Changes in context-analysis.rst

c17ee635fd3a482b2ad2bf5e269755c2eae5f25e - Merge drm/drm-fixes into drm-misc-fixes

Mon, 23 Feb 2026 09:09:45 +0000

Merge drm/drm-fixes into drm-misc-fixes7.0-rc1 was just released, let's merge it to kick the new release cycle.Signed-off-by: Maxime Ripard List of files: /linux/Documentation/dev-tools/context-analysis.rst

0923fd0419a1a2c8846e15deacac11b619e996d9 - Merge tag 'locking-core-2026-02-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Tue, 10 Feb 2026 20:28:44 +0000

Merge tag 'locking-core-2026-02-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipPull locking updates from Ingo Molnar: "Lock debugging: - Implement compiler-driven static analysis locking context checking, using the upcoming Clang 22 compiler's context analysis features (Marco Elver) We removed Sparse context analysis support, because prior to removal even a defconfig kernel produced 1,700+ context tracking Sparse warnings, the overwhelming majority of which are false positives. On an allmodconfig kernel the number of false positive context tracking Sparse warnings grows to over 5,200... On the plus side of the balance actual locking bugs found by Sparse context analysis is also rather ... sparse: I found only 3 such commits in the last 3 years. So the rate of false positives and the maintenance overhead is rather high and there appears to be no active policy in place to achieve a zero-warnings baseline to move the annotations & fixers to developers who introduce new code. Clang context analysis is more complete and more aggressive in trying to find bugs, at least in principle. Plus it has a different model to enabling it: it's enabled subsystem by subsystem, which results in zero warnings on all relevant kernel builds (as far as our testing managed to cover it). Which allowed us to enable it by default, similar to other compiler warnings, with the expectation that there are no warnings going forward. This enforces a zero-warnings baseline on clang-22+ builds (Which are still limited in distribution, admittedly) Hopefully the Clang approach can lead to a more maintainable zero-warnings status quo and policy, with more and more subsystems and drivers enabling the feature. Context tracking can be enabled for all kernel code via WARN_CONTEXT_ANALYSIS_ALL=y (default disabled), but this will generate a lot of false positives. ( Having said that, Sparse support could still be added back, if anyone is interested - the removal patch is still relatively straightforward to revert at this stage. ) Rust integration updates: (Alice Ryhl, Fujita Tomonori, Boqun Feng) - Add support for Atomic and replace most Rust native AtomicBool usages with Atomic - Clean up LockClassKey and improve its documentation - Add missing Send and Sync trait implementation for SetOnce - Make ARef Unpin as it is supposed to be - Add __rust_helper to a few Rust helpers as a preparation for helper LTO - Inline various lock related functions to avoid additional function calls WW mutexes: - Extend ww_mutex tests and other test-ww_mutex updates (John Stultz) Misc fixes and cleanups: - rcu: Mark lockdep_assert_rcu_helper() __always_inline (Arnd Bergmann) - locking/local_lock: Include more missing headers (Peter Zijlstra) - seqlock: fix scoped_seqlock_read kernel-doc (Randy Dunlap) - rust: sync: Replace `kernel::c_str!` with C-Strings (Tamir Duberstein)"* tag 'locking-core-2026-02-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (90 commits) locking/rwlock: Fix write_trylock_irqsave() with CONFIG_INLINE_WRITE_TRYLOCK rcu: Mark lockdep_assert_rcu_helper() __always_inline compiler-context-analysis: Remove __assume_ctx_lock from initializers tomoyo: Use scoped init guard crypto: Use scoped init guard kcov: Use scoped init guard compiler-context-analysis: Introduce scoped init guards cleanup: Make __DEFINE_LOCK_GUARD handle commas in initializers seqlock: fix scoped_seqlock_read kernel-doc tools: Update context analysis macros in compiler_types.h rust: sync: Replace `kernel::c_str!` with C-Strings rust: sync: Inline various lock related methods rust: helpers: Move #define __rust_helper out of atomic.c rust: wait: Add __rust_helper to helpers rust: time: Add __rust_helper to helpers rust: task: Add __rust_helper to helpers rust: sync: Add __rust_helper to helpers rust: refcount: Add __rust_helper to helpers rust: rcu: Add __rust_helper to helpers rust: processor: Add __rust_helper to helpers ... List of files: /linux/Documentation/dev-tools/context-analysis.rst

d084a73714f818ce509022e1aa9483cabf797c16 - compiler-context-analysis: Introduce scoped init guards

