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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull non-MM updates from Andrew Morton:
- "taskstats: fix TGID dead-thread stat retention" (Yiyang Chen)
Fix a taskstats TGID aggregation bug where fields added in the TGID
query path were not preserved after thread exit, and adds a kselftest
covering the regression.
- "lib/tests: string_helpers: Slight improvements" (Andy Shevchenko)
Improve lib/tests/string_helpers_kunit.c a little
- "lib/base64: decode fixes" (Josh Law)
Address minor issues in lib/base64.c
- "selftests/filelock: Make output more kselftestish" (Mark Brown)
Make the output from the ofdlocks test a bit easier for tooling to
work with. Also ignore the generated file
- "uaccess: unify inline vs outline copy_{from,to}_user() selection"
(Yury Norov)
Simplify the usercopy code by removing the selectability of inlining
copy_{from,to}_user().
- "ocfs2: validate inline xattr header consumers" (ZhengYuan Huang)
Fix a number of possible issues in the ocfs2 xattr code
- "lib and lib/cmdline enhancements" (Dmitry Antipov)
Provide additional robustness checking in the cmdline handling code
and its in-kernel testing and selftests
- "cleanup the RAID6 P/Q library" (Christoph Hellwig)
Clean up the RAID6 P/Q library to match the recent updates to the
RAID 5 XOR library and other CRC/crypto libraries
- "ocfs2: harden inode validators against forged metadata" (Michael
Bommarito)
Add three structural checks to OCFS2 dinode validation so malformed
on-disk fields are rejected before ocfs2_populate_inode() copies them
into the in-core inode
- "lib/raid: replace __get_free_pages() call with kmalloc()" (Mike
Rapoport)
Clean up the lib/raid code by using kmalloc() in more places
* tag 'mm-nonmm-stable-2026-06-21-10-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (108 commits)
ocfs2: fix circular locking dependency in ocfs2_dio_end_io_write
ocfs2: fix NULL h_transaction deref in ocfs2_assure_trans_credits
lib: interval_tree_test: validate benchmark parameters
ocfs2: avoid moving extents to occupied clusters
treewide: fix transposed "sign" typos and update spelling.txt
ocfs2: fix UBSAN array-index-out-of-bounds in ocfs2_sum_rightmost_rec
fat: reject BPB volumes whose data area starts beyond total sectors
selftests/uevent: increase __UEVENT_BUFFER_SIZE to avoid ENOBUFS on busy systems
lib/test_firmware: allocate the configured into_buf size
fs: efs: remove unneeded debug prints
checkpatch: cuppress warnings when Reported-by: is followed by Link:
MAINTAINERS: add Alexander as a kcov reviewer
mailmap: update Alexander Sverdlin's Email addresses
fs: fat: inode: replace sprintf() with scnprintf()
ocfs2: fix out-of-bounds write in ocfs2_remove_refcount_extent
ocfs2: fix race between ocfs2_control_install_private() and ocfs2_control_release()
ocfs2/dlm: require a ref for locking_state debugfs open
ocfs2: reject FITRIM ranges shorter than a cluster
ocfs2: validate fast symlink target during inode read
ocfs2: add journal NULL check in ocfs2_checkpoint_inode()
...
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git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull dcache updates from Al Viro:
- d_alloc_parallel() API change (Neil's with my changes)
- NORCU fixes
- Reorganization and simplification of dentry eviction logic
- Simplifying rcu_read_lock() scopes in fs/dcache.c
- Secondary roots work - getting rid of NFS fake root dentries and
dealing with remaining shrink_dcache_for_umount() and
shrink_dentry_list() races
- making cursors NORCU (surprisingly easy)
* tag 'pull-dcache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (22 commits)
make cursors NORCU
nfs: get rid of fake root dentries
wind ->s_roots via ->d_sib instead of ->d_hash
shrink_dentry_tree(): unify the calls of shrink_dentry_list()
shrinking rcu_read_lock() scope in d_alloc_parallel()
d_walk(): shrink rcu_read_lock() scope
document dentry_kill()
adjust calling conventions of lock_for_kill(), fold __dentry_kill() into dentry_kill()
Document rcu_read_lock() use in select_collect2()
Shift rcu_read_{,un}lock() inside fast_dput()
simplify safety for lock_for_kill() slowpath
fold lock_for_kill() and __dentry_kill() into common helper
fold lock_for_kill() into shrink_kill()
shrink_dentry_list(): start with removing from shrink list
d_prune_aliases(): make sure to skip NORCU aliases
kill d_dispose_if_unused()
make to_shrink_list() return whether it has moved dentry to list
select_collect(): ignore dentries on shrink lists if they have positive refcounts
find_acceptable_alias(): skip NORCU aliases with zero refcount
fix a race between d_find_any_alias() and final dput() of NORCU dentries
...
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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull procfs updates from Christian Brauner:
- Revamp fs/filesystems.c
The file was a mess with a hand-rolled linked list in desperate need
of a cleanup. The filesystems list is now RCU-ified, /proc files can
be marked permanent from outside fs/proc/, and the string emitted
when reading /proc/filesystems is pre-generated and cached instead of
pointer-chasing and printfing entry by entry on every read.
The file is read frequently because libselinux reads it and is linked
into numerous frequently used programs (even ones you would not
suspect, like sed!). Scalability also improves since reference
maintenance on open/close is bypassed.
open+read+close cycle single-threaded (ops/s):
before: 442732
after: 1063462 (+140%)
open+read+close cycle with 20 processes (ops/s):
before: 606177
after: 3300576 (+444%)
A follow-up patch adds missing unlocks in some corner cases and
tidies things up.
- Relax the mount visibility check for subset=pid mounts
When procfs is mounted with subset=pid, all static files become
unavailable and only the dynamic pid information is accessible. In
that case there is no point in imposing the full mount visibility
restrictions on the mounter - everything that can be hidden in procfs
is already inaccessible. These restrictions prevented procfs from
being mounted inside rootless containers since almost all container
implementations overmount parts of procfs to hide certain
directories.
As part of this /proc/self/net is only shown in subset=pid mounts for
CAP_NET_ADMIN, reconfiguring subset=pid is rejected, the
SB_I_USERNS_VISIBLE superblock flag is replaced with an
FS_USERNS_MOUNT_RESTRICTED filesystem flag, fully visible mounts are
recorded in a list, and the mount restrictions are finally
documented.
- Protect ptrace_may_access() with exec_update_lock in procfs
Most uses of ptrace_may_access() in procfs should hold
exec_update_lock to avoid TOCTOU issues with concurrent privileged
execve() (like setuid binary execution).
This fixes the easy cases - the owner and visibility checks and the
FD link permission checks - with the gnarlier ones to follow later.
* tag 'vfs-7.2-rc1.procfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
fs: fix ups and tidy ups to /proc/filesystems caching
proc: protect ptrace_may_access() with exec_update_lock (FD links)
proc: protect ptrace_may_access() with exec_update_lock (part 1)
docs: proc: add documentation about mount restrictions
proc: handle subset=pid separately in userns visibility checks
proc: prevent reconfiguring subset=pid
proc: subset=pid: Show /proc/self/net only for CAP_NET_ADMIN
fs: cache the string generated by reading /proc/filesystems
sysfs: remove trivial sysfs_get_tree() wrapper
fs: RCU-ify filesystems list
fs: move SB_I_USERNS_VISIBLE to FS_USERNS_MOUNT_RESTRICTED
proc: allow to mark /proc files permanent outside of fs/proc/
namespace: record fully visible mounts in list
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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull misc vfs updates from Christian Brauner:
"Features:
- Reduce pipe->mutex contention by pre-allocating pages outside the
lock in anon_pipe_write().
anon_pipe_write() called alloc_page() once per page while holding
pipe->mutex. The allocation can sleep doing direct reclaim and runs
memcg charging, which extends the critical section and stalls any
concurrent reader on the same mutex. Now up to 8 pages are
pre-allocated before the mutex is taken, leftovers are recycled
into the per-pipe tmp_page[] cache before unlock, and any remainder
is released after unlock, keeping the allocator out of the critical
section on both sides. On a writers x readers sweep with 64KB
writes against a 1 MB pipe throughput improves 6-28% and average
write latency drops 5-22%; under memory pressure - when the cost of
holding the mutex across reclaim is highest - throughput improves
21-48% and latency drops 17-33%. The microbenchmark is added to
selftests.
- uaccess/sockptr: fix the ignored_trailing logic in
copy_struct_to_user() to behave as documented and the usize check
in copy_struct_from_sockptr() for user pointers, and add
copy_struct_{from,to}_bounce_buffer() and copy_struct_to_sockptr()
helpers for upcoming users (IPPROTO_SMBDIRECT, IPPROTO_QUIC).
- bpf: add a sleepable bpf_real_inode() kfunc that resolves the real
inode backing a dentry via d_real_inode(). On overlayfs the inode
attached to the dentry doesn't carry the underlying device
information; this is used by the filesystem restriction BPF program
that was merged into systemd.
- docs: add guidelines for submitting new filesystems, motivated by
the maintenance burden abandoned and untestable filesystems impose
on VFS developers, blocking infrastructure work like folio
conversions and iomap migration.
Fixes:
- libfs: set SB_I_NOEXEC and SB_I_NODEV by default in init_pseudo()
and drop the now-redundant assignments in callers. This began as a
one-line dma-buf fix for a path_noexec() warning; a pseudo
filesystem has no reason not to set SB_I_NOEXEC. All init_pseudo()
callers were audited: the only visible effect is on dma-buf where
SB_I_NOEXEC silences the warning.
- Handle set_blocksize() failures in legacy filesystems (bfs, hpfs,
qnx4, jfs, befs, affs, isofs, minix, ntfs3, omfs). Mounting a
device with a sector size > PAGE_SIZE crashed roughly half of them;
the rest had the same missing error handling pattern. Plus a
follow-up releasing the superblock buffer_head when setting the
minix v3 block size fails.
- mount: honour SB_NOUSER in the new mount API.
- fs/fcntl: fix a SOFTIRQ-unsafe lock order in fasync signaling by
switching the process-group paths of send_sigio() and send_sigurg()
from read_lock(&tasklist_lock) to RCU, matching the single-PID
path.
