extern int atomic_notifier_call_chain(struct atomic_notifier_head *nh,
unsigned long val, void *v);
-extern int __atomic_notifier_call_chain(struct atomic_notifier_head *nh,
- unsigned long val, void *v, int nr_to_call, int *nr_calls);
extern int blocking_notifier_call_chain(struct blocking_notifier_head *nh,
unsigned long val, void *v);
-extern int __blocking_notifier_call_chain(struct blocking_notifier_head *nh,
- unsigned long val, void *v, int nr_to_call, int *nr_calls);
extern int raw_notifier_call_chain(struct raw_notifier_head *nh,
unsigned long val, void *v);
-extern int __raw_notifier_call_chain(struct raw_notifier_head *nh,
- unsigned long val, void *v, int nr_to_call, int *nr_calls);
extern int srcu_notifier_call_chain(struct srcu_notifier_head *nh,
unsigned long val, void *v);
-extern int __srcu_notifier_call_chain(struct srcu_notifier_head *nh,
- unsigned long val, void *v, int nr_to_call, int *nr_calls);
+
+extern int atomic_notifier_call_chain_robust(struct atomic_notifier_head *nh,
+ unsigned long val_up, unsigned long val_down, void *v);
+extern int blocking_notifier_call_chain_robust(struct blocking_notifier_head *nh,
+ unsigned long val_up, unsigned long val_down, void *v);
+extern int raw_notifier_call_chain_robust(struct raw_notifier_head *nh,
+ unsigned long val_up, unsigned long val_down, void *v);
#define NOTIFY_DONE 0x0000 /* Don't care */
#define NOTIFY_OK 0x0001 /* Suits me */
static ATOMIC_NOTIFIER_HEAD(cpu_pm_notifier_chain);
-static int cpu_pm_notify(enum cpu_pm_event event, int nr_to_call, int *nr_calls)
+static int cpu_pm_notify(enum cpu_pm_event event)
{
int ret;
/*
- * __atomic_notifier_call_chain has a RCU read critical section, which
+ * atomic_notifier_call_chain has a RCU read critical section, which
* could be disfunctional in cpu idle. Copy RCU_NONIDLE code to let
* RCU know this.
*/
rcu_irq_enter_irqson();
- ret = __atomic_notifier_call_chain(&cpu_pm_notifier_chain, event, NULL,
- nr_to_call, nr_calls);
+ ret = atomic_notifier_call_chain(&cpu_pm_notifier_chain, event, NULL);
+ rcu_irq_exit_irqson();
+
+ return notifier_to_errno(ret);
+}
+
+static int cpu_pm_notify_robust(enum cpu_pm_event event_up, enum cpu_pm_event event_down)
+{
+ int ret;
+
+ rcu_irq_enter_irqson();
+ ret = atomic_notifier_call_chain_robust(&cpu_pm_notifier_chain, event_up, event_down, NULL);
rcu_irq_exit_irqson();
return notifier_to_errno(ret);
*/
int cpu_pm_enter(void)
{
- int nr_calls = 0;
- int ret = 0;
-
- ret = cpu_pm_notify(CPU_PM_ENTER, -1, &nr_calls);
- if (ret)
- /*
- * Inform listeners (nr_calls - 1) about failure of CPU PM
- * PM entry who are notified earlier to prepare for it.
- */
- cpu_pm_notify(CPU_PM_ENTER_FAILED, nr_calls - 1, NULL);
-
- return ret;
+ return cpu_pm_notify_robust(CPU_PM_ENTER, CPU_PM_ENTER_FAILED);
}
EXPORT_SYMBOL_GPL(cpu_pm_enter);
*/
int cpu_pm_exit(void)
{
- return cpu_pm_notify(CPU_PM_EXIT, -1, NULL);
+ return cpu_pm_notify(CPU_PM_EXIT);
}
EXPORT_SYMBOL_GPL(cpu_pm_exit);
*/
int cpu_cluster_pm_enter(void)
{
- int nr_calls = 0;
- int ret = 0;
-
- ret = cpu_pm_notify(CPU_CLUSTER_PM_ENTER, -1, &nr_calls);
- if (ret)
- /*
- * Inform listeners (nr_calls - 1) about failure of CPU cluster
- * PM entry who are notified earlier to prepare for it.
- */
- cpu_pm_notify(CPU_CLUSTER_PM_ENTER_FAILED, nr_calls - 1, NULL);
-
- return ret;
+ return cpu_pm_notify_robust(CPU_CLUSTER_PM_ENTER, CPU_CLUSTER_PM_ENTER_FAILED);
}
EXPORT_SYMBOL_GPL(cpu_cluster_pm_enter);
*/
int cpu_cluster_pm_exit(void)
{
- return cpu_pm_notify(CPU_CLUSTER_PM_EXIT, -1, NULL);
+ return cpu_pm_notify(CPU_CLUSTER_PM_EXIT);
}
EXPORT_SYMBOL_GPL(cpu_cluster_pm_exit);
}
NOKPROBE_SYMBOL(notifier_call_chain);
+/**
+ * notifier_call_chain_robust - Inform the registered notifiers about an event
+ * and rollback on error.
+ * @nl: Pointer to head of the blocking notifier chain
+ * @val_up: Value passed unmodified to the notifier function
+ * @val_down: Value passed unmodified to the notifier function when recovering
+ * from an error on @val_up
+ * @v Pointer passed unmodified to the notifier function
+ *
+ * NOTE: It is important the @nl chain doesn't change between the two
+ * invocations of notifier_call_chain() such that we visit the
+ * exact same notifier callbacks; this rules out any RCU usage.
