diff --git a/Documentation/dev-tools/context-analysis.rst b/Documentation/dev-tools/context-analysis.rst index 54d9ee28de98..8e71e1e75b5b 100644 --- a/Documentation/dev-tools/context-analysis.rst +++ b/Documentation/dev-tools/context-analysis.rst @@ -17,7 +17,7 @@ features. To enable for Clang, configure the kernel with:: CONFIG_WARN_CONTEXT_ANALYSIS=y -The feature requires Clang 22 or later. +The feature requires Clang 23 or later. The analysis is *opt-in by default*, and requires declaring which modules and subsystems should be analyzed in the respective `Makefile`:: diff --git a/include/linux/compiler-context-analysis.h b/include/linux/compiler-context-analysis.h index a9317571e6af..8302ebc2ea8c 100644 --- a/include/linux/compiler-context-analysis.h +++ b/include/linux/compiler-context-analysis.h @@ -39,12 +39,14 @@ # define __assumes_shared_ctx_lock(...) __attribute__((assert_shared_capability(__VA_ARGS__))) /** - * __guarded_by - struct member and globals attribute, declares variable - * only accessible within active context + * __guarded_by() - struct member and globals attribute, declares variable + * only accessible within active context + * @...: context lock instance pointer(s) * * Declares that the struct member or global variable is only accessible within - * the context entered by the given context lock. Read operations on the data - * require shared access, while write operations require exclusive access. + * the context entered by the given context lock(s). Read operations on the data + * require shared access to at least one of the context locks, while write + * operations require exclusive access to all listed context locks. * * .. code-block:: c * @@ -52,17 +54,24 @@ * spinlock_t lock; * long counter __guarded_by(&lock); * }; + * + * struct some_state { + * spinlock_t lock1, lock2; + * long counter __guarded_by(&lock1, &lock2); + * }; */ # define __guarded_by(...) __attribute__((guarded_by(__VA_ARGS__))) /** - * __pt_guarded_by - struct member and globals attribute, declares pointed-to - * data only accessible within active context + * __pt_guarded_by() - struct member and globals attribute, declares pointed-to + * data only accessible within active context + * @...: context lock instance pointer(s) * * Declares that the data pointed to by the struct member pointer or global * pointer is only accessible within the context entered by the given context - * lock. Read operations on the data require shared access, while write - * operations require exclusive access. + * lock(s). Read operations on the data require shared access to at least one + * of the context locks, while write operations require exclusive access to all + * listed context locks. * * .. code-block:: c * @@ -70,6 +79,11 @@ * spinlock_t lock; * long *counter __pt_guarded_by(&lock); * }; + * + * struct some_state { + * spinlock_t lock1, lock2; + * long *counter __pt_guarded_by(&lock1, &lock2); + * }; */ # define __pt_guarded_by(...) __attribute__((pt_guarded_by(__VA_ARGS__))) diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 8ff5adcfe1e0..b0f3028a213d 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -630,7 +630,7 @@ config DEBUG_FORCE_WEAK_PER_CPU config WARN_CONTEXT_ANALYSIS bool "Compiler context-analysis warnings" - depends on CC_IS_CLANG && CLANG_VERSION >= 220100 + depends on CC_IS_CLANG && CLANG_VERSION >= 230000 # Branch profiling re-defines "if", which messes with the compiler's # ability to analyze __cond_acquires(..), resulting in false positives. depends on !TRACE_BRANCH_PROFILING @@ -641,7 +641,7 @@ config WARN_CONTEXT_ANALYSIS and releasing user-definable "context locks". Clang's name of the feature is "Thread Safety Analysis". Requires - Clang 22.1.0 or later. + Clang 23 or later. Produces warnings by default. Select CONFIG_WERROR if you wish to turn these warnings into errors. diff --git a/lib/test_context-analysis.c b/lib/test_context-analysis.c index 06b4a6a028e0..316f4dfcda65 100644 --- a/lib/test_context-analysis.c +++ b/lib/test_context-analysis.c @@ -159,6 +159,10 @@ TEST_SPINLOCK_COMMON(read_lock, struct test_mutex_data { struct mutex mtx; int counter __guarded_by(&mtx); + + struct mutex mtx2; + int anyread __guarded_by(&mtx, &mtx2); + int *anyptr __pt_guarded_by(&mtx, &mtx2); }; static void __used test_mutex_init(struct test_mutex_data *d) @@ -219,6 +223,26 @@ static void __used test_mutex_cond_guard(struct test_mutex_data *d) } } +static void __used test_mutex_multiguard(struct test_mutex_data *d) +{ + mutex_lock(&d->mtx); + (void)d->anyread; + (void)*d->anyptr; + mutex_unlock(&d->mtx); + + mutex_lock(&d->mtx2); + (void)d->anyread; + (void)*d->anyptr; + mutex_unlock(&d->mtx2); + + mutex_lock(&d->mtx); + mutex_lock(&d->mtx2); + d->anyread++; + (*d->anyptr)++; + mutex_unlock(&d->mtx2); + mutex_unlock(&d->mtx); +} + struct test_seqlock_data { seqlock_t sl; int counter __guarded_by(&sl);