- vfs: add an FS_USERNS_DELEGATABLE flag and set it for NFS, fixing
delegated NFS mounts (fsopen() in a container with the mount
performed by a privileged daemon) that broke when non-init
s_user_ns was tied to FS_USERNS_MOUNT.
- selftests/namespaces: fix a hang in nsid_test where an unreaped
grandchild kept the TAP pipe write-end open, a waitpid(-1) race in
listns_efault_test, and a false FAIL on kernels without listns()
where the tests should SKIP.
- filelock: fix the break_lease() stub signature for
CONFIG_FILE_LOCKING=n.
- init/initramfs_test: wait for the async initramfs unpacking before
running; the test and do_populate_rootfs() share the parser state.
- fs/coredump: reduce redundant log noise in
validate_coredump_safety().
- iomap: pass the correct length to fserror_report_io() in
__iomap_write_begin().
- backing-file: fix the backing_file_open() kerneldoc.
Cleanups:
- initramfs: refactor the cpio hex header parsing to use hex2bin()
instead of the hand-rolled simple_strntoul() which is reverted, and
extend the initramfs KUnit tests to cover header fields with 0x
prefixes.
- Replace __get_free_pages() and friends with kmalloc()/kzalloc()
across quota, proc, ocfs2/dlm, nilfs2, nfs, nfsd, libfs, jfs, jbd2,
isofs, fuse, select, namespace, configfs, binfmt_misc, bfs, and the
do_mounts init code - part of the larger work of replacing page
allocator calls with kmalloc().
- Use clear_and_wake_up_bit() in unlock_buffer() and
journal_end_buffer_io_sync() instead of open-coding the sequence.
- Drop unused VFS exports: unexport drop_super_exclusive(), remove
start_removing_user_path_at(), and fold __start_removing_path()
into start_removing_path().
- fs/read_write: narrow the __kernel_write() export with
EXPORT_SYMBOL_FOR_MODULES().
- vfs: uapi: retire octal and hex constants in favor of (1 << n) for
the O_ flags. Finding a free bit for a new flag across the
architectures was needlessly hard with the mixed bases.
- dcache: add extra sanity checks of dead dentries in dentry_free()
via a new DENTRY_WARN_ONCE() that also prints d_flags.
- iov_iter: use kmemdup_array() in dup_iter() to harden the
allocation against multiplication overflow.
- fs/pipe: write to ->poll_usage only once.
- vfs: remove an always-taken if-branch in find_next_fd().
- dcache: use kmalloc_flex() for struct external_name in __d_alloc().
- namei: use QSTR() instead of QSTR_INIT() in path_pts().
- sync_file_range: delete dead S_ISLNK code.
- Comment fixes: retire a stale comment in fget_task_next() and fix
assorted spelling mistakes"
* tag 'vfs-7.2-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (73 commits)
backing-file: fix backing_file_open() kerneldoc parameter
iomap: pass the correct len to fserror_report_io in __iomap_write_begin
vfs: add FS_USERNS_DELEGATABLE flag and set it for NFS
filelock: fix break_lease() stub signature for CONFIG_FILE_LOCKING=n
vfs: uapi: retire octal and hex numbers in favor of (1 << n) for O_ flags
bpf: add bpf_real_inode() kfunc
fs/read_write: Do not export __kernel_write() to the entire world
libfs: drop redundant SB_I_NOEXEC/SB_I_NODEV in init_pseudo() callers
libfs: set SB_I_NOEXEC and SB_I_NODEV by default in init_pseudo()
mount: honour SB_NOUSER in the new mount API
fs/fcntl: fix SOFTIRQ-unsafe lock order in fasync signaling
selftests/pipe: add pipe_bench microbenchmark
fs/pipe: pre-allocate pages outside pipe->mutex in anon_pipe_write
fs: retire stale comment in fget_task_next()
fs: fix spelling mistakes in comment
bfs: replace get_zeroed_page() with kzalloc()
binfmt_misc: replace __get_free_page() with kmalloc()
configfs: replace __get_free_pages() with kzalloc()
fs/namespace: use __getname() to allocate mntpath buffer
fs/select: replace __get_free_page() with kmalloc()
...
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proc_pid_get_link() and proc_pid_readlink() currently look up the task from
the pid once, then do the ptrace access check on that task, then look up
the task from the pid a second time to do the actual access.
That's racy in several ways.
To fix it, pass the task to the ->proc_get_link() handler, and instead of
proc_fd_access_allowed(), introduce a new helper call_proc_get_link() that
looks up and locks the task, does the access check, and calls
->proc_get_link().
Fixes: 778c1144771f ("[PATCH] proc: Use sane permission checks on the /proc/<pid>/fd/ symlinks")
Cc: stable@vger.kernel.org
Signed-off-by: Jann Horn <jannh@google.com>
Link: https://patch.msgid.link/20260518-procfs-lockfix-part1-v1-2-5c3d20e0ac33@google.com
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
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Fix the easy cases where procfs currently calls ptrace_may_access() without
exec_update_lock protection, where the fix is to simply add the extra lock
or use mm_access():
- do_task_stat(): grab exec_update_lock
- proc_pid_wchan(): grab exec_update_lock
- proc_map_files_lookup(): use mm_access() instead of get_task_mm()
- proc_map_files_readdir(): use mm_access() instead of get_task_mm()
- proc_ns_get_link(): grab exec_update_lock
- proc_ns_readlink(): grab exec_update_lock
Fixes: f83ce3e6b02d ("proc: avoid information leaks to non-privileged processes")
Cc: stable@vger.kernel.org
Signed-off-by: Jann Horn <jannh@google.com>
Link: https://patch.msgid.link/20260518-procfs-lockfix-part1-v1-1-5c3d20e0ac33@google.com
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
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Parallel lookup starts with a call of d_alloc_parallel(). That primitive
either returns a matching hashed dentry or allocates a new one in the
in-lookup state and returns it to the caller. Once the caller is done
with lookup, it indicates so either by call of d_{splice_alias,add}()
or by call of d_done_lookup(); at that point dentry leaves the in-lookup
state.
If d_alloc_parallel() finds a matching in-lookup dentry, it must wait for
that dentry to leave the in-lookup state, one way or another. Currently
by supplying wait_queue_head to d_alloc_parallel(). If d_alloc_parallel()
creates a new in-lookup dentry, the address of that wait_queue_head is stored
in ->d_wait of new dentry and stays there while it's in the in-lookup;
subsequent d_alloc_parallel() will wait on the queue found in the matching
in-lookup dentry. Transition out of in-lookup state wakes waiters on that
queue (if any).
That works, but the calling conventions are inconvenient - the caller must
supply wait_queue_head and make sure that it survives at least until the new
in-lookup dentry leaves the in-lookup state. That amounts to boilerplate
in the d_alloc_parallel() callers that are followed by a call of d_lookup_done()
in the same function; in cases like nfs asynchronous unlink it gets worse than
that.
This patch changes d_alloc_parallel() to use wake_up_var_locked() to
wake up waiters, and wait_var_event_spinlock() to wait. dentry->d_lock
is used for synchronisation as it is already held and the relevant
times.
That eliminates the need of caller-supplied wait_queue_head, simplifying
the calling conventions. Better yet, we only need one bit of information
stored in dentry itself: whether there are any waiters to be woken up,
and that can be easily stored in ->d_flags; ->d_wait goes away.
The reason we need that bit (DCACHE_LOOKUP_WAITERS) is that with wait_var
machinery the queues are shared with all kinds of stuff and there's
no way tell if any of the waiters have anything to do with our dentry;
most of the time none of them will be relevant, so we need to avoid the
pointless wakeups.
Another benefit of the new scheme comes from the fact that wakeups
have to be done outside of write-side critical areas of ->i_dir_seq;
with the old scheme we need to carry the value picked from ->d_wait from
__d_lookup_unhash() to the place where we actually wake the waiters up.
Now we can just leave DCACHE_LOOKUP_WAITERS in ->d_flags until we get
to doing wakeups - that's done within the same ->d_lock scope, so we
are fine; new bit is accessed only under ->d_lock and it's seen only
on dentries with DCACHE_PAR_LOOKUP in ->d_flags.
__d_lookup_unhash() no longer needs to re-init ->d_lru. That was
previously shared (in a union) with ->d_wait but ->d_wait is now gone
so it no longer corrupts ->d_lru.
Co-developed-by: Al Viro <viro@zeniv.linux.org.uk> # saner handling of flags
Signed-off-by: NeilBrown <neil@brown.name>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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* deduplicate "iter.tgid += 1" line,
Right now it is done once inside next_tgid() itself and second time
inside "for" loop.
* deduplicate next_tgid() call itself with different loop style:
auto it = make_tgid_iter();
while (next_tgid(&it)) {
...
}
gcc seems to inline it twice:
$ ./scripts/bloat-o-meter ../vmlinux-000 ../obj/vmlinux
add/remove: 0/1 grow/shrink: 1/0 up/down: 100/-245 (-145)
Function old new delta
proc_pid_readdir 531 631 +100
next_tgid 245 - -245
* make tgid_iter.pid_ns const
it never changes during readdir anyway
[akpm@linux-foundation.org: remove newline]
Link: https://lore.kernel.org/20260422191745.435556-2-adobriyan@gmail.com
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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next_tgid() accepts pid namespace as an argument, but it never changes
during readdir (which would be unthinkable thing to do anyway).
Move it inside iterator type and hide from direct usage.
Link: https://lore.kernel.org/20260422191745.435556-1-adobriyan@gmail.com
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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A few functions in fs/proc/base.c use __get_free_page() to allocate a
temporary buffer.
kmalloc() is a better API for such use and it also provides better
scalability and more debugging possibilities.
Replace use of __get_free_page() with kmalloc().
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Link: https://patch.msgid.link/20260523-b4-fs-v1-2-275e36a83f0e@kernel.org
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
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The dumpable flag captured at execve() is consulted by
__ptrace_may_access() and several /proc owner / visibility checks.
It lives on mm_struct today, which exit_mm() clears from the task
long before the task itself is reaped.
exec_state is anchored to the execve() that established the current
privilege domain. CLONE_VM siblings refcount-share the parent's
exec_state via copy_exec_state(); non-CLONE_VM clones allocate a
fresh exec_state inheriting the parent's dumpable mode and user_ns
reference via task_exec_state_copy(). execve() allocates a fresh
instance (via alloc_task_exec_state() in begin_new_exec()) and
installs it under task_lock + exec_update_lock with
task_exec_state_replace(). init_task uses a static instance.
