Commit Graph

1412037 Commits

Author SHA1 Message Date
Marco Elver
322366b8f1 rhashtable: Enable context analysis
Enable context analysis for rhashtable, which was used as an initial
test as it contains a combination of RCU, mutex, and bit_spinlock usage.

Users of rhashtable now also benefit from annotations on the API, which
will now warn if the RCU read lock is not held where required.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20251219154418.3592607-33-elver@google.com
2026-01-05 16:43:35 +01:00
Marco Elver
c3d3023f1c stackdepot: Enable context analysis
Enable context analysis for stackdepot.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20251219154418.3592607-32-elver@google.com
2026-01-05 16:43:35 +01:00
Marco Elver
0eaa911f89 kcsan: Enable context analysis
Enable context analysis for the KCSAN subsystem.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20251219154418.3592607-31-elver@google.com
2026-01-05 16:43:35 +01:00
Marco Elver
6556fde265 kcov: Enable context analysis
Enable context analysis for the KCOV subsystem.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20251219154418.3592607-30-elver@google.com
2026-01-05 16:43:34 +01:00
Marco Elver
0f5d764862 kfence: Enable context analysis
Enable context analysis for the KFENCE subsystem.

Notable, kfence_handle_page_fault() required minor restructure, which
also fixed a subtle race; arguably that function is more readable now.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20251219154418.3592607-29-elver@google.com
2026-01-05 16:43:34 +01:00
Marco Elver
48eb4b9a3d MAINTAINERS: Add entry for Context Analysis
Add entry for all new files added for Clang's context analysis.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://patch.msgid.link/20251219154418.3592607-28-elver@google.com
2026-01-05 16:43:34 +01:00
Marco Elver
3635ad8782 compiler: Let data_race() imply disabled context analysis
Many patterns that involve data-racy accesses often deliberately ignore
normal synchronization rules to avoid taking a lock.

If we have a lock-guarded variable on which we do a lock-less data-racy
access, rather than having to write context_unsafe(data_race(..)),
simply make the data_race(..) macro imply context-unsafety. The
data_race() macro already denotes the intent that something subtly
unsafe is about to happen, so it should be clear enough as-is.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20251219154418.3592607-27-elver@google.com
2026-01-05 16:43:34 +01:00
Marco Elver
c237f1ceee compiler-context-analysis: Introduce header suppressions
While we can opt in individual subsystems which add the required
annotations, such subsystems inevitably include headers from other
subsystems which may not yet have the right annotations, which then
result in false positive warnings.

Making compatible by adding annotations across all common headers
currently requires an excessive number of __no_context_analysis
annotations, or carefully analyzing non-trivial cases to add the correct
annotations. While this is desirable long-term, providing an incremental
path causes less churn and headaches for maintainers not yet interested
in dealing with such warnings.

Rather than clutter headers unnecessary and mandate all subsystem
maintainers to keep their headers working with context analysis,
suppress all -Wthread-safety warnings in headers. Explicitly opt in
headers with context-enabled primitives.

With this in place, we can start enabling the analysis on more complex
subsystems in subsequent changes.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20251219154418.3592607-26-elver@google.com
2026-01-05 16:43:33 +01:00
Marco Elver
e4588c25c9 compiler-context-analysis: Remove __cond_lock() function-like helper
As discussed in [1], removing __cond_lock() will improve the readability
of trylock code. Now that Sparse context tracking support has been
removed, we can also remove __cond_lock().

Change existing APIs to either drop __cond_lock() completely, or make
use of the __cond_acquires() function attribute instead.

In particular, spinlock and rwlock implementations required switching
over to inline helpers rather than statement-expressions for their
trylock_* variants.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/all/20250207082832.GU7145@noisy.programming.kicks-ass.net/ [1]
Link: https://patch.msgid.link/20251219154418.3592607-25-elver@google.com
2026-01-05 16:43:33 +01:00
Marco Elver
5b63d0ae94 compiler-context-analysis: Remove Sparse support
Remove Sparse support as discussed at [1].

The kernel codebase is still scattered with numerous places that try to
appease Sparse's context tracking ("annotation for sparse", "fake out
sparse", "work around sparse", etc.). Eventually, as more subsystems
enable Clang's context analysis, these places will show up and need
adjustment or removal of the workarounds altogether.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/all/20250207083335.GW7145@noisy.programming.kicks-ass.net/ [1]
Link: https://lore.kernel.org/all/Z6XTKTo_LMj9KmbY@elver.google.com/ [2]
Link: https://patch.msgid.link/20251219154418.3592607-24-elver@google.com
2026-01-05 16:43:33 +01:00
Marco Elver
4f109baeea um: Fix incorrect __acquires/__releases annotations
With Clang's context analysis, the compiler is a bit more strict about
what goes into the __acquires/__releases annotations and can't refer to
non-existent variables.

