From c4e05116a2c4d8187127dbf77ab790aa57a47388 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 3 Jul 2006 00:24:29 -0700 Subject: [PATCH] lockdep: clean up rwsems Clean up rwsems. Signed-off-by: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/rwsem-spinlock.c | 46 ++-------------------------------------------- lib/rwsem.c | 31 ------------------------------- 2 files changed, 2 insertions(+), 75 deletions(-) (limited to 'lib') diff --git a/lib/rwsem-spinlock.c b/lib/rwsem-spinlock.c index 40ffde940a..03b6097eb0 100644 --- a/lib/rwsem-spinlock.c +++ b/lib/rwsem-spinlock.c @@ -17,16 +17,6 @@ struct rwsem_waiter { #define RWSEM_WAITING_FOR_WRITE 0x00000002 }; -#if RWSEM_DEBUG -void rwsemtrace(struct rw_semaphore *sem, const char *str) -{ - if (sem->debug) - printk("[%d] %s({%d,%d})\n", - current->pid, str, sem->activity, - list_empty(&sem->wait_list) ? 0 : 1); -} -#endif - /* * initialise the semaphore */ @@ -35,9 +25,6 @@ void fastcall init_rwsem(struct rw_semaphore *sem) sem->activity = 0; spin_lock_init(&sem->wait_lock); INIT_LIST_HEAD(&sem->wait_list); -#if RWSEM_DEBUG - sem->debug = 0; -#endif } /* @@ -56,8 +43,6 @@ __rwsem_do_wake(struct rw_semaphore *sem, int wakewrite) struct task_struct *tsk; int woken; - rwsemtrace(sem, "Entering __rwsem_do_wake"); - waiter = list_entry(sem->wait_list.next, struct rwsem_waiter, list); if (!wakewrite) { @@ -104,7 +89,6 @@ __rwsem_do_wake(struct rw_semaphore *sem, int wakewrite) sem->activity += woken; out: - rwsemtrace(sem, "Leaving __rwsem_do_wake"); return sem; } @@ -138,8 +122,6 @@ void fastcall __sched __down_read(struct rw_semaphore *sem) struct rwsem_waiter waiter; struct task_struct *tsk; - rwsemtrace(sem, "Entering __down_read"); - spin_lock_irq(&sem->wait_lock); if (sem->activity >= 0 && list_empty(&sem->wait_list)) { @@ -171,9 +153,8 @@ void fastcall __sched __down_read(struct rw_semaphore *sem) } tsk->state = TASK_RUNNING; - out: - rwsemtrace(sem, "Leaving __down_read"); + ; } /* @@ -184,7 +165,6 @@ int fastcall __down_read_trylock(struct rw_semaphore *sem) unsigned long flags; int ret = 0; - rwsemtrace(sem, "Entering __down_read_trylock"); spin_lock_irqsave(&sem->wait_lock, flags); @@ -196,7 +176,6 @@ int fastcall __down_read_trylock(struct rw_semaphore *sem) spin_unlock_irqrestore(&sem->wait_lock, flags); - rwsemtrace(sem, "Leaving __down_read_trylock"); return ret; } @@ -209,8 +188,6 @@ void fastcall __sched __down_write(struct rw_semaphore *sem) struct rwsem_waiter waiter; struct task_struct *tsk; - rwsemtrace(sem, "Entering __down_write"); - spin_lock_irq(&sem->wait_lock); if (sem->activity == 0 && list_empty(&sem->wait_list)) { @@ -242,9 +219,8 @@ void fastcall __sched __down_write(struct rw_semaphore *sem) } tsk->state = TASK_RUNNING; - out: - rwsemtrace(sem, "Leaving __down_write"); + ; } /* @@ -255,8 +231,6 @@ int fastcall __down_write_trylock(struct rw_semaphore *sem) unsigned long flags; int ret = 0; - rwsemtrace(sem, "Entering __down_write_trylock"); - spin_lock_irqsave(&sem->wait_lock, flags); if (sem->activity == 0 && list_empty(&sem->wait_list)) { @@ -267,7 +241,6 @@ int fastcall __down_write_trylock(struct rw_semaphore *sem) spin_unlock_irqrestore(&sem->wait_lock, flags); - rwsemtrace(sem, "Leaving __down_write_trylock"); return ret; } @@ -278,16 +251,12 @@ void fastcall __up_read(struct rw_semaphore *sem) { unsigned long flags; - rwsemtrace(sem, "Entering __up_read"); - spin_lock_irqsave(&sem->wait_lock, flags); if (--sem->activity == 0 && !list_empty(&sem->wait_list)) sem = __rwsem_wake_one_writer(sem); spin_unlock_irqrestore(&sem->wait_lock, flags); - - rwsemtrace(sem, "Leaving __up_read"); } /* @@ -297,8 +266,6 @@ void fastcall __up_write(struct rw_semaphore *sem) { unsigned long flags; - rwsemtrace(sem, "Entering __up_write"); - spin_lock_irqsave(&sem->wait_lock, flags); sem->activity = 0; @@ -306,8 +273,6 @@ void fastcall __up_write(struct rw_semaphore *sem) sem = __rwsem_do_wake(sem, 1); spin_unlock_irqrestore(&sem->wait_lock, flags); - - rwsemtrace(sem, "Leaving __up_write"); } /* @@ -318,8 +283,6 @@ void fastcall __downgrade_write(struct rw_semaphore *sem) { unsigned long flags; - rwsemtrace(sem, "Entering __downgrade_write"); - spin_lock_irqsave(&sem->wait_lock, flags); sem->activity = 1; @@ -327,8 +290,6 @@ void fastcall __downgrade_write(struct rw_semaphore *sem) sem = __rwsem_do_wake(sem, 0); spin_unlock_irqrestore(&sem->wait_lock, flags); - - rwsemtrace(sem, "Leaving __downgrade_write"); } EXPORT_SYMBOL(init_rwsem); @@ -339,6 +300,3 @@ EXPORT_SYMBOL(__down_write_trylock); EXPORT_SYMBOL(__up_read); EXPORT_SYMBOL(__up_write); EXPORT_SYMBOL(__downgrade_write); -#if RWSEM_DEBUG -EXPORT_SYMBOL(rwsemtrace); -#endif diff --git a/lib/rwsem.c b/lib/rwsem.c index 62fa4eba9f..bae5972848 100644 --- a/lib/rwsem.c +++ b/lib/rwsem.c @@ -16,17 +16,6 @@ struct rwsem_waiter { #define RWSEM_WAITING_FOR_WRITE 0x00000002 }; -#if RWSEM_DEBUG -#undef rwsemtrace -void rwsemtrace(struct rw_semaphore *sem, const char *str) -{ - printk("sem=%p\n", sem); - printk("(sem)=%08lx\n", sem->count); - if (sem->debug) - printk("[%d] %s({%08lx})\n", current->pid, str, sem->count); -} -#endif - /* * handle the lock release when processes blocked on it that can now run * - if we come here from up_xxxx(), then: @@ -45,8 +34,6 @@ __rwsem_do_wake(struct rw_semaphore *sem, int downgrading) struct list_head *next; signed long oldcount, woken, loop; - rwsemtrace(sem, "Entering __rwsem_do_wake"); - if (downgrading) goto dont_wake_writers; @@ -127,7 +114,6 @@ __rwsem_do_wake(struct rw_semaphore *sem, int downgrading) next->prev = &sem->wait_list; out: - rwsemtrace(sem, "Leaving __rwsem_do_wake"); return sem; /* undo the change to count, but check for a transition 1->0 */ @@ -186,13 +172,9 @@ rwsem_down_read_failed(struct rw_semaphore *sem) { struct rwsem_waiter waiter; - rwsemtrace(sem, "Entering rwsem_down_read_failed"); - waiter.flags = RWSEM_WAITING_FOR_READ; rwsem_down_failed_common(sem, &waiter, RWSEM_WAITING_BIAS - RWSEM_ACTIVE_BIAS); - - rwsemtrace(sem, "Leaving rwsem_down_read_failed"); return sem; } @@ -204,12 +186,9 @@ rwsem_down_write_failed(struct rw_semaphore *sem) { struct rwsem_waiter waiter; - rwsemtrace(sem, "Entering rwsem_down_write_failed"); - waiter.flags = RWSEM_WAITING_FOR_WRITE; rwsem_down_failed_common(sem, &waiter, -RWSEM_ACTIVE_BIAS); - rwsemtrace(sem, "Leaving rwsem_down_write_failed"); return sem; } @@ -221,8 +200,6 @@ struct rw_semaphore fastcall *rwsem_wake(struct rw_semaphore *sem) { unsigned long flags; - rwsemtrace(sem, "Entering rwsem_wake"); - spin_lock_irqsave(&sem->wait_lock, flags); /* do nothing if list empty */ @@ -231,8 +208,6 @@ struct rw_semaphore fastcall *rwsem_wake(struct rw_semaphore *sem) spin_unlock_irqrestore(&sem->wait_lock, flags); - rwsemtrace(sem, "Leaving rwsem_wake"); - return sem; } @@ -245,8 +220,6 @@ struct rw_semaphore fastcall *rwsem_downgrade_wake(struct rw_semaphore *sem) { unsigned long flags; - rwsemtrace(sem, "Entering rwsem_downgrade_wake"); - spin_lock_irqsave(&sem->wait_lock, flags); /* do nothing if list empty */ @@ -255,7 +228,6 @@ struct rw_semaphore fastcall *rwsem_downgrade_wake(struct rw_semaphore *sem) spin_unlock_irqrestore(&sem->wait_lock, flags); - rwsemtrace(sem, "Leaving rwsem_downgrade_wake"); return sem; } @@ -263,6 +235,3 @@ EXPORT_SYMBOL(rwsem_down_read_failed); EXPORT_SYMBOL(rwsem_down_write_failed); EXPORT_SYMBOL(rwsem_wake); EXPORT_SYMBOL(rwsem_downgrade_wake); -#if RWSEM_DEBUG -EXPORT_SYMBOL(rwsemtrace); -#endif -- cgit v1.2.2 From fb7e42413a098cc45b3adf858da290033af62bae Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 3 Jul 2006 00:24:31 -0700 Subject: [PATCH] lockdep: remove mutex deadlock checking code With the lock validator we detect mutex deadlocks (and more), the mutex deadlock checking code is both redundant and slower. So remove it. Signed-off-by: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/Kconfig.debug | 8 -------- 1 file changed, 8 deletions(-) (limited to 'lib') diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index e4fcbd12cf..7b3863d4f5 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -115,14 +115,6 @@ config DEBUG_PREEMPT if kernel code uses it in a preemption-unsafe way. Also, the kernel will detect preemption count underflows. -config DEBUG_MUTEXES - bool "Mutex debugging, deadlock detection" - default n - depends on DEBUG_KERNEL - help - This allows mutex semantics violations and mutex related deadlocks - (lockups) to be detected and reported automatically. - config DEBUG_RT_MUTEXES bool "RT Mutex debugging, deadlock detection" depends on DEBUG_KERNEL && RT_MUTEXES -- cgit v1.2.2 From 9a11b49a805665e13a56aa067afaf81d43ec1514 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 3 Jul 2006 00:24:33 -0700 Subject: [PATCH] lockdep: better lock debugging Generic lock debugging: - generalized lock debugging framework. For example, a bug in one lock subsystem turns off debugging in all lock subsystems. - got rid of the caller address passing (__IP__/__IP_DECL__/etc.) from the mutex/rtmutex debugging code: it caused way too much prototype hackery, and lockdep will give the same information anyway. - ability to do silent tests - check lock freeing in vfree too. - more finegrained debugging options, to allow distributions to turn off more expensive debugging features. There's