmpressure() by skipping unnecessary work on cgroup v2 for
userspace event notifications and refactor v1-only eventfd handling
into mm/memcontrol-v1.c to reduce memory overhead and code complexity
- "selftests/mm: refactor pkey helpers and fix mmap error handling"
(Hongfu Li)
Refactor pkeys shared tracing and assertion helpers into a common
file, unify protection key selftests to use consistent diagnostic
logging and assertions, and enforce standardized MAP_FAILED return
checks for mmap() calls across the tests
- "mm/damon: optimize out nr_accesses_bp" (SJ Park)
Replace the error-prone, continuously updated nr_accesses_bp field in
damon_region with an on-demand moving sum function, reducing
structure memory overhead and avoiding state corruption bugs
- "Open HugeTLB allocation routine for more generic use" (Ackerley Tng)
Decouple HugeTLB folio allocation from VMA dependencies by
introducing hugetlb_alloc_folio(), enabling subsystems like
guest_memfd to allocate HugeTLB folios without standard VMA
reservations or pseudo-VMAs
- "mm/damon: provide pseudo moving sum probe_hits" (SJ Park)
Integrate DAMON's probe_hits attribute counter into the pseudo moving
sum infrastructure, enabling real-time, online monitoring without
waiting for full aggregation intervals
- "mm: Some cleanups for page allocator APIs" (Brendan Jackman)
Simplify and refactor the page allocator entry points and flags by
unifying allocation paths, adding internal alloc_flags arguments, and
eliminating redundant __ prefixed alloc_pages variants.
- "Fix incorrect access of hugetlb pte entries" (Dev Jain)
Enforce the consistent use of huge_ptep_get() instead of ptep_get()
for HugeTLB entries and fixes an unaligned address issue in arm64's
huge_ptep_get() implementation
- "mm/damon: validate all parameters in the core" (SJ Park)
Consolidate parameter validation into the DAMON core specifically
within damon_start() and damon_commit_ctx() to centralize error
checking, eliminate caller-side redundant checks and to improve
maintenance efficiency
- "tools/mm/page_owner_sort: fix filtering and cleanup issues" (Yichong
Chen)
Rename is_need() to filter_record() for clearer return semantics, fix
per-record allocation memory leaks and bound output copies in
search_pattern() to address an existing buffer issue
- "memcg: bail out reclaim when memcg is dying" (Jiayuan Chen)
Mitigate a system-wide stall which occurs when a cgroup is removed
while one of its memory control files is doing synchronous reclaim
- "mm/memory-failure: add panic option for unrecoverable pages" (Breno
Leitao)
Introduce an opt-in vm.panic_on_unrecoverable_memory_failure sysctl
that immediately panics the kernel on unrecoverable memory errors in
kernel-owned pages to preserve error context and prevent delayed,
silent data corruption
- "mm/damon: refactor damon_{start,stop,commit}() for simple error
handling" (SJ Park)
Refactor the DAMON core API functions to guarantee that all contexts
are fully stopped when damon_start(), damon_stop(), or damon_commit()
fail, eliminating the need for complex and error-prone caller-side
cleanup code
- "Keep tail page private zero at free and folio split" (Zi Yan)
Add checks to ensure tail_page->private is zero when freeing compound
or high-order pages and when promoting tail pages during large folio
splits. By validating these fields at free and split time, it allows
the removal of redundant private field clearing inside
prep_compound_tail()
- "mm: drop redundant lru_add_drain in anon folio reuse paths" (Barry
Song)
Eliminate redundant lru_add_drain() calls in
wp_can_reuse_anon_folio() and do_swap_page() to reduce LRU lock
contention and system overhead
By validating folio refcounts against the LRU cache before draining
and removing unnecessary drains in the swap path, it achieves up to a
30.5% reduction in drain calls during heavy swap workloads
- "mm: clean up folio LRU and swap declarations" (Jianyue Wu)
Reorganize folio LRU and swap code by relocating page-cluster state
to mm/swap_state.c, renaming mm/swap.c to mm/folio.c, and moving
MM-internal reclaim declarations into mm/internal.h.
- "userfaultfd: working set tracking for VM guest memory" (Kiryl
Shutsemau)
Add userfaultfd support for tracking the working set of VM guest
memory, so a VMM can identify hot pages and reclaim cold ones to
tiered or remote storage
- "mm: remove CONFIG_HAVE_BOOTMEM_INFO_NODE (Part 2)" (David
Hildenbrand)
Remove the remaining pieces of CONFIG_HAVE_BOOTMEM_INFO_NODE,
performing some smaller cleanups around freeing of reserved vmemmap
pages on the way.
- "mm/damon: update probe hits for runtime parameter commits" (SJ Park)
Ensure that DAMON's probe_hits attribute counter is properly updated
when monitoring intervals are changed at runtime, matching the
behavior of nr_accesses. To achieve this, it refactors and renames
existing helper functions for shared use, applies the updates to
probe_hits, and handles edge cases in damon_probe_hits_mvsum() to
maintain measurement accuracy.