On an UM build, mm_id.h is transitively included into mm_types.h, and we
can observe the following error (if context analysis is enabled in e.g.
stackdepot.c):

   In file included from lib/stackdepot.c:17:
   In file included from include/linux/debugfs.h:15:
   In file included from include/linux/fs.h:5:
   In file included from include/linux/fs/super.h:5:
   In file included from include/linux/fs/super_types.h:7:
   In file included from include/linux/list_lru.h:14:
   In file included from include/linux/xarray.h:16:
   In file included from include/linux/gfp.h:7:
   In file included from include/linux/mmzone.h:22:
   In file included from include/linux/mm_types.h:26:
   In file included from arch/um/include/asm/mmu.h:12:
>> arch/um/include/shared/skas/mm_id.h:24:54: error: use of undeclared identifier 'turnstile'
      24 | void enter_turnstile(struct mm_id *mm_id) __acquires(turnstile);
         |                                                      ^~~~~~~~~
   arch/um/include/shared/skas/mm_id.h:25:53: error: use of undeclared identifier 'turnstile'
      25 | void exit_turnstile(struct mm_id *mm_id) __releases(turnstile);
         |                                                     ^~~~~~~~~

One (discarded) option was to use token_context_lock(turnstile) to just
define a token with the already used name, but that would not allow the
compiler to distinguish between different mm_id-dependent instances.

Another constraint is that struct mm_id is only declared and incomplete
in the header, so even if we tried to construct an expression to get to
the mutex instance, this would fail (including more headers transitively
everywhere should also be avoided).

Instead, just declare an mm_id-dependent helper to return the mutex, and
use the mm_id-dependent call expression in the __acquires/__releases
attributes; the compiler will consider the identity of the mutex to be
the call expression. Then using __get_turnstile() in the lock/unlock
wrappers (with context analysis enabled for mmu.c) the compiler will be
able to verify the implementation of the wrappers as-is.

We leave context analysis disabled in arch/um/kernel/skas/ for now. This
change is a preparatory change to allow enabling context analysis in
subsystems that include any of the above headers.

No functional change intended.

Closes: https://lore.kernel.org/oe-kbuild-all/202512171220.vHlvhpCr-lkp@intel.com/
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20251219154418.3592607-23-elver@google.com
2026-01-05 16:43:32 +01:00
Marco Elver
6e530e2e31 debugfs: Make debugfs_cancellation a context lock struct
When compiling include/linux/debugfs.h with CONTEXT_ANALYSIS enabled, we
can see this error:

./include/linux/debugfs.h:239:17: error: use of undeclared identifier 'cancellation'
  239 | void __acquires(cancellation)

Move the __acquires(..) attribute after the declaration, so that the
compiler can see the cancellation function argument, as well as making
struct debugfs_cancellation a real context lock to benefit from Clang's
context analysis.

This change is a preparatory change to allow enabling context analysis
in subsystems that include the above header.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://patch.msgid.link/20251219154418.3592607-22-elver@google.com
2026-01-05 16:43:32 +01:00
Marco Elver
47907461e4 locking/ww_mutex: Support Clang's context analysis
Add support for Clang's context analysis for ww_mutex.

The programming model for ww_mutex is subtly more complex than other
locking primitives when using ww_acquire_ctx. Encoding the respective
pre-conditions for ww_mutex lock/unlock based on ww_acquire_ctx state
using Clang's context analysis makes incorrect use of the API harder.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20251219154418.3592607-21-elver@google.com
2026-01-05 16:43:32 +01:00
Marco Elver
d3febf16de locking/local_lock: Support Clang's context analysis
Add support for Clang's context analysis for local_lock_t and
local_trylock_t.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20251219154418.3592607-20-elver@google.com
2026-01-05 16:43:31 +01:00
Marco Elver
8c9c8566e1 locking/local_lock: Include missing headers
Including <linux/local_lock.h> into an empty TU will result in the
compiler complaining:

./include/linux/local_lock.h: In function ‘class_local_lock_irqsave_constructor’:
./include/linux/local_lock_internal.h:95:17: error: implicit declaration of function ‘local_irq_save’; <...>
   95 |                 local_irq_save(flags);                          \
      |                 ^~~~~~~~~~~~~~

