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authorLinus Torvalds <torvalds@linux-foundation.org>2026-02-10 12:28:44 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2026-02-10 12:28:44 -0800
commit0923fd0419a1a2c8846e15deacac11b619e996d9 (patch)
tree7cc5fecc1680f5881f1d4183be400b51c81e6943 /tools/include/linux
parent4d84667627c4ff70826b349c449bbaf63b9af4e5 (diff)
parent7a562d5d2396c9c78fbbced7ae81bcfcfa0fde3f (diff)
Merge tag 'locking-core-2026-02-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull 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<i8/i16/bool> and replace most Rust native AtomicBool usages with Atomic<bool> - 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 ...
Diffstat (limited to 'tools/include/linux')
-rw-r--r--tools/include/linux/compiler-context-analysis.h42
-rw-r--r--tools/include/linux/compiler_types.h18
2 files changed, 43 insertions, 17 deletions
diff --git a/tools/include/linux/compiler-context-analysis.h b/tools/include/linux/compiler-context-analysis.h
new file mode 100644
index 000000000000..13a9115e9e58
--- /dev/null
+++ b/tools/include/linux/compiler-context-analysis.h
@@ -0,0 +1,42 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _TOOLS_LINUX_COMPILER_CONTEXT_ANALYSIS_H
+#define _TOOLS_LINUX_COMPILER_CONTEXT_ANALYSIS_H
+
+/*
+ * Macros and attributes for compiler-based static context analysis.
+ * No-op stubs for tools.
+ */
+
+#define __guarded_by(...)
+#define __pt_guarded_by(...)
+
+#define context_lock_struct(name, ...) struct __VA_ARGS__ name
+
+#define __no_context_analysis
+#define __context_unsafe(comment)
+#define context_unsafe(...) ({ __VA_ARGS__; })
+#define context_unsafe_alias(p)
+#define disable_context_analysis()
+#define enable_context_analysis()
+
+#define __must_hold(...)
+#define __must_not_hold(...)
+#define __acquires(...)
+#define __cond_acquires(ret, x)
+#define __releases(...)
+#define __acquire(x) (void)0
+#define __release(x) (void)0
+
+#define __must_hold_shared(...)
+#define __acquires_shared(...)
+#define __cond_acquires_shared(ret, x)
+#define __releases_shared(...)
+#define __acquire_shared(x) (void)0
+#define __release_shared(x) (void)0
+
+#define __acquire_ret(call, expr) (call)
+#define __acquire_shared_ret(call, expr) (call)
+#define __acquires_ret
+#define __acquires_shared_ret
+
+#endif /* _TOOLS_LINUX_COMPILER_CONTEXT_ANALYSIS_H */
diff --git a/tools/include/linux/compiler_types.h b/tools/include/linux/compiler_types.h
index d09f9dc172a4..14e420467eee 100644
--- a/tools/include/linux/compiler_types.h
+++ b/tools/include/linux/compiler_types.h
@@ -13,23 +13,7 @@
#define __has_builtin(x) (0)
#endif
-#ifdef __CHECKER__
-/* context/locking */
-# define __must_hold(x) __attribute__((context(x,1,1)))
-# define __acquires(x) __attribute__((context(x,0,1)))
-# define __releases(x) __attribute__((context(x,1,0)))
-# define __acquire(x) __context__(x,1)
-# define __release(x) __context__(x,-1)
-# define __cond_lock(x,c) ((c) ? ({ __acquire(x); 1; }) : 0)
-#else /* __CHECKER__ */
-/* context/locking */
-# define __must_hold(x)
-# define __acquires(x)
-# define __releases(x)
-# define __acquire(x) (void)0
-# define __release(x) (void)0
-# define __cond_lock(x,c) (c)
-#endif /* __CHECKER__ */
+#include <linux/compiler-context-analysis.h>
/* Compiler specific macros. */
#ifdef __GNUC__