The dumpable mode now lives on task->exec_state->dumpable.
task->mm->flags no longer carries dumpability; MMF_DUMPABLE_MASK is
removed, but MMF_DUMPABLE_BITS is reserved so MMF_DUMP_FILTER_* bit
positions remain stable for the /proc/<pid>/coredump_filter ABI. The
task->user_dumpable cache bit and its assignment in exit_mm() are
removed; readers go through get_dumpable(task) directly.
coredump_params gains a snapshot field cprm.dumpable, populated from
get_dumpable(current) at vfs_coredump() entry, replacing the previous
__get_dumpable(cprm->mm_flags) consumers in fs/coredump.c and
fs/pidfs.c.
The user namespace recorded at execve() is consulted by
__ptrace_may_access() and by /proc/PID/* owner derivation. Move the
captured user_ns onto task_exec_state, which stays attached to the task
past exit_mm() and across exit_files().
bprm grows a user_ns field staged in bprm_mm_init() with the caller's
user_ns, narrowed by would_dump() to the closest privileged ancestor,
and consumed by exec_mmap() via alloc_task_exec_state(bprm->user_ns).
free_bprm() releases the staging reference.
mm_struct loses ->user_ns entirely. Initializers in init-mm, efi_mm,
and the implicit one in mm_init()/dup_mm()/mm_alloc() are removed;
__mmdrop() drops the matching put_user_ns(). The kthread_use_mm()
WARN_ON_ONCE(!mm->user_ns) is no longer meaningful and goes too.
Reviewed-by: Jann Horn <jannh@google.com>
Link: https://patch.msgid.link/20260520-work-task_exec_state-v3-4-69f895bc1385@kernel.org
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
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Replace the SUID_DUMP_DISABLE/USER/ROOT preprocessor constants with
enum task_dumpable. Numeric values are preserved (kernel.suid_dumpable
sysctl and prctl(PR_SET_DUMPABLE) ABI), so this is a pure rename with
no behavioral change.
Subsequent commits relocate dumpability onto a per-task structure
where the enum type will allow stronger type-checking on the new API.
Reviewed-by: Jann Horn <jannh@google.com>
Reviewed-by: David Hildenbrand (arm) <david@kernel.org>
Link: https://patch.msgid.link/20260520-work-task_exec_state-v3-1-69f895bc1385@kernel.org
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull misc vfs updates from Christian Brauner:
"Features:
- coredump: add tracepoint for coredump events
- fs: hide file and bfile caches behind runtime const machinery
Fixes:
- fix architecture-specific compat_ftruncate64 implementations
- dcache: Limit the minimal number of bucket to two
- fs/omfs: reject s_sys_blocksize smaller than OMFS_DIR_START
- fs/mbcache: cancel shrink work before destroying the cache
- dcache: permit dynamic_dname()s up to NAME_MAX
Cleanups:
- remove or unexport unused fs_context infrastructure
- trivial ->setattr cleanups
- selftests/filesystems: Assume that TIOCGPTPEER is defined
- writeback: fix kernel-doc function name mismatch for wb_put_many()
- autofs: replace manual symlink buffer allocation in autofs_dir_symlink
- init/initramfs.c: trivial fix: FSM -> Finite-state machine
- fs: remove stale and duplicate forward declarations
- readdir: Introduce dirent_size()
- fs: Replace user_access_{begin/end} by scoped user access
- kernel: acct: fix duplicate word in comment
- fs: write a better comment in step_into() concerning .mnt assignment
- fs: attr: fix comment formatting and spelling issues"
* tag 'vfs-7.1-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (28 commits)
dcache: permit dynamic_dname()s up to NAME_MAX
fs: attr: fix comment formatting and spelling issues
fs: hide file and bfile caches behind runtime const machinery
fs: write a better comment in step_into() concerning .mnt assignment
proc: rename proc_notify_change to proc_setattr
proc: rename proc_setattr to proc_nochmod_setattr
affs: rename affs_notify_change to affs_setattr
adfs: rename adfs_notify_change to adfs_setattr
hfs: update comments on hfs_inode_setattr
kernel: acct: fix duplicate word in comment
fs: Replace user_access_{begin/end} by scoped user access
readdir: Introduce dirent_size()
coredump: add tracepoint for coredump events
fs: remove do_sys_truncate
fs: pass on FTRUNCATE_* flags to do_truncate
fs: fix archiecture-specific compat_ftruncate64
fs: remove stale and duplicate forward declarations
init/initramfs.c: trivial fix: FSM -> Finite-state machine
autofs: replace manual symlink buffer allocation in autofs_dir_symlink
fs/mbcache: cancel shrink work before destroying the cache
...
|
|
What is currently proc_setattr is a special version added after the more
general procfs ->seattr in commit 6d76fa58b050 ("Don't allow chmod() on
the /proc/<pid>/ files"). Give it a name that reflects that to free the
proc_setattr name and better describe what is doing.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://patch.msgid.link/20260325063711.3298685-5-hch@lst.de
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
The function try_lookup_noperm() can return an error pointer. Add check
for error pointer.
Detected by Smatch:
fs/proc/base.c:2148 proc_fill_cache() error:
'child' dereferencing possible ERR_PTR()
Fixes: 1df98b8bbcca ("proc_fill_cache(): clean up, get rid of pointless find_inode_number() use")
Signed-off-by: Ethan Tidmore <ethantidmore06@gmail.com>
Link: https://patch.msgid.link/20260219221001.1117135-1-ethantidmore06@gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull persistent dentry infrastructure and conversion from Al Viro:
"Some filesystems use a kinda-sorta controlled dentry refcount leak to
pin dentries of created objects in dcache (and undo it when removing
those). A reference is grabbed and not released, but it's not actually
_stored_ anywhere.
That works, but it's hard to follow and verify; among other things, we
have no way to tell _which_ of the increments is intended to be an
unpaired one. Worse, on removal we need to decide whether the
reference had already been dropped, which can be non-trivial if that
removal is on umount and we need to figure out if this dentry is
pinned due to e.g. unlink() not done. Usually that is handled by using
kill_litter_super() as ->kill_sb(), but there are open-coded special
cases of the same (consider e.g. /proc/self).
Things get simpler if we introduce a new dentry flag
(DCACHE_PERSISTENT) marking those "leaked" dentries. Having it set
claims responsibility for +1 in refcount.
The end result this series is aiming for:
- get these unbalanced dget() and dput() replaced with new primitives
that would, in addition to adjusting refcount, set and clear
persistency flag.
- instead of having kill_litter_super() mess with removing the
remaining "leaked" references (e.g. for all tmpfs files that hadn't
been removed prior to umount), have the regular
shrink_dcache_for_umount() strip DCACHE_PERSISTENT of all dentries,
dropping the corresponding reference if it had been set. After that
kill_litter_super() becomes an equivalent of kill_anon_super().
Doing that in a single step is not feasible - it would affect too many
places in too many filesystems. It has to be split into a series.
This work has really started early in 2024; quite a few preliminary
pieces have already gone into mainline. This chunk is finally getting
to the meat of that stuff - infrastructure and most of the conversions
to it.
Some pieces are still sitting in the local branches, but the bulk of
that stuff is here"
* tag 'pull-persistency' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (54 commits)
d_make_discardable(): warn if given a non-persistent dentry
kill securityfs_recursive_remove()
convert securityfs
get rid of kill_litter_super()
convert rust_binderfs
convert nfsctl
convert rpc_pipefs
convert hypfs
hypfs: swich hypfs_create_u64() to returning int
hypfs: switch hypfs_create_str() to returning int
hypfs: don't pin dentries twice
convert gadgetfs
gadgetfs: switch to simple_remove_by_name()
convert functionfs
functionfs: switch to simple_remove_by_name()
functionfs: fix the open/removal races
functionfs: need to cancel ->reset_work in ->kill_sb()
functionfs: don't bother with ffs->ref in ffs_data_{opened,closed}()
functionfs: don't abuse ffs_data_closed() on fs shutdown
convert selinuxfs
...
|
|
... and there's no need to remember those pointers anywhere - ->kill_sb()
no longer needs to bother since kill_anon_super() will take care of
them anyway and proc_pid_readdir() only wants the inumbers, which
we had in a couple of static variables all along.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
|
To simplify the code and make it more readable.
[peterz: change to new interface]
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull non-MM updates from Andrew Morton:
- "ida: Remove the ida_simple_xxx() API" from Christophe Jaillet
completes the removal of this legacy IDR API
- "panic: introduce panic status function family" from Jinchao Wang
provides a number of cleanups to the panic code and its various
helpers, which were rather ad-hoc and scattered all over the place
- "tools/delaytop: implement real-time keyboard interaction support"
from Fan Yu adds a few nice user-facing usability changes to the
delaytop monitoring tool
- "efi: Fix EFI boot with kexec handover (KHO)" from Evangelos
Petrongonas fixes a panic which was happening with the combination of
EFI and KHO
- "Squashfs: performance improvement and a sanity check" from Phillip
Lougher teaches squashfs's lseek() about SEEK_DATA/SEEK_HOLE. A mere
150x speedup was measured for a well-chosen microbenchmark
- plus another 50-odd singleton patches all over the place
* tag 'mm-nonmm-stable-2025-10-02-15-29' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (75 commits)
Squashfs: reject negative file sizes in squashfs_read_inode()
kallsyms: use kmalloc_array() instead of kmalloc()
MAINTAINERS: update Sibi Sankar's email address
Squashfs: add SEEK_DATA/SEEK_HOLE support
Squashfs: add additional inode sanity checking
lib/genalloc: fix device leak in of_gen_pool_get()
panic: remove CONFIG_PANIC_ON_OOPS_VALUE
ocfs2: fix double free in user_cluster_connect()
checkpatch: suppress strscpy warnings for userspace tools
cramfs: fix incorrect physical page address calculation
kernel: prevent prctl(PR_SET_PDEATHSIG) from racing with parent process exit
Squashfs: fix uninit-value in squashfs_get_parent
kho: only fill kimage if KHO is finalized
ocfs2: avoid extra calls to strlen() after ocfs2_sprintf_system_inode_name()
kernel/sys.c: fix the racy usage of task_lock(tsk->group_leader) in sys_prlimit64() paths
sched/task.h: fix the wrong comment on task_lock() nesting with tasklist_lock
coccinelle: platform_no_drv_owner: handle also built-in drivers
coccinelle: of_table: handle SPI device ID tables
lib/decompress: use designated initializers for struct compress_format
efi: support booting with kexec handover (KHO)
...
|
|
Use '%d' instead of '%u' for int.
