*/
#include <linux/kernel_stat.h>
-#include <linux/module.h>
+#include <linux/export.h>
#include <linux/interrupt.h>
#include <linux/percpu.h>
#include <linux/init.h>
}
}
+/* 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
debug_object_activate(timer, &timer_debug_descr);
return 0;
} else {
- WARN_ON_ONCE(1);
+ setup_timer(timer, stub_timer, 0);
+ return 1;
}
return 0;
}
}
+/*
+ * 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)
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);
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)
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)
unsigned long expires_limit, mask;
int bit;
- expires_limit = expires;
-
if (timer->slack >= 0) {
expires_limit = expires + timer->slack;
} else {
- unsigned long now = jiffies;
+ long delta = expires - jiffies;
+
+ if (delta < 256)
+ return expires;
- /* No slack, if already expired else auto slack 0.4% */
- if (time_after(expires, now))
- expires_limit = expires + (expires - now)/256;
+ expires_limit = expires + delta / 256;
}
mask = expires ^ expires_limit;
if (mask == 0)
*/
int mod_timer(struct timer_list *timer, unsigned long expires)
{
+ expires = apply_slack(timer, expires);
+
/*
* This is a common optimization triggered by the
* networking code - if the timer is re-modified
if (timer_pending(timer) && timer->expires == expires)
return 1;
- expires = apply_slack(timer, expires);
-
return __mod_timer(timer, expires, false, TIMER_NOT_PINNED);
}
EXPORT_SYMBOL(mod_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);
unsigned long flags;
int ret = -1;
+ debug_assert_init(timer);
+
base = lock_timer_base(timer, &flags);
if (base->running_timer == timer)
* add_timer_on(). Upon exit the timer is not queued and the handler is
* not running on any CPU.
*
+ * Note: You must not hold locks that are held in interrupt context
+ * while calling this function. Even if the lock has nothing to do
+ * with the timer in question. Here's why:
+ *
+ * CPU0 CPU1
+ * ---- ----
+ * <SOFTIRQ>
+ * call_timer_fn();
+ * base->running_timer = mytimer;
+ * spin_lock_irq(somelock);
+ * <IRQ>
+ * spin_lock(somelock);
+ * del_timer_sync(mytimer);
+ * while (base->running_timer == mytimer);
+ *
+ * Now del_timer_sync() will never return and never release somelock.
+ * The interrupt on the other CPU is waiting to grab somelock but
+ * it has interrupted the softirq that CPU0 is waiting to finish.
+ *
* The function returns whether it has deactivated a pending timer or not.
*/
int del_timer_sync(struct timer_list *timer)
#ifdef CONFIG_LOCKDEP
unsigned long flags;
+ /*
+ * If lockdep gives a backtrace here, please reference
+ * the synchronization rules above.
+ */
local_irq_save(flags);
lock_map_acquire(&timer->lockdep_map);
lock_map_release(&timer->lockdep_map);
raise_softirq(TIMER_SOFTIRQ);
}
-/*
- * The 64-bit jiffies value is not atomic - you MUST NOT read it
- * without sampling the sequence number in xtime_lock.
- * jiffies is defined in the linker script...
- */
-
-void do_timer(unsigned long ticks)
-{
- jiffies_64 += ticks;
- update_wall_time();
- calc_global_load(ticks);
-}
-
#ifdef __ARCH_WANT_SYS_ALARM
/*
int pid;
rcu_read_lock();
- pid = task_tgid_vnr(current->real_parent);
+ pid = task_tgid_vnr(rcu_dereference(current->real_parent));
rcu_read_unlock();
return pid;
projects / linux-flexiantxendom0-3.2.10.git / blobdiff