Add support for Clang's capability analysis for mutex. Signed-off-by: Marco Elver --- v3: * Switch to DECLARE_LOCK_GUARD_1_ATTRS() (suggested by Peter) * __assert -> __assume rename --- .../dev-tools/capability-analysis.rst | 2 +- include/linux/mutex.h | 35 +++++----- include/linux/mutex_types.h | 4 +- lib/test_capability-analysis.c | 64 +++++++++++++++++++ 4 files changed, 87 insertions(+), 18 deletions(-) diff --git a/Documentation/dev-tools/capability-analysis.rst b/Documentation/dev-tools/capability-analysis.rst index 9abd7f62cf4e..89f9c991f7cf 100644 --- a/Documentation/dev-tools/capability-analysis.rst +++ b/Documentation/dev-tools/capability-analysis.rst @@ -81,7 +81,7 @@ Supported Kernel Primitives ~~~~~~~~~~~~~~~~~~~~~~~~~~~ Currently the following synchronization primitives are supported: -`raw_spinlock_t`, `spinlock_t`, `rwlock_t`. +`raw_spinlock_t`, `spinlock_t`, `rwlock_t`, `mutex`. For capabilities with an initialization function (e.g., `spin_lock_init()`), calling this function on the capability instance before initializing any diff --git a/include/linux/mutex.h b/include/linux/mutex.h index 847b81ca6436..7e4eb778d269 100644 --- a/include/linux/mutex.h +++ b/include/linux/mutex.h @@ -62,6 +62,7 @@ do { \ static struct lock_class_key __key; \ \ __mutex_init((mutex), #mutex, &__key); \ + __assume_cap(mutex); \ } while (0) /** @@ -157,13 +158,13 @@ static inline int __must_check __devm_mutex_init(struct device *dev, struct mute * Also see Documentation/locking/mutex-design.rst. */ #ifdef CONFIG_DEBUG_LOCK_ALLOC -extern void mutex_lock_nested(struct mutex *lock, unsigned int subclass); +extern void mutex_lock_nested(struct mutex *lock, unsigned int subclass) __acquires(lock); extern void _mutex_lock_nest_lock(struct mutex *lock, struct lockdep_map *nest_lock); extern int __must_check mutex_lock_interruptible_nested(struct mutex *lock, - unsigned int subclass); + unsigned int subclass) __cond_acquires(0, lock); extern int __must_check _mutex_lock_killable(struct mutex *lock, - unsigned int subclass, struct lockdep_map *nest_lock); -extern void mutex_lock_io_nested(struct mutex *lock, unsigned int subclass); + unsigned int subclass, struct lockdep_map *nest_lock) __cond_acquires(0, lock); +extern void mutex_lock_io_nested(struct mutex *lock, unsigned int subclass) __acquires(lock); #define mutex_lock(lock) mutex_lock_nested(lock, 0) #define mutex_lock_interruptible(lock) mutex_lock_interruptible_nested(lock, 0) @@ -186,10 +187,10 @@ do { \ _mutex_lock_killable(lock, subclass, NULL) #else -extern void mutex_lock(struct mutex *lock); -extern int __must_check mutex_lock_interruptible(struct mutex *lock); -extern int __must_check mutex_lock_killable(struct mutex *lock); -extern void mutex_lock_io(struct mutex *lock); +extern void mutex_lock(struct mutex *lock) __acquires(lock); +extern int __must_check mutex_lock_interruptible(struct mutex *lock) __cond_acquires(0, lock); +extern int __must_check mutex_lock_killable(struct mutex *lock) __cond_acquires(0, lock); +extern void mutex_lock_io(struct mutex *lock) __acquires(lock); # define mutex_lock_nested(lock, subclass) mutex_lock(lock) # define mutex_lock_interruptible_nested(lock, subclass) mutex_lock_interruptible(lock) @@ -207,7 +208,7 @@ extern void mutex_lock_io(struct mutex *lock); */ #ifdef CONFIG_DEBUG_LOCK_ALLOC -extern int _mutex_trylock_nest_lock(struct mutex *lock, struct lockdep_map *nest_lock); +extern int _mutex_trylock_nest_lock(struct mutex *lock, struct lockdep_map *nest_lock) __cond_acquires(true, lock); #define mutex_trylock_nest_lock(lock, nest_lock) \ ( \ @@ -217,17 +218,21 @@ extern int _mutex_trylock_nest_lock(struct mutex *lock, struct lockdep_map *nest #define mutex_trylock(lock) _mutex_trylock_nest_lock(lock, NULL) #else -extern int mutex_trylock(struct mutex *lock); +extern int mutex_trylock(struct mutex *lock) __cond_acquires(true, lock); #define mutex_trylock_nest_lock(lock, nest_lock) mutex_trylock(lock) #endif -extern void mutex_unlock(struct mutex *lock); +extern void mutex_unlock(struct mutex *lock) __releases(lock); -extern int atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *lock); +extern int atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *lock) __cond_acquires(true, lock); -DEFINE_GUARD(mutex, struct mutex *, mutex_lock(_T), mutex_unlock(_T)) -DEFINE_GUARD_COND(mutex, _try, mutex_trylock(_T)) -DEFINE_GUARD_COND(mutex, _intr, mutex_lock_interruptible(_T), _RET == 0) +DEFINE_LOCK_GUARD_1(mutex, struct mutex, mutex_lock(_T->lock), mutex_unlock(_T->lock)) +DEFINE_LOCK_GUARD_1_COND(mutex, _try, mutex_trylock(_T->lock)) +DEFINE_LOCK_GUARD_1_COND(mutex, _intr, mutex_lock_interruptible(_T->lock), _RET == 0) + +DECLARE_LOCK_GUARD_1_ATTRS(mutex, __assumes_cap(_T), /* */) +DECLARE_LOCK_GUARD_1_ATTRS(mutex_try, __assumes_cap(_T), /* */) +DECLARE_LOCK_GUARD_1_ATTRS(mutex_intr, __assumes_cap(_T), /* */) extern unsigned long mutex_get_owner(struct mutex *lock); diff --git a/include/linux/mutex_types.h b/include/linux/mutex_types.h index fdf7f515fde8..e1a5ea12d53c 100644 --- a/include/linux/mutex_types.h +++ b/include/linux/mutex_types.h @@ -38,7 +38,7 @@ * - detects multi-task circular deadlocks and prints out all affected * locks and tasks (and only those tasks) */ -struct mutex { +struct_with_capability(mutex) { atomic_long_t owner; raw_spinlock_t wait_lock; #ifdef CONFIG_MUTEX_SPIN_ON_OWNER @@ -59,7 +59,7 @@ struct mutex { */ #include -struct mutex { +struct_with_capability(mutex) { struct rt_mutex_base rtmutex; #ifdef CONFIG_DEBUG_LOCK_ALLOC struct lockdep_map dep_map; diff --git a/lib/test_capability-analysis.c b/lib/test_capability-analysis.c index 84060bace61d..286723b47328 100644 --- a/lib/test_capability-analysis.c +++ b/lib/test_capability-analysis.c @@ -5,6 +5,7 @@ */ #include +#include #include /* @@ -144,3 +145,66 @@ TEST_SPINLOCK_COMMON(read_lock, read_unlock, read_trylock, TEST_OP_RO); + +struct test_mutex_data { + struct mutex mtx; + int counter __guarded_by(&mtx); +}; + +static void __used test_mutex_init(struct test_mutex_data *d) +{ + mutex_init(&d->mtx); + d->counter = 0; +} + +static void __used test_mutex_lock(struct test_mutex_data *d) +{ + mutex_lock(&d->mtx); + d->counter++; + mutex_unlock(&d->mtx); + mutex_lock_io(&d->mtx); + d->counter++; + mutex_unlock(&d->mtx); +} + +static void __used test_mutex_trylock(struct test_mutex_data *d, atomic_t *a) +{ + if (!mutex_lock_interruptible(&d->mtx)) { + d->counter++; + mutex_unlock(&d->mtx); + } + if (!mutex_lock_killable(&d->mtx)) { + d->counter++; + mutex_unlock(&d->mtx); + } + if (mutex_trylock(&d->mtx)) { + d->counter++; + mutex_unlock(&d->mtx); + } + if (atomic_dec_and_mutex_lock(a, &d->mtx)) { + d->counter++; + mutex_unlock(&d->mtx); + } +} + +static void __used test_mutex_assert(struct test_mutex_data *d) +{ + lockdep_assert_held(&d->mtx); + d->counter++; +} + +static void __used test_mutex_guard(struct test_mutex_data *d) +{ + guard(mutex)(&d->mtx); + d->counter++; +} + +static void __used test_mutex_cond_guard(struct test_mutex_data *d) +{ + scoped_cond_guard(mutex_try, return, &d->mtx) { + d->counter++; + } + scoped_cond_guard(mutex_intr, return, &d->mtx) { + d->counter++; + } +} -- 2.51.0.384.g4c02a37b29-goog