Link: https://lkml.kernel.org/r/20250903083948.2536-1-zhangjiao2@cmss.chinamobile.com
Signed-off-by: zhang jiao <zhangjiao2@cmss.chinamobile.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: xu xin <xu.xin16@zte.com.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
As part of the effort to move to mm->flags becoming a bitmap field,
convert existing users to making use of the mm_flags_*() accessors which
will, when the conversion is complete, be the only means of accessing
mm_struct flags.
No functional change intended.
Link: https://lkml.kernel.org/r/cc67a56f9a8746a8ec7d9791853dc892c1c33e0b.1755012943.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Ben Segall <bsegall@google.com>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Marc Rutland <mark.rutland@arm.com>
Cc: Mariano Pache <npache@redhat.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Namhyung kim <namhyung@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: Valentin Schneider <vschneid@redhat.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: xu xin <xu.xin16@zte.com.cn>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
The coredump logic is slightly different from other users in that it both
stores mm flags and additionally sets and gets using masks.
Since the MMF_DUMPABLE_* flags must remain as they are for uABI reasons,
and of course these are within the first 32-bits of the flags, it is
reasonable to provide access to these in the same fashion so this logic
can all still keep working as it has been.
Therefore, introduce coredump-specific helpers __mm_flags_get_dumpable()
and __mm_flags_set_mask_dumpable() for this purpose, and update all core
dump users of mm flags to use these.
[lorenzo.stoakes@oracle.com: abstract set_mask_bits() invocation to mm_types.h to satisfy ARC]
Link: https://lkml.kernel.org/r/0e7ad263-1ff7-446d-81fe-97cff9c0e7ed@lucifer.local
Link: https://lkml.kernel.org/r/2a5075f7e3c5b367d988178c79a3063d12ee53a9.1755012943.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Ben Segall <bsegall@google.com>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: David Rientjes <rientjes@google.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Marc Rutland <mark.rutland@arm.com>
Cc: Mariano Pache <npache@redhat.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Namhyung kim <namhyung@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: Valentin Schneider <vschneid@redhat.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
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/kees/linux
Pull hardening updates from Kees Cook:
- Introduce and start using TRAILING_OVERLAP() helper for fixing
embedded flex array instances (Gustavo A. R. Silva)
- mux: Convert mux_control_ops to a flex array member in mux_chip
(Thorsten Blum)
- string: Group str_has_prefix() and strstarts() (Andy Shevchenko)
- Remove KCOV instrumentation from __init and __head (Ritesh Harjani,
Kees Cook)
- Refactor and rename stackleak feature to support Clang
- Add KUnit test for seq_buf API
- Fix KUnit fortify test under LTO
* tag 'hardening-v6.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (22 commits)
sched/task_stack: Add missing const qualifier to end_of_stack()
kstack_erase: Support Clang stack depth tracking
kstack_erase: Add -mgeneral-regs-only to silence Clang warnings
init.h: Disable sanitizer coverage for __init and __head
kstack_erase: Disable kstack_erase for all of arm compressed boot code
x86: Handle KCOV __init vs inline mismatches
arm64: Handle KCOV __init vs inline mismatches
s390: Handle KCOV __init vs inline mismatches
arm: Handle KCOV __init vs inline mismatches
mips: Handle KCOV __init vs inline mismatch
powerpc/mm/book3s64: Move kfence and debug_pagealloc related calls to __init section
configs/hardening: Enable CONFIG_INIT_ON_FREE_DEFAULT_ON
configs/hardening: Enable CONFIG_KSTACK_ERASE
stackleak: Split KSTACK_ERASE_CFLAGS from GCC_PLUGINS_CFLAGS
stackleak: Rename stackleak_track_stack to __sanitizer_cov_stack_depth
stackleak: Rename STACKLEAK to KSTACK_ERASE
seq_buf: Introduce KUnit tests
string: Group str_has_prefix() and strstarts()
kunit/fortify: Add back "volatile" for sizeof() constants
acpi: nfit: intel: avoid multiple -Wflex-array-member-not-at-end warnings
...
|
|
In preparation for adding Clang sanitizer coverage stack depth tracking
that can support stack depth callbacks:
- Add the new top-level CONFIG_KSTACK_ERASE option which will be
implemented either with the stackleak GCC plugin, or with the Clang
stack depth callback support.
- Rename CONFIG_GCC_PLUGIN_STACKLEAK as needed to CONFIG_KSTACK_ERASE,
but keep it for anything specific to the GCC plugin itself.
- Rename all exposed "STACKLEAK" names and files to "KSTACK_ERASE" (named
for what it does rather than what it protects against), but leave as
many of the internals alone as possible to avoid even more churn.
While here, also split "prev_lowest_stack" into CONFIG_KSTACK_ERASE_METRICS,
since that's the only place it is referenced from.
Suggested-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20250717232519.2984886-1-kees@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>
|
|
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull non-MM updates from Andrew Morton:
- "hung_task: extend blocking task stacktrace dump to semaphore" from
Lance Yang enhances the hung task detector.
The detector presently dumps the blocking tasks's stack when it is
blocked on a mutex. Lance's series extends this to semaphores
- "nilfs2: improve sanity checks in dirty state propagation" from
Wentao Liang addresses a couple of minor flaws in nilfs2
- "scripts/gdb: Fixes related to lx_per_cpu()" from Illia Ostapyshyn
fixes a couple of issues in the gdb scripts
- "Support kdump with LUKS encryption by reusing LUKS volume keys" from
Coiby Xu addresses a usability problem with kdump.
When the dump device is LUKS-encrypted, the kdump kernel may not have
the keys to the encrypted filesystem. A full writeup of this is in
the series [0/N] cover letter
- "sysfs: add counters for lockups and stalls" from Max Kellermann adds
/sys/kernel/hardlockup_count and /sys/kernel/hardlockup_count and
/sys/kernel/rcu_stall_count
- "fork: Page operation cleanups in the fork code" from Pasha Tatashin
implements a number of code cleanups in fork.c
- "scripts/gdb/symbols: determine KASLR offset on s390 during early
boot" from Ilya Leoshkevich fixes some s390 issues in the gdb
scripts
* tag 'mm-nonmm-stable-2025-05-31-15-28' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (67 commits)
llist: make llist_add_batch() a static inline
delayacct: remove redundant code and adjust indentation
squashfs: add optional full compressed block caching
crash_dump, nvme: select CONFIGFS_FS as built-in
scripts/gdb/symbols: determine KASLR offset on s390 during early boot
scripts/gdb/symbols: factor out pagination_off()
scripts/gdb/symbols: factor out get_vmlinux()
kernel/panic.c: format kernel-doc comments
mailmap: update and consolidate Casey Connolly's name and email
nilfs2: remove wbc->for_reclaim handling
fork: define a local GFP_VMAP_STACK
fork: check charging success before zeroing stack
fork: clean-up naming of vm_stack/vm_struct variables in vmap stacks code
fork: clean-up ifdef logic around stack allocation
kernel/rcu/tree_stall: add /sys/kernel/rcu_stall_count
kernel/watchdog: add /sys/kernel/{hard,soft}lockup_count
x86/crash: make the page that stores the dm crypt keys inaccessible
x86/crash: pass dm crypt keys to kdump kernel
Revert "x86/mm: Remove unused __set_memory_prot()"
crash_dump: retrieve dm crypt keys in kdump kernel
...
|
|
proc_mem_open() can return an errno, NULL, or mm_struct*. If it fails to
acquire mm, it returns NULL, but the caller does not check for the case
when the return value is NULL.
The following conditions lead to failure in acquiring mm:
- The task is a kernel thread (PF_KTHREAD)
- The task is exiting (PF_EXITING)
Changes:
- Add documentation comments for the return value of proc_mem_open().
- Add checks in the caller to return -ESRCH when proc_mem_open()
returns NULL.
Link: https://lkml.kernel.org/r/20250404063357.78891-1-superman.xpt@gmail.com
Reported-by: syzbot+f9238a0a31f9b5603fef@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/000000000000f52642060d4e3750@google.com
Signed-off-by: Penglei Jiang <superman.xpt@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Adrian Ratiu <adrian.ratiu@collabora.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Felix Moessbauer <felix.moessbauer@siemens.com>
Cc: Jeff layton <jlayton@kernel.org>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: xu xin <xu.xin16@zte.com.cn>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
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try_lookup_noperm() and d_hash_and_lookup() are nearly identical. The
former does some validation of the name where the latter doesn't.
Outside of the VFS that validation is likely valuable, and having only
one exported function for this task is certainly a good idea.
So make d_hash_and_lookup() local to VFS files and change all other
callers to try_lookup_noperm(). Note that the arguments are swapped.
Signed-off-by: NeilBrown <neilb@suse.de>
Link: https://lore.kernel.org/r/20250319031545.2999807-6-neil@brown.name
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull non-MM updates from Andrew Morton:
- The series "powerpc/crash: use generic crashkernel reservation" from
Sourabh Jain changes powerpc's kexec code to use more of the generic
layers.
- The series "get_maintainer: report subsystem status separately" from
Vlastimil Babka makes some long-requested improvements to the
get_maintainer output.
- The series "ucount: Simplify refcounting with rcuref_t" from
Sebastian Siewior cleans up and optimizing the refcounting in the
ucount code.
- The series "reboot: support runtime configuration of emergency
hw_protection action" from Ahmad Fatoum improves the ability for a
driver to perform an emergency system shutdown or reboot.
- The series "Converge on using secs_to_jiffies() part two" from Easwar
Hariharan performs further migrations from msecs_to_jiffies() to
secs_to_jiffies().
- The series "lib/interval_tree: add some test cases and cleanup" from
Wei Yang permits more userspace testing of kernel library code, adds
some more tests and performs some cleanups.
- The series "hung_task: Dump the blocking task stacktrace" from Masami
Hiramatsu arranges for the hung_task detector to dump the stack of
the blocking task and not just that of the blocked task.
- The series "resource: Split and use DEFINE_RES*() macros" from Andy
Shevchenko provides some cleanups to the resource definition macros.
