add hrtimer specific debugobjects code

hrtimers have now dynamic users in the network code.  Put them under
debugobjects surveillance as well.

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>
Cc: Greg KH <greg@kroah.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/hrtimer.h

@@ -266,6 +266,21 @@ extern ktime_t ktime_get_real(void);
 extern void hrtimer_init(struct hrtimer *timer, clockid_t which_clock,
 			 enum hrtimer_mode mode);
 
+#ifdef CONFIG_DEBUG_OBJECTS_TIMERS
+extern void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t which_clock,
+				  enum hrtimer_mode mode);
+
+extern void destroy_hrtimer_on_stack(struct hrtimer *timer);
+#else
+static inline void hrtimer_init_on_stack(struct hrtimer *timer,
+					 clockid_t which_clock,
+					 enum hrtimer_mode mode)
+{
+	hrtimer_init(timer, which_clock, mode);
+}
+static inline void destroy_hrtimer_on_stack(struct hrtimer *timer) { }
+#endif
+
 /* Basic timer operations: */
 extern int hrtimer_start(struct hrtimer *timer, ktime_t tim,
 			 const enum hrtimer_mode mode);

kernel/futex.c

@@ -1266,11 +1266,13 @@ static int futex_wait(u32 __user *uaddr, struct rw_semaphore *fshared,
 		if (!abs_time)
 			schedule();
 		else {
-			hrtimer_init(&t.timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
+			hrtimer_init_on_stack(&t.timer, CLOCK_MONOTONIC,
+						HRTIMER_MODE_ABS);
 			hrtimer_init_sleeper(&t, current);
 			t.timer.expires = *abs_time;
 
-			hrtimer_start(&t.timer, t.timer.expires, HRTIMER_MODE_ABS);
+			hrtimer_start(&t.timer, t.timer.expires,
+						HRTIMER_MODE_ABS);
 			if (!hrtimer_active(&t.timer))
 				t.task = NULL;
 
@@ -1286,6 +1288,8 @@ static int futex_wait(u32 __user *uaddr, struct rw_semaphore *fshared,
 
 			/* Flag if a timeout occured */
 			rem = (t.task == NULL);
+
+			destroy_hrtimer_on_stack(&t.timer);
 		}
 	}
 	__set_current_state(TASK_RUNNING);
@@ -1367,7 +1371,8 @@ static int futex_lock_pi(u32 __user *uaddr, struct rw_semaphore *fshared,
 
 	if (time) {
 		to = &timeout;
-		hrtimer_init(&to->timer, CLOCK_REALTIME, HRTIMER_MODE_ABS);
+		hrtimer_init_on_stack(&to->timer, CLOCK_REALTIME,
+				      HRTIMER_MODE_ABS);
 		hrtimer_init_sleeper(to, current);
 		to->timer.expires = *time;
 	}
@@ -1581,13 +1586,17 @@ static int futex_lock_pi(u32 __user *uaddr, struct rw_semaphore *fshared,
 	unqueue_me_pi(&q);
 	futex_unlock_mm(fshared);
 
+	if (to)
+		destroy_hrtimer_on_stack(&to->timer);
 	return ret != -EINTR ? ret : -ERESTARTNOINTR;
 
  out_unlock_release_sem:
 	queue_unlock(&q, hb);
 
  out_release_sem:
 	futex_unlock_mm(fshared);
+	if (to)
+		destroy_hrtimer_on_stack(&to->timer);
 	return ret;
 
  uaddr_faulted:
@@ -1615,6 +1624,8 @@ static int futex_lock_pi(u32 __user *uaddr, struct rw_semaphore *fshared,
 	if (!ret && (uval != -EFAULT))
 		goto retry;
 
+	if (to)
+		destroy_hrtimer_on_stack(&to->timer);
 	return ret;
 }
 

kernel/hrtimer.c

@@ -43,6 +43,7 @@
 #include <linux/tick.h>
 #include <linux/seq_file.h>
 #include <linux/err.h>
+#include <linux/debugobjects.h>
 
 #include <asm/uaccess.h>
 
@@ -342,6 +343,115 @@ ktime_t ktime_add_safe(const ktime_t lhs, const ktime_t rhs)
 	return res;
 }
 