- "KSM: performance optimizations for rmap_walk_ksm" (xu xin)
Resolve a severe KSM reverse-mapping performance bottleneck where
thousands of split VMAs sharing a single anon_vma cause extended lock
contention.
By adding an interval-filtering check during the rmap walk, it
reduces worst-case anon_vma lock hold times from over 500ms down to
under 2ms, preventing application freezes and latency spikes under
memory pressure.
- "mm: split a couple of headers from internal.h" (Mike Rapoport)
Split declarations related to mm_init, memblock, vmalloc and sparse
into new headers
- "KSM: use linear_page_index in collect_procs_ksm()" (xu xin)
Apply the interval tree optimization from rmap_walk_ksm() to
collect_procs_ksm() to avoid iterating over non-matching VMAs during
KSM memory error handling.
It hoists loop-invariant address initialization and restricts the
anon_vma_interval_tree_foreach walk to a targeted page offset range,
reducing redundant checks and improving lookup efficiency.
- "selftests/mm: avoid false failures in hugetlb and KSM tests" (Sayali
Patil)
Fix issues in the hugetlb and KSM MM selftest categories that can
report failures when the prerequisites for the tests are not
satisfied
- "mm/damon: introduce data attributes only monitoring" (SJ Park)
Introduce attribute-weighted region management in DAMON, allowing
users to prioritize specific data attributes (such as page sizes or
cgroups) over or instead of access monitoring.
By assigning weights to attribute probes, DAMON can completely
disable access tracking and adjust monitoring regions based on
weighted probe-hit counters to optimize monitoring quality for
attribute-focused workloads.
- "mm/hmm: Add mmap lock-drop support for userfaultfd-backed mappings"
(Stanislav Kinsburskii)
Extend hmm_range_fault() to support userfaultfd-backed regions by
allowing the mmap lock to be dropped during fault handling via a new
hmm_range_fault_locked() helper.
By accepting a locked pointer and signaling retry status when lock
release occurs, it enables page fault resolution in userfaultfd
regions while preserving backward compatibility for existing callers.
- "mm: make VMA page offset handling more consistent" (Lorenzo Stoakes)
Clean up and standardize how vma->vm_pgoff is accessed and
manipulated across file-backed and anonymous mappings in the kernel
It introduces dedicated helper functions such as vma_start_pgoff(),
vma_end_pgoff(), vma_set_pgoff() and linear_page_delta() while
renaming rmap interval tree helpers to better reflect their
functionality.
These changes establish a cleaner foundation for future work that
will unify virtual page offset indexing for all anonymous and CoW'd
folios.
- "mm: handle device-private PMDs in walk callbacks" (Usama Arif)
Address kernel panics and state corruption caused by MM walk
callbacks reaching non-present device-private PMD swap entries
created during HMM migrations
It ensures that functions which acquire pmd_trans_huge_lock()
properly recognize device-private PMDs instead of assuming a present
THP or a standard migration entry.
- "mm/rmap: Refactor try_to_unmap_one" (Dev Jain)
Refactor try_to_unmap_one by modularizing Hugetlb,
anonymous-lazyfree, and anonymous-swapbacked logic into dedicated
functions, laying the structural groundwork for batched anonymous
large folio unmapping.
- "Docs/ABI/damon: sysfs ABI document fixes and additions" (Song Hu)
Fix typos and fills in missing entries in the DAMON sysfs ABI
document
- "dax/kmem: atomic whole-device hotplug via sysfs" (Gregory Price)
Introduce an atomic sysfs state attribute and supporting DAX/MM
infrastructure to prevent userland races when offlining and removing
entire memory regions
By adding an unplugged state alongside standard online modes, it
enables whole-device atomic hotplug control while preserving backward
compatibility.
- "mm: convert more vm_flags_t users to vma_flags_t" (Lorenzo Stoakes)
Continue transitioning the kernel from the deprecated vm_flags_t type
to vma_flags_t across core memory management infrastructure.
It replaces legacy type usage in core functions such as do_mmap(),
unmapped area allocation, mm->def_vma_flags, and VMA operations like
mlock, mprotect, and mremap.
- "Two small patches to clean up mm/mm_slot.h" (xu xin)
Refactor mm_slot.h by introducing mm_slot_remove() to unify duplicate
slot deletion sequences in khugepaged and KSM. It also adds code
documentation explaining why mm_slot_lookup and mm_slot_insert must
remain as preprocessor macros rather than static inline functions.
- "mm/damon/core: hide core-private struct fields" (SJ Park)
Clean up DAMON core structures by consistently marking internal-only
fields with private: comment tags to prevent improper direct access
from outer layers.