Mon, 19 Jan 2026 09:05:52 +0000

compiler-context-analysis: Introduce scoped init guardsAdd scoped init guard definitions for common synchronization primitivessupported by context analysis.The scoped init guards treat the context as active within initializationscope of the underlying context lock, given initialization impliesexclusive access to the underlying object. This allows initialization ofguarded members without disabling context analysis, while documentinginitialization from subsequent usage.The documentation is updated with the new recommendation. Where scopedinit guards are not provided or cannot be implemented (ww_mutex omittedfor lack of multi-arg guard initializers), the alternative is to justdisable context analysis where guarded members are initialized.Suggested-by: Peter Zijlstra Signed-off-by: Marco Elver Signed-off-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/all/20251212095943.GM3911114@noisy.programming.kicks-ass.net/Link: https://patch.msgid.link/20260119094029.1344361-3-elver@google.com List of files: /linux/Documentation/dev-tools/context-analysis.rst

e4588c25c9d122b5847b88e18b184404b6959160 - compiler-context-analysis: Remove __cond_lock() function-like helper

Fri, 19 Dec 2025 15:40:13 +0000

compiler-context-analysis: Remove __cond_lock() function-like helperAs discussed in [1], removing __cond_lock() will improve the readabilityof trylock code. Now that Sparse context tracking support has beenremoved, we can also remove __cond_lock().Change existing APIs to either drop __cond_lock() completely, or makeuse of the __cond_acquires() function attribute instead.In particular, spinlock and rwlock implementations required switchingover to inline helpers rather than statement-expressions for theirtrylock_* variants.Suggested-by: Peter Zijlstra Signed-off-by: Marco Elver Signed-off-by: Peter Zijlstra (Intel) 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 List of files: /linux/Documentation/dev-tools/context-analysis.rst

47907461e4f6fcdce8cf91dd164369192deeb7c4 - locking/ww_mutex: Support Clang's context analysis

Fri, 19 Dec 2025 15:40:09 +0000

locking/ww_mutex: Support Clang's context analysisAdd support for Clang's context analysis for ww_mutex.The programming model for ww_mutex is subtly more complex than otherlocking primitives when using ww_acquire_ctx. Encoding the respectivepre-conditions for ww_mutex lock/unlock based on ww_acquire_ctx stateusing Clang's context analysis makes incorrect use of the API harder.Signed-off-by: Marco Elver Signed-off-by: Peter Zijlstra (Intel) Link: https://patch.msgid.link/20251219154418.3592607-21-elver@google.com List of files: /linux/Documentation/dev-tools/context-analysis.rst

d3febf16dee28a74b01ba43195ee4965edb6208f - locking/local_lock: Support Clang's context analysis

Fri, 19 Dec 2025 15:40:08 +0000

locking/local_lock: Support Clang's context analysisAdd support for Clang's context analysis for local_lock_t andlocal_trylock_t.Signed-off-by: Marco Elver Signed-off-by: Peter Zijlstra (Intel) Link: https://patch.msgid.link/20251219154418.3592607-20-elver@google.com List of files: /linux/Documentation/dev-tools/context-analysis.rst

e4fd3be884cf33a42c5bcde087b0722a5b8f25ca - locking/rwsem: Support Clang's context analysis

Fri, 19 Dec 2025 15:40:06 +0000

locking/rwsem: Support Clang's context analysisAdd support for Clang's context analysis for rw_semaphore.Signed-off-by: Marco Elver Signed-off-by: Peter Zijlstra (Intel) Link: https://patch.msgid.link/20251219154418.3592607-18-elver@google.com List of files: /linux/Documentation/dev-tools/context-analysis.rst

f0b7ce22d71810c8c11abcd912fbd6f57c2e9677 - srcu: Support Clang's context analysis

