diff --git a/drivers/parport/ieee1284.c b/drivers/parport/ieee1284.c
index 54a6ef72906ed741e2a0ba4ddbeb343de5418480..0338b09126742300efd226e4fce332a0e2c0bbad 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 99c2352906a021cf42e6673faf71a9519bea05d4..b5253e77eb2f137ee5b1346f848514ad991801e1 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 a9c31be7052c4bcbd4593963ebf32303b338e04f..9f31683728fd7e2c59f738ae35ab6835066270c1 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 979fefdeb86210c15e318cc7eb8986f813181c75..d4ba79248a27fab0f33a9697deebd02bfb9440e3 100644
--- a/include/linux/timer.h
+++ b/include/linux/timer.h
@@ -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
diff --git a/kernel/timer.c b/kernel/timer.c
index f3d35d4ea42eff89e09db3e741022c22e593c3a9..ceacc6626572a7c2e2c345ba136bd456a267ba64 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -320,14 +320,130 @@ static void timer_stats_account_timer(struct timer_list *timer)
static void timer_stats_account_timer(struct timer_list *timer) {}
#endif
-/**
- * init_timer - initialize a timer.
- * @timer: the timer to be initialized
- *
- * init_timer() must be done to a timer prior calling *any* of the
- * other timer functions.
+#ifdef CONFIG_DEBUG_OBJECTS_TIMERS
+
+static struct debug_obj_descr timer_debug_descr;
+
+/*
+ * fixup_init is called when:
+ * - an active object is initialized
*/
-void init_timer(struct timer_list *timer)
+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);
@@ -337,6 +453,19 @@ void init_timer(struct timer_list *timer)
memset(timer->start_comm, 0, TASK_COMM_LEN);
#endif
}
+
+/**
+ * init_timer - initialize a timer.
+ * @timer: the timer to be initialized
+ *
+ * init_timer() must be done to a timer prior calling *any* of the
+ * other timer functions.
+ */
+void init_timer(struct timer_list *timer)
+{
+ debug_timer_init(timer);
+ __init_timer(timer);
+}
EXPORT_SYMBOL(init_timer);
void init_timer_deferrable(struct timer_list *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 3e132b0a59cc64623cf6654c193164b64ce8877a..d2099f41aa1ebe46bc614c7187290f7a32dd941c 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