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authorLinus Torvalds <torvalds@linux-foundation.org>2012-01-06 07:53:34 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2012-01-06 07:53:34 -0800
commit8c717b72dec32a50666175b62b41de24e4b39be7 (patch)
treee2b4335496cbddb5cded7b1bfd7579ee33f60505 /kernel/timer.c
parent07d106d0a33d6063d2061305903deb02489eba20 (diff)
parentdc4218bd0fe499fce2896f88101ea42dac1f60fc (diff)
Merge branch 'core-debugobjects-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
* 'core-debugobjects-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: timer: Use debugobjects to catch deletion of uninitialized timers timer: Setup uninitialized timer with a stub callback debugobjects: Extend to assert that an object is initialized debugobjects: Be smarter about static objects
Diffstat (limited to 'kernel/timer.c')
-rw-r--r--kernel/timer.c62
1 files changed, 56 insertions, 6 deletions
diff --git a/kernel/timer.c b/kernel/timer.c
index 9c3c62b0c4bc..a297ffcf888e 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -427,6 +427,12 @@ static int timer_fixup_init(void *addr, enum debug_obj_state state)
}
}
+/* Stub timer callback for improperly used timers. */
+static void stub_timer(unsigned long data)
+{
+ WARN_ON(1);
+}
+
/*
* fixup_activate is called when:
* - an active object is activated
@@ -450,7 +456,8 @@ static int timer_fixup_activate(void *addr, enum debug_obj_state state)
debug_object_activate(timer, &timer_debug_descr);
return 0;
} else {
- WARN_ON_ONCE(1);
+ setup_timer(timer, stub_timer, 0);
+ return 1;
}
return 0;
@@ -480,12 +487,40 @@ static int timer_fixup_free(void *addr, enum debug_obj_state state)
}
}
+/*
+ * fixup_assert_init is called when:
+ * - an untracked/uninit-ed object is found
+ */
+static int timer_fixup_assert_init(void *addr, enum debug_obj_state state)
+{
+ struct timer_list *timer = addr;
+
+ switch (state) {
+ case ODEBUG_STATE_NOTAVAILABLE:
+ if (timer->entry.prev == TIMER_ENTRY_STATIC) {
+ /*
+ * This is not really a fixup. The timer was
+ * statically initialized. We just make sure that it
+ * is tracked in the object tracker.
+ */
+ debug_object_init(timer, &timer_debug_descr);
+ return 0;
+ } else {
+ setup_timer(timer, stub_timer, 0);
+ return 1;
+ }
+ default:
+ return 0;
+ }
+}
+
static struct debug_obj_descr timer_debug_descr = {
- .name = "timer_list",
- .debug_hint = timer_debug_hint,
- .fixup_init = timer_fixup_init,
- .fixup_activate = timer_fixup_activate,
- .fixup_free = timer_fixup_free,
+ .name = "timer_list",
+ .debug_hint = timer_debug_hint,
+ .fixup_init = timer_fixup_init,
+ .fixup_activate = timer_fixup_activate,
+ .fixup_free = timer_fixup_free,
+ .fixup_assert_init = timer_fixup_assert_init,
};
static inline void debug_timer_init(struct timer_list *timer)
@@ -508,6 +543,11 @@ static inline void debug_timer_free(struct timer_list *timer)
debug_object_free(timer, &timer_debug_descr);
}
+static inline void debug_timer_assert_init(struct timer_list *timer)
+{
+ debug_object_assert_init(timer, &timer_debug_descr);
+}
+
static void __init_timer(struct timer_list *timer,
const char *name,
struct lock_class_key *key);
@@ -531,6 +571,7 @@ EXPORT_SYMBOL_GPL(destroy_timer_on_stack);
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) { }
+static inline void debug_timer_assert_init(struct timer_list *timer) { }
#endif
static inline void debug_init(struct timer_list *timer)
@@ -552,6 +593,11 @@ static inline void debug_deactivate(struct timer_list *timer)
trace_timer_cancel(timer);
}
+static inline void debug_assert_init(struct timer_list *timer)
+{
+ debug_timer_assert_init(timer);
+}
+
static void __init_timer(struct timer_list *timer,
const char *name,
struct lock_class_key *key)
@@ -902,6 +948,8 @@ int del_timer(struct timer_list *timer)
unsigned long flags;
int ret = 0;
+ debug_assert_init(timer);
+
timer_stats_timer_clear_start_info(timer);
if (timer_pending(timer)) {
base = lock_timer_base(timer, &flags);
@@ -932,6 +980,8 @@ int try_to_del_timer_sync(struct timer_list *timer)
unsigned long flags;
int ret = -1;
+ debug_assert_init(timer);
+
base = lock_timer_base(timer, &flags);
if (base->running_timer == timer)