- Jump label fixes, including a perf events fix that originally
manifested as jump label failures, but was a serialization bug
at the usage site.
- Mark down_write*() helpers as __always_inline, to improve
WCHAN debuggability.
- Misc cleanups and fixes.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
-----BEGIN PGP SIGNATURE-----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=T1KT
-----END PGP SIGNATURE-----
Merge tag 'locking-core-2024-07-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking updates from Ingo Molnar:
- Jump label fixes, including a perf events fix that originally
manifested as jump label failures, but was a serialization bug at the
usage site
- Mark down_write*() helpers as __always_inline, to improve WCHAN
debuggability
- Misc cleanups and fixes
* tag 'locking-core-2024-07-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
locking/rwsem: Add __always_inline annotation to __down_write_common() and inlined callers
jump_label: Simplify and clarify static_key_fast_inc_cpus_locked()
jump_label: Clarify condition in static_key_fast_inc_not_disabled()
jump_label: Fix concurrency issues in static_key_slow_dec()
perf/x86: Serialize set_attr_rdpmc()
cleanup: Standardize the header guard define's name
Add a helper that returns the file descriptor and ensures that the old
variable contains a negative value. This makes it easy to rely on
CLASS(get_unused_fd).
Link: https://lore.kernel.org/r/20240627-work-pidfs-v1-1-7e9ab6cc3bb1@kernel.org
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
At some point during early development, the <linux/cleanup.h> header
must have been named <linux/guard.h>, as evidenced by the header
guard name:
#ifndef __LINUX_GUARDS_H
#define __LINUX_GUARDS_H
It ended up being <linux/cleanup.h>, but the old guard name for
a file name that was never upstream never changed.
Do that now - and while at it, also use the canonical _LINUX prefix,
instead of the less common __LINUX prefix.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/171664113181.10875.8784434350512348496.tip-bot2@tip-bot2
Adds:
- DEFINE_GUARD_COND() / DEFINE_LOCK_GUARD_1_COND() to extend existing
guards with conditional lock primitives, eg. mutex_trylock(),
mutex_lock_interruptible().
nb. both primitives allow NULL 'locks', which cause the lock to
fail (obviously).
- extends scoped_guard() to not take the body when the the
conditional guard 'fails'. eg.
scoped_guard (mutex_intr, &task->signal_cred_guard_mutex) {
...
}
will only execute the body when the mutex is held.
- provides scoped_cond_guard(name, fail, args...); which extends
scoped_guard() to do fail when the lock-acquire fails.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20231102110706.460851167%40infradead.org
recent discussion brought about the realization that it makes sense for
no_free_ptr() to have __must_check semantics in order to avoid leaking
the resource.
Additionally, add a few comments to clarify why/how things work.
All credit to Linus on how to combine __must_check and the
stmt-expression.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20230816103102.GF980931@hirez.programming.kicks-ass.net
Use __attribute__((__cleanup__(func))) to build:
- simple auto-release pointers using __free()
- 'classes' with constructor and destructor semantics for
scope-based resource management.
- lock guards based on the above classes.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20230612093537.614161713%40infradead.org