+#ifdef CONFIG_DEBUG_OBJECTS_TIMERS
+
+static struct debug_obj_descr hrtimer_debug_descr;
+
+/*
+ * fixup_init is called when:
+ * - an active object is initialized
+ */
+static int hrtimer_fixup_init(void *addr, enum debug_obj_state state)
+{
+	struct hrtimer *timer = addr;
+
+	switch (state) {
+	case ODEBUG_STATE_ACTIVE:
+		hrtimer_cancel(timer);
+		debug_object_init(timer, &hrtimer_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 hrtimer_fixup_activate(void *addr, enum debug_obj_state state)
+{
+	switch (state) {
+
+	case ODEBUG_STATE_NOTAVAILABLE:
+		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 hrtimer_fixup_free(void *addr, enum debug_obj_state state)
+{
+	struct hrtimer *timer = addr;
+
+	switch (state) {
+	case ODEBUG_STATE_ACTIVE:
+		hrtimer_cancel(timer);
+		debug_object_free(timer, &hrtimer_debug_descr);
+		return 1;
+	default:
+		return 0;
+	}
+}
+
+static struct debug_obj_descr hrtimer_debug_descr = {
+	.name		= "hrtimer",
+	.fixup_init	= hrtimer_fixup_init,
+	.fixup_activate	= hrtimer_fixup_activate,
+	.fixup_free	= hrtimer_fixup_free,
+};
+
+static inline void debug_hrtimer_init(struct hrtimer *timer)
+{
+	debug_object_init(timer, &hrtimer_debug_descr);
+}
+
+static inline void debug_hrtimer_activate(struct hrtimer *timer)
+{
+	debug_object_activate(timer, &hrtimer_debug_descr);
+}
+
+static inline void debug_hrtimer_deactivate(struct hrtimer *timer)
+{
+	debug_object_deactivate(timer, &hrtimer_debug_descr);
+}
+
+static inline void debug_hrtimer_free(struct hrtimer *timer)
+{
+	debug_object_free(timer, &hrtimer_debug_descr);
+}
+
+static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
+			   enum hrtimer_mode mode);
+
+void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t clock_id,
+			   enum hrtimer_mode mode)
+{
+	debug_object_init_on_stack(timer, &hrtimer_debug_descr);
+	__hrtimer_init(timer, clock_id, mode);
+}
+
+void destroy_hrtimer_on_stack(struct hrtimer *timer)
+{
+	debug_object_free(timer, &hrtimer_debug_descr);
+}
+
+#else
+static inline void debug_hrtimer_init(struct hrtimer *timer) { }
+static inline void debug_hrtimer_activate(struct hrtimer *timer) { }
+static inline void debug_hrtimer_deactivate(struct hrtimer *timer) { }
+#endif
+
 /*
  * Check, whether the timer is on the callback pending list
  */
@@ -567,6 +677,7 @@ static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer,
 		/* Timer is expired, act upon the callback mode */
 		switch(timer->cb_mode) {
 		case HRTIMER_CB_IRQSAFE_NO_RESTART:
+			debug_hrtimer_deactivate(timer);
 			/*
 			 * We can call the callback from here. No restart
 			 * happens, so no danger of recursion
@@ -581,6 +692,7 @@ static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer,
 			 * the tick timer in the softirq ! The calling site
 			 * takes care of this.
 			 */
+			debug_hrtimer_deactivate(timer);
 			return 1;
 		case HRTIMER_CB_IRQSAFE:
 		case HRTIMER_CB_SOFTIRQ:
@@ -735,6 +847,8 @@ static void enqueue_hrtimer(struct hrtimer *timer,
 	struct hrtimer *entry;
 	int leftmost = 1;
 
+	debug_hrtimer_activate(timer);
+
 	/*
 	 * Find the right place in the rbtree:
 	 */
@@ -831,6 +945,7 @@ remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base)
 		 * reprogramming happens in the interrupt handler. This is a
 		 * rare case and less expensive than a smp call.
 		 */
+		debug_hrtimer_deactivate(timer);
 		timer_stats_hrtimer_clear_start_info(timer);
 		reprogram = base->cpu_base == &__get_cpu_var(hrtimer_bases);
 		__remove_hrtimer(timer, base, HRTIMER_STATE_INACTIVE,
@@ -878,6 +993,7 @@ hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode)
 		tim = ktime_add_safe(tim, base->resolution);
 #endif
 	}
+
 	timer->expires = tim;
 
 	timer_stats_hrtimer_set_start_info(timer);
@@ -1011,14 +1127,8 @@ ktime_t hrtimer_get_next_event(void)
 }
 #endif
 
-/**
- * hrtimer_init - initialize a timer to the given clock
- * @timer:	the timer to be initialized
- * @clock_id:	the clock to be used
- * @mode:	timer mode abs/rel
- */
-void hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
-		  enum hrtimer_mode mode)
+static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
+			   enum hrtimer_mode mode)
 {
 	struct hrtimer_cpu_base *cpu_base;
 