- Plus the usual shower of singleton patches - please see the
individual changelogs for details.
* tag 'mm-nonmm-stable-2025-03-30-18-23' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (77 commits)
mailmap: consolidate email addresses of Alexander Sverdlin
fs/procfs: fix the comment above proc_pid_wchan()
relay: use kasprintf() instead of fixed buffer formatting
resource: replace open coded variant of DEFINE_RES()
resource: replace open coded variants of DEFINE_RES_*_NAMED()
resource: replace open coded variant of DEFINE_RES_NAMED_DESC()
resource: split DEFINE_RES_NAMED_DESC() out of DEFINE_RES_NAMED()
samples: add hung_task detector mutex blocking sample
hung_task: show the blocker task if the task is hung on mutex
kexec_core: accept unaccepted kexec segments' destination addresses
watchdog/perf: optimize bytes copied and remove manual NUL-termination
lib/interval_tree: fix the comment of interval_tree_span_iter_next_gap()
lib/interval_tree: skip the check before go to the right subtree
lib/interval_tree: add test case for span iteration
lib/interval_tree: add test case for interval_tree_iter_xxx() helpers
lib/rbtree: add random seed
lib/rbtree: split tests
lib/rbtree: enable userland test suite for rbtree related data structure
checkpatch: describe --min-conf-desc-length
scripts/gdb/symbols: determine KASLR offset on s390
...
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer core updates from Thomas Gleixner:
- Fix a memory ordering issue in posix-timers
Posix-timer lookup is lockless and reevaluates the timer validity
under the timer lock, but the update which validates the timer is not
protected by the timer lock. That allows the store to be reordered
against the initialization stores, so that the lookup side can
observe a partially initialized timer. That's mostly a theoretical
problem, but incorrect nevertheless.
- Fix a long standing inconsistency of the coarse time getters
The coarse time getters read the base time of the current update
cycle without reading the actual hardware clock. NTP frequency
adjustment can set the base time backwards. The fine grained
interfaces compensate this by reading the clock and applying the new
conversion factor, but the coarse grained time getters use the base
time directly. That allows the user to observe time going backwards.
Cure it by always forwarding base time, when NTP changes the
frequency with an immediate step.
- Rework of posix-timer hashing
The posix-timer hash is not scalable and due to the CRIU timer
restore mechanism prone to massive contention on the global hash
bucket lock.
Replace the global hash lock with a fine grained per bucket locking
scheme to address that.
- Rework the proc/$PID/timers interface.
/proc/$PID/timers is provided for CRIU to be able to restore a timer.
The printout happens with sighand lock held and interrupts disabled.
That's not required as this can be done with RCU protection as well.
- Provide a sane mechanism for CRIU to restore a timer ID
CRIU restores timers by creating and deleting them until the kernel
internal per process ID counter reached the requested ID. That's
horribly slow for sparse timer IDs.
Provide a prctl() which allows CRIU to restore a timer with a given
ID. When enabled the ID pointer is used as input pointer to read the
requested ID from user space. When disabled, the normal allocation
scheme (next ID) is active as before. This is backwards compatible
for both kernel and user space.
- Make hrtimer_update_function() less expensive.
The sanity checks are valuable, but expensive for high frequency
usage in io/uring. Make the debug checks conditional and enable them
only when lockdep is enabled.
- Small updates, cleanups and improvements
* tag 'timers-core-2025-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (27 commits)
selftests/timers: Improve skew_consistency by testing with other clockids
timekeeping: Fix possible inconsistencies in _COARSE clockids
posix-timers: Drop redundant memset() invocation
selftests/timers/posix-timers: Add a test for exact allocation mode
posix-timers: Provide a mechanism to allocate a given timer ID
posix-timers: Dont iterate /proc/$PID/timers with sighand:: Siglock held
posix-timers: Make per process list RCU safe
posix-timers: Avoid false cacheline sharing
posix-timers: Switch to jhash32()
posix-timers: Improve hash table performance
posix-timers: Make signal_struct:: Next_posix_timer_id an atomic_t
posix-timers: Make lock_timer() use guard()
posix-timers: Rework timer removal
posix-timers: Simplify lock/unlock_timer()
posix-timers: Use guards in a few places
posix-timers: Remove SLAB_PANIC from kmem cache
posix-timers: Remove a few paranoid warnings
posix-timers: Cleanup includes
posix-timers: Add cond_resched() to posix_timer_add() search loop
posix-timers: Initialise timer before adding it to the hash table
...
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proc_pid_wchan() used to report kernel addresses to user space but that is
no longer the case today. Bring the comment above proc_pid_wchan() in
sync with the implementation.
Link: https://lkml.kernel.org/r/20250319210222.1518771-1-bvanassche@acm.org
Fixes: b2f73922d119 ("fs/proc, core/debug: Don't expose absolute kernel addresses via wchan")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Cc: Kees Cook <kees@kernel.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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All the big Linux distros enable CONFIG_SCHED_DEBUG, because
the various features it provides help not just with kernel
development, but with system administration and user-space
software development as well.
Reflect this reality and enable this functionality
unconditionally.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ben Segall <bsegall@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Valentin Schneider <vschneid@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20250317104257.3496611-4-mingo@kernel.org
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The readout of /proc/$PID/timers holds sighand::siglock with interrupts
disabled. That is required to protect against concurrent modifications of
the task::signal::posix_timers list because the list is not RCU safe.
With the conversion of the timer storage to a RCU protected hlist, this is
not longer required.
The only requirement is to protect the returned entry against a concurrent
free, which is trivial as the timers are RCU protected.
Removing the trylock of sighand::siglock is benign because the life time of
task_struct::signal is bound to the life time of the task_struct itself.
There are two scenarios where this matters:
1) The process is life and not about to be checkpointed
2) The process is stopped via ptrace for checkpointing
#1 is a racy snapshot of the armed timers and nothing can rely on it. It's
not more than debug information and it has been that way before because
sighand lock is dropped when the buffer is full and the restart of
the iteration might find a completely different set of timers.
The task and therefore task::signal cannot be freed as timers_start()
acquired a reference count via get_pid_task().
#2 the process is stopped for checkpointing so nothing can delete or create
timers at this point. Neither can the process exit during the traversal.
If CRIU fails to observe an exit in progress prior to the dissimination
of the timers, then there are more severe problems to solve in the CRIU
mechanics as they can't rely on posix timers being enabled in the first
place.
Therefore replace the lock acquisition with rcu_read_lock() and switch the
timer storage traversal over to seq_hlist_*_rcu().
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/all/20250308155624.465175807@linutronix.de
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git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs d_revalidate updates from Al Viro:
"Provide stable parent and name to ->d_revalidate() instances
Most of the filesystem methods where we care about dentry name and
parent have their stability guaranteed by the callers;
->d_revalidate() is the major exception.
It's easy enough for callers to supply stable values for expected name
and expected parent of the dentry being validated. That kills quite a
bit of boilerplate in ->d_revalidate() instances, along with a bunch
of races where they used to access ->d_name without sufficient
precautions"
* tag 'pull-revalidate' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
9p: fix ->rename_sem exclusion
orangefs_d_revalidate(): use stable parent inode and name passed by caller
ocfs2_dentry_revalidate(): use stable parent inode and name passed by caller
nfs: fix ->d_revalidate() UAF on ->d_name accesses
nfs{,4}_lookup_validate(): use stable parent inode passed by caller
gfs2_drevalidate(): use stable parent inode and name passed by caller
fuse_dentry_revalidate(): use stable parent inode and name passed by caller
vfat_revalidate{,_ci}(): use stable parent inode passed by caller
exfat_d_revalidate(): use stable parent inode passed by caller
fscrypt_d_revalidate(): use stable parent inode passed by caller
ceph_d_revalidate(): propagate stable name down into request encoding
ceph_d_revalidate(): use stable parent inode passed by caller
afs_d_revalidate(): use stable name and parent inode passed by caller
Pass parent directory inode and expected name to ->d_revalidate()
generic_ci_d_compare(): use shortname_storage
ext4 fast_commit: make use of name_snapshot primitives
dissolve external_name.u into separate members
make take_dentry_name_snapshot() lockless
dcache: back inline names with a struct-wrapped array of unsigned long
make sure that DNAME_INLINE_LEN is a multiple of word size
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->d_revalidate() often needs to access dentry parent and name; that has
to be done carefully, since the locking environment varies from caller
to caller. We are not guaranteed that dentry in question will not be
moved right under us - not unless the filesystem is such that nothing
on it ever gets renamed.
It can be dealt with, but that results in boilerplate code that isn't
even needed - the callers normally have just found the dentry via dcache
lookup and want to verify that it's in the right place; they already
have the values of ->d_parent and ->d_name stable. There is a couple
of exceptions (overlayfs and, to less extent, ecryptfs), but for the
majority of calls that song and dance is not needed at all.
It's easier to make ecryptfs and overlayfs find and pass those values if
there's a ->d_revalidate() instance to be called, rather than doing that
in the instances.
This commit only changes the calling conventions; making use of supplied
values is left to followups.
NOTE: some instances need more than just the parent - things like CIFS
may need to build an entire path from filesystem root, so they need
more precautions than the usual boilerplate. This series doesn't
do anything to that need - these filesystems have to keep their locking
mechanisms (rename_lock loops, use of dentry_path_raw(), private rwsem
a-la v9fs).
One thing to keep in mind when using name is that name->name will normally
point into the pathname being resolved; the filename in question occupies
name->len bytes starting at name->name, and there is NUL somewhere after it,
but it the next byte might very well be '/' rather than '\0'. Do not
ignore name->len.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Gabriel Krisman Bertazi <gabriel@krisman.be>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
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In /proc/<pid>/ksm_stat, add two extra ksm involvement items including
KSM_mergeable and KSM_merge_any. It helps administrators to better know
the system's KSM behavior at process level.
ksm_merge_any: yes/no
whether the process'mm is added by prctl() into the candidate list
of KSM or not, and fully enabled at process level.
ksm_mergeable: yes/no
whether any VMAs of the process'mm are currently applicable to KSM.
Purpose
=======
These two items are just to improve the observability of KSM at process
level, so that users can know if a certain process has enabled KSM.
For example, if without these two items, when we look at
/proc/<pid>/ksm_stat and there's no merging pages found, We are not sure
whether it is because KSM was not enabled or because KSM did not
successfully merge any pages.