As well as (some architectures only, such as 'sh'):

./include/linux/local_lock_internal.h: In function ‘local_lock_acquire’:
./include/linux/local_lock_internal.h:33:20: error: ‘current’ undeclared (first use in this function)
   33 |         l->owner = current;

Include missing headers to allow including local_lock.h where the
required headers are not otherwise included.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://patch.msgid.link/20251219154418.3592607-19-elver@google.com
2026-01-05 16:43:31 +01:00
Marco Elver
e4fd3be884 locking/rwsem: Support Clang's context analysis
Add support for Clang's context analysis for rw_semaphore.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20251219154418.3592607-18-elver@google.com
2026-01-05 16:43:31 +01:00
Marco Elver
5e256db932 kref: Add context-analysis annotations
Mark functions that conditionally acquire the passed lock.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://patch.msgid.link/20251219154418.3592607-17-elver@google.com
2026-01-05 16:43:31 +01:00
Marco Elver
f0b7ce22d7 srcu: Support Clang's context analysis
Add support for Clang's context analysis for SRCU.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://patch.msgid.link/20251219154418.3592607-16-elver@google.com
2026-01-05 16:43:30 +01:00
Marco Elver
fe00f6e846 rcu: Support Clang's context analysis
Improve the existing annotations to properly support Clang's context
analysis.

The old annotations distinguished between RCU, RCU_BH, and RCU_SCHED;
however, to more easily be able to express that "hold the RCU read lock"
without caring if the normal, _bh(), or _sched() variant was used we'd
have to remove the distinction of the latter variants: change the _bh()
and _sched() variants to also acquire "RCU".

When (and if) we introduce context locks to denote more generally that
"IRQ", "BH", "PREEMPT" contexts are disabled, it would make sense to
acquire these instead of RCU_BH and RCU_SCHED respectively.

The above change also simplified introducing __guarded_by support, where
only the "RCU" context lock needs to be held: introduce __rcu_guarded,
where Clang's context analysis warns if a pointer is dereferenced
without any of the RCU locks held, or updated without the appropriate
helpers.

The primitives rcu_assign_pointer() and friends are wrapped with
context_unsafe(), which enforces using them to update RCU-protected
pointers marked with __rcu_guarded.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://patch.msgid.link/20251219154418.3592607-15-elver@google.com
2026-01-05 16:43:30 +01:00
Marco Elver
eb7d96a13b bit_spinlock: Support Clang's context analysis
The annotations for bit_spinlock.h have simply been using "bitlock" as
the token. For Sparse, that was likely sufficient in most cases. But
Clang's context analysis is more precise, and we need to ensure we
can distinguish different bitlocks.

To do so, add a token context, and a macro __bitlock(bitnum, addr)
that is used to construct unique per-bitlock tokens.

Add the appropriate test.

<linux/list_bl.h> is implicitly included through other includes, and
requires 2 annotations to indicate that acquisition (without release)
and release (without prior acquisition) of its bitlock is intended.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20251219154418.3592607-14-elver@google.com
2026-01-05 16:43:30 +01:00
Marco Elver
5f7ba05971 bit_spinlock: Include missing <asm/processor.h>
Including <linux/bit_spinlock.h> into an empty TU will result in the
compiler complaining:

./include/linux/bit_spinlock.h:34:4: error: call to undeclared function 'cpu_relax'; <...>
   34 |                         cpu_relax();
      |                         ^
1 error generated.

Include <asm/processor.h> to allow including bit_spinlock.h where
<asm/processor.h> is not otherwise included.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://patch.msgid.link/20251219154418.3592607-13-elver@google.com
2026-01-05 16:43:29 +01:00
Marco Elver
8f8a55f49c locking/seqlock: Support Clang's context analysis
Add support for Clang's context analysis for seqlock_t.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20251219154418.3592607-12-elver@google.com
2026-01-05 16:43:29 +01:00
Marco Elver
370f0a345a locking/mutex: Support Clang's context analysis
Add support for Clang's context analysis for mutex.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20251219154418.3592607-11-elver@google.com
2026-01-05 16:43:29 +01:00
Marco Elver
38f1311a22 compiler-context-analysis: Change __cond_acquires to take return value
While Sparse is oblivious to the return value of conditional acquire
functions, Clang's context analysis needs to know the return value
which indicates successful acquisition.