Fri, 19 Dec 2025 15:40:04 +0000

srcu: Support Clang's context analysisAdd support for Clang's context analysis for SRCU.Signed-off-by: Marco Elver Signed-off-by: Peter Zijlstra (Intel) Acked-by: Paul E. McKenney Link: https://patch.msgid.link/20251219154418.3592607-16-elver@google.com List of files: /linux/Documentation/dev-tools/context-analysis.rst

fe00f6e84621ad441aa99005f2f0fefd0e5e1a2c - rcu: Support Clang's context analysis

Fri, 19 Dec 2025 15:40:03 +0000

rcu: Support Clang's context analysisImprove the existing annotations to properly support Clang's contextanalysis.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'dhave 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 toacquire these instead of RCU_BH and RCU_SCHED respectively.The above change also simplified introducing __guarded_by support, whereonly the "RCU" context lock needs to be held: introduce __rcu_guarded,where Clang's context analysis warns if a pointer is dereferencedwithout any of the RCU locks held, or updated without the appropriatehelpers.The primitives rcu_assign_pointer() and friends are wrapped withcontext_unsafe(), which enforces using them to update RCU-protectedpointers marked with __rcu_guarded.Signed-off-by: Marco Elver Signed-off-by: Peter Zijlstra (Intel) Acked-by: Paul E. McKenney Link: https://patch.msgid.link/20251219154418.3592607-15-elver@google.com List of files: /linux/Documentation/dev-tools/context-analysis.rst

eb7d96a13bf45f86909006a59e7855d8810f020a - bit_spinlock: Support Clang's context analysis

Fri, 19 Dec 2025 15:40:02 +0000

bit_spinlock: Support Clang's context analysisThe annotations for bit_spinlock.h have simply been using "bitlock" asthe token. For Sparse, that was likely sufficient in most cases. ButClang's context analysis is more precise, and we need to ensure wecan 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. is implicitly included through other includes, andrequires 2 annotations to indicate that acquisition (without release)and release (without prior acquisition) of its bitlock is intended.Signed-off-by: Marco Elver Signed-off-by: Peter Zijlstra (Intel) Link: https://patch.msgid.link/20251219154418.3592607-14-elver@google.com List of files: /linux/Documentation/dev-tools/context-analysis.rst

8f8a55f49cda5fee914bbea1ab5af8df3a6ba8af - locking/seqlock: Support Clang's context analysis

Fri, 19 Dec 2025 15:40:00 +0000

locking/seqlock: Support Clang's context analysisAdd support for Clang's context analysis for seqlock_t.Signed-off-by: Marco Elver Signed-off-by: Peter Zijlstra (Intel) Link: https://patch.msgid.link/20251219154418.3592607-12-elver@google.com List of files: /linux/Documentation/dev-tools/context-analysis.rst

370f0a345a70fe36d0185abf87c7ee8e70572e06 - locking/mutex: Support Clang's context analysis

Fri, 19 Dec 2025 15:39:59 +0000

locking/mutex: Support Clang's context analysisAdd support for Clang's context analysis for mutex.Signed-off-by: Marco Elver Signed-off-by: Peter Zijlstra (Intel) Link: https://patch.msgid.link/20251219154418.3592607-11-elver@google.com List of files: /linux/Documentation/dev-tools/context-analysis.rst

f16a802d402d735a55731f8c94952b3bbb5ddfe8 - locking/rwlock, spinlock: Support Clang's context analysis

Fri, 19 Dec 2025 15:39:57 +0000

locking/rwlock, spinlock: Support Clang's context analysisAdd support for Clang's context analysis for raw_spinlock_t,spinlock_t, and rwlock. This wholesale conversion is required becauseall three of them are interdependent.To avoid warnings in constructors, the initialization functions mark alock as acquired when initialized before guarded variables.The test verifies that common patterns do not generate false positives.Signed-off-by: Marco Elver Signed-off-by: Peter Zijlstra (Intel) Link: https://patch.msgid.link/20251219154418.3592607-9-elver@google.com List of files: /linux/Documentation/dev-tools/context-analysis.rst

8f32441d7a532804a8d9e2ae36f9b13c353934d7 - Documentation: Add documentation for Compiler-Based Context Analysis

Fri, 19 Dec 2025 15:39:53 +0000

Documentation: Add documentation for Compiler-Based Context AnalysisAdds documentation in Documentation/dev-tools/context-analysis.rst, andadds it to the index.Signed-off-by: Marco Elver Signed-off-by: Peter Zijlstra (Intel) Link: https://patch.msgid.link/20251219154418.3592607-5-elver@google.com List of files: /linux/Documentation/dev-tools/context-analysis.rst