no separate 'held mutexes' list anymore - but there's a 'held locks' stack within lockdep, which unifies deadlock detection across all lock classes. (this is independent of the lockdep validation stuff - lockdep first checks whether we are holding a lock already) Here are the current debugging options: CONFIG_DEBUG_MUTEXES=y CONFIG_DEBUG_LOCK_ALLOC=y which do: config DEBUG_MUTEXES bool "Mutex debugging, basic checks" config DEBUG_LOCK_ALLOC bool "Detect incorrect freeing of live mutexes" Signed-off-by: Ingo Molnar Signed-off-by: Arjan van de Ven Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/Makefile | 2 +- lib/debug_locks.c | 45 ++++++++++++++++++++++++++++++++++++++ lib/spinlock_debug.c | 62 ++++++++++++++++++++++------------------------------ 3 files changed, 72 insertions(+), 37 deletions(-) create mode 100644 lib/debug_locks.c (limited to 'lib') diff --git a/lib/Makefile b/lib/Makefile index 10c13c9d78..4f5d01922f 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -11,7 +11,7 @@ lib-$(CONFIG_SMP) += cpumask.o lib-y += kobject.o kref.o kobject_uevent.o klist.o -obj-y += sort.o parser.o halfmd4.o iomap_copy.o +obj-y += sort.o parser.o halfmd4.o iomap_copy.o debug_locks.o ifeq ($(CONFIG_DEBUG_KOBJECT),y) CFLAGS_kobject.o += -DDEBUG diff --git a/lib/debug_locks.c b/lib/debug_locks.c new file mode 100644 index 0000000000..0ef01d1472 --- /dev/null +++ b/lib/debug_locks.c @@ -0,0 +1,45 @@ +/* + * lib/debug_locks.c + * + * Generic place for common debugging facilities for various locks: + * spinlocks, rwlocks, mutexes and rwsems. + * + * Started by Ingo Molnar: + * + * Copyright (C) 2006 Red Hat, Inc., Ingo Molnar + */ +#include +#include +#include +#include +#include + +/* + * We want to turn all lock-debugging facilities on/off at once, + * via a global flag. The reason is that once a single bug has been + * detected and reported, there might be cascade of followup bugs + * that would just muddy the log. So we report the first one and + * shut up after that. + */ +int debug_locks = 1; + +/* + * The locking-testsuite uses to get a + * 'silent failure': nothing is printed to the console when + * a locking bug is detected. + */ +int debug_locks_silent; + +/* + * Generic 'turn off all lock debugging' function: + */ +int debug_locks_off(void) +{ + if (xchg(&debug_locks, 0)) { + if (!debug_locks_silent) { + console_verbose(); + return 1; + } + } + return 0; +} diff --git a/lib/spinlock_debug.c b/lib/spinlock_debug.c index 93c15ee3f8..3de2ccf48a 100644 --- a/lib/spinlock_debug.c +++ b/lib/spinlock_debug.c @@ -8,38 +8,35 @@ #include #include +#include #include +#include static void spin_bug(spinlock_t *lock, const char *msg) { - static long print_once = 1; struct task_struct *owner = NULL; - if (xchg(&print_once, 0)) { - if (lock->owner && lock->owner != SPINLOCK_OWNER_INIT) - owner = lock->owner; - printk(KERN_EMERG "BUG: spinlock %s on CPU#%d, %s/%d\n", - msg, raw_smp_processor_id(), - current->comm, current->pid); - printk(KERN_EMERG " lock: %p, .magic: %08x, .owner: %s/%d, " - ".owner_cpu: %d\n", - lock, lock->magic, - owner ? owner->comm : "", - owner ? owner->pid : -1, - lock->owner_cpu); - dump_stack(); -#ifdef CONFIG_SMP - /* - * We cannot continue on SMP: - */ -// panic("bad locking"); -#endif - } + if (!debug_locks_off()) + return; + + if (lock->owner && lock->owner != SPINLOCK_OWNER_INIT) + owner = lock->owner; + printk(KERN_EMERG "BUG: spinlock %s on CPU#%d, %s/%d\n", + msg, raw_smp_processor_id(), + current->comm, current->pid); + printk(KERN_EMERG " lock: %p, .magic: %08x, .owner: %s/%d, " + ".owner_cpu: %d\n", + lock, lock->magic, + owner ? owner->comm : "", + owner ? owner->pid : -1, + lock->owner_cpu); + dump_stack(); } #define SPIN_BUG_ON(cond, lock, msg) if (unlikely(cond)) spin_bug(lock, msg) -static inline void debug_spin_lock_before(spinlock_t *lock) +static inline void +debug_spin_lock_before(spinlock_t *lock) { SPIN_BUG_ON(lock->magic != SPINLOCK_MAGIC, lock, "bad magic"); SPIN_BUG_ON(lock->owner == current, lock, "recursion"); @@ -118,20 +115,13 @@ void _raw_spin_unlock(spinlock_t *lock) static void rwlock_bug(rwlock_t *lock, const char *msg) { - static long print_once = 1; - - if (xchg(&print_once, 0)) { - printk(KERN_EMERG "BUG: rwlock %s on CPU#%d, %s/%d, %p\n", - msg, raw_smp_processor_id(), current->comm, - current->pid, lock); - dump_stack(); -#ifdef CONFIG_SMP - /* - * We cannot continue on SMP: - */ - panic("bad locking"); -#endif - } + if (!debug_locks_off()) + return; + + printk(KERN_EMERG "BUG: rwlock %s on CPU#%d, %s/%d, %p\n", + msg, raw_smp_processor_id(), current->comm, + current->pid, lock); + dump_stack(); } #define RWLOCK_BUG_ON(cond, lock, msg) if (unlikely(cond)) rwlock_bug(lock, msg) -- cgit v1.2.2 From 8637c09901049f061b94f684915d4f18ecf91d79 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 3 Jul 2006 00:24:38 -0700 Subject: [PATCH] lockdep: stacktrace subsystem, core Framework to generate and save stacktraces quickly, without printing anything to the console. Signed-off-by: Ingo Molnar Signed-off-by: Arjan van de Ven Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/Kconfig.debug | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'lib') diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 7b3863d4f5..04e374c6fd 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -107,7 +107,7 @@ config DEBUG_SLAB_LEAK config DEBUG_PREEMPT bool "Debug preemptible kernel" - depends on DEBUG_KERNEL && PREEMPT + depends on DEBUG_KERNEL && PREEMPT && TRACE_IRQFLAGS_SUPPORT default y help If you say Y here then the kernel will use a debug variant of the @@ -149,6 +149,10 @@ config DEBUG_SPINLOCK_SLEEP If you say Y here, various routines which may sleep will become very noisy if they are called with a spinlock held. +config STACKTRACE + bool + depends on STACKTRACE_SUPPORT + config DEBUG_KOBJECT bool "kobject debugging" depends on DEBUG_KERNEL -- cgit v1.2.2 From cbbd1fa72d22896332301ca7e6b7164284be105c Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Mon, 3 Jul 2006 00:24:38 -0700 Subject: [PATCH] lockdep: s390 CONFIG_FRAME_POINTER support CONFIG_FRAME_POINTER support for s390. Signed-off-by: Heiko Carstens Acked-by: Ingo Molnar Cc: Martin Schwidefsky Cc: Arjan van de Ven Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/Kconfig.debug | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'lib') diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 04e374c6fd..91e338a3d0 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -208,7 +208,7 @@ config DEBUG_VM config FRAME_POINTER bool "Compile the kernel with frame pointers" - depends on DEBUG_KERNEL && (X86 || CRIS || M68K || M68KNOMMU || FRV || UML) + depends on DEBUG_KERNEL && (X86 || CRIS || M68K || M68KNOMMU || FRV || UML || S390) default y if DEBUG_INFO && UML help If you say Y here the resulting kernel image will be slightly larger -- cgit v1.2.2 From cae2ed9aa573415c6e5de9a09b7ff0d74af793bc Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 3 Jul 2006 00:24:48 -0700 Subject: [PATCH] lockdep: locking API self tests Introduce DEBUG_LOCKING_API_SELFTESTS, which uses the generic lock debugging code's silent-failure feature to run a matrix of testcases. There are 210 testcases currently: +----------------------- | Locking API testsuite: +------------------------------+------+------+------+------+------+------+ | spin |wlock |rlock |mutex | wsem | rsem | -------------------------------+------+------+------+------+------+------+ A-A deadlock: ok | ok | ok | ok | ok | ok | A-B-B-A deadlock: ok | ok | ok | ok | ok | ok | A-B-B-C-C-A deadlock: ok | ok | ok | ok | ok | ok | A-B-C-A-B-C deadlock: ok | ok | ok | ok | ok | ok | A-B-B-C-C-D-D-A deadlock: ok | ok | ok | ok | ok | ok | A-B-C-D-B-D-D-A deadlock: ok | ok | ok | ok | ok | ok | A-B-C-D-B-C-D-A deadlock: ok | ok | ok | ok | ok | ok | double unlock: ok | ok | ok | ok | ok | ok | bad unlock order: ok | ok | ok | ok | ok | ok | --------------------------------------+------+------+------+------+------+ recursive read-lock: | ok | | ok | --------------------------------------+------+------+------+------+------+ non-nested unlock: ok | ok | ok | ok | --------------------------------------+------+------+------+ hard-irqs-on + irq-safe-A/12: ok | ok | ok | soft-irqs-on + irq-safe-A/12: ok | ok | ok | hard-irqs-on + irq-safe-A/21: ok | ok | ok | soft-irqs-on + irq-safe-A/21: ok | ok | ok | sirq-safe-A => hirqs-on/12: ok | ok | ok | sirq-safe-A => hirqs-on/21: ok | ok | ok | hard-safe-A + irqs-on/12: ok | ok | ok | soft-safe-A + irqs-on/12: ok | ok | ok | hard-safe-A + irqs-on/21: ok | ok | ok | soft-safe-A + irqs-on/21: ok | ok | ok | hard-safe-A + unsafe-B #1/123: ok | ok | ok | soft-safe-A + unsafe-B #1/123: ok | ok | ok | hard-safe-A + unsafe-B #1/132: ok | ok | ok | soft-safe-A + unsafe-B #1/132: ok | ok | ok | hard-safe-A + unsafe-B #1/213: ok | ok | ok | soft-safe-A + unsafe-B #1/213: ok | ok | ok | hard-safe-A + unsafe-B #1/231: ok | ok | ok | soft-safe-A + unsafe-B #1/231: ok | ok | ok | hard-safe-A + unsafe-B #1/312: ok | ok | ok | soft-safe-A + unsafe-B #1/312: ok | ok | ok | hard-safe-A + unsafe-B #1/321: ok | ok | ok | soft-safe-A + unsafe-B #1/321: ok | ok | ok | hard-safe-A + unsafe-B #2/123: ok | ok | ok | soft-safe-A + unsafe-B #2/123: ok | ok | ok | hard-safe-A + unsafe-B #2/132: ok | ok | ok | soft-safe-A + unsafe-B #2/132: ok | ok | ok | hard-safe-A + unsafe-B #2/213: ok | ok | ok | soft-safe-A + unsafe-B #2/213: ok | ok | ok | hard-safe-A + unsafe-B #2/231: ok | ok | ok | soft-safe-A + unsafe-B #2/231: ok | ok | ok | hard-safe-A + unsafe-B #2/312: ok | ok | ok | soft-safe-A + unsafe-B #2/312: ok | ok | ok | hard-safe-A + unsafe-B #2/321: ok | ok | ok | soft-safe-A + unsafe-B #2/321: ok | ok | ok | hard-irq lock-inversion/123: ok | ok | ok | soft-irq lock-inversion/123: ok | ok | ok | hard-irq lock-inversion/132: ok | ok | ok | soft-irq lock-inversion/132: ok | ok | ok | hard-irq lock-inversion/213: ok | ok | ok | soft-irq lock-inversion/213: ok | ok | ok | hard-irq lock-inversion/231: ok | ok | ok | soft-irq lock-inversion/231: ok | ok | ok | hard-irq lock-inversion/312: ok | ok | ok | soft-irq lock-inversion/312: ok | ok | ok | hard-irq lock-inversion/321: ok | ok | ok | soft-irq lock-inversion/321: ok | ok | ok | hard-irq read-recursion/123: ok | soft-irq read-recursion/123: ok | hard-irq read-recursion/132: ok | soft-irq read-recursion/132: ok | hard-irq read-recursion/213: ok | soft-irq read-recursion/213: ok | hard-irq read-recursion/231: ok | soft-irq read-recursion/231: ok | hard-irq read-recursion/312: ok | soft-irq read-recursion/312: ok | hard-irq read-recursion/321: ok | soft-irq read-recursion/321: ok | --------------------------------+-----+---------------- Good, all 210 testcases passed! | --------------------------------+ Signed-off-by: Ingo Molnar Signed-off-by: Arjan van de Ven Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/Kconfig.debug | 11 + lib/Makefile | 1 + lib/locking-selftest-hardirq.h | 9 + lib/locking-selftest-mutex.h | 11 + lib/locking-selftest-rlock-hardirq.h | 2 + lib/locking-selftest-rlock-softirq.h | 2 + lib/locking-selftest-rlock.h | 14 + lib/locking-selftest-rsem.h | 14 + lib/locking-selftest-softirq.h | 9 + lib/locking-selftest-spin-hardirq.h | 2 + lib/locking-selftest-spin-softirq.h | 2 + lib/locking-selftest-spin.h | 11 + lib/locking-selftest-wlock-hardirq.h | 2 + lib/locking-selftest-wlock-softirq.h | 2 + lib/locking-selftest-wlock.h | 14 + lib/locking-selftest-wsem.h | 14 + lib/locking-selftest.c | 1218 ++++++++++++++++++++++++++++++++++ 17 files changed, 1338 insertions(+) create mode 100644 lib/locking-selftest-hardirq.h create mode 100644 lib/locking-selftest-mutex.h create mode 100644 lib/locking-selftest-rlock-hardirq.h create mode 100644 lib/locking-selftest-rlock-softirq.h create mode 100644 lib/locking-selftest-rlock.h create mode 100644 lib/locking-selftest-rsem.h create mode 100644 lib/locking-selftest-softirq.h create mode 100644 lib/locking-selftest-spin-hardirq.h create mode 100644 lib/locking-selftest-spin-softirq.h create mode 100644 lib/locking-selftest-spin.h create mode 100644 lib/locking-selftest-wlock-hardirq.h create mode 100644 lib/locking-selftest-wlock-softirq.h create mode 100644 lib/locking-selftest-wlock.h create mode 100644 lib/locking-selftest-wsem.h create mode 100644 lib/locking-selftest.c (limited to 'lib') diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 91e338a3d0..16021b09c1 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -149,6 +149,17 @@ config DEBUG_SPINLOCK_SLEEP If you say Y here, various routines which may sleep will become very noisy if they are called with a spinlock held. +config DEBUG_LOCKING_API_SELFTESTS + bool "Locking API boot-time self-tests" + depends on DEBUG_KERNEL + help + Say Y here if you want the kernel to run a short self-test during + bootup. The self-test checks whether common types of locking bugs + are detected by debugging mechanisms or not. (if you disable + lock debugging then those bugs wont be detected of course.) + The following locking APIs are covered: spinlocks, rwlocks, + mutexes and rwsems. + config STACKTRACE bool depends on STACKTRACE_SUPPORT diff --git a/lib/Makefile b/lib/Makefile index 4f5d01922f..be9719ae82 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -18,6 +18,7 @@ CFLAGS_kobject.o += -DDEBUG CFLAGS_kobject_uevent.o += -DDEBUG endif +obj-$(CONFIG_DEBUG_LOCKING_API_SELFTESTS) += locking-selftest.o obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock_debug.o lib-$(CONFIG_RWSEM_GENERIC_SPINLOCK) += rwsem-spinlock.o lib-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += rwsem.o diff --git a/lib/locking-selftest-hardirq.h b/lib/locking-selftest-hardirq.h new file mode 100644 index 0000000000..10d4a150b2 --- /dev/null +++ b/lib/locking-selftest-hardirq.h @@ -0,0 +1,9 @@ +#undef IRQ_DISABLE +#undef IRQ_ENABLE +#undef IRQ_ENTER +#undef IRQ_EXIT + +#define IRQ_ENABLE HARDIRQ_ENABLE +#define IRQ_DISABLE HARDIRQ_DISABLE +#define IRQ_ENTER HARDIRQ_ENTER +#define IRQ_EXIT HARDIRQ_EXIT diff --git a/lib/locking-selftest-mutex.h b/lib/locking-selftest-mutex.h new file mode 100644 index 0000000000..68601b6f58 --- /dev/null +++ b/lib/locking-selftest-mutex.h @@ -0,0 +1,11 @@ +#undef LOCK +#define LOCK ML + +#undef UNLOCK +#define UNLOCK MU + +#undef RLOCK +#undef WLOCK + +#undef INIT +#define INIT MI diff --git a/lib/locking-selftest-rlock-hardirq.h b/lib/locking-selftest-rlock-hardirq.h new file mode 100644 index 0000000000..9f517ebcb7 --- /dev/null +++ b/lib/locking-selftest-rlock-hardirq.h @@ -0,0 +1,2 @@ +#include "locking-selftest-rlock.h" +#include "locking-selftest-hardirq.h" diff --git a/lib/locking-selftest-rlock-softirq.h b/lib/locking-selftest-rlock-softirq.h new file mode 100644 index 0000000000..981455db7f --- /dev/null +++ b/lib/locking-selftest-rlock-softirq.h @@ -0,0 +1,2 @@ +#include "locking-selftest-rlock.h" +#include "locking-selftest-softirq.h" diff --git a/lib/locking-selftest-rlock.h b/lib/locking-selftest-rlock.h new file mode 100644 index 0000000000..6789044f4d --- /dev/null +++ b/lib/locking-selftest-rlock.h @@ -0,0 +1,14 @@ +#undef LOCK +#define LOCK RL + +#undef UNLOCK +#define UNLOCK RU + +#undef RLOCK +#define RLOCK RL + +#undef WLOCK +#define WLOCK WL + +#undef INIT +#define INIT RWI diff --git a/lib/locking-selftest-rsem.h b/lib/locking-selftest-rsem.h new file mode 100644 index 0000000000..62da886680 --- /dev/null +++ b/lib/locking-selftest-rsem.h @@ -0,0 +1,14 @@ +#undef LOCK +#define LOCK RSL + +#undef UNLOCK +#define UNLOCK RSU + +#undef RLOCK +#define RLOCK RSL + +#undef WLOCK +#define WLOCK WSL + +#undef INIT +#define INIT RWSI diff --git a/lib/locking-selftest-softirq.h b/lib/locking-selftest-softirq.h new file mode 100644 index 0000000000..a83de2a04a --- /dev/null +++ b/lib/locking-selftest-softirq.h @@ -0,0 +1,9 @@ +#undef IRQ_DISABLE +#undef IRQ_ENABLE +#undef IRQ_ENTER +#undef IRQ_EXIT + +#define IRQ_DISABLE SOFTIRQ_DISABLE +#define IRQ_ENABLE SOFTIRQ_ENABLE +#define IRQ_ENTER SOFTIRQ_ENTER +#define IRQ_EXIT SOFTIRQ_EXIT diff --git a/lib/locking-selftest-spin-hardirq.h b/lib/locking-selftest-spin-hardirq.h new file mode 100644 index 0000000000..693198dce3 --- /dev/null +++ b/lib/locking-selftest-spin-hardirq.h @@ -0,0 +1,2 @@ +#include "locking-selftest-spin.h" +#include "locking-selftest-hardirq.h" diff --git a/lib/locking-selftest-spin-softirq.h b/lib/locking-selftest-spin-softirq.h new file mode 100644 index 0000000000..c472e2a87f --- /dev/null +++ b/lib/locking-selftest-spin-softirq.h @@ -0,0 +1,2 @@ +#include "locking-selftest-spin.h" +#include "locking-selftest-softirq.h" diff --git a/lib/locking-selftest-spin.h b/lib/locking-selftest-spin.h new file mode 100644 index 0000000000..ccd1b4b097 --- /dev/null +++ b/lib/locking-selftest-spin.h @@ -0,0 +1,11 @@ +#undef LOCK +#define LOCK L + +#undef UNLOCK +#define UNLOCK U + +#undef RLOCK +#undef WLOCK + +#undef INIT +#define INIT SI diff --git a/lib/locking-selftest-wlock-hardirq.h b/lib/locking-selftest-wlock-hardirq.h new file mode 100644 index 0000000000..2dd2e5122c --- /dev/null +++ b/lib/locking-selftest-wlock-hardirq.h @@ -0,0 +1,2 @@ +#include "locking-selftest-wlock.h" +#include "locking-selftest-hardirq.h" diff --git a/lib/locking-selftest-wlock-softirq.h b/lib/locking-selftest-wlock-softirq.h new file mode 100644 index 0000000000..cb80d1cb94 --- /dev/null +++ b/lib/locking-selftest-wlock-softirq.h @@ -0,0 +1,2 @@ +#include "locking-selftest-wlock.h" +#include "locking-selftest-softirq.h" diff --git a/lib/locking-selftest-wlock.h b/lib/locking-selftest-wlock.h new file mode 100644 index 0000000000..0815322d99 --- /dev/null +++ b/lib/locking-selftest-wlock.h @@ -0,0 +1,14 @@ +#undef LOCK +#define LOCK WL + +#undef UNLOCK +#define UNLOCK WU + +#undef RLOCK +#define RLOCK RL + +#undef WLOCK +#define WLOCK WL + +#undef INIT +#define INIT RWI diff --git a/lib/locking-selftest-wsem.h b/lib/locking-selftest-wsem.h new file mode 100644 index 0000000000..b88c5f2dc5 --- /dev/null +++ b/lib/locking-selftest-wsem.h @@ -0,0 +1,14 @@ +#undef LOCK +#define LOCK WSL + +#undef UNLOCK +#define UNLOCK WSU + +#undef RLOCK +#define RLOCK RSL + +#undef WLOCK +#define WLOCK WSL + +#undef INIT +#define INIT RWSI diff --git a/lib/locking-selftest.c b/lib/locking-selftest.c new file mode 100644 index 0000000000..5cd05f20bd --- /dev/null +++ b/lib/locking-selftest.c @@ -0,0 +1,1218 @@ +/* + * lib/locking-selftest.c + * + * Testsuite for various locking APIs: spinlocks, rwlocks, + * mutexes and rw-semaphores. + * + * It is checking both false positives and false negatives. + * + * Started by Ingo Molnar: + * + * Copyright (C) 2006 Red Hat, Inc., Ingo Molnar + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* + * Change this to 1 if you want to see the failure printouts: + */ +static unsigned int debug_locks_verbose; + +static int __init setup_debug_locks_verbose(char *str) +{ + get_option(&str, &debug_locks_verbose); + + return 1; +} + +__setup("debug_locks_verbose=", setup_debug_locks_verbose); + +#define FAILURE 0 +#define SUCCESS 1 + +#define LOCKTYPE_SPIN 0x1 +#define LOCKTYPE_RWLOCK 0x2 +#define LOCKTYPE_MUTEX 0x4 +#define LOCKTYPE_RWSEM 0x8 + +/* + * Normal standalone locks, for the circular and irq-context + * dependency tests: + */ +static DEFINE_SPINLOCK(lock_A); +static DEFINE_SPINLOCK(lock_B); +static DEFINE_SPINLOCK(lock_C); +static DEFINE_SPINLOCK(lock_D); + +static DEFINE_RWLOCK(rwlock_A); +static DEFINE_RWLOCK(rwlock_B); +static DEFINE_RWLOCK(rwlock_C); +static DEFINE_RWLOCK(rwlock_D); + +static DEFINE_MUTEX(mutex_A); +static DEFINE_MUTEX(mutex_B); +static DEFINE_MUTEX(mutex_C); +static DEFINE_MUTEX(mutex_D); + +static DECLARE_RWSEM(rwsem_A); +static DECLARE_RWSEM(rwsem_B); +static DECLARE_RWSEM(rwsem_C); +static DECLARE_RWSEM(rwsem_D); + +/* + * Locks that we initialize dynamically as well so that + * e.g. X1 and X2 becomes two instances of the same class, + * but X* and Y* are different classes. We do this so that + * we do not trigger a real lockup: + */ +static DEFINE_SPINLOCK(lock_X1); +static DEFINE_SPINLOCK(lock_X2); +static DEFINE_SPINLOCK(lock_Y1); +static DEFINE_SPINLOCK(lock_Y2); +static DEFINE_SPINLOCK(lock_Z1); +static DEFINE_SPINLOCK(lock_Z2); + +static DEFINE_RWLOCK(rwlock_X1); +static DEFINE_RWLOCK(rwlock_X2); +static DEFINE_RWLOCK(rwlock_Y1); +static DEFINE_RWLOCK(rwlock_Y2); +static DEFINE_RWLOCK(rwlock_Z1); +static DEFINE_RWLOCK(rwlock_Z2); + +static DEFINE_MUTEX(mutex_X1); +static DEFINE_MUTEX(mutex_X2); +static DEFINE_MUTEX(mutex_Y1); +static DEFINE_MUTEX(mutex_Y2); +static DEFINE_MUTEX(mutex_Z1); +static DEFINE_MUTEX(mutex_Z2); + +static DECLARE_RWSEM(rwsem_X1); +static DECLARE_RWSEM(rwsem_X2); +static DECLARE_RWSEM(rwsem_Y1); +static DECLARE_RWSEM(rwsem_Y2); +static DECLARE_RWSEM(rwsem_Z1); +static DECLARE_RWSEM(rwsem_Z2); + +/* + * non-inlined runtime initializers, to let separate locks share + * the same lock-class: + */ +#define INIT_CLASS_FUNC(class) \ +static noinline void \ +init_class_##class(spinlock_t *lock, rwlock_t *rwlock, struct mutex *mutex, \ + struct rw_semaphore *rwsem) \ +{ \ + spin_lock_init(lock); \ + rwlock_init(rwlock); \ + mutex_init(mutex); \ + init_rwsem(rwsem); \ +} + +INIT_CLASS_FUNC(X) +INIT_CLASS_FUNC(Y) +INIT_CLASS_FUNC(Z) + +static void init_shared_classes(void) +{ + init_class_X(&lock_X1, &rwlock_X1, &mutex_X1, &rwsem_X1); + init_class_X(&lock_X2, &rwlock_X2, &mutex_X2, &rwsem_X2); + + init_class_Y(&lock_Y1, &rwlock_Y1, &mutex_Y1, &rwsem_Y1); + init_class_Y(&lock_Y2, &rwlock_Y2, &mutex_Y2, &rwsem_Y2); + + init_class_Z(&lock_Z1, &rwlock_Z1, &mutex_Z1, &rwsem_Z1); + init_class_Z(&lock_Z2, &rwlock_Z2, &mutex_Z2, &rwsem_Z2); +} + +/* + * For spinlocks and rwlocks we also do hardirq-safe / softirq-safe tests. + * The following functions use a lock from a simulated hardirq/softirq + * context, causing the locks to be marked as hardirq-safe/softirq-safe: + */ + +#define HARDIRQ_DISABLE local_irq_disable +#define HARDIRQ_ENABLE local_irq_enable + +#define HARDIRQ_ENTER() \ + local_irq_disable(); \ + irq_enter(); \ + WARN_ON(!in_irq()); + +#define HARDIRQ_EXIT() \ + __irq_exit(); \ + local_irq_enable(); + +#define SOFTIRQ_DISABLE local_bh_disable +#define SOFTIRQ_ENABLE local_bh_enable + +#define SOFTIRQ_ENTER() \ + local_bh_disable(); \ + local_irq_disable(); \ + trace_softirq_enter(); \ + WARN_ON(!in_softirq()); + +#define SOFTIRQ_EXIT() \ + trace_softirq_exit(); \ + local_irq_enable(); \ + local_bh_enable(); + +/* + * Shortcuts for lock/unlock API variants, to keep + * the testcases compact: + */ +#define L(x) spin_lock(&lock_##x) +#define U(x) spin_unlock(&lock_##x) +#define LU(x) L(x); U(x) +#define SI(x) spin_lock_init(&lock_##x) + +#define WL(x) write_lock(&rwlock_##x) +#define WU(x) write_unlock(&rwlock_##x) +#define WLU(x) WL(x); WU(x) + +#define RL(x) read_lock(&rwlock_##x) +#define RU(x) read_unlock(&rwlock_##x) +#define RLU(x) RL(x); RU(x) +#define RWI(x) rwlock_init(&rwlock_##x) + +#define ML(x) mutex_lock(&mutex_##x) +#define MU(x) mutex_unlock(&mutex_##x) +#define MI(x) mutex_init(&mutex_##x) + +#define WSL(x) down_write(&rwsem_##x) +#define WSU(x) up_write(&rwsem_##x) + +#define RSL(x) down_read(&rwsem_##x) +#define RSU(x) up_read(&rwsem_##x) +#define RWSI(x) init_rwsem(&rwsem_##x) + +#define LOCK_UNLOCK_2(x,y) LOCK(x); LOCK(y); UNLOCK(y); UNLOCK(x) + +/* + * Generate different permutations of the same testcase, using + * the same basic lock-dependency/state events: + */ + +#define GENERATE_TESTCASE(name) \ + \ +static void name(void) { E(); } + +#define GENERATE_PERMUTATIONS_2_EVENTS(name) \ + \ +static void name##_12(void) { E1(); E2(); } \ +static void name##_21(void) { E2(); E1(); } + +#define GENERATE_PERMUTATIONS_3_EVENTS(name) \ + \ +static void name##_123(void) { E1(); E2(); E3(); } \ +static void name##_132(void) { E1(); E3(); E2(); } \ +static void name##_213(void) { E2(); E1(); E3(); } \ +static void name##_231(void) { E2(); E3(); E1(); } \ +static void name##_312(void) { E3(); E1(); E2(); } \ +static void name##_321(void) { E3(); E2(); E1(); } + +/* + * AA deadlock: + */ + +#define E() \ + \ + LOCK(X1); \ + LOCK(X2); /* this one should fail */ + +/* + * 6 testcases: + */ +#include "locking-selftest-spin.h" +GENERATE_TESTCASE(AA_spin) +#include "locking-selftest-wlock.h" +GENERATE_TESTCASE(AA_wlock) +#include "locking-selftest-rlock.h" +GENERATE_TESTCASE(AA_rlock) +#include "locking-selftest-mutex.h" +GENERATE_TESTCASE(AA_mutex) +#include "locking-selftest-wsem.h" +GENERATE_TESTCASE(AA_wsem) +#include "locking-selftest-rsem.h" +GENERATE_TESTCASE(AA_rsem) + +#undef E + +/* + * Special-case for read-locking, they are + * allowed to recurse on the same lock instance: + */ +static void rlock_AA1(void) +{ + RL(X1); + RL(X1); // this one should NOT fail +} + +static void rlock_AA1B(void) +{ + RL(X1); + RL(X2); // this one should fail +} + +static void rsem_AA1(void) +{ + RSL(X1); + RSL(X1); // this one should fail +} + +static void rsem_AA1B(void) +{ + RSL(X1); + RSL(X2); // this one should fail +} +/* + * The mixing of read and write locks is not allowed: + */ +static void rlock_AA2(void) +{ + RL(X1); + WL(X2); // this one should fail +} + +static void rsem_AA2(void) +{ + RSL(X1); + WSL(X2); // this one should fail +} + +static void rlock_AA3(void) +{ + WL(X1); + RL(X2); // this one should fail +} + +static void rsem_AA3(void) +{ + WSL(X1); + RSL(X2); // this one should fail +} + +/* + * ABBA deadlock: + */ + +#define E() \ + \ + LOCK_UNLOCK_2(A, B); \ + LOCK_UNLOCK_2(B, A); /* fail */ + +/* + * 6 testcases: + */ +#include "locking-selftest-spin.h" +GENERATE_TESTCASE(ABBA_spin) +#include "locking-selftest-wlock.h" +GENERATE_TESTCASE(ABBA_wlock) +#include "locking-selftest-rlock.h" +GENERATE_TESTCASE(ABBA_rlock) +#include "locking-selftest-mutex.h" +GENERATE_TESTCASE(ABBA_mutex) +#include "locking-selftest-wsem.h" +GENERATE_TESTCASE(ABBA_wsem) +#include "locking-selftest-rsem.h" +GENERATE_TESTCASE(ABBA_rsem) + +#undef E + +/* + * AB BC CA deadlock: + */ + +#define E() \ + \ + LOCK_UNLOCK_2(A, B); \ + LOCK_UNLOCK_2(B, C); \ + LOCK_UNLOCK_2(C, A); /* fail */ + +/* + * 6 testcases: + */ +#include "locking-selftest-spin.h" +GENERATE_TESTCASE(ABBCCA_spin) +#include "locking-selftest-wlock.h" +GENERATE_TESTCASE(ABBCCA_wlock) +#include "locking-selftest-rlock.h" +GENERATE_TESTCASE(ABBCCA_rlock) +#include "locking-selftest-mutex.h" +GENERATE_TESTCASE(ABBCCA_mutex) +#include "locking-selftest-wsem.h" +GENERATE_TESTCASE(ABBCCA_wsem) +#include "locking-selftest-rsem.h" +GENERATE_TESTCASE(ABBCCA_rsem) + +#undef E + +/* + * AB CA BC deadlock: + */ + +#define E() \ + \ + LOCK_UNLOCK_2(A, B); \ + LOCK_UNLOCK_2(C, A); \ + LOCK_UNLOCK_2(B, C); /* fail */ + +/* + * 6 testcases: + */ +#include "locking-selftest-spin.h" +GENERATE_TESTCASE(ABCABC_spin) +#include "locking-selftest-wlock.h" +GENERATE_TESTCASE(ABCABC_wlock) +#include "locking-selftest-rlock.h" +GENERATE_TESTCASE(ABCABC_rlock) +#include "locking-selftest-mutex.h" +GENERATE_TESTCASE(ABCABC_mutex) +#include "locking-selftest-wsem.h" +GENERATE_TESTCASE(ABCABC_wsem) +#include "locking-selftest-rsem.h" +GENERATE_TESTCASE(ABCABC_rsem) + +#undef E + +/* + * AB BC CD DA deadlock: + */ + +#define E() \ + \ + LOCK_UNLOCK_2(A, B); \ + LOCK_UNLOCK_2(B, C); \ + LOCK_UNLOCK_2(C, D); \ + LOCK_UNLOCK_2(D, A); /* fail */ + +/* + * 6 testcases: + */ +#include "locking-selftest-spin.h" +GENERATE_TESTCASE(ABBCCDDA_spin) +#include "locking-selftest-wlock.h" +GENERATE_TESTCASE(ABBCCDDA_wlock) +#include "locking-selftest-rlock.h" +GENERATE_TESTCASE(ABBCCDDA_rlock) +#include "locking-selftest-mutex.h" +GENERATE_TESTCASE(ABBCCDDA_mutex) +#include "locking-selftest-wsem.h" +GENERATE_TESTCASE(ABBCCDDA_wsem) +#include "locking-selftest-rsem.h" +GENERATE_TESTCASE(ABBCCDDA_rsem) + +#undef E + +/* + * AB CD BD DA deadlock: + */ +#define E() \ + \ + LOCK_UNLOCK_2(A, B); \ + LOCK_UNLOCK_2(C, D); \ + LOCK_UNLOCK_2(B, D); \ + LOCK_UNLOCK_2(D, A); /* fail */ + +/* + * 6 testcases: + */ +#include "locking-selftest-spin.h" +GENERATE_TESTCASE(ABCDBDDA_spin) +#include "locking-selftest-wlock.h" +GENERATE_TESTCASE(ABCDBDDA_wlock) +#include "locking-selftest-rlock.h" +GENERATE_TESTCASE(ABCDBDDA_rlock) +#include "locking-selftest-mutex.h" +GENERATE_TESTCASE(ABCDBDDA_mutex) +#include "locking-selftest-wsem.h" +GENERATE_TESTCASE(ABCDBDDA_wsem) +#include "locking-selftest-rsem.h" +GENERATE_TESTCASE(ABCDBDDA_rsem) + +#undef E + +/* + * AB CD BC DA deadlock: + */ +#define E() \ + \ + LOCK_UNLOCK_2(A, B); \ + LOCK_UNLOCK_2(C, D); \ + LOCK_UNLOCK_2(B, C); \ + LOCK_UNLOCK_2(D, A); /* fail */ + +/* + * 6 testcases: + */ +#include "locking-selftest-spin.h" +GENERATE_TESTCASE(ABCDBCDA_spin) +#include "locking-selftest-wlock.h" +GENERATE_TESTCASE(ABCDBCDA_wlock) +#include "locking-selftest-rlock.h" +GENERATE_TESTCASE(ABCDBCDA_rlock) +#include "locking-selftest-mutex.h" +GENERATE_TESTCASE(ABCDBCDA_mutex) +#include "locking-selftest-wsem.h" +GENERATE_TESTCASE(ABCDBCDA_wsem) +#include "locking-selftest-rsem.h" +GENERATE_TESTCASE(ABCDBCDA_rsem) + +#undef E + +/* + * Double unlock: + */ +#define E() \ + \ + LOCK(A); \ + UNLOCK(A); \ + UNLOCK(A); /* fail */ + +/* + * 6 testcases: + */ +#include "locking-selftest-spin.h" +GENERATE_TESTCASE(double_unlock_spin) +#include "locking-selftest-wlock.h" +GENERATE_TESTCASE(double_unlock_wlock) +#include "locking-selftest-rlock.h" +GENERATE_TESTCASE(double_unlock_rlock) +#include "locking-selftest-mutex.h" +GENERATE_TESTCASE(double_unlock_mutex) +#include "locking-selftest-wsem.h" +GENERATE_TESTCASE(double_unlock_wsem) +#include "locking-selftest-rsem.h" +GENERATE_TESTCASE(double_unlock_rsem) + +#undef E + +/* + * Bad unlock ordering: + */ +#define E() \ + \ + LOCK(A); \ + LOCK(B); \ + UNLOCK(A); /* fail */ \ + UNLOCK(B); + +/* + * 6 testcases: + */ +#include "locking-selftest-spin.h" +GENERATE_TESTCASE(bad_unlock_order_spin) +#include "locking-selftest-wlock.h" +GENERATE_TESTCASE(bad_unlock_order_wlock) +#include "locking-selftest-rlock.h" +GENERATE_TESTCASE(bad_unlock_order_rlock) +#include "locking-selftest-mutex.h" +GENERATE_TESTCASE(bad_unlock_order_mutex) +#include "locking-selftest-wsem.h" +GENERATE_TESTCASE(bad_unlock_order_wsem) +#include "locking-selftest-rsem.h" +GENERATE_TESTCASE(bad_unlock_order_rsem) + +#undef E + +/* + * initializing a held lock: + */ +#define E() \ + \ + LOCK(A); \ + INIT(A); /* fail */ + +/* + * 6 testcases: + */ +#include "locking-selftest-spin.h" +GENERATE_TESTCASE(init_held_spin) +#include "locking-selftest-wlock.h" +GENERATE_TESTCASE(init_held_wlock) +#include "locking-selftest-rlock.h" +GENERATE_TESTCASE(init_held_rlock) +#include "locking-selftest-mutex.h" +GENERATE_TESTCASE(init_held_mutex) +#include "locking-selftest-wsem.h" +GENERATE_TESTCASE(init_held_wsem) +#include "locking-selftest-rsem.h" +GENERATE_TESTCASE(init_held_rsem) + +#undef E + +/* + * locking an irq-safe lock with irqs enabled: + */ +#define E1() \ + \ + IRQ_ENTER(); \ + LOCK(A); \ + UNLOCK(A); \ + IRQ_EXIT(); + +#define E2() \ + \ + LOCK(A); \ + UNLOCK(A); + +/* + * Generate 24 testcases: + */ +#include "locking-selftest-spin-hardirq.h" +GENERATE_PERMUTATIONS_2_EVENTS(irqsafe1_hard_spin) + +#include "locking-selftest-rlock-hardirq.h" +GENERATE_PERMUTATIONS_2_EVENTS(irqsafe1_hard_rlock) + +#include "locking-selftest-wlock-hardirq.h" +GENERATE_PERMUTATIONS_2_EVENTS(irqsafe1_hard_wlock) + +#include "locking-selftest-spin-softirq.h" +GENERATE_PERMUTATIONS_2_EVENTS(irqsafe1_soft_spin) + +#include "locking-selftest-rlock-softirq.h" +GENERATE_PERMUTATIONS_2_EVENTS(irqsafe1_soft_rlock) + +#include "locking-selftest-wlock-softirq.h" +GENERATE_PERMUTATIONS_2_EVENTS(irqsafe1_soft_wlock) + +#undef E1 +#undef E2 + +/* + * Enabling hardirqs with a softirq-safe lock held: + */ +#define E1() \ + \ + SOFTIRQ_ENTER(); \ + LOCK(A); \ + UNLOCK(A); \ + SOFTIRQ_EXIT(); + +#define E2() \ + \ + HARDIRQ_DISABLE(); \ + LOCK(A); \ + HARDIRQ_ENABLE(); \ + UNLOCK(A); + +/* + * Generate 12 testcases: + */ +#include "locking-selftest-spin.h" +GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2A_spin) + +#include "locking-selftest-wlock.h" +GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2A_wlock) + +#include "locking-selftest-rlock.h" +GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2A_rlock) + +#undef E1 +#undef E2 + +/* + * Enabling irqs with an irq-safe lock held: + */ +#define E1() \ + \ + IRQ_ENTER(); \ + LOCK(A); \ + UNLOCK(A); \ + IRQ_EXIT(); + +#define E2() \ + \ + IRQ_DISABLE(); \ + LOCK(A); \ + IRQ_ENABLE(); \ + UNLOCK(A); + +/* + * Generate 24 testcases: + */ +#include "locking-selftest-spin-hardirq.h" +GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2B_hard_spin) + +#include "locking-selftest-rlock-hardirq.h" +GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2B_hard_rlock) + +#include "locking-selftest-wlock-hardirq.h" +GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2B_hard_wlock) + +#include "locking-selftest-spin-softirq.h" +GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2B_soft_spin) + +#include "locking-selftest-rlock-softirq.h" +GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2B_soft_rlock) + +#include "locking-selftest-wlock-softirq.h" +GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2B_soft_wlock) + +#undef E1 +#undef E2 + +/* + * Acquiring a irq-unsafe lock while holding an irq-safe-lock: + */ +#define E1() \ + \ + LOCK(A); \ + LOCK(B); \ + UNLOCK(B); \ + UNLOCK(A); \ + +#define E2() \ + \ + LOCK(B); \ + UNLOCK(B); + +#define E3() \ + \ + IRQ_ENTER(); \ + LOCK(A); \ + UNLOCK(A); \ + IRQ_EXIT(); + +/* + * Generate 36 testcases: + */ +#include "locking-selftest-spin-hardirq.h" +GENERATE_PERMUTATIONS_3_EVENTS(irqsafe3_hard_spin) + +#include "locking-selftest-rlock-hardirq.h" +GENERATE_PERMUTATIONS_3_EVENTS(irqsafe3_hard_rlock) + +#include "locking-selftest-wlock-hardirq.h" +GENERATE_PERMUTATIONS_3_EVENTS(irqsafe3_hard_wlock) + +#include "locking-selftest-spin-softirq.h" +GENERATE_PERMUTATIONS_3_EVENTS(irqsafe3_soft_spin) + +#include "locking-selftest-rlock-softirq.h" +GENERATE_PERMUTATIONS_3_EVENTS(irqsafe3_soft_rlock) + +#include "locking-selftest-wlock-softirq.h" +GENERATE_PERMUTATIONS_3_EVENTS(irqsafe3_soft_wlock) + +#undef E1 +#undef E2 +#undef E3 + +/* + * If a lock turns into softirq-safe, but earlier it took + * a softirq-unsafe lock: + */ + +#define E1() \ + IRQ_DISABLE(); \ + LOCK(A); \ + LOCK(B); \ + UNLOCK(B); \ + UNLOCK(A); \ + IRQ_ENABLE(); + +#define E2() \ + LOCK(B); \ + UNLOCK(B); + +#define E3() \ + IRQ_ENTER(); \ + LOCK(A); \ + UNLOCK(A); \ + IRQ_EXIT(); + +/* + * Generate 36 testcases: + */ +#include "locking-selftest-spin-hardirq.h" +GENERATE_PERMUTATIONS_3_EVENTS(irqsafe4_hard_spin) + +#include "locking-selftest-rlock-hardirq.h" +GENERATE_PERMUTATIONS_3_EVENTS(irqsafe4_hard_rlock) + +#include "locking-selftest-wlock-hardirq.h" +GENERATE_PERMUTATIONS_3_EVENTS(irqsafe4_hard_wlock) + +#include "locking-selftest-spin-softirq.h" +GENERATE_PERMUTATIONS_3_EVENTS(irqsafe4_soft_spin) + +#include "locking-selftest-rlock-softirq.h" +GENERATE_PERMUTATIONS_3_EVENTS(irqsafe4_soft_rlock) + +#include "locking-selftest-wlock-softirq.h" +GENERATE_PERMUTATIONS_3_EVENTS(irqsafe4_soft_wlock) + +#undef E1 +#undef E2 +#undef E3 + +/* + * read-lock / write-lock irq inversion. + * + * Deadlock scenario: + * + * CPU#1 is at #1, i.e. it has write-locked A, but has not + * taken B yet. + * + * CPU#2 is at #2, i.e. it has locked B. + * + * Hardirq hits CPU#2 at point #2 and is trying to read-lock A. + * + * The deadlock occurs because CPU#1 will spin on B, and CPU#2 + * will spin on A. + */ + +#define E1() \ + \ + IRQ_DISABLE(); \ + WL(A); \ + LOCK(B); \ + UNLOCK(B); \ + WU(A); \ + IRQ_ENABLE(); + +#define E2() \ + \ + LOCK(B); \ + UNLOCK(B); + +#define E3() \ + \ + IRQ_ENTER(); \ + RL(A); \ + RU(A); \ + IRQ_EXIT(); + +/* + * Generate 36 testcases: + */ +#include "locking-selftest-spin-hardirq.h" +GENERATE_PERMUTATIONS_3_EVENTS(irq_inversion_hard_spin) + +#include "locking-selftest-rlock-hardirq.h" +GENERATE_PERMUTATIONS_3_EVENTS(irq_inversion_hard_rlock) + +#include "locking-selftest-wlock-hardirq.h" +GENERATE_PERMUTATIONS_3_EVENTS(irq_inversion_hard_wlock) + +#include "locking-selftest-spin-softirq.h" +GENERATE_PERMUTATIONS_3_EVENTS(irq_inversion_soft_spin) + +#include "locking-selftest-rlock-softirq.h" +GENERATE_PERMUTATIONS_3_EVENTS(irq_inversion_soft_rlock) + +#include "locking-selftest-wlock-softirq.h" +GENERATE_PERMUTATIONS_3_EVENTS(irq_inversion_soft_wlock) + +#undef E1 +#undef E2 +#undef E3 + +/* + * read-lock / write-lock recursion that is actually safe. + */ + +#define E1() \ + \ + IRQ_DISABLE(); \ + WL(A); \ + WU(A); \ + IRQ_ENABLE(); + +#define E2() \ + \ + RL(A); \ + RU(A); \ + +#define E3() \ + \ + IRQ_ENTER(); \ + RL(A); \ + L(B); \ + U(B); \ + RU(A); \ + IRQ_EXIT(); + +/* + * Generate 12 testcases: + */ +#include "locking-selftest-hardirq.h" +GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion_hard) + +#include "locking-selftest-softirq.h" +GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion_soft) + +#undef E1 +#undef E2 +#undef E3 + +/* + * read-lock / write-lock recursion that is unsafe. + */ + +#define E1() \ + \ + IRQ_DISABLE(); \ + L(B); \ + WL(A); \ + WU(A); \ + U(B); \ + IRQ_ENABLE(); + +#define