Add the additional argument, and convert existing uses.

Notably, Clang's interpretation of the value merely relates to the use
in a later conditional branch, i.e. 1 ==> context lock acquired in
branch taken if condition non-zero, and 0 ==> context lock acquired in
branch taken if condition is zero. Given the precise value does not
matter, introduce symbolic variants to use instead of either 0 or 1,
which should be more intuitive.

No functional change intended.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20251219154418.3592607-10-elver@google.com
2026-01-05 16:43:29 +01:00
Marco Elver
f16a802d40 locking/rwlock, spinlock: Support Clang's context analysis
Add support for Clang's context analysis for raw_spinlock_t,
spinlock_t, and rwlock. This wholesale conversion is required because
all three of them are interdependent.

To avoid warnings in constructors, the initialization functions mark a
lock as acquired when initialized before guarded variables.

The test verifies that common patterns do not generate false positives.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20251219154418.3592607-9-elver@google.com
2026-01-05 16:43:28 +01:00
Marco Elver
7c45154174 lockdep: Annotate lockdep assertions for context analysis
Clang's context analysis can be made aware of functions that assert that
locks are held.

Presence of these annotations causes the analysis to assume the context
lock is held after calls to the annotated function, and avoid false
positives with complex control-flow; for example, where not all
control-flow paths in a function require a held lock, and therefore
marking the function with __must_hold(..) is inappropriate.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20251219154418.3592607-8-elver@google.com
2026-01-05 16:43:28 +01:00
Marco Elver
3931d4b980 cleanup: Basic compatibility with context analysis
Introduce basic compatibility with cleanup.h infrastructure.

We need to allow the compiler to see the acquisition and release of the
context lock at the start and end of a scope. However, the current
"cleanup" helpers wrap the lock in a struct passed through separate
helper functions, which hides the lock alias from the compiler (no
inter-procedural analysis).

While Clang supports scoped guards in C++, it's not possible to apply in
C code: https://clang.llvm.org/docs/ThreadSafetyAnalysis.html#scoped-context

However, together with recent improvements to Clang's alias analysis
abilities, idioms such as this work correctly now:

        void spin_unlock_cleanup(spinlock_t **l) __releases(*l) { .. }
        ...
        {
            spinlock_t *lock_scope __cleanup(spin_unlock_cleanup) = &lock;
            spin_lock(&lock);  // lock through &lock
            ... critical section ...
        }  // unlock through lock_scope -[alias]-> &lock (no warnings)

To generalize this pattern and make it work with existing lock guards,
introduce DECLARE_LOCK_GUARD_1_ATTRS() and WITH_LOCK_GUARD_1_ATTRS().

These allow creating an explicit alias to the context lock instance that
is "cleaned" up with a separate cleanup helper. This helper is a dummy
function that does nothing at runtime, but has the release attributes to
tell the compiler what happens at the end of the scope.

Example usage:

  DECLARE_LOCK_GUARD_1_ATTRS(mutex, __acquires(_T), __releases(*(struct mutex **)_T))
  #define class_mutex_constructor(_T) WITH_LOCK_GUARD_1_ATTRS(mutex, _T)

Note: To support the for-loop based scoped helpers, the auxiliary
variable must be a pointer to the "class" type because it is defined in
the same statement as the guard variable. However, we initialize it with
the lock pointer (despite the type mismatch, the compiler's alias
analysis still works as expected). The "_unlock" attribute receives a
pointer to the auxiliary variable (a double pointer to the class type),
and must be cast and dereferenced appropriately.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20251219154418.3592607-7-elver@google.com
2026-01-05 16:43:28 +01:00
Marco Elver
25d3b21e1d checkpatch: Warn about context_unsafe() without comment
Warn about applications of context_unsafe() without a comment, to
encourage documenting the reasoning behind why it was deemed safe.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20251219154418.3592607-6-elver@google.com
2026-01-05 16:43:27 +01:00
Marco Elver
8f32441d7a Documentation: Add documentation for Compiler-Based Context Analysis
Adds documentation in Documentation/dev-tools/context-analysis.rst, and
adds it to the index.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20251219154418.3592607-5-elver@google.com
2026-01-05 16:43:27 +01:00
Marco Elver
9b00c1609d compiler-context-analysis: Add test stub
Add a simple test stub where we will add common supported patterns that
should not generate false positives for each new supported context lock.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20251219154418.3592607-4-elver@google.com
2026-01-05 16:43:27 +01:00
Marco Elver
3269701cb2 compiler-context-analysis: Add infrastructure for Context Analysis with Clang
Context Analysis is a language extension, which enables statically
checking that required contexts are active (or inactive), by acquiring
and releasing user-definable "context locks". An obvious application is
lock-safety checking for the kernel's various synchronization primitives
(each of which represents a "context lock"), and checking that locking
rules are not violated.