Although "mg" in /proc/<pid>/smaps indicate VM_MERGEABLE, it's opaque
and not very obvious for non professionals.
[akpm@linux-foundation.org: wording tweaks, per David and akpm]
Link: https://lkml.kernel.org/r/20250110174034304QOb8eDoqtFkp3_t8mqnqc@zte.com.cn
Signed-off-by: xu xin <xu.xin16@zte.com.cn>
Acked-by: David Hildenbrand <david@redhat.com>
Tested-by: Mario Casquero <mcasquer@redhat.com>
Cc: Wang Yaxin <wang.yaxin@zte.com.cn>
Cc: Yang Yang <yang.yang29@zte.com.cn>
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 MM updates from Andrew Morton:
- The series "zram: optimal post-processing target selection" from
Sergey Senozhatsky improves zram's post-processing selection
algorithm. This leads to improved memory savings.
- Wei Yang has gone to town on the mapletree code, contributing several
series which clean up the implementation:
- "refine mas_mab_cp()"
- "Reduce the space to be cleared for maple_big_node"
- "maple_tree: simplify mas_push_node()"
- "Following cleanup after introduce mas_wr_store_type()"
- "refine storing null"
- The series "selftests/mm: hugetlb_fault_after_madv improvements" from
David Hildenbrand fixes this selftest for s390.
- The series "introduce pte_offset_map_{ro|rw}_nolock()" from Qi Zheng
implements some rationaizations and cleanups in the page mapping
code.
- The series "mm: optimize shadow entries removal" from Shakeel Butt
optimizes the file truncation code by speeding up the handling of
shadow entries.
- The series "Remove PageKsm()" from Matthew Wilcox completes the
migration of this flag over to being a folio-based flag.
- The series "Unify hugetlb into arch_get_unmapped_area functions" from
Oscar Salvador implements a bunch of consolidations and cleanups in
the hugetlb code.
- The series "Do not shatter hugezeropage on wp-fault" from Dev Jain
takes away the wp-fault time practice of turning a huge zero page
into small pages. Instead we replace the whole thing with a THP. More
consistent cleaner and potentiall saves a large number of pagefaults.
- The series "percpu: Add a test case and fix for clang" from Andy
Shevchenko enhances and fixes the kernel's built in percpu test code.
- The series "mm/mremap: Remove extra vma tree walk" from Liam Howlett
optimizes mremap() by avoiding doing things which we didn't need to
do.
- The series "Improve the tmpfs large folio read performance" from
Baolin Wang teaches tmpfs to copy data into userspace at the folio
size rather than as individual pages. A 20% speedup was observed.
- The series "mm/damon/vaddr: Fix issue in
damon_va_evenly_split_region()" fro Zheng Yejian fixes DAMON
splitting.
- The series "memcg-v1: fully deprecate charge moving" from Shakeel
Butt removes the long-deprecated memcgv2 charge moving feature.
- The series "fix error handling in mmap_region() and refactor" from
Lorenzo Stoakes cleanup up some of the mmap() error handling and
addresses some potential performance issues.
- The series "x86/module: use large ROX pages for text allocations"
from Mike Rapoport teaches x86 to use large pages for
read-only-execute module text.
- The series "page allocation tag compression" from Suren Baghdasaryan
is followon maintenance work for the new page allocation profiling
feature.
- The series "page->index removals in mm" from Matthew Wilcox remove
most references to page->index in mm/. A slow march towards shrinking
struct page.
- The series "damon/{self,kunit}tests: minor fixups for DAMON debugfs
interface tests" from Andrew Paniakin performs maintenance work for
DAMON's self testing code.
- The series "mm: zswap swap-out of large folios" from Kanchana Sridhar
improves zswap's batching of compression and decompression. It is a
step along the way towards using Intel IAA hardware acceleration for
this zswap operation.
- The series "kasan: migrate the last module test to kunit" from
Sabyrzhan Tasbolatov completes the migration of the KASAN built-in
tests over to the KUnit framework.
- The series "implement lightweight guard pages" from Lorenzo Stoakes
permits userapace to place fault-generating guard pages within a
single VMA, rather than requiring that multiple VMAs be created for
this. Improved efficiencies for userspace memory allocators are
expected.
- The series "memcg: tracepoint for flushing stats" from JP Kobryn uses
tracepoints to provide increased visibility into memcg stats flushing
activity.
- The series "zram: IDLE flag handling fixes" from Sergey Senozhatsky
fixes a zram buglet which potentially affected performance.
- The series "mm: add more kernel parameters to control mTHP" from
Maíra Canal enhances our ability to control/configuremultisize THP
from the kernel boot command line.
- The series "kasan: few improvements on kunit tests" from Sabyrzhan
Tasbolatov has a couple of fixups for the KASAN KUnit tests.
- The series "mm/list_lru: Split list_lru lock into per-cgroup scope"
from Kairui Song optimizes list_lru memory utilization when lockdep
is enabled.
* tag 'mm-stable-2024-11-18-19-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (215 commits)
cma: enforce non-zero pageblock_order during cma_init_reserved_mem()
mm/kfence: add a new kunit test test_use_after_free_read_nofault()
zram: fix NULL pointer in comp_algorithm_show()
memcg/hugetlb: add hugeTLB counters to memcg
vmstat: call fold_vm_zone_numa_events() before show per zone NUMA event
mm: mmap_lock: check trace_mmap_lock_$type_enabled() instead of regcount
zram: ZRAM_DEF_COMP should depend on ZRAM
MAINTAINERS/MEMORY MANAGEMENT: add document files for mm
Docs/mm/damon: recommend academic papers to read and/or cite
mm: define general function pXd_init()
kmemleak: iommu/iova: fix transient kmemleak false positive
mm/list_lru: simplify the list_lru walk callback function
mm/list_lru: split the lock to per-cgroup scope
mm/list_lru: simplify reparenting and initial allocation
mm/list_lru: code clean up for reparenting
mm/list_lru: don't export list_lru_add
mm/list_lru: don't pass unnecessary key parameters
kasan: add kunit tests for kmalloc_track_caller, kmalloc_node_track_caller
kasan: change kasan_atomics kunit test as KUNIT_CASE_SLOW
kasan: use EXPORT_SYMBOL_IF_KUNIT to export symbols
...
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer updates from Thomas Gleixner:
"A rather large update for timekeeping and timers:
- The final step to get rid of auto-rearming posix-timers
posix-timers are currently auto-rearmed by the kernel when the
signal of the timer is ignored so that the timer signal can be
delivered once the corresponding signal is unignored.
This requires to throttle the timer to prevent a DoS by small
intervals and keeps the system pointlessly out of low power states
for no value. This is a long standing non-trivial problem due to
the lock order of posix-timer lock and the sighand lock along with
life time issues as the timer and the sigqueue have different life
time rules.
Cure this by:
- Embedding the sigqueue into the timer struct to have the same
life time rules. Aside of that this also avoids the lookup of
the timer in the signal delivery and rearm path as it's just a
always valid container_of() now.
- Queuing ignored timer signals onto a seperate ignored list.
- Moving queued timer signals onto the ignored list when the
signal is switched to SIG_IGN before it could be delivered.
- Walking the ignored list when SIG_IGN is lifted and requeue the
signals to the actual signal lists. This allows the signal
delivery code to rearm the timer.
This also required to consolidate the signal delivery rules so they
are consistent across all situations. With that all self test
scenarios finally succeed.
- Core infrastructure for VFS multigrain timestamping
This is required to allow the kernel to use coarse grained time
stamps by default and switch to fine grained time stamps when inode
attributes are actively observed via getattr().
These changes have been provided to the VFS tree as well, so that
the VFS specific infrastructure could be built on top.
- Cleanup and consolidation of the sleep() infrastructure
- Move all sleep and timeout functions into one file
- Rework udelay() and ndelay() into proper documented inline
functions and replace the hardcoded magic numbers by proper
defines.
- Rework the fsleep() implementation to take the reality of the
timer wheel granularity on different HZ values into account.
Right now the boundaries are hard coded time ranges which fail
to provide the requested accuracy on different HZ settings.
- Update documentation for all sleep/timeout related functions
and fix up stale documentation links all over the place
- Fixup a few usage sites
- Rework of timekeeping and adjtimex(2) to prepare for multiple PTP
clocks
A system can have multiple PTP clocks which are participating in
seperate and independent PTP clock domains. So far the kernel only
considers the PTP clock which is based on CLOCK TAI relevant as
that's the clock which drives the timekeeping adjustments via the
various user space daemons through adjtimex(2).
The non TAI based clock domains are accessible via the file
descriptor based posix clocks, but their usability is very limited.
They can't be accessed fast as they always go all the way out to
the hardware and they cannot be utilized in the kernel itself.
As Time Sensitive Networking (TSN) gains traction it is required to
provide fast user and kernel space access to these clocks.
The approach taken is to utilize the timekeeping and adjtimex(2)
infrastructure to provide this access in a similar way how the
kernel provides access to clock MONOTONIC, REALTIME etc.
Instead of creating a duplicated infrastructure this rework
converts timekeeping and adjtimex(2) into generic functionality
which operates on pointers to data structures instead of using
static variables.
This allows to provide time accessors and adjtimex(2) functionality
for the independent PTP clocks in a subsequent step.
- Consolidate hrtimer initialization
hrtimers are set up by initializing the data structure and then
seperately setting the callback function for historical reasons.
That's an extra unnecessary step and makes Rust support less
straight forward than it should be.
Provide a new set of hrtimer_setup*() functions and convert the
core code and a few usage sites of the less frequently used
interfaces over.
The bulk of the htimer_init() to hrtimer_setup() conversion is
already prepared and scheduled for the next merge window.
- Drivers:
- Ensure that the global timekeeping clocksource is utilizing the
cluster 0 timer on MIPS multi-cluster systems.
Otherwise CPUs on different clusters use their cluster specific
clocksource which is not guaranteed to be synchronized with
other clusters.