It enforces encapsulation across core structures including
damon_region, damon_target, and damon_ctx and updates DAMON_SYSFS to
interact through approved access APIs instead of exposing raw struct
members.
- "mm/damon: unurgent fixes for infinite loop, NULL de-ref and races"
(SJ Park)
Address potential infinite loops, NULL dereferences, and race
conditions identified in DAMON
It fixes an infinite loop triggered by extreme user configurations, a
NULL pointer dereference within unit tests and minor monitoring
accuracy degradation caused by subtle runtime races.
- "mm/page_alloc: fixes for free_pages_nolock() on RT/UP" (Brendan
Jackman)
Fix an NMI safety flaw in __free_frozen_pages() where freeing pages
on non-SMP or PREEMPT_RT kernels can bypass can_spin_trylock() checks
via non-PCP or isolated migration paths.
It also resolves potential kernel crashes and privilege escalation
risks triggered when BPF tracing runs in NMI context alongside memory
hotplug or large allocation frees.
- "mm/page_alloc: couple of followups for recent cleanups" (Brendan
Jackman)
Clean up and update page allocator nomenclature, documentation, and
debug assertions.
It aligns internal FPI_ flags with the public "nolock" naming
convention, removes outdated internal implementation details from
high-level page allocator comments, and eliminates obsolete
VM_BUG_ON() assertions in allocation paths.
- "mm/mseal: further cleanups" (Lorenzo Stoakes)
Refactor and simplify the mseal implementation by clarifying API
boundaries and removing unnecessary code complexity.
It replaces generic do_mseal() usage outside the syscall with a
dedicated mseal_mmap_page_zero() helper for MMAP_PAGE_ZERO,
eliminates mm_struct parameters to enforce that sealing applies only
to current->mm, and streamlines overall logic and comments with no
functional changes intended.
- "mm/vmscan: fix swappiness=max and clean up per-node proactive
reclaim" (Ridong Chen)
Resolve reclaim behavior bugs and clean up function parameters across
memory reclaim paths
It fixes swappiness=max in both standard reclaim and MGLRU so
unswappable anonymous memory no longer falls back to evicting page
cache, ensures reclaim_store() returns accurate error codes instead
of collapsing all failures into -EAGAIN, and removes the obsolete
gfp_mask parameter from __node_reclaim().
- "mm: mincore: misc cleanups" (Kefeng Wang)
Clean up and simplifies the mincore code. Most importantly, it
removes the historical special behavior that always reports VM_PFNMAP
pages as non-resident.
- "mm/huge_memory: drop dead split helper variants" (Kiryl Shutsemau)
Two trivial cleanups in the folio split API
- "mm/damon: fix uninitialized DAMOS field and kunit exec expectation
bugs" (SJ Park)
Resolve minor operational and testing bugs in DAMON identified by
Sashiko. It initializes the damos->last_applied field to prevent
occasional efficiency degradation and fixes invalid memory accesses
in DAMON KUnit tests during test failure handling.
- "cleanup for stable_page_flags()" (Jinjiang Tu)
Clean up and refactor stable_page_flags() used by /proc/kpageflags
without altering functionality.
It uses BIT_ULL() to prevent shift-overflow warnings on 64-bit flag
bits, converts folio-specific flag checks to standard folio_test_*()
helpers, and removes redundant CONFIG_PAGE_IDLE_FLAG handling.
- "Batch unmap of uffd-wp file folios" (Dev Jain)
Extend batched folio unmapping support to file folios within
userfaultfd write-protect (uffd-wp) VMAs by adding batching
capabilities to pte_install_uffd_wp_if_needed().
This removes special-case restrictions on uffd-wp VMAs in
try_to_unmap_one(), significantly simplifying the function's control
flow and complexity.
- "mm/early_ioremap: clarify and clean up early_ioremap_reset()"
(Sang-Heon Jeon)
Clarify and clean up the architecture-specific usage of
__late_set_fixmap() and __late_clear_fixmap() after
early_ioremap_reset()
It adds explicit documentation regarding when early_ioremap_reset()
must be called and removes redundant macro definitions and reset
calls in the RISC-V and ARM64 architectures.
- "mm: fix reclaim storms in defrag_mode" (Johannes Weiner)
Address severe performance regressions, swap storms, and spurious
OOMs caused by vm.defrag_mode=1 under high memory pressure in Meta
production
It updates the page allocator slowpath so non-movable allocation
requests actively trigger direct reclaim and direct compaction at
pageblock_order scale, allowing them to claim whole pageblocks rather
than spinning unproductively.
- "zram: lockmap tweaks" (Sebastian Siewior)
Optimize and fix lockdep tracking for zram devices by consolidating
per-entry lockmaps and isolate lock classes across multiple instances
This reduces memory overhead by replacing per-entry lockdep_map
instances with a single map per struct zram, and assigns a dynamic
lock_class_key to each instance to prevent false deadlock reports
when different zram devices are backed by distinct filesystems.
