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 <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Greg KH <greg@kroah.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Thomas Gleixner 2008-04-30 00:55:03 -07:00 committed by Linus Torvalds
parent 691cc54c7d
commit c6f3a97f86
6 changed files with 187 additions and 13 deletions

View file

@ -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;
}

View file

@ -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;
}

View file

@ -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.

View file

@ -4,6 +4,7 @@
#include <linux/list.h>
#include <linux/ktime.h>
#include <linux/stddef.h>
#include <linux/debugobjects.h>
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

View file

@ -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:

View file

@ -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