- Mostly boring cleanups, fixes, improvements and code movement"
* tag 'timers-core-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (140 commits)
posix-timers: Fix spurious warning on double enqueue versus do_exit()
clocksource/drivers/arm_arch_timer: Use of_property_present() for non-boolean properties
clocksource/drivers/gpx: Remove redundant casts
clocksource/drivers/timer-ti-dm: Fix child node refcount handling
dt-bindings: timer: actions,owl-timer: convert to YAML
clocksource/drivers/ralink: Add Ralink System Tick Counter driver
clocksource/drivers/mips-gic-timer: Always use cluster 0 counter as clocksource
clocksource/drivers/timer-ti-dm: Don't fail probe if int not found
clocksource/drivers:sp804: Make user selectable
clocksource/drivers/dw_apb: Remove unused dw_apb_clockevent functions
hrtimers: Delete hrtimer_init_on_stack()
alarmtimer: Switch to use hrtimer_setup() and hrtimer_setup_on_stack()
io_uring: Switch to use hrtimer_setup_on_stack()
sched/idle: Switch to use hrtimer_setup_on_stack()
hrtimers: Delete hrtimer_init_sleeper_on_stack()
wait: Switch to use hrtimer_setup_sleeper_on_stack()
timers: Switch to use hrtimer_setup_sleeper_on_stack()
net: pktgen: Switch to use hrtimer_setup_sleeper_on_stack()
futex: Switch to use hrtimer_setup_sleeper_on_stack()
fs/aio: Switch to use hrtimer_setup_sleeper_on_stack()
...
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To cure the SIG_IGN handling for posix interval timers, the preallocated
sigqueue needs to be embedded into struct k_itimer to prevent life time
races of all sorts.
Now that the prerequisites are in place, embed the sigqueue into struct
k_itimer and fixup the relevant usage sites.
Aside of preparing for proper SIG_IGN handling, this spares an extra
allocation.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/all/20241105064213.719695194@linutronix.de
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mm_access() can return NULL if the mm is not found, but this is handled
the same as an error in all callers, with some translating this into an
-ESRCH error.
Only proc_mem_open() returns NULL if no mm is found, however in this case
it is clearer and makes more sense to explicitly handle the error.
Additionally we take the opportunity to refactor the function to eliminate
unnecessary nesting.
Simplify things by simply returning -ESRCH if no mm is found - this both
eliminates confusing use of the IS_ERR_OR_NULL() macro, and simplifies
callers which would return -ESRCH by returning this error directly.
[lorenzo.stoakes@oracle.com: prefer neater pointer error comparison]
Link: https://lkml.kernel.org/r/2fae1834-749a-45e1-8594-5e5979cf7103@lucifer.local
Link: https://lkml.kernel.org/r/20240924201023.193135-1-lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
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some of those used to be needed, some had been cargo-culted for
no reason...
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
- Implement the SCHED_DEADLINE server infrastructure - Daniel Bristot
de Oliveira's last major contribution to the kernel:
"SCHED_DEADLINE servers can help fixing starvation issues of low
priority tasks (e.g., SCHED_OTHER) when higher priority tasks
monopolize CPU cycles. Today we have RT Throttling; DEADLINE
servers should be able to replace and improve that."
(Daniel Bristot de Oliveira, Peter Zijlstra, Joel Fernandes, Youssef
Esmat, Huang Shijie)
- Preparatory changes for sched_ext integration:
- Use set_next_task(.first) where required
- Fix up set_next_task() implementations
- Clean up DL server vs. core sched
- Split up put_prev_task_balance()
- Rework pick_next_task()
- Combine the last put_prev_task() and the first set_next_task()
- Rework dl_server
- Add put_prev_task(.next)
(Peter Zijlstra, with a fix by Tejun Heo)
- Complete the EEVDF transition and refine EEVDF scheduling:
- Implement delayed dequeue
- Allow shorter slices to wakeup-preempt
- Use sched_attr::sched_runtime to set request/slice suggestion
- Document the new feature flags
- Remove unused and duplicate-functionality fields
- Simplify & unify pick_next_task_fair()
- Misc debuggability enhancements
(Peter Zijlstra, with fixes/cleanups by Dietmar Eggemann, Valentin
Schneider and Chuyi Zhou)
- Initialize the vruntime of a new task when it is first enqueued,
resulting in significant decrease in latency of newly woken tasks
(Zhang Qiao)
- Introduce SM_IDLE and an idle re-entry fast-path in __schedule()
(K Prateek Nayak, Peter Zijlstra)
- Clean up and clarify the usage of Clean up usage of rt_task()
(Qais Yousef)
- Preempt SCHED_IDLE entities in strict cgroup hierarchies
(Tianchen Ding)
- Clarify the documentation of time units for deadline scheduler
parameters (Christian Loehle)
- Remove the HZ_BW chicken-bit feature flag introduced a year ago,
the original change seems to be working fine (Phil Auld)
- Misc fixes and cleanups (Chen Yu, Dan Carpenter, Huang Shijie,
Peilin He, Qais Yousefm and Vincent Guittot)
* tag 'sched-core-2024-09-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (64 commits)
sched/cpufreq: Use NSEC_PER_MSEC for deadline task
cpufreq/cppc: Use NSEC_PER_MSEC for deadline task
sched/deadline: Clarify nanoseconds in uapi
sched/deadline: Convert schedtool example to chrt
sched/debug: Fix the runnable tasks output
sched: Fix sched_delayed vs sched_core
kernel/sched: Fix util_est accounting for DELAY_DEQUEUE
kthread: Fix task state in kthread worker if being frozen
sched/pelt: Use rq_clock_task() for hw_pressure
sched/fair: Move effective_cpu_util() and effective_cpu_util() in fair.c
sched/core: Introduce SM_IDLE and an idle re-entry fast-path in __schedule()
sched: Add put_prev_task(.next)
sched: Rework dl_server
sched: Combine the last put_prev_task() and the first set_next_task()
sched: Rework pick_next_task()
sched: Split up put_prev_task_balance()
sched: Clean up DL server vs core sched
sched: Fixup set_next_task() implementations
sched: Use set_next_task(.first) where required
sched/fair: Properly deactivate sched_delayed task upon class change
...
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer updates from Thomas Gleixner:
"Core:
- Overhaul of posix-timers in preparation of removing the workaround
for periodic timers which have signal delivery ignored.
- Remove the historical extra jiffie in msleep()
msleep() adds an extra jiffie to the timeout value to ensure
minimal sleep time. The timer wheel ensures minimal sleep time
since the large rewrite to a non-cascading wheel, but the extra
jiffie in msleep() remained unnoticed. Remove it.
- Make the timer slack handling correct for realtime tasks.
The procfs interface is inconsistent and does neither reflect
reality nor conforms to the man page. Show the correct 0 slack for
real time tasks and enforce it at the core level instead of having
inconsistent individual checks in various timer setup functions.
- The usual set of updates and enhancements all over the place.
Drivers:
- Allow the ACPI PM timer to be turned off during suspend
- No new drivers
- The usual updates and enhancements in various drivers"
* tag 'timers-core-2024-09-16' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (43 commits)
ntp: Make sure RTC is synchronized when time goes backwards
treewide: Fix wrong singular form of jiffies in comments
cpu: Use already existing usleep_range()
timers: Rename next_expiry_recalc() to be unique
platform/x86:intel/pmc: Fix comment for the pmc_core_acpi_pm_timer_suspend_resume function
clocksource/drivers/jcore: Use request_percpu_irq()
clocksource/drivers/cadence-ttc: Add missing clk_disable_unprepare in ttc_setup_clockevent
clocksource/drivers/asm9260: Add missing clk_disable_unprepare in asm9260_timer_init
clocksource/drivers/qcom: Add missing iounmap() on errors in msm_dt_timer_init()
clocksource/drivers/ingenic: Use devm_clk_get_enabled() helpers
platform/x86:intel/pmc: Enable the ACPI PM Timer to be turned off when suspended
clocksource: acpi_pm: Add external callback for suspend/resume
clocksource/drivers/arm_arch_timer: Using for_each_available_child_of_node_scoped()
dt-bindings: timer: rockchip: Add rk3576 compatible
timers: Annotate possible non critical data race of next_expiry
timers: Remove historical extra jiffie for timeout in msleep()
hrtimer: Use and report correct timerslack values for realtime tasks
hrtimer: Annotate hrtimer_cpu_base_.*_expiry() for sparse.
timers: Add sparse annotation for timer_sync_wait_running().
signal: Replace BUG_ON()s
...
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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull procfs updates from Christian Brauner:
"This contains the following changes for procfs:
- Add config options and parameters to block forcing memory writes.
This adds a Kconfig option and boot param to allow removing the
FOLL_FORCE flag from /proc/<pid>/mem write calls as this can be
used in various attacks.
The traditional forcing behavior is kept as default because it can
break GDB and some other use cases.
This is the simpler version that you had requested.
- Restrict overmounting of ephemeral entities.
It is currently possible to mount on top of various ephemeral
entities in procfs. This specifically includes magic links. To
recap, magic links are links of the form /proc/<pid>/fd/<nr>. They
serve as references to a target file and during path lookup they
cause a jump to the target path. Such magic links disappear if the
corresponding file descriptor is closed.
Currently it is possible to overmount such magic links. This is
mostly interesting for an attacker that wants to somehow trick a
process into e.g., reopening something that it didn't intend to
reopen or to hide a malicious file descriptor.
But also it risks leaking mounts for long-running processes. When
overmounting a magic link like above, the mount will not be
detached when the file descriptor is closed. Only the target
mountpoint will disappear. Which has the consequence of making it
impossible to unmount that mount afterwards. So the mount will
stick around until the process exits and the /proc/<pid>/ directory
is cleaned up during proc_flush_pid() when the dentries are pruned
and invalidated.
That in turn means it's possible for a program to accidentally leak
mounts and it's also possible to make a task leak mounts without
it's knowledge if the attacker just keeps overmounting things under
/proc/<pid>/fd/<nr>.
Disallow overmounting of such ephemeral entities.
- Cleanup the readdir method naming in some procfs file operations.
- Replace kmalloc() and strcpy() with a simple kmemdup() call"
* tag 'vfs-6.12.procfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
proc: fold kmalloc() + strcpy() into kmemdup()
proc: block mounting on top of /proc/<pid>/fdinfo/*
proc: block mounting on top of /proc/<pid>/fd/*
proc: block mounting on top of /proc/<pid>/map_files/*
proc: add proc_splice_unmountable()
proc: proc_readfdinfo() -> proc_fdinfo_iterate()
proc: proc_readfd() -> proc_fd_iterate()
proc: add config & param to block forcing mem writes
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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs file updates from Christian Brauner:
"This is the work to cleanup and shrink struct file significantly.