* tag 'mm-stable-2026-08-18-18-39' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (501 commits)
selftests/mm: thuge-gen: fix test_shmget() for PAGE_SIZE check
selftests/mm: unpoison pages in memory-failure teardown
mm/shmem: downgrade final i_blocks check in shmem_evict_inode() to pr_warn()
mm/khugepaged: replace mutex_lock/mutex_unlock usage with guard macro
mm/zsmalloc: fix release order of locks in zs_page_migrate()
Documentation: zram: remove sections numbering
ksm: stop iterating VMAs when ksm_test_exit returns true
mm: fold userfaultfd_rwp() to false without CONFIG_ARCH_HAS_PTE_PROTNONE
mm/migrate: report RCU-tasks quiescent states in migrate_pages_batch()
zram: use a custom key for each zram object
zram: move lockmap to be per-zram instead per table
selftests/mm: fix gup_longterm EINVAL error message
mm: page_alloc: fix non-movable reclaim storm in defrag_mode
mm: page_alloc: move capture_control to the page allocator
mm: compaction: support non-movable compaction for pageblock requests
mm: page_alloc: __GFP_FS lockdep annotation for direct compaction
hugetlb: evaluate subpool free state while locked
mm/damon: remove trailing semicolons after function definitions
mm/damon/ops-common: prevent migration fallback to non-target nodes
mm/damon: update outdated comment about DAMOS filter handling
...
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git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl
Pull sysctl updates from Joel Granados:
- Fix kernel-doc warnings by adjusting in file documentation
- Consolidate do_proc_* function into do_proc_vec
Consolidate three slightly different implementations of applying a
converter on all elements of a vector. Fixes to this function now
propagate to the three types.
- Replace CONFIG_PROC_SYSCTL with CONFIG_SYSCTL (they were the same)
and restrict cad_pid modifications to global root (GLOBAL_ROOT_UID)
* tag 'sysctl-7.03-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl:
sysctl: remove CONFIG_PROC_SYSCTL, it just mirrors CONFIG_SYSCTL
sysctl: move the "cad_pid" entry from pid_table[] to kern_reboot_table[]
sysctl: repair some kernel-doc comments
sysctl: add Returns: kernel-doc for all functions
sysctl: Update API function documentation
sysctl: Rename proc_doulongvec_minmax_conv to proc_doulongvec_conv
sysctl: Group proc_handler declarations and document
sysctl: Replace do_proc_do{int,ulong,uint}vec with do_proc_vec
sysctl: Add negp parameter to douintvec converter functions
sysctl: Move default converter assignment out of do_proc_dointvec
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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull kthread vfs updates from Christian Brauner:
"This stops kernel threads from sharing filesystem state with
userspace. This work is about 3 cycles old and has been in -next
for about that time.
When the kernel boots init_task creates PID 1 and then kthreadd. From
that point every kthread and PID 1 share the same fs_struct. That is
why pivot_root() has to rewrite the fs_struct of all kthreads. The
rewriting exists so that kthreads can use init's filesystem state when
they want to. It also means userspace can move the ground out from
under the kernel.
PID 1 now gets a completely separate fs_struct. All kthreads are
anchored in a private SB_KERNMOUNT instance of nullfs that cannot be
mounted on and cannot be used to follow other mounts. Userspace init
can no longer affect kthread filesystem state and kthreads can no
longer affect userspace fs state without explicit opting in to that.
Path lookup from a kthread now fails by default. It makes it
deliberately hard to offload security sensitive operations into init's
filesystem state from a kthread.
Places that legitimately need to look something up there opt in
through the new scoped_with_init_fs() which temporarily overrides the
caller's fs_struct with init's. usermodehelpers remain the only kernel
tasks that genuinely share init's filesystem state, since they execute
random binaries in the root filesystem (excellent...).
The visible result is that /proc/2/root is a nullfs with an empty
mountinfo while /proc/1/root is the real root"
* tag 'vfs-7.3-rc1.kthread' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (26 commits)
initramfs_test: use test init/exit hooks to override init fs
fs: stop rewriting paths for PF_EXITING | PF_DUMPCORE
fs: stop rewriting kthread fs structs
fs: start all kthreads in nullfs
nullfs: make nullfs multi-instance
devtmpfs: create private mount namespace
fs: add umh argument to struct kernel_clone_args
fs: stop sharing fs_struct between init_task and pid 1
af_unix: use scoped_with_init_fs() for coredump socket lookup
initramfs: use scoped_with_init_fs() for rootfs unpacking
pnfs/blocklayout: use scoped_with_init_fs() for SCSI device lookup
ksmbd: use scoped_with_init_fs() for VFS path operations
ksmbd: use scoped_with_init_fs() for filesystem info path lookup
ksmbd: use scoped_with_init_fs() for share path resolution
fs: use scoped_with_init_fs() for kernel_read_file_from_path_initns()
coredump: use scoped_with_init_fs() for coredump path resolution
btrfs: use scoped_with_init_fs() for update_dev_time()
scsi: target: use scoped_with_init_fs() for APTPL metadata
scsi: target: use scoped_with_init_fs() for ALUA metadata
crypto: ccp: use scoped_with_init_fs() for SEV file access
...