E2() \ + \ + RL(A); \ + RU(A); \ + +#define E3() \ + \ + IRQ_ENTER(); \ + L(B); \ + U(B); \ + IRQ_EXIT(); + +/* + * Generate 12 testcases: + */ +#include "locking-selftest-hardirq.h" +// GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion2_hard) + +#include "locking-selftest-softirq.h" +// GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion2_soft) + +#define lockdep_reset() +#define lockdep_reset_lock(x) + +#ifdef CONFIG_DEBUG_LOCK_ALLOC +# define I_SPINLOCK(x) lockdep_reset_lock(&lock_##x.dep_map) +# define I_RWLOCK(x) lockdep_reset_lock(&rwlock_##x.dep_map) +# define I_MUTEX(x) lockdep_reset_lock(&mutex_##x.dep_map) +# define I_RWSEM(x) lockdep_reset_lock(&rwsem_##x.dep_map) +#else +# define I_SPINLOCK(x) +# define I_RWLOCK(x) +# define I_MUTEX(x) +# define I_RWSEM(x) +#endif + +#define I1(x) \ + do { \ + I_SPINLOCK(x); \ + I_RWLOCK(x); \ + I_MUTEX(x); \ + I_RWSEM(x); \ + } while (0) + +#define I2(x) \ + do { \ + spin_lock_init(&lock_##x); \ + rwlock_init(&rwlock_##x); \ + mutex_init(&mutex_##x); \ + init_rwsem(&rwsem_##x); \ + } while (0) + +static void reset_locks(void) +{ + local_irq_disable(); + I1(A); I1(B); I1(C); I1(D); + I1(X1); I1(X2); I1(Y1); I1(Y2); I1(Z1); I1(Z2); + lockdep_reset(); + I2(A); I2(B); I2(C); I2(D); + init_shared_classes(); + local_irq_enable(); +} + +#undef I + +static int testcase_total; +static int testcase_successes; +static int expected_testcase_failures; +static int unexpected_testcase_failures; + +static void dotest(void (*testcase_fn)(void), int expected, int lockclass_mask) +{ + unsigned long saved_preempt_count = preempt_count(); + int expected_failure = 0; + + WARN_ON(irqs_disabled()); + + testcase_fn(); + /* + * Filter out expected failures: + */ +#ifndef CONFIG_PROVE_LOCKING + if ((lockclass_mask & LOCKTYPE_SPIN) && debug_locks != expected) + expected_failure = 1; + if ((lockclass_mask & LOCKTYPE_RWLOCK) && debug_locks != expected) + expected_failure = 1; + if ((lockclass_mask & LOCKTYPE_MUTEX) && debug_locks != expected) + expected_failure = 1; + if ((lockclass_mask & LOCKTYPE_RWSEM) && debug_locks != expected) + expected_failure = 1; +#endif + if (debug_locks != expected) { + if (expected_failure) { + expected_testcase_failures++; + printk("failed|"); + } else { + unexpected_testcase_failures++; + printk("FAILED|"); + } + } else { + testcase_successes++; + printk(" ok |"); + } + testcase_total++; + + if (debug_locks_verbose) + printk(" lockclass mask: %x, debug_locks: %d, expected: %d\n", + lockclass_mask, debug_locks, expected); + /* + * Some tests (e.g. double-unlock) might corrupt the preemption + * count, so restore it: + */ + preempt_count() = saved_preempt_count; +#ifdef CONFIG_TRACE_IRQFLAGS + if (softirq_count()) + current->softirqs_enabled = 0; + else + current->softirqs_enabled = 1; +#endif + + reset_locks(); +} + +static inline void print_testname(const char *testname) +{ + printk("%33s:", testname); +} + +#define DO_TESTCASE_1(desc, name, nr) \ + print_testname(desc"/"#nr); \ + dotest(name##_##nr, SUCCESS, LOCKTYPE_RWLOCK); \ + printk("\n"); + +#define DO_TESTCASE_1B(desc, name, nr) \ + print_testname(desc"/"#nr); \ + dotest(name##_##nr, FAILURE, LOCKTYPE_RWLOCK); \ + printk("\n"); + +#define DO_TESTCASE_3(desc, name, nr) \ + print_testname(desc"/"#nr); \ + dotest(name##_spin_##nr, FAILURE, LOCKTYPE_SPIN); \ + dotest(name##_wlock_##nr, FAILURE, LOCKTYPE_RWLOCK); \ + dotest(name##_rlock_##nr, SUCCESS, LOCKTYPE_RWLOCK); \ + printk("\n"); + +#define DO_TESTCASE_3RW(desc, name, nr) \ + print_testname(desc"/"#nr); \ + dotest(name##_spin_##nr, FAILURE, LOCKTYPE_SPIN|LOCKTYPE_RWLOCK);\ + dotest(name##_wlock_##nr, FAILURE, LOCKTYPE_RWLOCK); \ + dotest(name##_rlock_##nr, SUCCESS, LOCKTYPE_RWLOCK); \ + printk("\n"); + +#define DO_TESTCASE_6(desc, name) \ + print_testname(desc); \ + dotest(name##_spin, FAILURE, LOCKTYPE_SPIN); \ + dotest(name##_wlock, FAILURE, LOCKTYPE_RWLOCK); \ + dotest(name##_rlock, FAILURE, LOCKTYPE_RWLOCK); \ + dotest(name##_mutex, FAILURE, LOCKTYPE_MUTEX); \ + dotest(name##_wsem, FAILURE, LOCKTYPE_RWSEM); \ + dotest(name##_rsem, FAILURE, LOCKTYPE_RWSEM); \ + printk("\n"); + +#define DO_TESTCASE_6_SUCCESS(desc, name) \ + print_testname(desc); \ + dotest(name##_spin, SUCCESS, LOCKTYPE_SPIN); \ + dotest(name##_wlock, SUCCESS, LOCKTYPE_RWLOCK); \ + dotest(name##_rlock, SUCCESS, LOCKTYPE_RWLOCK); \ + dotest(name##_mutex, SUCCESS, LOCKTYPE_MUTEX); \ + dotest(name##_wsem, SUCCESS, LOCKTYPE_RWSEM); \ + dotest(name##_rsem, SUCCESS, LOCKTYPE_RWSEM); \ + printk("\n"); + +/* + * 'read' variant: rlocks must not trigger. + */ +#define DO_TESTCASE_6R(desc, name) \ + print_testname(desc); \ + dotest(name##_spin, FAILURE, LOCKTYPE_SPIN); \ + dotest(name##_wlock, FAILURE, LOCKTYPE_RWLOCK); \ + dotest(name##_rlock, SUCCESS, LOCKTYPE_RWLOCK); \ + dotest(name##_mutex, FAILURE, LOCKTYPE_MUTEX); \ + dotest(name##_wsem, FAILURE, LOCKTYPE_RWSEM); \ + dotest(name##_rsem, FAILURE, LOCKTYPE_RWSEM); \ + printk("\n"); + +#define DO_TESTCASE_2I(desc, name, nr) \ + DO_TESTCASE_1("hard-"desc, name##_hard, nr); \ + DO_TESTCASE_1("soft-"desc, name##_soft, nr); + +#define DO_TESTCASE_2IB(desc, name, nr) \ + DO_TESTCASE_1B("hard-"desc, name##_hard, nr); \ + DO_TESTCASE_1B("soft-"desc, name##_soft, nr); + +#define DO_TESTCASE_6I(desc, name, nr) \ + DO_TESTCASE_3("hard-"desc, name##_hard, nr); \ + DO_TESTCASE_3("soft-"desc, name##_soft, nr); + +#define DO_TESTCASE_6IRW(desc, name, nr) \ + DO_TESTCASE_3RW("hard-"desc, name##_hard, nr); \ + DO_TESTCASE_3RW("soft-"desc, name##_soft, nr); + +#define DO_TESTCASE_2x3(desc, name) \ + DO_TESTCASE_3(desc, name, 12); \ + DO_TESTCASE_3(desc, name, 21); + +#define DO_TESTCASE_2x6(desc, name) \ + DO_TESTCASE_6I(desc, name, 12); \ + DO_TESTCASE_6I(desc, name, 21); + +#define DO_TESTCASE_6x2(desc, name) \ + DO_TESTCASE_2I(desc, name, 123); \ + DO_TESTCASE_2I(desc, name, 132); \ + DO_TESTCASE_2I(desc, name, 213); \ + DO_TESTCASE_2I(desc, name, 231); \ + DO_TESTCASE_2I(desc, name, 312); \ + DO_TESTCASE_2I(desc, name, 321); + +#define DO_TESTCASE_6x2B(desc, name) \ + DO_TESTCASE_2IB(desc, name, 123); \ + DO_TESTCASE_2IB(desc, name, 132); \ + DO_TESTCASE_2IB(desc, name, 213); \ + DO_TESTCASE_2IB(desc, name, 231); \ + DO_TESTCASE_2IB(desc, name, 312); \ + DO_TESTCASE_2IB(desc, name, 321); + +#define DO_TESTCASE_6x6(desc, name) \ + DO_TESTCASE_6I(desc, name, 123); \ + DO_TESTCASE_6I(desc, name, 132); \ + DO_TESTCASE_6I(desc, name, 213); \ + DO_TESTCASE_6I(desc, name, 231); \ + DO_TESTCASE_6I(desc, name, 312); \ + DO_TESTCASE_6I(desc, name, 321); + +#define DO_TESTCASE_6x6RW(desc, name) \ + DO_TESTCASE_6IRW(desc, name, 123); \ + DO_TESTCASE_6IRW(desc, name, 132); \ + DO_TESTCASE_6IRW(desc, name, 213); \ + DO_TESTCASE_6IRW(desc, name, 231); \ + DO_TESTCASE_6IRW(desc, name, 312); \ + DO_TESTCASE_6IRW(desc, name, 321); + + +void locking_selftest(void) +{ + /* + * Got a locking failure before the selftest ran? + */ + if (!debug_locks) { + printk("----------------------------------\n"); + printk("| Locking API testsuite disabled |\n"); + printk("----------------------------------\n"); + return; + } + + /* + * Run the testsuite: + */ + printk("------------------------\n"); + printk("| Locking API testsuite:\n"); + printk("----------------------------------------------------------------------------\n"); + printk(" | spin |wlock |rlock |mutex | wsem | rsem |\n"); + printk(" --------------------------------------------------------------------------\n"); + + init_shared_classes(); + debug_locks_silent = !debug_locks_verbose; + + DO_TESTCASE_6("A-A deadlock", AA); + DO_TESTCASE_6R("A-B-B-A deadlock", ABBA); + DO_TESTCASE_6R("A-B-B-C-C-A deadlock", ABBCCA); + DO_TESTCASE_6R("A-B-C-A-B-C deadlock", ABCABC); + DO_TESTCASE_6R("A-B-B-C-C-D-D-A deadlock", ABBCCDDA); + DO_TESTCASE_6R("A-B-C-D-B-D-D-A deadlock", ABCDBDDA); + DO_TESTCASE_6R("A-B-C-D-B-C-D-A deadlock", ABCDBCDA); + DO_TESTCASE_6("double unlock", double_unlock); + DO_TESTCASE_6("initialize held", init_held); + DO_TESTCASE_6_SUCCESS("bad unlock order", bad_unlock_order); + + printk(" --------------------------------------------------------------------------\n"); + print_testname("recursive read-lock"); + printk(" |"); + dotest(rlock_AA1, SUCCESS, LOCKTYPE_RWLOCK); + printk(" |"); + dotest(rsem_AA1, FAILURE, LOCKTYPE_RWSEM); + printk("\n"); + + print_testname("recursive read-lock #2"); + printk(" |"); + dotest(rlock_AA1B, FAILURE, LOCKTYPE_RWLOCK); + printk(" |"); + dotest(rsem_AA1B, FAILURE, LOCKTYPE_RWSEM); + printk("\n"); + + print_testname("mixed read-write-lock"); + printk(" |"); + dotest(rlock_AA2, FAILURE, LOCKTYPE_RWLOCK); + printk(" |"); + dotest(rsem_AA2, FAILURE, LOCKTYPE_RWSEM); + printk("\n"); + + print_testname("mixed write-read-lock"); + printk(" |"); + dotest(rlock_AA3, FAILURE, LOCKTYPE_RWLOCK); + printk(" |"); + dotest(rsem_AA3, FAILURE, LOCKTYPE_RWSEM); + printk("\n"); + + printk(" --------------------------------------------------------------------------\n"); + + /* + * irq-context testcases: + */ + DO_TESTCASE_2x6("irqs-on + irq-safe-A", irqsafe1); + DO_TESTCASE_2x3("sirq-safe-A => hirqs-on", irqsafe2A); + DO_TESTCASE_2x6("safe-A + irqs-on", irqsafe2B); + DO_TESTCASE_6x6("safe-A + unsafe-B #1", irqsafe3); + DO_TESTCASE_6x6("safe-A + unsafe-B #2", irqsafe4); + DO_TESTCASE_6x6RW("irq