@@ -1039,6 +1149,19 @@ void hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
 	memset(timer->start_comm, 0, TASK_COMM_LEN);
 #endif
 }
+
+/**
+ * hrtimer_init - initialize a timer to the given clock
+ * @timer:	the timer to be initialized
+ * @clock_id:	the clock to be used
+ * @mode:	timer mode abs/rel
+ */
+void hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
+		  enum hrtimer_mode mode)
+{
+	debug_hrtimer_init(timer);
+	__hrtimer_init(timer, clock_id, mode);
+}
 EXPORT_SYMBOL_GPL(hrtimer_init);
 
 /**
@@ -1072,6 +1195,7 @@ static void run_hrtimer_pending(struct hrtimer_cpu_base *cpu_base)
 		timer = list_entry(cpu_base->cb_pending.next,
 				   struct hrtimer, cb_entry);
 
+		debug_hrtimer_deactivate(timer);
 		timer_stats_account_hrtimer(timer);
 
 		fn = timer->function;
@@ -1120,6 +1244,7 @@ static void __run_hrtimer(struct hrtimer *timer)
 	enum hrtimer_restart (*fn)(struct hrtimer *);
 	int restart;
 
+	debug_hrtimer_deactivate(timer);
 	__remove_hrtimer(timer, base, HRTIMER_STATE_CALLBACK, 0);
 	timer_stats_account_hrtimer(timer);
 
@@ -1378,43 +1503,51 @@ long __sched hrtimer_nanosleep_restart(struct restart_block *restart)
 {
 	struct hrtimer_sleeper t;
 	struct timespec __user  *rmtp;
+	int ret = 0;
 
-	hrtimer_init(&t.timer, restart->nanosleep.index, HRTIMER_MODE_ABS);
+	hrtimer_init_on_stack(&t.timer, restart->nanosleep.index,
+				HRTIMER_MODE_ABS);
 	t.timer.expires.tv64 = restart->nanosleep.expires;
 
 	if (do_nanosleep(&t, HRTIMER_MODE_ABS))
-		return 0;
+		goto out;
 
 	rmtp = restart->nanosleep.rmtp;
 	if (rmtp) {
-		int ret = update_rmtp(&t.timer, rmtp);
+		ret = update_rmtp(&t.timer, rmtp);
 		if (ret <= 0)
-			return ret;
+			goto out;
 	}
 
 	/* The other values in restart are already filled in */
-	return -ERESTART_RESTARTBLOCK;
+	ret = -ERESTART_RESTARTBLOCK;
+out:
+	destroy_hrtimer_on_stack(&t.timer);
+	return ret;
 }
 
 long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp,
 		       const enum hrtimer_mode mode, const clockid_t clockid)
 {
 	struct restart_block *restart;
 	struct hrtimer_sleeper t;
+	int ret = 0;
 
-	hrtimer_init(&t.timer, clockid, mode);
+	hrtimer_init_on_stack(&t.timer, clockid, mode);
 	t.timer.expires = timespec_to_ktime(*rqtp);
 	if (do_nanosleep(&t, mode))
-		return 0;
+		goto out;
 
 	/* Absolute timers do not update the rmtp value and restart: */
-	if (mode == HRTIMER_MODE_ABS)
-		return -ERESTARTNOHAND;
+	if (mode == HRTIMER_MODE_ABS) {
+		ret = -ERESTARTNOHAND;
+		goto out;
+	}
 
 	if (rmtp) {
-		int ret = update_rmtp(&t.timer, rmtp);
+		ret = update_rmtp(&t.timer, rmtp);
 		if (ret <= 0)
-			return ret;
+			goto out;
 	}
 
 	restart = &current_thread_info()->restart_block;
@@ -1423,7 +1556,10 @@ long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp,
 	restart->nanosleep.rmtp = rmtp;
 	restart->nanosleep.expires = t.timer.expires.tv64;
 
-	return -ERESTART_RESTARTBLOCK;
+	ret = -ERESTART_RESTARTBLOCK;
+out:
+	destroy_hrtimer_on_stack(&t.timer);
+	return ret;
 }
 
 asmlinkage long
@@ -1468,6 +1604,7 @@ static void migrate_hrtimer_list(struct hrtimer_clock_base *old_base,
 	while ((node = rb_first(&old_base->active))) {
 		timer = rb_entry(node, struct hrtimer, node);
 		BUG_ON(hrtimer_callback_running(timer));
+		debug_hrtimer_deactivate(timer);
 		__remove_hrtimer(timer, old_base, HRTIMER_STATE_INACTIVE, 0);
 		timer->base = new_base;
 		/*