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For KPF_IDLE, folio_test_idle() check in set_ps_flags() already handles
all config cases, so remove the duplicate code in stable_page_flags() that
deals with CONFIG_PAGE_IDLE_FLAG for the 64‑bit case.
No functional change is intended.
Link: https://lore.kernel.org/20260720033021.4091944-4-tujinjiang@huawei.com
Signed-off-by: Jinjiang Tu <tujinjiang@huawei.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Luiz Capitulino <luizcap@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Nanyong Sun <sunnanyong@huawei.com>
Cc: Svetly Todorov <svetly.todorov@memverge.com>
Cc: xu xin <xu.xin16@zte.com.cn>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Since commit 304daa8132a9 ("maps4: add /proc/kpageflags interface"),
/proc/kpageflags directly operates on page->flags to determine page
status. Later, commit 177975495914 ("proc: export more page flags in
/proc/kpageflags") started using page helper functions when exposing new
flags, leading to a mix of both approaches.
For tail pages, the original code did not return corresponding status.
commit 0a71649cb724 ("/proc/kpageflags: return KPF_SLAB for slab tail
pages") and commit 832fc1de01ae ("/proc/kpageflags: return KPF_BUDDY for
"tail" buddy pages") made tail slab/buddy pages also return corresponding
status. Then commit dee3d0bef2b0 ("proc: rewrite stable_page_flags()")
made all tail pages return the same status as their head page, except for
hwpoison and mapped flags. It also cached the folio's flags and operate
on the flags directly to avoid concurrency issues if using folio_test_*()
helpers.
Since commit 476d87d6a061 ("fs: stable_page_flags(): use
snapshot_page()"), we can now safely switch to folio_test_*() helpers
instead of directly operating on flags, which is more readable and
consistent with the rest of the kernel. Only convert cfolio-specific
flags (i.e., anon, ksm, swapcache) to folio_test_*() helpers, which
reduces redundant code. Keep others unchanged due to they aren't
folio-specific flags or coverting them doesn't cleanup.
No functional change is intended.
Link: https://lore.kernel.org/20260720033021.4091944-3-tujinjiang@huawei.com
Signed-off-by: Jinjiang Tu <tujinjiang@huawei.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Luiz Capitulino <luizcap@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Nanyong Sun <sunnanyong@huawei.com>
Cc: Svetly Todorov <svetly.todorov@memverge.com>
Cc: xu xin <xu.xin16@zte.com.cn>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Patch series "cleanup for stable_page_flags()", v2.
This series cleans up stable_page_flags(), see the details in the commit
messages.
This patch (of 3):
The stable_page_flags() function currently sets page flag bits using "1 <<
KPF_xxx" for various KPF_* definitions. KPF_* may be larger than 32,
which will trigger -Wshift-count-overflow warning. All KPF_* values
currently used in "1 << KPF_xxx" are smaller than 33, so no warning is
triggered with current code.
Replace all occurrences of "1 << KPF_*" with the BIT_ULL() macro to ensure
all shifts are performed on a 64-bit unsigned type. This makes the code
robust, and safe for future extension.
No functional change is intended.
Link: https://lore.kernel.org/20260720033021.4091944-1-tujinjiang@huawei.com
Link: https://lore.kernel.org/20260720033021.4091944-2-tujinjiang@huawei.com
Signed-off-by: Jinjiang Tu <tujinjiang@huawei.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Acked-by: Zi Yan <ziy@nvidia.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Luiz Capitulino <luizcap@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Nanyong Sun <sunnanyong@huawei.com>
Cc: Svetly Todorov <svetly.todorov@memverge.com>
Cc: xu xin <xu.xin16@zte.com.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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CONFIG_SYSCTL used to make sense as a separate hidden bool before commit
61a47c1ad3a4 ("sysctl: Remove the sysctl system call"); it was selected
by both CONFIG_SYSCTL_SYSCALL and CONFIG_PROC_SYSCTL.
Today CONFIG_PROC_SYSCTL is the only selector, so the two are always
equal. Kill the hidden bool, rename the PROC_SYSCTL prompt to SYSCTL,
and s/CONFIG_PROC_SYSCTL/CONFIG_SYSCTL/ tree-wide.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Joel Granados <joel.granados@kernel.org>
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PAGEMAP_SCAN already reports PAGE_IS_WRITTEN from the inverted uffd PTE
bit, targeting the UFFDIO_WRITEPROTECT workflow. UFFDIO_RWPROTECT reuses
the same PTE bit as a marker for read-write protection, but "has been
written" and "has been accessed" are distinct semantic signals — they
happen to share one PTE bit today only because the two implementations
share infrastructure.
