GitHub-Mirror/Star64_linux
2
0
Fork 0
mirror of https://github.com/Fishwaldo/Star64_linux.git synced 2025-06-20 05:31:15 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

timer: implement lockdep deadlock detection

Browse source 
This modifies the timer code in a way to allow lockdep to detect
deadlocks resulting from a lock being taken in the timer function
as well as around the del_timer_sync() call.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
This commit is contained in:
Johannes Berg 2009-01-29 16:03:20 +01:00 • committed by Ingo Molnar
parent 673f820591
commit 6f2b9b9a9d
2 changed files with 141 additions and 20 deletions
Download patch file Download diff file Expand all files Collapse all files

68
kernel/timer.c
View file

@ -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"