From 7ff495e26a39f3e7a3d4058df59b5b6d6f943cab Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Mon, 30 Jun 2025 09:51:38 +0200 Subject: local_lock: Move this_cpu_ptr() notation from internal to main header local_lock.h is the main header for the local_lock_t type and provides wrappers around internal functions prefixed with __ in local_lock_internal.h. Move the this_cpu_ptr() dereference of the variable from the internal to the main header. Since it is all macro implemented, this_cpu_ptr() will still happen within the preempt/ IRQ disabled section. This frees the internal implementation (__) to be used on local_lock_t types which are local variables and must not be accessed via this_cpu_ptr(). Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Thomas Gleixner Acked-by: Waiman Long Acked-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/all/20250630075138.3448715-2-bigeasy@linutronix.de --- include/linux/local_lock.h | 20 ++++++++++---------- include/linux/local_lock_internal.h | 30 +++++++++++++++--------------- 2 files changed, 25 insertions(+), 25 deletions(-) (limited to 'include/linux') diff --git a/include/linux/local_lock.h b/include/linux/local_lock.h index 16a2ee4f8310..2ba846419524 100644 --- a/include/linux/local_lock.h +++ b/include/linux/local_lock.h @@ -13,13 +13,13 @@ * local_lock - Acquire a per CPU local lock * @lock: The lock variable */ -#define local_lock(lock) __local_lock(lock) +#define local_lock(lock) __local_lock(this_cpu_ptr(lock)) /** * local_lock_irq - Acquire a per CPU local lock and disable interrupts * @lock: The lock variable */ -#define local_lock_irq(lock) __local_lock_irq(lock) +#define local_lock_irq(lock) __local_lock_irq(this_cpu_ptr(lock)) /** * local_lock_irqsave - Acquire a per CPU local lock, save and disable @@ -28,19 +28,19 @@ * @flags: Storage for interrupt flags */ #define local_lock_irqsave(lock, flags) \ - __local_lock_irqsave(lock, flags) + __local_lock_irqsave(this_cpu_ptr(lock), flags) /** * local_unlock - Release a per CPU local lock * @lock: The lock variable */ -#define local_unlock(lock) __local_unlock(lock) +#define local_unlock(lock) __local_unlock(this_cpu_ptr(lock)) /** * local_unlock_irq - Release a per CPU local lock and enable interrupts * @lock: The lock variable */ -#define local_unlock_irq(lock) __local_unlock_irq(lock) +#define local_unlock_irq(lock) __local_unlock_irq(this_cpu_ptr(lock)) /** * local_unlock_irqrestore - Release a per CPU local lock and restore @@ -49,7 +49,7 @@ * @flags: Interrupt flags to restore */ #define local_unlock_irqrestore(lock, flags) \ - __local_unlock_irqrestore(lock, flags) + __local_unlock_irqrestore(this_cpu_ptr(lock), flags) /** * local_lock_init - Runtime initialize a lock instance @@ -64,7 +64,7 @@ * locking constrains it will _always_ fail to acquire the lock in NMI or * HARDIRQ context on PREEMPT_RT. */ -#define local_trylock(lock) __local_trylock(lock) +#define local_trylock(lock) __local_trylock(this_cpu_ptr(lock)) /** * local_trylock_irqsave - Try to acquire a per CPU local lock, save and disable @@ -77,7 +77,7 @@ * HARDIRQ context on PREEMPT_RT. */ #define local_trylock_irqsave(lock, flags) \ - __local_trylock_irqsave(lock, flags) + __local_trylock_irqsave(this_cpu_ptr(lock), flags) DEFINE_GUARD(local_lock, local_lock_t __percpu*, local_lock(_T), @@ -91,10 +91,10 @@ DEFINE_LOCK_GUARD_1(local_lock_irqsave, local_lock_t __percpu, unsigned long flags) #define local_lock_nested_bh(_lock) \ - __local_lock_nested_bh(_lock) + __local_lock_nested_bh(this_cpu_ptr(_lock)) #define local_unlock_nested_bh(_lock) \ - __local_unlock_nested_bh(_lock) + __local_unlock_nested_bh(this_cpu_ptr(_lock)) DEFINE_GUARD(local_lock_nested_bh, local_lock_t __percpu*, local_lock_nested_bh(_T), diff --git a/include/linux/local_lock_internal.h b/include/linux/local_lock_internal.h index 8d5ac16a9b17..d80b5306a2c0 100644 --- a/include/linux/local_lock_internal.h +++ b/include/linux/local_lock_internal.h @@ -99,14 +99,14 @@ do { \ local_trylock_t *tl; \ local_lock_t *l; \ \ - l = (local_lock_t *)this_cpu_ptr(lock); \ + l = (local_lock_t *)(lock); \ tl = (local_trylock_t *)l; \ _Generic((lock), \ - __percpu local_trylock_t *: ({ \ + local_trylock_t *: ({ \ lockdep_assert(tl->acquired == 0); \ WRITE_ONCE(tl->acquired, 1); \ }), \ - __percpu local_lock_t *: (void)0); \ + local_lock_t *: (void)0); \ local_lock_acquire(l); \ } while (0) @@ -133,7 +133,7 @@ do { \ local_trylock_t *tl; \ \ preempt_disable(); \ - tl = this_cpu_ptr(lock); \ + tl = (lock); \ if (READ_ONCE(tl->acquired)) { \ preempt_enable(); \ tl = NULL; \ @@ -150,7 +150,7 @@ do { \ local_trylock_t *tl; \ \ local_irq_save(flags); \ - tl = this_cpu_ptr(lock); \ + tl = (lock); \ if (READ_ONCE(tl->acquired)) { \ local_irq_restore(flags); \ tl = NULL; \ @@ -167,15 +167,15 @@ do { \ local_trylock_t *tl; \ local_lock_t *l; \ \ - l = (local_lock_t *)this_cpu_ptr(lock); \ + l = (local_lock_t *)(lock); \ tl = (local_trylock_t *)l; \ local_lock_release(l); \ _Generic((lock), \ - __percpu local_trylock_t *: ({ \ + local_trylock_t *: ({ \ lockdep_assert(tl->acquired == 1); \ WRITE_ONCE(tl->acquired, 0); \ }), \ - __percpu local_lock_t *: (void)0); \ + local_lock_t *: (void)0); \ } while (0) #define __local_unlock(lock) \ @@ -199,11 +199,11 @@ do { \ #define __local_lock_nested_bh(lock) \ do { \ lockdep_assert_in_softirq(); \ - local_lock_acquire(this_cpu_ptr(lock)); \ + local_lock_acquire((lock)); \ } while (0) #define __local_unlock_nested_bh(lock) \ - local_lock_release(this_cpu_ptr(lock)) + local_lock_release((lock)) #else /* !CONFIG_PREEMPT_RT */ @@ -227,7 +227,7 @@ typedef spinlock_t local_trylock_t; #define __local_lock(__lock) \ do { \ migrate_disable(); \ - spin_lock(this_cpu_ptr((__lock))); \ + spin_lock((__lock)); \ } while (0) #define __local_lock_irq(lock) __local_lock(lock) @@ -241,7 +241,7 @@ typedef spinlock_t local_trylock_t; #define __local_unlock(__lock) \ do { \ - spin_unlock(this_cpu_ptr((__lock))); \ + spin_unlock((__lock)); \ migrate_enable(); \ } while (0) @@ -252,12 +252,12 @@ typedef spinlock_t local_trylock_t; #define __local_lock_nested_bh(lock) \ do { \ lockdep_assert_in_softirq_func(); \ - spin_lock(this_cpu_ptr(lock)); \ + spin_lock((lock)); \ } while (0) #define __local_unlock_nested_bh(lock) \ do { \ - spin_unlock(this_cpu_ptr((lock))); \ + spin_unlock((lock)); \ } while (0) #define __local_trylock(lock) \ @@ -268,7 +268,7 @@ do { \ __locked = 0; \ } else { \ migrate_disable(); \ - __locked = spin_trylock(this_cpu_ptr((lock))); \ + __locked = spin_trylock((lock)); \ if (!__locked) \ migrate_enable(); \ } \ -- cgit v1.2.3 From daec29dcc8731b7596690ab9f647839e4584a86d Mon Sep 17 00:00:00 2001 From: Thomas Weißschuh Date: Tue, 17 Jun 2025 19:08:14 +0200 Subject: locking/mutex: Mark devm_mutex_init() as __must_check MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit devm_mutex_init() can fail. With CONFIG_DEBUG_MUTEXES=y the mutex will be marked as unusable and trigger errors on usage. Enforce all callers check the return value through the compiler. As devm_mutex_init() itself is a macro, it can not be annotated directly. Annotate __devm_mutex_init() instead. Unfortunately __must_check/warn_unused_result don't propagate through statement expression. So move the statement expression into the argument list of the call to __devm_mutex_init() through a helper macro. Suggested-by: Peter Zijlstra Signed-off-by: Thomas Weißschuh Reviewed-by: Andy Shevchenko Reviewed-by: Bartosz Golaszewski Signed-off-by: Boqun Feng Link: https://lore.kernel.org/r/20250617-must_check-devm_mutex_init-v7-3-d9e449f4d224@weissschuh.net --- include/linux/mutex.h | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) (limited to 'include/linux') diff --git a/include/linux/mutex.h b/include/linux/mutex.h index a039fa8c1780..00afd341d293 100644 --- a/include/linux/mutex.h +++ b/include/linux/mutex.h @@ -126,11 +126,11 @@ do { \ #ifdef CONFIG_DEBUG_MUTEXES -int __devm_mutex_init(struct device *dev, struct mutex *lock); +int __must_check __devm_mutex_init(struct device *dev, struct mutex *lock); #else -static inline int __devm_mutex_init(struct device *dev, struct mutex *lock) +static inline int __must_check __devm_mutex_init(struct device *dev, struct mutex *lock) { /* * When CONFIG_DEBUG_MUTEXES is off mutex_destroy() is just a nop so @@ -141,14 +141,17 @@ static inline int __devm_mutex_init(struct device *dev, struct mutex *lock) #endif -#define devm_mutex_init(dev, mutex) \ +#define __mutex_init_ret(mutex) \ ({ \ typeof(mutex) mutex_ = (mutex); \ \ mutex_init(mutex_); \ - __devm_mutex_init(dev, mutex_); \ + mutex_; \ }) +#define devm_mutex_init(dev, mutex) \ + __devm_mutex_init(dev, __mutex_init_ret(mutex)) + /* * See kernel/locking/mutex.c for detailed documentation of these APIs. * Also see Documentation/locking/mutex-design.rst. -- cgit v1.2.3 From d7c36d6350b5a4b27256eaeeea3b72621a819c9a Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Tue, 10 Jun 2025 11:29:21 +0200 Subject: locking/lockdep: Avoid struct return in lock_stats() Returning a large structure from the lock_stats() function causes clang to have multiple copies of it on the stack and copy between them, which can end up exceeding the frame size warning limit: kernel/locking/lockdep.c:300:25: error: stack frame size (1464) exceeds limit (1280) in 'lock_stats' [-Werror,-Wframe-larger-than] 300 | struct lock_class_stats lock_stats(struct lock_class *class) Change the calling conventions to directly operate on the caller's copy, which apparently is what gcc does already. Signed-off-by: Arnd Bergmann Signed-off-by: Boqun Feng Link: https://lore.kernel.org/r/20250610092941.2642847-1-arnd@kernel.org --- include/linux/lockdep_types.h | 2 +- kernel/locking/lockdep.c | 27 ++++++++++++--------------- kernel/locking/lockdep_proc.c | 2 +- 3 files changed, 14 insertions(+), 17 deletions(-) (limited to 'include/linux') diff --git a/include/linux/lockdep_types.h b/include/linux/lockdep_types.h index 9f361d3ab9d9..eae115a26488 100644 --- a/include/linux/lockdep_types.h +++ b/include/linux/lockdep_types.h @@ -175,7 +175,7 @@ struct lock_class_stats { unsigned long bounces[nr_bounce_types]; }; -struct lock_class_stats lock_stats(struct lock_class *class); +void lock_stats(struct lock_class *class, struct lock_class_stats *stats); void clear_lock_stats(struct lock_class *class); #endif diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index dd2bbf73718b..0c941418a215 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -297,33 +297,30 @@ static inline void lock_time_add(struct lock_time *src, struct lock_time *dst) dst->nr += src->nr; } -struct lock_class_stats lock_stats(struct lock_class *class) +void lock_stats(struct lock_class *class, struct lock_class_stats *stats) { - struct lock_class_stats stats; int cpu, i; - memset(&stats, 0, sizeof(struct lock_class_stats)); + memset(stats, 0, sizeof(struct lock_class_stats)); for_each_possible_cpu(cpu) { struct lock_class_stats *pcs = &per_cpu(cpu_lock_stats, cpu)[class - lock_classes]; - for (i = 0; i < ARRAY_SIZE(stats.contention_point); i++) - stats.contention_point[i] += pcs->contention_point[i]; + for (i = 0; i < ARRAY_SIZE(stats->contention_point); i++) + stats->contention_point[i] += pcs->contention_point[i]; - for (i = 0; i < ARRAY_SIZE(stats.contending_point); i++) - stats.contending_point[i] += pcs->contending_point[i]; + for (i = 0; i < ARRAY_SIZE(stats->contending_point); i++) + stats->contending_point[i] += pcs->contending_point[i]; - lock_time_add(&pcs->read_waittime, &stats.read_waittime); - lock_time_add(&pcs->write_waittime, &stats.write_waittime); + lock_time_add(&pcs->read_waittime, &stats->read_waittime); + lock_time_add(&pcs->write_waittime, &stats->write_waittime); - lock_time_add(&pcs->read_holdtime, &stats.read_holdtime); - lock_time_add(&pcs->write_holdtime, &stats.write_holdtime); + lock_time_add(&pcs->read_holdtime, &stats->read_holdtime); + lock_time_add(&pcs->write_holdtime, &stats->write_holdtime); - for (i = 0; i < ARRAY_SIZE(stats.bounces); i++) - stats.bounces[i] += pcs->bounces[i]; + for (i = 0; i < ARRAY_SIZE(stats->bounces); i++) + stats->bounces[i] += pcs->bounces[i]; } - - return stats; } void clear_lock_stats(struct lock_class *class) diff --git a/kernel/locking/lockdep_proc.c b/kernel/locking/lockdep_proc.c index b52c07c4707c..1916db9aa46b 100644 --- a/kernel/locking/lockdep_proc.c +++ b/kernel/locking/lockdep_proc.c @@ -657,7 +657,7 @@ static int lock_stat_open(struct inode *inode, struct file *file) if (!test_bit(idx, lock_classes_in_use)) continue; iter->class = class; - iter->stats = lock_stats(class); + lock_stats(class, &iter->stats); iter++; } -- cgit v1.2.3