Give RWP its own pagemap category so the UAPI does not conflate them:
PAGE_IS_WRITTEN reported on VM_UFFD_WP VMAs, !pte_uffd(pte)
PAGE_IS_ACCESSED reported on VM_UFFD_RWP VMAs, !pte_uffd(pte)
Both still read the same PTE bit today, but each is scoped to the VMA
whose registered mode makes the bit meaningful. If a future
implementation moves RWP to a separate PTE bit, only PAGE_IS_ACCESSED
switches over.
This is a UAPI narrowing. Outside VM_UFFD_WP VMAs the uffd bit is always
clear, so PAGEMAP_SCAN used to flag PAGE_IS_WRITTEN on every present PTE
there — a meaningless duplicate of PAGE_IS_PRESENT. Now PAGE_IS_WRITTEN
fires only inside VM_UFFD_WP VMAs.
pagemap_hugetlb_category() now takes the vma like its PTE/PMD peers.
Link: https://lore.kernel.org/20260708111417.173443-12-kirill@shutemov.name
Signed-off-by: Kiryl Shutsemau <kas@kernel.org>
Assisted-by: Claude:claude-opus-4-6
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: James Houghton <jthoughton@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Preparatory patch for userfaultfd read-write protection (RWP). RWP
extends userfaultfd protection from plain write-protection (WP) to full
read-write protection: accesses to an RWP-protected range -- reads as well
as writes -- trap through userfaultfd.
Reserve VM_UFFD_RWP, add the userfaultfd_rwp() and userfaultfd_protected()
helpers, and wire up the smaps "ur" entry and the trace-flag table the
rest of the series will use. The flag is gated on CONFIG_USERFAULTFD_RWP,
which is introduced together with the UAPI in a later patch; until then
VM_UFFD_RWP aliases VM_NONE and every downstream check folds to dead code.
Nothing sets or queries the flag yet.
Link: https://lore.kernel.org/20260708111417.173443-6-kirill@shutemov.name
Signed-off-by: Kiryl Shutsemau <kas@kernel.org>
Assisted-by: Claude:claude-opus-4-6
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: SeongJae Park <sj@kernel.org>
Reviewed-by: Lorenzo Stoakes <ljs@kernel.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: James Houghton <jthoughton@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam Howlett <liam@infradead.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Userfaultfd RWP will reuse the uffd-wp PTE bit to mark access-tracking
PTEs, alongside the write-protected ones it already marks. The bit's
meaning now depends on the VMA flag (WP or RWP), not on its name.
Rename the kernel-internal names that describe the bit:
- pte/pmd/huge_pte accessors (and swap variants)
- pgtable_supports_uffd() capability query
- SCAN_PTE_UFFD khugepaged enum
The ftrace string emitted by mm_khugepaged_scan_pmd for this enum is
kept as "pte_uffd_wp" so existing trace-based tooling keeps matching.
Pure mechanical rename -- no behavior change.
Link: https://lore.kernel.org/20260708111417.173443-4-kirill@shutemov.name
Signed-off-by: Kiryl Shutsemau <kas@kernel.org>
Assisted-by: Claude:claude-opus-4-6
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: SeongJae Park <sj@kernel.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: James Houghton <jthoughton@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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pagemap_pmd_range_thp() assumes that every non-present PMD is a migration
entry and unconditionally calls softleaf_to_page(). This will crash on
any non-present PMD type that does not encode a PFN, such as the upcoming
PMD-level swap entries.
Guard the page lookup with softleaf_has_pfn(), matching how
pte_to_pagemap_entry() already handles non-present PTEs.
Link: https://lore.kernel.org/20260706114320.1643046-4-usama.arif@linux.dev
Signed-off-by: Usama Arif <usama.arif@linux.dev>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Baoquan He <baoquan.he@linux.dev>
Cc: Barry Song <baohua@kernel.org>
Cc: Chris Li <chrisl@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Kiryl Shutsemau <kas@kernel.org>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Nico Pache <npache@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull misc fixes from Andrew Morton:
"13 hotfixes. All are cc:stable. 11 are for MM. All are singletons -
please see the changelogs for details"
* tag 'mm-hotfixes-stable-2026-07-27-14-18' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
fs/proc/task_mmu: fix PAGEMAP_SCAN written state for PMD holes
mm/hugetlb: fix list corruption in allocate_file_region_entries()
mm: mglru: fix stale batch updates after memcg reparenting
selftest: fix headers in fclog.c
ocfs2: fix boundary check in ocfs2_check_dir_entry() to use buffer offset
mm/percpu-km: fix bitmap overflow and accounting in pcpu_create_chunk()
mm/util: don't read __page_2 for order-1 folios in snapshot_page()
mm/hugetlb: fix swap entry corruption when clearing uffd-wp at fork()
mm: migrate_device: fix pte_pfn/pte_dirty called on non-present PTE
fs/proc/task_mmu: fix PAGEMAP_SCAN written state for unpopulated ptes
userfaultfd: wait on source PMD during UFFDIO_MOVE
lib: test_hmm: use device devt for coherent device range selection
mm/vmstat: fold stranded per-cpu node stats when a node comes online
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Don't return the return value of down_read_killable() (0) when a ptrace
access check fails, return -EACCES as intended.