Clang originally called the feature "Thread Safety Analysis" [1]. This
was later changed and the feature became more flexible, gaining the
ability to define custom "capabilities". Its foundations can be found in
"Capability Systems" [2], used to specify the permissibility of
operations to depend on some "capability" being held (or not held).

Because the feature is not just able to express "capabilities" related
to synchronization primitives, and "capability" is already overloaded in
the kernel, the naming chosen for the kernel departs from Clang's
"Thread Safety" and "capability" nomenclature; we refer to the feature
as "Context Analysis" to avoid confusion. The internal implementation
still makes references to Clang's terminology in a few places, such as
`-Wthread-safety` being the warning option that also still appears in
diagnostic messages.

 [1] https://clang.llvm.org/docs/ThreadSafetyAnalysis.html
 [2] https://www.cs.cornell.edu/talc/papers/capabilities.pdf

See more details in the kernel-doc documentation added in this and
subsequent changes.

Clang version 22+ is required.

[peterz: disable the thing for __CHECKER__ builds]
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20251219154418.3592607-3-elver@google.com
2026-01-05 16:43:26 +01:00
Marco Elver
de15fecae4 compiler_types: Move lock checking attributes to compiler-context-analysis.h
The conditional definition of lock checking macros and attributes is
about to become more complex. Factor them out into their own header for
better readability, and to make it obvious which features are supported
by which mode (currently only Sparse). This is the first step towards
generalizing towards "context analysis".

No functional change intended.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://patch.msgid.link/20251219154418.3592607-2-elver@google.com
2026-01-05 16:43:26 +01:00
John Stultz
de2c5a1523 test-ww_mutex: Allow test to be run (and re-run) from userland
In cases where the ww_mutex test was occasionally tripping on
hard to find issues, leaving qemu in a reboot loop was my best
way to reproduce problems. These reboots however wasted time
when I just wanted to run the test-ww_mutex logic.

So tweak the test-ww_mutex test so that it can be re-triggered
via a sysfs file, so the test can be run repeatedly without
doing module loads or restarting.

This has been particularly valuable to stressing and finding
issues with the proxy-exec series.

To use, run as root:
  echo 1 > /sys/kernel/test_ww_mutex/run_tests

Signed-off-by: John Stultz <jstultz@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20251205013515.759030-4-jstultz@google.com
2025-12-18 10:45:23 +01:00
John Stultz
d327e7166e test-ww_mutex: Move work to its own UNBOUND workqueue
The test-ww_mutex test already allocates its own workqueue
so be sure to use it for the mtx.work and abba.work rather
then the default system workqueue.

This resolves numerous messages of the sort:
"workqueue: test_abba_work hogged CPU... consider switching to WQ_UNBOUND"
"workqueue: test_mutex_work hogged CPU... consider switching to WQ_UNBOUND"

Signed-off-by: John Stultz <jstultz@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20251205013515.759030-3-jstultz@google.com
2025-12-18 10:45:23 +01:00
John Stultz
34d80c93a5 test-ww_mutex: Extend ww_mutex tests to test both classes of ww_mutexes
Currently the test-ww_mutex tool only utilizes the wait-die
class of ww_mutexes, and thus isn't very helpful in exercising
the wait-wound class of ww_mutexes.

So extend the test to exercise both classes of ww_mutexes for
all of the subtests.