Right now, (focusing on x86) struct file is 232 bytes. After this
series struct file will be 184 bytes aka 3 cacheline and a spare 8
bytes for future extensions at the end of the struct.
With struct file being as ubiquitous as it is this should make a
difference for file heavy workloads and allow further optimizations in
the future.
- struct fown_struct was embedded into struct file letting it take up
32 bytes in total when really it shouldn't even be embedded in
struct file in the first place. Instead, actual users of struct
fown_struct now allocate the struct on demand. This frees up 24
bytes.
- Move struct file_ra_state into the union containg the cleanup hooks
and move f_iocb_flags out of the union. This closes a 4 byte hole
we created earlier and brings struct file to 192 bytes. Which means
struct file is 3 cachelines and we managed to shrink it by 40
bytes.
- Reorder struct file so that nothing crosses a cacheline.
I suspect that in the future we will end up reordering some members
to mitigate false sharing issues or just because someone does
actually provide really good perf data.
- Shrinking struct file to 192 bytes is only part of the work.
Files use a slab that is SLAB_TYPESAFE_BY_RCU and when a kmem cache
is created with SLAB_TYPESAFE_BY_RCU the free pointer must be
located outside of the object because the cache doesn't know what
part of the memory can safely be overwritten as it may be needed to
prevent object recycling.
That has the consequence that SLAB_TYPESAFE_BY_RCU may end up
adding a new cacheline.
So this also contains work to add a new kmem_cache_create_rcu()
function that allows the caller to specify an offset where the
freelist pointer is supposed to be placed. Thus avoiding the
implicit addition of a fourth cacheline.
- And finally this removes the f_version member in struct file.
The f_version member isn't particularly well-defined. It is mainly
used as a cookie to detect concurrent seeks when iterating
directories. But it is also abused by some subsystems for
completely unrelated things.
It is mostly a directory and filesystem specific thing that doesn't
really need to live in struct file and with its wonky semantics it
really lacks a specific function.
For pipes, f_version is (ab)used to defer poll notifications until
a write has happened. And struct pipe_inode_info is used by
multiple struct files in their ->private_data so there's no chance
of pushing that down into file->private_data without introducing
another pointer indirection.
But pipes don't rely on f_pos_lock so this adds a union into struct
file encompassing f_pos_lock and a pipe specific f_pipe member that
pipes can use. This union of course can be extended to other file
types and is similar to what we do in struct inode already"
* tag 'vfs-6.12.file' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (26 commits)
fs: remove f_version
pipe: use f_pipe
fs: add f_pipe
ubifs: store cookie in private data
ufs: store cookie in private data
udf: store cookie in private data
proc: store cookie in private data
ocfs2: store cookie in private data
input: remove f_version abuse
ext4: store cookie in private data
ext2: store cookie in private data
affs: store cookie in private data
fs: add generic_llseek_cookie()
fs: use must_set_pos()
fs: add must_set_pos()
fs: add vfs_setpos_cookie()
s390: remove unused f_version
ceph: remove unused f_version
adi: remove unused f_version
mm: Removed @freeptr_offset to prevent doc warning
...
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Store the cookie to detect concurrent seeks on directories in
file->private_data.
Link: https://lore.kernel.org/r/20240830-vfs-file-f_version-v1-14-6d3e4816aa7b@kernel.org
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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This is another flag that is statically set and doesn't need to use up
an FMODE_* bit. Move it to ->fop_flags and free up another FMODE_* bit.
(1) mem_open() used from proc_mem_operations
(2) adi_open() used from adi_fops
(3) drm_open_helper():
(3.1) accel_open() used from DRM_ACCEL_FOPS
(3.2) drm_open() used from
(3.2.1) amdgpu_driver_kms_fops
(3.2.2) psb_gem_fops
(3.2.3) i915_driver_fops
(3.2.4) nouveau_driver_fops
(3.2.5) panthor_drm_driver_fops
(3.2.6) radeon_driver_kms_fops
(3.2.7) tegra_drm_fops
(3.2.8) vmwgfx_driver_fops
(3.2.9) xe_driver_fops
(3.2.10) DRM_GEM_FOPS
(3.2.11) DEFINE_DRM_GEM_DMA_FOPS
(4) struct memdev sets fmode flags based on type of device opened. For
devices using struct mem_fops unsigned offset is used.
Mark all these file operations as FOP_UNSIGNED_OFFSET and add asserts
into the open helper to ensure that the flag is always set.
Link: https://lore.kernel.org/r/20240809-work-fop_unsigned-v1-1-658e054d893e@kernel.org
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Christian Brauner <brauner@kernel.org> says:
It is currently possible to mount on top of various ephemeral entities
in procfs. This specifically includes magic links. To recap, magic links
are links of the form /proc/<pid>/fd/<nr>. They serve as references to
a target file and during path lookup they cause a jump to the target
path. Such magic links disappear if the corresponding file descriptor is
closed.
Currently it is possible to overmount such magic links:
int fd = open("/mnt/foo", O_RDONLY);
sprintf(path, "/proc/%d/fd/%d", getpid(), fd);
int fd2 = openat(AT_FDCWD, path, O_PATH | O_NOFOLLOW);
mount("/mnt/bar", path, "", MS_BIND, 0);
Arguably, this is nonsensical and is mostly interesting for an attacker
that wants to somehow trick a process into e.g., reopening something
that they didn't intend to reopen or to hide a malicious file
descriptor.
But also it risks leaking mounts for long-running processes. When
overmounting a magic link like above, the mount will not be detached
when the file descriptor is closed. Only the target mountpoint will
disappear. Which has the consequence of making it impossible to unmount
that mount afterwards. So the mount will stick around until the process
exits and the /proc/<pid>/ directory is cleaned up during
proc_flush_pid() when the dentries are pruned and invalidated.
That in turn means it's possible for a program to accidentally leak
mounts and it's also possible to make a task leak mounts without it's
knowledge if the attacker just keeps overmounting things under
/proc/<pid>/fd/<nr>.
I think it's wrong to try and fix this by us starting to play games with
close() or somewhere else to undo these mounts when the file descriptor
is closed. The fact that we allow overmounting of such magic links is
simply a bug and one that we need to fix.
Similar things can be said about entries under fdinfo/ and map_files/ so
those are restricted as well.
I have a further more aggressive patch that gets out the big hammer and
makes everything under /proc/<pid>/*, as well as immediate symlinks such
as /proc/self, /proc/thread-self, /proc/mounts, /proc/net that point
into /proc/<pid>/ not overmountable. Imho, all of this should be blocked
if we can get away with it. It's only useful to hide exploits such as in [1].
And again, overmounting of any global procfs files remains unaffected
and is an existing and supported use-case.
Link: https://righteousit.com/2024/07/24/hiding-linux-processes-with-bind-mounts [1]
// Note that repro uses the traditional way of just mounting over
// /proc/<pid>/fd/<nr>. This could also all be achieved just based on
// file descriptors using move_mount(). So /proc/<pid>/fd/<nr> isn't the
// only entry vector here. It's also possible to e.g., mount directly
// onto /proc/<pid>/map_files/* without going over /proc/<pid>/fd/<nr>.
int main(int argc, char *argv[])
{
char path[PATH_MAX];
creat("/mnt/foo", 0777);
creat("/mnt/bar", 0777);
/*
* For illustration use a bunch of file descriptors in the upper
* range that are unused.
*/
for (int i = 10000; i >= 256; i--) {
printf("I'm: /proc/%d/\n", getpid());
int fd2 = open("/mnt/foo", O_RDONLY);
if (fd2 < 0) {
printf("%m - Failed to open\n");
_exit(1);
}
int newfd = dup2(fd2, i);
if (newfd < 0) {
printf("%m - Failed to dup\n");
_exit(1);
}
close(fd2);
sprintf(path, "/proc/%d/fd/%d", getpid(), newfd);
int fd = openat(AT_FDCWD, path, O_PATH | O_NOFOLLOW);
if (fd < 0) {
printf("%m - Failed to open\n");
_exit(3);
}
sprintf(path, "/proc/%d/fd/%d", getpid(), fd);
printf("Mounting on top of %s\n", path);
if (mount("/mnt/bar", path, "", MS_BIND, 0)) {
printf("%m - Failed to mount\n");
_exit(4);
}
close(newfd);
close(fd2);
}
/*
* Give some time to look at things. The mounts now linger until
* the process exits.
*/
sleep(10000);
_exit(0);
}
* patches from https://lore.kernel.org/r/20240806-work-procfs-v1-0-fb04e1d09f0c@kernel.org:
proc: block mounting on top of /proc/<pid>/fdinfo/*
proc: block mounting on top of /proc/<pid>/fd/*
proc: block mounting on top of /proc/<pid>/map_files/*
proc: add proc_splice_unmountable()
proc: proc_readfdinfo() -> proc_fdinfo_iterate()
proc: proc_readfd() -> proc_fd_iterate()
Link: https://lore.kernel.org/r/20240806-work-procfs-v1-0-fb04e1d09f0c@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Entries under /proc/<pid>/map_files/* are ephemeral and may go away
before the process dies. As such allowing them to be used as mount
points creates the ability to leak mounts that linger until the process
dies with no ability to unmount them until then. Don't allow using them
as mountpoints.
Link: https://lore.kernel.org/r/20240806-work-procfs-v1-4-fb04e1d09f0c@kernel.org
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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This adds a Kconfig option and boot param to allow removing
the FOLL_FORCE flag from /proc/pid/mem write calls because
it can be abused.
The traditional forcing behavior is kept as default because
it can break GDB and some other use cases.
Previously we tried a more sophisticated approach allowing
distributions to fine-tune /proc/pid/mem behavior, however
that got NAK-ed by Linus [1], who prefers this simpler
approach with semantics also easier to understand for users.
Link: https://lore.kernel.org/lkml/CAHk-=wiGWLChxYmUA5HrT5aopZrB7_2VTa0NLZcxORgkUe5tEQ@mail.gmail.com/ [1]
Cc: Doug Anderson <dianders@chromium.org>
Cc: Jeff Xu <jeffxu@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Adrian Ratiu <adrian.ratiu@collabora.com>
Link: https://lore.kernel.org/r/20240802080225.89408-1-adrian.ratiu@collabora.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
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