Reported-by: Magnus Lindholm <linmag7@gmail.com>
Closes: https://lore.kernel.org/r/20260706170735.2941493-1-linmag7@gmail.com
Fixes: 6650527444da ("proc: protect ptrace_may_access() with exec_update_lock (part 1)")
Cc: stable@vger.kernel.org
Signed-off-by: Jann Horn <jannh@google.com>
Link: https://patch.msgid.link/20260706-procfs-ns-eacces-fix-v1-1-a69ab14c02e6@google.com
Tested-by: Magnus Lindholm <linmag7@gmail.com>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
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PAGEMAP_SCAN reports an unpopulated PTE in a uffd-wp VMA as written, but a
range with no page table at all -- a PMD hole -- is skipped:
pagemap_scan_pte_hole() tests p->cur_vma_category, which never carries
PAGE_IS_WRITTEN, so the hole is neither reported nor (under
PM_SCAN_WP_MATCHING) armed.
In a uffd-wp VMA, WP_UNPOPULATED installs uffd-wp markers when protecting
a range, allocating page tables as needed, so an unpopulated slot is
treated as written -- see the pte_none() handling in
pagemap_page_category(). A missing marker therefore means the range was
zapped, e.g. via MADV_DONTNEED. This applies to anon and shmem VMAs.
An anonymous THP is write-protected in place as a huge PMD, so a full-PMD
MADV_DONTNEED clears it to pmd_none -- a hole with no page table -- and
pagemap_scan_pte_hole() misses it. For a MAP_PRIVATE|MAP_ANON mapping
MADV_DONTNEED has fill-with-zeros semantics, so a write-tracking
checkpoint/migration tool (e.g. CRIU) treats the range as unchanged and
keeps its previous contents; after restore or live migration the process
reads stale data instead of zeroes -- data corruption.
Report a hole in a non-hugetlb uffd-wp VMA as written, matching the
pte_none handling in pagemap_page_category(); the existing
PM_SCAN_WP_MATCHING path then arms it via uffd_wp_range().
hugetlb is excluded: pagemap_hugetlb_category() reports an empty hugetlb
entry (huge_pte_none) as not-written, unlike pagemap_page_category(),
which reports pte_none as written. pagemap_scan_pte_hole() fires for a
hugetlb slot only when it has no page table; keeping that not-written
matches how an allocated-but-empty hugetlb entry reads, so the hole and
the empty-entry cases agree within the VMA.
Link: https://lore.kernel.org/20260715144234.442721-2-kirill@shutemov.name
Fixes: 2bad466cc9d9 ("mm/uffd: UFFD_FEATURE_WP_UNPOPULATED")
Signed-off-by: Kiryl Shutsemau <kas@kernel.org>
Reported-by: Sashiko AI review <sashiko-bot@kernel.org>
Closes: https://sashiko.dev/#/patchset/20260707151349.92143-1-kirill@shutemov.name
Tested-by: Muhammad Usama Anjum <usama.anjum@arm.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Zenghui Yu <zenghui.yu@linux.dev>
Assisted-by: Claude:claude-fable-5
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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PAGEMAP_SCAN reports an unpopulated pte differently depending on which
path serves the request. The PAGE_IS_WRITTEN fast path in
pagemap_scan_pmd_entry() reports a pte_none as written (and, under
PM_SCAN_WP_MATCHING, arms a marker); pagemap_page_category() returns 0 for
the same pte_none. A request that cannot take the fast path (an extra
category bit, category_anyof_mask or category_inverted) therefore reports
the pte as clean and skips arming it.
A range that was populated and then MADV_DONTNEED'd reads as written via
one mask and clean via another, and in the latter case is not re-armed for
the next round -- an incremental-dump consumer (e.g. CRIU) using a richer
mask drops the zapped range and stops tracking writes to it.
Report pte_none as written in pagemap_page_category() too. A pte_none
carries no uffd-wp marker, i.e. it is not write-protected -- the same
condition under which the present and swap cases already report
PAGE_IS_WRITTEN. The fast path applies no VMA test, so neither does this.
The hugetlb and fully-unpopulated-PMD (no page table) scans have no
PAGE_IS_WRITTEN fast path, so they do not exhibit the per-entry divergence
and are left unchanged.