lock-inversion", irq_inversion); + + DO_TESTCASE_6x2("irq read-recursion", irq_read_recursion); +// DO_TESTCASE_6x2B("irq read-recursion #2", irq_read_recursion2); + + if (unexpected_testcase_failures) { + printk("-----------------------------------------------------------------\n"); + debug_locks = 0; + printk("BUG: %3d unexpected failures (out of %3d) - debugging disabled! |\n", + unexpected_testcase_failures, testcase_total); + printk("-----------------------------------------------------------------\n"); + } else if (expected_testcase_failures && testcase_successes) { + printk("--------------------------------------------------------\n"); + printk("%3d out of %3d testcases failed, as expected. |\n", + expected_testcase_failures, testcase_total); + printk("----------------------------------------------------\n"); + debug_locks = 1; + } else if (expected_testcase_failures && !testcase_successes) { + printk("--------------------------------------------------------\n"); + printk("All %3d testcases failed, as expected. |\n", + expected_testcase_failures); + printk("----------------------------------------\n"); + debug_locks = 1; + } else { + printk("-------------------------------------------------------\n"); + printk("Good, all %3d testcases passed! |\n", + testcase_successes); + printk("---------------------------------\n"); + debug_locks = 1; + } + debug_locks_silent = 0; +} -- cgit v1.2.2 From fbb9ce9530fd9b66096d5187fa6a115d16d9746c Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 3 Jul 2006 00:24:50 -0700 Subject: [PATCH] lockdep: core Do 'make oldconfig' and accept all the defaults for new config options - reboot into the kernel and if everything goes well it should boot up fine and you should have /proc/lockdep and /proc/lockdep_stats files. Typically if the lock validator finds some problem it will print out voluminous debug output that begins with "BUG: ..." and which syslog output can be used by kernel developers to figure out the precise locking scenario. What does the lock validator do? It "observes" and maps all locking rules as they occur dynamically (as triggered by the kernel's natural use of spinlocks, rwlocks, mutexes and rwsems). Whenever the lock validator subsystem detects a new locking scenario, it validates this new rule against the existing set of rules. If this new rule is consistent with the existing set of rules then the new rule is added transparently and the kernel continues as normal. If the new rule could create a deadlock scenario then this condition is printed out. When determining validity of locking, all possible "deadlock scenarios" are considered: assuming arbitrary number of CPUs, arbitrary irq context and task context constellations, running arbitrary combinations of all the existing locking scenarios. In a typical system this means millions of separate scenarios. This is why we call it a "locking correctness" validator - for all rules that are observed the lock validator proves it with mathematical certainty that a deadlock could not occur (assuming that the lock validator implementation itself is correct and its internal data structures are not corrupted by some other kernel subsystem). [see more details and conditionals of this statement in include/linux/lockdep.h and Documentation/lockdep-design.txt] Furthermore, this "all possible scenarios" property of the validator also enables the finding of complex, highly unlikely multi-CPU multi-context races via single single-context rules, increasing the likelyhood of finding bugs drastically. In practical terms: the lock validator already found a bug in the upstream kernel that could only occur on systems with 3 or more CPUs, and which needed 3 very unlikely code sequences to occur at once on the 3 CPUs. That bug was found and reported on a single-CPU system (!). So in essence a race will be found "piecemail-wise", triggering all the necessary components for the race, without having to reproduce the race scenario itself! In its short existence the lock validator found and reported many bugs before they actually caused a real deadlock. To further increase the efficiency of the validator, the mapping is not per "lock instance", but per "lock-class". For example, all struct inode objects in the kernel have inode->inotify_mutex. If there are 10,000 inodes cached, then there are 10,000 lock objects. But ->inotify_mutex is a single "lock type", and all locking activities that occur against ->inotify_mutex are "unified" into this single lock-class. The advantage of the lock-class approach is that all historical ->inotify_mutex uses are mapped into a single (and as narrow as possible) set of locking rules - regardless of how many different tasks or inode structures it took to build this set of rules. The set of rules persist during the lifetime of the kernel. To see the rough magnitude of checking that the lock validator does, here's a portion of /proc/lockdep_stats, fresh after bootup: lock-classes: 694 [max: 2048] direct dependencies: 1598 [max: 8192] indirect dependencies: 17896 all direct dependencies: 16206 dependency chains: 1910 [max: 8192] in-hardirq chains: 17 in-softirq chains: 105 in-process chains: 1065 stack-trace entries: 38761 [max: 131072] combined max dependencies: 2033928 hardirq-safe locks: 24 hardirq-unsafe locks: 176 softirq-safe locks: 53 softirq-unsafe locks: 137 irq-safe locks: 59 irq-unsafe locks: 176 The lock validator has observed 1598 actual single-thread locking patterns, and has validated all possible 2033928 distinct locking scenarios. More details about the design of the lock validator can be found in Documentation/lockdep-design.txt, which can also found at: http://redhat.com/~mingo/lockdep-patches/lockdep-design.txt [bunk@stusta.de: cleanups] Signed-off-by: Ingo Molnar Signed-off-by: Arjan van de Ven Signed-off-by: Adrian Bunk Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/Kconfig.debug | 2 +- lib/locking-selftest.c | 4 +--- 2 files changed, 2 insertions(+), 4 deletions(-) (limited to 'lib') diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 16021b09c1..16c2e98b76 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -48,7 +48,7 @@ config DEBUG_KERNEL config LOG_BUF_SHIFT int "Kernel log buffer size (16 => 64KB, 17 => 128KB)" if DEBUG_KERNEL range 12 21 - default 17 if S390 + default 17 if S390 || LOCKDEP default 16 if X86_NUMAQ || IA64 default 15 if SMP default 14 diff --git a/lib/locking-selftest.c b/lib/locking-selftest.c index 5cd05f20bd..9bdc8d440b 100644 --- a/lib/locking-selftest.c +++ b/lib/locking-selftest.c @@ -15,6 +15,7 @@ #include #include #include +#include #include #include #include @@ -889,9 +890,6 @@ GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion_soft) #include "locking-selftest-softirq.h" // GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion2_soft) -#define lockdep_reset() -#define lockdep_reset_lock(x) - #ifdef CONFIG_DEBUG_LOCK_ALLOC # define I_SPINLOCK(x) lockdep_reset_lock(&lock_##x.dep_map) # define I_RWLOCK(x) lockdep_reset_lock(&rwlock_##x.dep_map) -- cgit v1.2.2 From 6c9076ec9cd448f43bbda871352a7067f456ee26 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 3 Jul 2006 00:24:51 -0700 Subject: [PATCH] lockdep: allow read_lock() recursion of same class From: Ingo Molnar lockdep so far only allowed read-recursion for the same lock instance. This is enough in the overwhelming majority of cases, but a hostap case triggered and reported by Miles Lane relies on same-class different-instance recursion. So we relax the restriction on read-lock recursion. (This change does not allow rwsem read-recursion, which is still forbidden.) Signed-off-by: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/locking-selftest.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'lib') diff --git a/lib/locking-selftest.c b/lib/locking-selftest.c index 9bdc8d440b..7945787f43 100644 --- a/lib/locking-selftest.c +++ b/lib/locking-selftest.c @@ -248,7 +248,7 @@ GENERATE_TESTCASE(AA_rsem) /* * Special-case for read-locking, they are - * allowed to recurse on the same lock instance: + * allowed to recurse on the same lock class: */ static void rlock_AA1(void) { @@ -259,7 +259,7 @@ static void rlock_AA1(void) static void rlock_AA1B(void) { RL(X1); - RL(X2); // this one should fail + RL(X2); // this one should NOT fail } static void rsem_AA1(void) @@ -1132,7 +1132,7 @@ void locking_selftest(void) init_shared_classes(); debug_locks_silent = !debug_locks_verbose; - DO_TESTCASE_6("A-A deadlock", AA); + DO_TESTCASE_6R("A-A deadlock", AA); DO_TESTCASE_6R("A-B-B-A deadlock", ABBA); DO_TESTCASE_6R("A-B-B-C-C-A deadlock", ABBCCA); DO_TESTCASE_6R("A-B-C-A-B-C deadlock", ABCABC); @@ -1153,7 +1153,7 @@ void locking_selftest(void) print_testname("recursive read-lock #2"); printk(" |"); - dotest(rlock_AA1B, FAILURE, LOCKTYPE_RWLOCK); + dotest(rlock_AA1B, SUCCESS, LOCKTYPE_RWLOCK); printk(" |"); dotest(rsem_AA1B, FAILURE, LOCKTYPE_RWSEM); printk("\n"); -- cgit v1.2.2 From 4ea2176dfa714882e88180b474e4cbcd888b70af Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 3 Jul 2006 00:24:53 -0700 Subject: [PATCH] lockdep: prove rwsem locking correctness Use the lock validator framework to prove rwsem locking correctness. Signed-off-by: Ingo Molnar Signed-off-by: Arjan van de Ven Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/rwsem-spinlock.c | 20 +++++++++++++++++--- lib/rwsem.c | 20 ++++++++++++++++++++ 2 files changed, 37 insertions(+), 3 deletions(-) (limited to 'lib') diff --git a/lib/rwsem-spinlock.c b/lib/rwsem-spinlock.c index 03b6097eb0..db4fed74b9 100644 --- a/lib/rwsem-spinlock.c +++ b/lib/rwsem-spinlock.c @@ -20,8 +20,16 @@ struct rwsem_waiter { /* * initialise the semaphore */ -void fastcall init_rwsem(struct rw_semaphore *sem) +void __init_rwsem(struct rw_semaphore *sem, const char *name, + struct lock_class_key *key) { +#ifdef CONFIG_DEBUG_LOCK_ALLOC + /* + * Make sure we are not reinitializing a held semaphore: + */ + debug_check_no_locks_freed((void *)sem, sizeof(*sem)); + lockdep_init_map(&sem->dep_map, name, key); +#endif sem->activity = 0; spin_lock_init(&sem->wait_lock); INIT_LIST_HEAD(&sem->wait_list); @@ -183,7 +191,7 @@ int fastcall __down_read_trylock(struct rw_semaphore *sem) * get a write lock on the semaphore * - we increment the waiting count anyway to indicate an exclusive lock */ -void fastcall __sched __down_write(struct rw_semaphore *sem) +void fastcall __sched __down_write_nested(struct rw_semaphore *sem, int subclass) { struct rwsem_waiter waiter; struct task_struct *tsk; @@ -223,6 +231,11 @@ void fastcall __sched __down_write(struct rw_semaphore *sem) ; } +void fastcall __sched __down_write(struct rw_semaphore *sem) +{ + __down_write_nested(sem, 0); +} + /* * trylock for writing -- returns 1 if successful, 0 if contention */ @@ -292,9 +305,10 @@ void fastcall __downgrade_write(struct rw_semaphore *sem) spin_unlock_irqrestore(&sem->wait_lock, flags); } -EXPORT_SYMBOL(init_rwsem); +EXPORT_SYMBOL(__init_rwsem); EXPORT_SYMBOL(__down_read); EXPORT_SYMBOL(__down_read_trylock); +EXPORT_SYMBOL(__down_write_nested); EXPORT_SYMBOL(__down_write); EXPORT_SYMBOL(__down_write_trylock); EXPORT_SYMBOL(__up_read); diff --git a/lib/rwsem.c b/lib/rwsem.c index bae5972848..b322421c29 100644 --- a/lib/rwsem.c +++ b/lib/rwsem.c @@ -8,6 +8,26 @@ #include #include +/* + * Initialize an rwsem: + */ +void __init_rwsem(struct rw_semaphore *sem, const char *name, + struct lock_class_key *key) +{ +#ifdef CONFIG_DEBUG_LOCK_ALLOC + /* + * Make sure we are not reinitializing a held semaphore: + */ + debug_check_no_locks_freed((void *)sem, sizeof(*sem)); + lockdep_init_map(&sem->dep_map, name, key); +#endif + sem->count = RWSEM_UNLOCKED_VALUE; + spin_lock_init(&sem->wait_lock); + INIT_LIST_HEAD(&sem->wait_list); +} + +EXPORT_SYMBOL(__init_rwsem); + struct rwsem_waiter { struct list_head list; struct task_struct *task; -- cgit v1.2.2 From 8a25d5debff2daee280e83e09d8c25d67c26a972 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 3 Jul 2006 00:24:54 -0700 Subject: [PATCH] lockdep: prove spinlock rwlock locking correctness Use the lock validator framework to prove spinlock and rwlock locking correctness. Signed-off-by: Ingo Molnar Signed-off-by: Arjan van de Ven Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/kernel_lock.c | 7 ++++++- lib/spinlock_debug.c | 36 ++++++++++++++++++++++++++++++++++++ 2 files changed, 42 insertions(+), 1 deletion(-) (limited to 'lib') diff --git a/lib/kernel_lock.c b/lib/kernel_lock.c index e713e86811..e0fdfddb40 100644 --- a/lib/kernel_lock.c +++ b/lib/kernel_lock.c @@ -177,7 +177,12 @@ static inline void __lock_kernel(void) static inline void __unlock_kernel(void) { - spin_unlock(&kernel_flag); + /* + * the BKL is not covered by lockdep, so we open-code the + * unlocking sequence (and thus avoid the dep-chain ops): + */ + _raw_spin_unlock(&kernel_flag); + preempt_enable(); } /* diff --git a/lib/spinlock_debug.c b/lib/spinlock_debug.c index 3de2ccf48a..3d9c4dc965 100644 --- a/lib/spinlock_debug.c +++ b/lib/spinlock_debug.c @@ -12,6 +12,42 @@ #include #include +void __spin_lock_init(spinlock_t *lock, const char *name, + struct lock_class_key *key) +{ +#ifdef CONFIG_DEBUG_LOCK_ALLOC + /* + * Make sure we are not reinitializing a held lock: + */ + debug_check_no_locks_freed((void *)lock, sizeof(*lock)); + lockdep_init_map(&lock->dep_map, name, key); +#endif + lock->raw_lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED; + lock->magic = SPINLOCK_MAGIC; + lock->owner = SPINLOCK_OWNER_INIT; + lock->owner_cpu = -1; +} + +EXPORT_SYMBOL(__spin_lock_init); + +void __rwlock_init(rwlock_t *lock, const char *name, + struct lock_class_key *key) +{ +#ifdef CONFIG_DEBUG_LOCK_ALLOC + /* + * Make sure we are not reinitializing a held lock: + */ + debug_check_no_locks_freed((void *)lock, sizeof(*lock)); + lockdep_init_map(&lock->dep_map, name, key); +#endif + lock->raw_lock = (raw_rwlock_t) __RAW_RW_LOCK_UNLOCKED; + lock->magic = RWLOCK_MAGIC; + lock->owner = SPINLOCK_OWNER_INIT; + lock->owner_cpu = -1; +} + +EXPORT_SYMBOL(__rwlock_init); + static void spin_bug(spinlock_t *lock, const char *msg) { struct task_struct *owner = NULL; -- cgit v1.2.2 From 4d9f34ad366a7935be3d6e7cca90805e6b7a692d Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 3 Jul 2006 00:24:55 -0700 Subject: [PATCH] lockdep: kconfig Offer the following lock validation options: CONFIG_PROVE_LOCKING Signed-off-by: Ingo Molnar Signed-off-by: Arjan van de Ven Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/Kconfig.debug | 98 +++++++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 96 insertions(+), 2 deletions(-) (limited to 'lib') diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 16c2e98b76..e5889b1a33 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -134,7 +134,7 @@ config RT_MUTEX_TESTER This option enables a rt-mutex tester. config DEBUG_SPINLOCK - bool "Spinlock debugging" + bool "Spinlock and rw-lock debugging: basic checks" depends on DEBUG_KERNEL help Say Y here and build SMP to catch missing spinlock initialization @@ -142,8 +142,102 @@ config DEBUG_SPINLOCK best used in conjunction with the NMI watchdog so that spinlock deadlocks are also debuggable. +config DEBUG_MUTEXES + bool "Mutex debugging: basic checks" + depends on DEBUG_KERNEL + help + This feature allows mutex semantics violations to be detected and + reported. + +config DEBUG_RWSEMS + bool "RW-sem debugging: basic checks" + depends on DEBUG_KERNEL + help + This feature allows read-write semaphore semantics violations to + be detected and reported. + +config DEBUG_LOCK_ALLOC + bool "Lock debugging: detect incorrect freeing of live locks" + depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT + select DEBUG_SPINLOCK + select DEBUG_MUTEXES + select DEBUG_RWSEMS + select LOCKDEP + help + This feature will check whether any held lock (spinlock, rwlock, + mutex or rwsem) is incorrectly freed by the kernel, via any of the + memory-freeing routines (kfree(), kmem_cache_free(), free_pages(), + vfree(), etc.), whether a live lock is incorrectly reinitialized via + spin_lock_init()/mutex_init()/etc., or whether there is any lock + held during task exit. + +config PROVE_LOCKING + bool "Lock debugging: prove locking correctness" + depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT + select LOCKDEP + select DEBUG_SPINLOCK + select DEBUG_MUTEXES + select DEBUG_RWSEMS + select DEBUG_LOCK_ALLOC + default n + help + This feature enables the kernel to prove that all locking + that occurs in the kernel runtime is mathematically + correct: that under no circumstance could an arbitrary (and + not yet triggered) combination of observed locking + sequences (on an arbitrary number of CPUs, running an + arbitrary number of tasks and interrupt contexts) cause a + deadlock. + + In short, this feature enables the kernel to report locking + related deadlocks before they actually occur. + + The proof does not depend on how hard and complex a + deadlock scenario would be to trigger: how many + participant CPUs, tasks and irq-contexts would be needed + for it to trigger. The proof also does not depend on + timing: if a race and a resulting deadlock is possible + theoretically (no matter how unlikely the race scenario + is), it will be proven so and will immediately be + reported by the kernel (once the event is observed that + makes the deadlock theoretically possible). + + If a deadlock is impossible (i.e. the locking rules, as + observed by the kernel, are mathematically correct), the + kernel reports nothing. + + NOTE: this feature can also be enabled for rwlocks, mutexes + and rwsems - in which case all dependencies between these + different locking variants are observed and mapped too, and + the proof of observed correctness is also maintained for an + arbitrary combination of these separate locking variants. + + For more details, see Documentation/lockdep-design.txt. + +config LOCKDEP + bool + depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT + select STACKTRACE + select FRAME_POINTER + select KALLSYMS + select KALLSYMS_ALL + +config DEBUG_LOCKDEP + bool "Lock dependency engine debugging" + depends on LOCKDEP + help + If you say Y here, the lock dependency engine will do + additional runtime checks to debug itself, at the price + of more runtime overhead. + +config TRACE_IRQFLAGS + bool + default y + depends on TRACE_IRQFLAGS_SUPPORT + depends on PROVE_LOCKING + config DEBUG_SPINLOCK_SLEEP - bool "Sleep-inside-spinlock checking" + bool "Spinlock debugging: sleep-inside-spinlock checking" depends on DEBUG_KERNEL help If you say Y here, various routines which may sleep will become very -- cgit v1.2.2