From c6f3a97f86a5c97be0ca255976110bb9c3cfe669 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 30 Apr 2008 00:55:03 -0700 Subject: [PATCH] debugobjects: add timer specific object debugging code Add calls to the generic object debugging infrastructure and provide fixup functions which allow to keep the system alive when recoverable problems have been detected by the object debugging core code. Signed-off-by: Thomas Gleixner Acked-by: Ingo Molnar Cc: Greg KH Cc: Randy Dunlap Cc: Kay Sievers Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/parport/ieee1284.c | 4 +- fs/aio.c | 5 +- include/linux/poison.h | 7 ++ include/linux/timer.h | 23 +++++- kernel/timer.c | 153 +++++++++++++++++++++++++++++++++++-- lib/Kconfig.debug | 8 ++ 6 files changed, 187 insertions(+), 13 deletions(-) diff --git a/drivers/parport/ieee1284.c b/drivers/parport/ieee1284.c index 54a6ef72906..0338b091267 100644 --- a/drivers/parport/ieee1284.c +++ b/drivers/parport/ieee1284.c @@ -76,7 +76,7 @@ int parport_wait_event (struct parport *port, signed long timeout) semaphore. */ return 1; - init_timer (&timer); + init_timer_on_stack(&timer); timer.expires = jiffies + timeout; timer.function = timeout_waiting_on_port; port_from_cookie[port->number % PARPORT_MAX] = port; @@ -88,6 +88,8 @@ int parport_wait_event (struct parport *port, signed long timeout) /* Timed out. */ ret = 1; + destroy_timer_on_stack(&timer); + return ret; } diff --git a/fs/aio.c b/fs/aio.c index 99c2352906a..b5253e77eb2 100644 --- a/fs/aio.c +++ b/fs/aio.c @@ -1078,9 +1078,7 @@ static void timeout_func(unsigned long data) static inline void init_timeout(struct aio_timeout *to) { - init_timer(&to->timer); - to->timer.data = (unsigned long)to; - to->timer.function = timeout_func; + setup_timer_on_stack(&to->timer, timeout_func, (unsigned long) to); to->timed_out = 0; to->p = current; } @@ -1213,6 +1211,7 @@ retry: if (timeout) clear_timeout(&to); out: + destroy_timer_on_stack(&to.timer); return i ? i : ret; } diff --git a/include/linux/poison.h b/include/linux/poison.h index a9c31be7052..9f31683728f 100644 --- a/include/linux/poison.h +++ b/include/linux/poison.h @@ -10,6 +10,13 @@ #define LIST_POISON1 ((void *) 0x00100100) #define LIST_POISON2 ((void *) 0x00200200) +/********** include/linux/timer.h **********/ +/* + * Magic number "tsta" to indicate a static timer initializer + * for the object debugging code. + */ +#define TIMER_ENTRY_STATIC ((void *) 0x74737461) + /********** mm/slab.c **********/ /* * Magic nums for obj red zoning. diff --git a/include/linux/timer.h b/include/linux/timer.h index 979fefdeb86..d4ba79248a2 100644 --- a/include/linux/timer.h +++ b/include/linux/timer.h @@ -4,6 +4,7 @@ #include #include #include +#include struct tvec_base; @@ -25,6 +26,7 @@ struct timer_list { extern struct tvec_base boot_tvec_bases; #define TIMER_INITIALIZER(_function, _expires, _data) { \ + .entry = { .prev = TIMER_ENTRY_STATIC }, \ .function = (_function), \ .expires = (_expires), \ .data = (_data), \ @@ -38,6 +40,17 @@ extern struct tvec_base boot_tvec_bases; void init_timer(struct timer_list *timer); void init_timer_deferrable(struct timer_list *timer); +#ifdef CONFIG_DEBUG_OBJECTS_TIMERS +extern void init_timer_on_stack(struct timer_list *timer); +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) +{ + init_timer(timer); +} +#endif + static inline void setup_timer(struct timer_list * timer, void (*function)(unsigned long), unsigned long data) @@ -47,6 +60,15 @@ static inline void setup_timer(struct timer_list * timer, init_timer(timer); } +static inline void setup_timer_on_stack(struct timer_list *timer, + void (*function)(unsigned long), + unsigned long data) +{ + timer->function = function; + timer->data = data; + init_timer_on_stack(timer); +} + /** * timer_pending - is a timer pending? * @timer: the timer in question @@ -164,5 +186,4 @@ unsigned long __round_jiffies_relative(unsigned long j, int cpu); unsigned long round_jiffies(unsigned long j); unsigned long round_jiffies_relative(unsigned long j); - #endif diff --git a/kernel/timer.c b/kernel/timer.c index f3d35d4ea42..ceacc662657 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -320,6 +320,140 @@ static void timer_stats_account_timer(struct timer_list *timer) static void timer_stats_account_timer(struct timer_list *timer) {} #endif +#ifdef CONFIG_DEBUG_OBJECTS_TIMERS + +static struct debug_obj_descr timer_debug_descr; + +/* + * fixup_init is called when: + * - an active object is initialized + */ +static int timer_fixup_init(void *addr, enum debug_obj_state state) +{ + struct timer_list *timer = addr; + + switch (state) { + case ODEBUG_STATE_ACTIVE: + del_timer_sync(timer); + debug_object_init(timer, &timer_debug_descr); + return 1; + default: + return 0; + } +} + +/* + * fixup_activate is called when: + * - an active object is activated + * - an unknown object is activated (might be a statically initialized object) + */ +static int timer_fixup_activate(void *addr, enum debug_obj_state state) +{ + struct timer_list *timer = addr; + + switch (state) { + + case ODEBUG_STATE_NOTAVAILABLE: + /* + * This is not really a fixup. The timer was + * statically initialized. We just make sure that it + * is tracked in the object tracker. + */ + if (timer->entry.next == NULL && + timer->entry.prev == TIMER_ENTRY_STATIC) { + debug_object_init(timer, &timer_debug_descr); + debug_object_activate(timer, &timer_debug_descr); + return 0; + } else { + WARN_ON_ONCE(1); + } + return 0; + + case ODEBUG_STATE_ACTIVE: + WARN_ON(1); + + default: + return 0; + } +} + +/* + * fixup_free is called when: + * - an active object is freed + */ +static int timer_fixup_free(void *addr, enum debug_obj_state state) +{ + struct timer_list *timer = addr; + + switch (state) { + case ODEBUG_STATE_ACTIVE: + del_timer_sync(timer); + debug_object_free(timer, &timer_debug_descr); + return 1; + default: + return 0; + } +} + +static struct debug_obj_descr timer_debug_descr = { + .name = "timer_list", + .fixup_init = timer_fixup_init, + .fixup_activate = timer_fixup_activate, + .fixup_free = timer_fixup_free, +}; + +static inline void debug_timer_init(struct timer_list *timer) +{ + debug_object_init(timer, &timer_debug_descr); +} + +static inline void debug_timer_activate(struct timer_list *timer) +{ + debug_object_activate(timer, &timer_debug_descr); +} + +static inline void debug_timer_deactivate(struct timer_list *timer) +{ + debug_object_deactivate(timer, &timer_debug_descr); +} + +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); + +void init_timer_on_stack(struct timer_list *timer) +{ + debug_object_init_on_stack(timer, &timer_debug_descr); + __init_timer(timer); +} +EXPORT_SYMBOL_GPL(init_timer_on_stack); + +void destroy_timer_on_stack(struct timer_list *timer) +{ + debug_object_free(timer, &timer_debug_descr); +} +EXPORT_SYMBOL_GPL(destroy_timer_on_stack); + +#else +static inline void debug_timer_init(struct timer_list *timer) { } +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) +{ + timer->entry.next = NULL; + timer->base = __raw_get_cpu_var(tvec_bases); +#ifdef CONFIG_TIMER_STATS + timer->start_site = NULL; + timer->start_pid = -1; + memset(timer->start_comm, 0, TASK_COMM_LEN); +#endif +} + /** * init_timer - initialize a timer. * @timer: the timer to be initialized @@ -329,13 +463,8 @@ static void timer_stats_account_timer(struct timer_list *timer) {} */ void init_timer(struct timer_list *timer) { - timer->entry.next = NULL; - timer->base = __raw_get_cpu_var(tvec_bases); -#ifdef CONFIG_TIMER_STATS - timer->start_site = NULL; - timer->start_pid = -1; - memset(timer->start_comm, 0, TASK_COMM_LEN); -#endif + debug_timer_init(timer); + __init_timer(timer); } EXPORT_SYMBOL(init_timer); @@ -351,6 +480,8 @@ static inline void detach_timer(struct timer_list *timer, { struct list_head *entry = &timer->entry; + debug_timer_deactivate(timer); + __list_del(entry->prev, entry->next); if (clear_pending) entry->next = NULL; @@ -405,6 +536,8 @@ int __mod_timer(struct timer_list *timer, unsigned long expires) ret = 1; } + debug_timer_activate(timer); + new_base = __get_cpu_var(tvec_bases); if (base != new_base) { @@ -450,6 +583,7 @@ void add_timer_on(struct timer_list *timer, int cpu) BUG_ON(timer_pending(timer) || !timer->function); spin_lock_irqsave(&base->lock, flags); timer_set_base(timer, base); + debug_timer_activate(timer); internal_add_timer(base, timer); /* * Check whether the other CPU is idle and needs to be @@ -1086,11 +1220,14 @@ signed long __sched schedule_timeout(signed long timeout) expire = timeout + jiffies; - setup_timer(&timer, process_timeout, (unsigned long)current); + setup_timer_on_stack(&timer, process_timeout, (unsigned long)current); __mod_timer(&timer, expire); schedule(); del_singleshot_timer_sync(&timer); + /* Remove the timer from the object tracker */ + destroy_timer_on_stack(&timer); + timeout = expire - jiffies; out: diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 3e132b0a59c..d2099f41aa1 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -217,6 +217,14 @@ config DEBUG_OBJECTS_FREE properly. This can make kmalloc/kfree-intensive workloads much slower. +config DEBUG_OBJECTS_TIMERS + bool "Debug timer objects" + depends on DEBUG_OBJECTS + help + If you say Y here, additional code will be inserted into the + timer routines to track the life time of timer objects and + validate the timer operations. + config DEBUG_SLAB bool "Debug slab memory allocations" depends on DEBUG_KERNEL && SLAB