Add a pagemap_ioctl selftest that populates a range, drops it with
MADV_DONTNEED, and checks that the fast path and the generic
(category_anyof_mask) path both report every page written.
Link: https://lore.kernel.org/20260707151349.92143-1-kirill@shutemov.name
Fixes: 12f6b01a0bcb ("fs/proc/task_mmu: add fast paths to get/clear PAGE_IS_WRITTEN flag")
Signed-off-by: Kiryl Shutsemau <kas@kernel.org>
Cc: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Assisted-by: Claude:claude-fable-5
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull misc fixes from Andrew Morton:
"20 hotfixes. 17 are for MM. 12 are cc:stable and the remaining 8
address post-7.1 issues or aren't considered suitable for backporting.
Two patches from SJ addresses a couple of quite old DAMON issues. And
two patches from Yichong Chen fixes tools/virtio build issues. The
remaining patches are singletons"
* tag 'mm-hotfixes-stable-2026-07-06-17-49' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
tools/include: include stdint.h for SIZE_MAX in overflow.h
tools/virtio: add missing compat definitions for vhost_net_test
mm: do file ownership checks with the proper mount idmap
samples/damon/mtier: fail early if address range parameters are invalid
mm: a second pagecache maintainer
mm/damon: add a kernel-doc comment for damon_ctx->rnd_state
mm/damon: add a kernel-doc comment for damon_ctx->probes
mailmap: add entries for Radu Rendec
selftests/mm: hmm-tests: include linux/mman.h to access MADV_COLLAPSE
selftests/mm: pagemap_ioctl: use the correct page size for transact_test()
fs/proc: fix KPF_KSM reported for all anonymous pages
mm: page_ext: add count limit to page_ext_iter_next to prevent invalid PFN access
mm/damon/ops-common: handle extreme intervals in damon_hot_score()
MAINTAINERS: add Lance as an rmap reviewer
mm/compaction: handle free_pages_prepare() properly in compaction_free()
mm/damon/sysfs-schemes: put stats for scheme_add_dirs() internal error
mm/damon/sysfs-schemes: fix dir put orders in access_pattern_add_dirs()
mm: shrinker: fix NULL pointer dereference in debugfs
mm: shrinker: fix shrinker_info teardown race with expansion
selftests/mm: fix ksft_process_madv.sh test category
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Reading /proc/kpageflags for any anonymous page returns KPF_KSM set, even
when KSM is not in use. As a result, tools misclassify all anonymous
pages as KSM merged.
In stable_page_flags(), if the page is anonymous, then use (mapping &
FOLIO_MAPPING_KSM) check to identify if the anonymous page is KSM page.
However, FOLIO_MAPPING_KSM is FOLIO_MAPPING_ANON | FOLIO_MAPPING_ANON_KSM,
(mapping & FOLIO_MAPPING_KSM) check returns true for all anonymous pages.
To fix it, use FOLIO_MAPPING_ANON_KSM instead.
Link: https://lore.kernel.org/20260629033122.774318-1-tujinjiang@huawei.com
Link: https://lore.kernel.org/20260626013252.2846774-1-tujinjiang@huawei.com
Fixes: dee3d0bef2b0 ("proc: rewrite stable_page_flags()")
Signed-off-by: Jinjiang Tu <tujinjiang@huawei.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Acked-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Xu Xin <xu.xin16@zte.com.cn>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Luiz Capitulino <luizcap@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Nanyong Sun <sunnanyong@huawei.com>
Cc: Svetly Todorov <svetly.todorov@memverge.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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proc_register() increments the parent directory's link count for every
entry it registers, while remove_proc_entry() and remove_proc_subtree()
decrement it only when the removed entry is a directory. Regular files
thus inflate the parent's count while they exist, and leak one link
permanently on every create and remove cycle.
For example, /proc/bus/pci/00 with twenty-two device files and no
subdirectories reports nlink 24 instead of 2, and SR-IOV VF enable
and disable cycles, each creating and removing the VF config space
entries under /proc/bus/pci/<bus>, inflate the link count of that
directory without bound.
Before commit e06689bf5701 ("proc: change ->nlink under
proc_subdir_lock"), the increment lived in proc_mkdir_data() and
proc_create_mount_point(), and was therefore applied only to
directories. Moving it into proc_register() to bring it under
proc_subdir_lock dropped the S_ISDIR check.
Thus, move the nlink accounting into pde_subdir_insert() and
pde_erase(), only updating it for directories in both, so the link
count is always changed together with the directory entry itself.
Fixes: e06689bf5701 ("proc: change ->nlink under proc_subdir_lock")
Cc: stable@vger.kernel.org # v5.5+
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Link: https://patch.msgid.link/20260613211005.921692-1-kwilczynski@kernel.org
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
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