Signed-off-by: John Stultz <jstultz@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20251205013515.759030-2-jstultz@google.com
2025-12-18 10:45:23 +01:00
Linus Torvalds
8f0b4cce44 Linux 6.19-rc1 v6.19-rc1 2025-12-14 16:05:07 +12:00
Linus Torvalds
6a1636e066 Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
Pull SCSI fixes from James Bottomley:
 "The only core fix is in doc; all the others are in drivers, with the
  biggest impacts in libsas being the rollback on error handling and in
  ufs coming from a couple of error handling fixes, one causing a crash
  if it's activated before scanning and the other fixing W-LUN
  resumption"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: ufs: qcom: Fix confusing cleanup.h syntax
  scsi: libsas: Add rollback handling when an error occurs
  scsi: device_handler: Return error pointer in scsi_dh_attached_handler_name()
  scsi: ufs: core: Fix a deadlock in the frequency scaling code
  scsi: ufs: core: Fix an error handler crash
  scsi: Revert "scsi: libsas: Fix exp-attached device scan after probe failure scanned in again after probe failed"
  scsi: ufs: core: Fix RPMB link error by reversing Kconfig dependencies
  scsi: qla4xxx: Use time conversion macros
  scsi: qla2xxx: Enable/disable IRQD_NO_BALANCING during reset
  scsi: ipr: Enable/disable IRQD_NO_BALANCING during reset
  scsi: imm: Fix use-after-free bug caused by unfinished delayed work
  scsi: target: sbp: Remove KMSG_COMPONENT macro
  scsi: core: Correct documentation for scsi_device_quiesce()
  scsi: mpi3mr: Prevent duplicate SAS/SATA device entries in channel 1
  scsi: target: Reset t_task_cdb pointer in error case
  scsi: ufs: core: Fix EH failure after W-LUN resume error
2025-12-14 15:35:35 +12:00
Linus Torvalds
0dfb36b2dc Merge tag 'ceph-for-6.19-rc1' of https://github.com/ceph/ceph-client
Pull ceph updates from Ilya Dryomov:
 "We have a patch that adds an initial set of tracepoints to the MDS
  client from Max, a fix that hardens osdmap parsing code from myself
  (marked for stable) and a few assorted fixups"

* tag 'ceph-for-6.19-rc1' of https://github.com/ceph/ceph-client:
  rbd: stop selecting CRC32, CRYPTO, and CRYPTO_AES
  ceph: stop selecting CRC32, CRYPTO, and CRYPTO_AES
  libceph: make decode_pool() more resilient against corrupted osdmaps
  libceph: Amend checking to fix `make W=1` build breakage
  ceph: Amend checking to fix `make W=1` build breakage
  ceph: add trace points to the MDS client
  libceph: fix log output race condition in OSD client
2025-12-14 15:24:10 +12:00
Linus Torvalds
4cfc21494a Merge tag 'tomoyo-pr-20251212' of git://git.code.sf.net/p/tomoyo/tomoyo
Pull tomoyo update from Tetsuo Handa:
 "Trivial optimization"

* tag 'tomoyo-pr-20251212' of git://git.code.sf.net/p/tomoyo/tomoyo:
  tomoyo: Use local kmap in tomoyo_dump_page()
2025-12-14 15:21:02 +12:00
Linus Torvalds
4a298a43f5 Merge tag 'smp-urgent-2025-12-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull CPU hotplug fix from Ingo Molnar:

 - Fix CPU hotplug callbacks to disable interrupts on UP kernels

* tag 'smp-urgent-2025-12-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  cpu: Make atomic hotplug callbacks run with interrupts disabled on UP
2025-12-14 06:12:46 +12:00
Linus Torvalds
cba09e3ed0 Merge tag 'perf-urgent-2025-12-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf event fixes from Ingo Molnar:

 - Fix NULL pointer dereference crash in the Intel PMU driver

 - Fix missing read event generation on task exit

 - Fix AMD uncore driver init error handling

 - Fix whitespace noise

* tag 'perf-urgent-2025-12-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/intel: Fix NULL event dereference crash in handle_pmi_common()
  perf/core: Fix missing read event generation on task exit
  perf/x86/amd/uncore: Fix the return value of amd_uncore_df_event_init() on error
  perf/uprobes: Remove <space><Tab> whitespace noise
2025-12-14 06:10:35 +12:00
Linus Torvalds
db0130185e Merge tag 'irq-urgent-2025-12-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq fixes from Ingo Molnar:

 - Fix error code in the irqchip/mchp-eic driver

 - Fix setup_percpu_irq() affinity assumptions

 - Remove the unused irq_domain_add_tree() function

* tag 'irq-urgent-2025-12-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/mchp-eic: Fix error code in mchp_eic_domain_alloc()
  irqdomain: Delete irq_domain_add_tree()
  genirq: Allow NULL affinity for setup_percpu_irq()
2025-12-14 06:07:09 +12:00
Linus Torvalds
edbe407235 Merge tag 'core-urgent-2025-12-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull misc core fixes from Ingo Molnar:

