diff options
| -rw-r--r-- | include/linux/timer.h | 93 | ||||
| -rw-r--r-- | kernel/timer.c | 68 |
2 files changed, 141 insertions, 20 deletions
diff --git a/include/linux/timer.h b/include/linux/timer.h index daf9685..51774eb 100644 --- a/include/linux/timer.h +++ b/include/linux/timer.h @@ -5,6 +5,7 @@ #include <linux/ktime.h> #include <linux/stddef.h> #include <linux/debugobjects.h> +#include <linux/stringify.h> struct tvec_base; @@ -21,52 +22,126 @@ struct timer_list { char start_comm[16]; int start_pid; #endif +#ifdef CONFIG_LOCKDEP + struct lockdep_map lockdep_map; +#endif }; extern struct tvec_base boot_tvec_bases; +#ifdef CONFIG_LOCKDEP +/* + * NB: because we have to copy the lockdep_map, setting the lockdep_map key + * (second argument) here is required, otherwise it could be initialised to + * the copy of the lockdep_map later! We use the pointer to and the string + * "<file>:<line>" as the key resp. the name of the lockdep_map. + */ +#define __TIMER_LOCKDEP_MAP_INITIALIZER(_kn) \ + .lockdep_map = STATIC_LOCKDEP_MAP_INIT(_kn, &_kn), +#else +#define __TIMER_LOCKDEP_MAP_INITIALIZER(_kn) +#endif + #define TIMER_INITIALIZER(_function, _expires, _data) { \ .entry = { .prev = TIMER_ENTRY_STATIC }, \ .function = (_function), \ .expires = (_expires), \ .data = (_data), \ .base = &boot_tvec_bases, \ + __TIMER_LOCKDEP_MAP_INITIALIZER( \ + __FILE__ ":" __stringify(__LINE__)) \ } #define DEFINE_TIMER(_name, _function, _expires, _data) \ struct timer_list _name = \ TIMER_INITIALIZER(_function, _expires, _data) -void init_timer(struct timer_list *timer); -void init_timer_deferrable(struct timer_list *timer); +void init_timer_key(struct timer_list *timer, + const char *name, + struct lock_class_key *key); +void init_timer_deferrable_key(struct timer_list *timer, + const char *name, + struct lock_class_key *key); + +#ifdef CONFIG_LOCKDEP +#define init_timer(timer) \ + do { \ + static struct lock_class_key __key; \ + init_timer_key((timer), #timer, &__key); \ + } while (0) + +#define init_timer_deferrable(timer) \ + do { \ + static struct lock_class_key __key; \ + init_timer_deferrable_key((timer), #timer, &__key); \ + } while (0) + +#define init_timer_on_stack(timer) \ + do { \ + static struct lock_class_key __key; \ + init_timer_on_stack_key((timer), #timer, &__key); \ + } while (0) + +#define setup_timer(timer, fn, data) \ + do { \ + static struct lock_class_key __key; \ + setup_timer_key((timer), #timer, &__key, (fn), (data));\ + } while (0) + +#define setup_timer_on_stack(timer, fn, data) \ + do { \ + static struct lock_class_key __key; \ + setup_timer_on_stack_key((timer), #timer, &__key, \ + (fn), (data)); \ + } while (0) +#else +#define init_timer(timer)\ + init_timer_key((timer), NULL, NULL) +#define init_timer_deferrable(timer)\ + init_timer_deferrable_key((timer), NULL, NULL) +#define init_timer_on_stack(timer)\ + init_timer_on_stack_key((timer), NULL, NULL) +#define setup_timer(timer, fn, data)\ + setup_timer_key((timer), NULL, NULL, (fn), (data)) +#define setup_timer_on_stack(timer, fn, data)\ + setup_timer_on_stack_key((timer), NULL, NULL, (fn), (data)) +#endif #ifdef CONFIG_DEBUG_OBJECTS_TIMERS -extern void init_timer_on_stack(struct timer_list *timer); +extern void init_timer_on_stack_key(struct timer_list *timer, + const char *name, + struct lock_class_key *key); extern void destroy_timer_on_stack(struct timer_list *timer); #else static inline void destroy_timer_on_stack(struct timer_list *timer) { } -static inline void init_timer_on_stack(struct timer_list *timer) +static inline void init_timer_on_stack_key(struct timer_list *timer, + const char *name, + struct lock_class_key *key) { - init_timer(timer); + init_timer_key(timer, name, key); } #endif -static inline void setup_timer(struct timer_list * timer, +static inline void setup_timer_key(struct timer_list * timer, + const char *name, + struct lock_class_key *key, void (*function)(unsigned long), unsigned long data) { timer->function = function; timer->data = data; - init_timer(timer); + init_timer_key(timer, name, key); } -static inline void setup_timer_on_stack(struct timer_list *timer, +static inline void setup_timer_on_stack_key(struct timer_list *timer, + const char *name, + struct lock_class_key *key, void (*function)(unsigned long), unsigned long data) { timer->function = function; timer->data = data; - init_timer_on_stack(timer); + init_timer_on_stack_key(timer, name, key); } /** diff --git a/kernel/timer.c b/kernel/timer.c index 13dd64f..ef1c385 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -491,14 +491,18 @@ static inline void debug_timer_free(struct timer_list *timer) debug_object_free(timer, &timer_debug_descr); } -static void __init_timer(struct timer_list *timer); +static void __init_timer(struct timer_list *timer, + const char *name, + struct lock_class_key *key); -void init_timer_on_stack(struct timer_list *timer) +void init_timer_on_stack_key(struct timer_list *timer, + const char *name, + struct lock_class_key *key) { debug_object_init_on_stack(timer, &timer_debug_descr); - __init_timer(timer); + __init_timer(timer, name, key); } -EXPORT_SYMBOL_GPL(init_timer_on_stack); +EXPORT_SYMBOL_GPL(init_timer_on_stack_key); void destroy_timer_on_stack(struct timer_list *timer) { @@ -512,7 +516,9 @@ static inline void debug_timer_activate(struct timer_list *timer) { } static inline void debug_timer_deactivate(struct timer_list *timer) { } #endif -static void __init_timer(struct timer_list *timer) +static void __init_timer(struct timer_list *timer, + const char *name, + struct lock_class_key *key) { timer->entry.next = NULL; timer->base = __raw_get_cpu_var(tvec_bases); @@ -521,6 +527,7 @@ static void __init_timer(struct timer_list *timer) timer->start_pid = -1; memset(timer->start_comm, 0, TASK_COMM_LEN); #endif + lockdep_init_map(&timer->lockdep_map, name, key, 0); } /** @@ -530,19 +537,23 @@ static void __init_timer(struct timer_list *timer) * init_timer() must be done to a timer prior calling *any* of the * other timer functions. */ -void init_timer(struct timer_list *timer) +void init_timer_key(struct timer_list *timer, + const char *name, + struct lock_class_key *key) { debug_timer_init(timer); - __init_timer(timer); + __init_timer(timer, name, key); } -EXPORT_SYMBOL(init_timer); +EXPORT_SYMBOL(init_timer_key); -void init_timer_deferrable(struct timer_list *timer) +void init_timer_deferrable_key(struct timer_list *timer, + const char *name, + struct lock_class_key *key) { - init_timer(timer); + init_timer_key(timer, name, key); timer_set_deferrable(timer); } -EXPORT_SYMBOL(init_timer_deferrable); +EXPORT_SYMBOL(init_timer_deferrable_key); static inline void detach_timer(struct timer_list *timer, int clear_pending) @@ -789,6 +800,15 @@ EXPORT_SYMBOL(try_to_del_timer_sync); */ int del_timer_sync(struct timer_list *timer) { +#ifdef CONFIG_LOCKDEP + unsigned long flags; + + local_irq_save(flags); + lock_map_acquire(&timer->lockdep_map); + lock_map_release(&timer->lockdep_map); + local_irq_restore(flags); +#endif + for (;;) { int ret = try_to_del_timer_sync(timer); if (ret >= 0) @@ -861,10 +881,36 @@ static inline void __run_timers(struct tvec_base *base) set_running_timer(base, timer); detach_timer(timer, 1); + spin_unlock_irq(&base->lock); { int preempt_count = preempt_count(); + +#ifdef CONFIG_LOCKDEP + /* + * It is permissible to free the timer from + * inside the function that is called from + * it, this we need to take into account for + * lockdep too. To avoid bogus "held lock + * freed" warnings as well as problems when + * looking into timer->lockdep_map, make a + * copy and use that here. + */ + struct lockdep_map lockdep_map = + timer->lockdep_map; +#endif + /* + * Couple the lock chain with the lock chain at + * del_timer_sync() by acquiring the lock_map + * around the fn() call here and in + * del_timer_sync(). + */ + lock_map_acquire(&lockdep_map); + fn(data); + + lock_map_release(&lockdep_map); + if (preempt_count != preempt_count()) { printk(KERN_ERR "huh, entered %p " "with preempt_count %08x, exited" |