 - Improve bug reporting

 - Suppress W=1 format warning

 - Improve rseq scalability on Clang builds

* tag 'core-urgent-2025-12-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  rseq: Always inline rseq_debug_syscall_return()
  bug: Hush suggest-attribute=format for __warn_printf()
  bug: Let report_bug_entry() provide the correct bugaddr
2025-12-14 06:04:16 +12:00
Linus Torvalds
9d9c1cfec0 Merge tag 'mm-nonmm-stable-2025-12-11-11-47' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull misc updates from Andrew Morton:
 "There are no significant series in this small merge. Please see the
  individual changelogs for details"

[ Editor's note: it's mainly ocfs2 and a couple of random fixes ]

* tag 'mm-nonmm-stable-2025-12-11-11-47' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  mm: memfd_luo: add CONFIG_SHMEM dependency
  mm: shmem: avoid build warning for CONFIG_SHMEM=n
  ocfs2: fix memory leak in ocfs2_merge_rec_left()
  ocfs2: invalidate inode if i_mode is zero after block read
  ocfs2: avoid -Wflex-array-member-not-at-end warning
  ocfs2: convert remaining read-only checks to ocfs2_emergency_state
  ocfs2: add ocfs2_emergency_state helper and apply to setattr
  checkpatch: add uninitialized pointer with __free attribute check
  args: fix documentation to reflect the correct numbers
  ocfs2: fix kernel BUG in ocfs2_find_victim_chain
  liveupdate: luo_core: fix redundant bound check in luo_ioctl()
  ocfs2: validate inline xattr size and entry count in ocfs2_xattr_ibody_list
  fs/fat: remove unnecessary wrapper fat_max_cache()
  ocfs2: replace deprecated strcpy with strscpy
  ocfs2: check tl_used after reading it from trancate log inode
  liveupdate: luo_file: don't use invalid list iterator
2025-12-13 20:55:12 +12:00
Linus Torvalds
2516a87153 Merge tag 'mm-stable-2025-12-11-11-39' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull more MM updates from Andrew Morton:

 - "powerpc/pseries/cmm: two smaller fixes" (David Hildenbrand)
   fixes a couple of minor things in ppc land

 - "Improve folio split related functions" (Zi Yan)
   some cleanups and minorish fixes in the folio splitting code

* tag 'mm-stable-2025-12-11-11-39' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  mm/damon/tests/core-kunit: avoid damos_test_commit stack warning
  mm: vmscan: correct nr_requested tracing in scan_folios
  MAINTAINERS: add idr core-api doc file to XARRAY
  mm/hugetlb: fix incorrect error return from hugetlb_reserve_pages()
  mm: fix CONFIG_STACK_GROWSUP typo in mm.h
  mm/huge_memory: fix folio split stats counting
  mm/huge_memory: make min_order_for_split() always return an order
  mm/huge_memory: replace can_split_folio() with direct refcount calculation
  mm/huge_memory: change folio_split_supported() to folio_check_splittable()
  mm/sparse: fix sparse_vmemmap_init_nid_early definition without CONFIG_SPARSEMEM
  powerpc/pseries/cmm: adjust BALLOON_MIGRATE when migrating pages
  powerpc/pseries/cmm: call balloon_devinfo_init() also without CONFIG_BALLOON_COMPACTION
2025-12-13 20:35:41 +12:00
Christian Brauner
d2ea4d254d file: ensure cleanup
Brown paper bag time. This is a silly oversight where I missed to drop
the error condition checking to ensure we clean up on early error
returns. I have an internal unit testset coming up for this which will
catch all such issues going forward.

Reported-by: Chris Mason <clm@fb.com>
Reported-by: Jeff Layton <jlayton@kernel.org>
Fixes: 011703a9ac ("file: add FD_{ADD,PREPARE}()")
Signed-off-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2025-12-13 20:04:32 +12:00
Linus Torvalds
d552fc632c x86/hv: Add gitignore entry for generated header file
Commit 7bfe3b8ea6 ("Drivers: hv: Introduce mshv_vtl driver") added a
new generated header file for the offsets into the mshv_vtl_cpu_context
structure to be used by the low-level assembly code.  But it didn't add
the .gitignore file to go with it, so 'git status' and friends will
mention it.

Let's add the gitignore file before somebody thinks that generated
header should be committed.

Fixes: 7bfe3b8ea6 ("Drivers: hv: Introduce mshv_vtl driver")
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2025-12-13 19:57:41 +12:00
Linus Torvalds
a859eca0e4 Merge tag 'drm-fixes-2025-12-13' of https://gitlab.freedesktop.org/drm/kernel
Pull more drm fixes from Dave Airlie:
 "These are the enqueued fixes that ended up in our fixes branch,
  nouveau mostly, along with some small fixes in other places.

  plane:
   - Handle IS_ERR vs NULL in drm_plane_create_hotspot_properties()

  ttm:
   - fix devcoredump for evicted bos

  panel:
   - Fix stack usage warning in novatek-nt35560

  nouveau:
   - alloc fwsec sb at boot to avoid s/r problems
   - fix strcpy usage
   - fix i2c encoder crash

  bridge:
   - Ignore spurious PLL_UNLOCK bit in ti-sn65dsi83

  mgag200:
   - Fix bigendian handling in mgag200

  tilcdc:
   - Fix probe failure in tilcdc"

* tag 'drm-fixes-2025-12-13' of https://gitlab.freedesktop.org/drm/kernel:
  drm/mgag200: Fix big-endian support
  drm/tilcdc: Fix removal actions in case of failed probe
  drm/ttm: Avoid NULL pointer deref for evicted BOs
  drm: nouveau: Replace sprintf() with sysfs_emit()
  drm/nouveau: fix circular dep oops from vendored i2c encoder
  drm/nouveau: refactor deprecated strcpy
  drm/plane: Fix IS_ERR() vs NULL check in drm_plane_create_hotspot_properties()
  drm/bridge: ti-sn65dsi83: ignore PLL_UNLOCK errors
  drm/nouveau/gsp: Allocate fwsec-sb at boot
  drm/panel: novatek-nt35560: avoid on-stack device structure
2025-12-13 17:39:28 +12:00
Linus Torvalds
237f1bbfe3 Merge tag 'drm-next-2025-12-13' of https://gitlab.freedesktop.org/drm/kernel
Pull drm fixes from Dave Airlie:
 "This is the weekly fixes for what is in next tree, mostly amdgpu and
  some i915, panthor and a core revert.

  core:
   - revert dumb bo 8 byte alignment

  amdgpu:
   - SI fix
   - DC reduce stack usage
   - HDMI fixes
   - VCN 4.0.5 fix
   - DP MST fix
   - DC memory allocation fix

  amdkfd:
   - SVM fix
   - Trap handler fix
   - VGPR fixes for GC 11.5

  i915:
   - Fix format string truncation warning
   - FIx runtime PM reference during fbdev BO creation

  panthor:
   - fix UAF

  renesas:
   - fix sync flag handling"

* tag 'drm-next-2025-12-13' of https://gitlab.freedesktop.org/drm/kernel:
  Revert "drm/amd/display: Fix pbn to kbps Conversion"
  drm/amd: Fix unbind/rebind for VCN 4.0.5
  drm/i915: Fix format string truncation warning
  drm/i915/fbdev: Hold runtime PM ref during fbdev BO creation
  drm/amd/display: Improve HDMI info retrieval
  drm/amdkfd: bump minimum vgpr size for gfx1151
  drm/amd/display: shrink struct members
  drm/amdkfd: Export the cwsr_size and ctl_stack_size to userspace
  drm/amd/display: Refactor dml_core_mode_support to reduce stack frame
  drm/amdgpu: don't attach the tlb fence for SI
  drm/amd/display: Use GFP_ATOMIC in dc_create_plane_state()
  drm/amdkfd: Trap handler support for expert scheduling mode
  drm/amdkfd: Use huge page size to check split svm range alignment
  drm/rcar-du: dsi: Handle both DRM_MODE_FLAG_N.SYNC and !DRM_MODE_FLAG_P.SYNC
  drm/gem-shmem: revert the 8-byte alignment constraint
  drm/gem-dma: revert the 8-byte alignment constraint
  drm/panthor: Prevent potential UAF in group creation
2025-12-13 17:25:26 +12:00
Linus Torvalds
d8cc0b917b Merge tag 'i3c/for-6.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux
Pull further i3c update from Alexandre Belloni:
 "We are removing a legacy API callback and having this sooner rather
  than later will help ensuring no one introduces a new driver using it.

  I've also added patches removing the "__free(...) = NULL" pattern
  because I'm sure we won't avoid people sending those following the
  mailing list discussion..."

* tag 'i3c/for-6.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux:
  i3c: adi: Fix confusing cleanup.h syntax
  i3c: master: Fix confusing cleanup.h syntax
  i3c: master: cleanup callback .priv_xfers()
  i3c: master: switch to use new callback .i3c_xfers() from .priv_xfers()
2025-12-13 17:15:16 +12:00