+ *
+ * Returns: the return value of the @val_up call.
+ */
+static int notifier_call_chain_robust(struct notifier_block **nl,
+ unsigned long val_up, unsigned long val_down,
+ void *v)
+{
+ int ret, nr = 0;
+
+ ret = notifier_call_chain(nl, val_up, v, -1, &nr);
+ if (ret & NOTIFY_STOP_MASK)
+ notifier_call_chain(nl, val_down, v, nr-1, NULL);
+
+ return ret;
+}
+
/*
* Atomic notifier chain routines. Registration and unregistration
* use a spinlock, and call_chain is synchronized by RCU (no locks).
}
EXPORT_SYMBOL_GPL(atomic_notifier_chain_unregister);
+int atomic_notifier_call_chain_robust(struct atomic_notifier_head *nh,
+ unsigned long val_up, unsigned long val_down, void *v)
+{
+ unsigned long flags;
+ int ret;
+
+ /*
+ * Musn't use RCU; because then the notifier list can
+ * change between the up and down traversal.
+ */
+ spin_lock_irqsave(&nh->lock, flags);
+ ret = notifier_call_chain_robust(&nh->head, val_up, val_down, v);
+ spin_unlock_irqrestore(&nh->lock, flags);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(atomic_notifier_call_chain_robust);
+NOKPROBE_SYMBOL(atomic_notifier_call_chain_robust);
+
/**
- * __atomic_notifier_call_chain - Call functions in an atomic notifier chain
+ * atomic_notifier_call_chain - Call functions in an atomic notifier chain
* @nh: Pointer to head of the atomic notifier chain
* @val: Value passed unmodified to notifier function
* @v: Pointer passed unmodified to notifier function
- * @nr_to_call: See the comment for notifier_call_chain.
- * @nr_calls: See the comment for notifier_call_chain.
*
* Calls each function in a notifier chain in turn. The functions
* run in an atomic context, so they must not block.
* Otherwise the return value is the return value
* of the last notifier function called.
*/
-int __atomic_notifier_call_chain(struct atomic_notifier_head *nh,
- unsigned long val, void *v,
- int nr_to_call, int *nr_calls)
+int atomic_notifier_call_chain(struct atomic_notifier_head *nh,
+ unsigned long val, void *v)
{
int ret;
rcu_read_lock();
- ret = notifier_call_chain(&nh->head, val, v, nr_to_call, nr_calls);
+ ret = notifier_call_chain(&nh->head, val, v, -1, NULL);
rcu_read_unlock();
- return ret;
-}
-EXPORT_SYMBOL_GPL(__atomic_notifier_call_chain);
-NOKPROBE_SYMBOL(__atomic_notifier_call_chain);
-int atomic_notifier_call_chain(struct atomic_notifier_head *nh,
- unsigned long val, void *v)
-{
- return __atomic_notifier_call_chain(nh, val, v, -1, NULL);
+ return ret;
}
EXPORT_SYMBOL_GPL(atomic_notifier_call_chain);
NOKPROBE_SYMBOL(atomic_notifier_call_chain);
}
EXPORT_SYMBOL_GPL(blocking_notifier_chain_unregister);
+int blocking_notifier_call_chain_robust(struct blocking_notifier_head *nh,
+ unsigned long val_up, unsigned long val_down, void *v)
+{
+ int ret = NOTIFY_DONE;
+
+ /*
+ * We check the head outside the lock, but if this access is
+ * racy then it does not matter what the result of the test
+ * is, we re-check the list after having taken the lock anyway:
+ */
+ if (rcu_access_pointer(nh->head)) {
+ down_read(&nh->rwsem);
+ ret = notifier_call_chain_robust(&nh->head, val_up, val_down, v);
+ up_read(&nh->rwsem);
+ }
+ return ret;
+}
+EXPORT_SYMBOL_GPL(blocking_notifier_call_chain_robust);
+
/**
- * __blocking_notifier_call_chain - Call functions in a blocking notifier chain
+ * blocking_notifier_call_chain - Call functions in a blocking notifier chain
* @nh: Pointer to head of the blocking notifier chain
* @val: Value passed unmodified to notifier function
* @v: Pointer passed unmodified to notifier function
- * @nr_to_call: See comment for notifier_call_chain.
- * @nr_calls: See comment for notifier_call_chain.
*
* Calls each function in a notifier chain in turn. The functions
* run in a process context, so they are allowed to block.
* Otherwise the return value is the return value
* of the last notifier function called.
*/
-int __blocking_notifier_call_chain(struct blocking_notifier_head *nh,
- unsigned long val, void *v,
- int nr_to_call, int *nr_calls)
+int blocking_notifier_call_chain(struct blocking_notifier_head *nh,
+ unsigned long val, void *v)
{
int ret = NOTIFY_DONE;
*/
if (rcu_access_pointer(nh->head)) {
down_read(&nh->rwsem);
- ret = notifier_call_chain(&nh->head, val, v, nr_to_call,
- nr_calls);
+ ret = notifier_call_chain(&nh->head, val, v, -1, NULL);
up_read(&nh->rwsem);
}
return ret;
}
-EXPORT_SYMBOL_GPL(__blocking_notifier_call_chain);
-
-int blocking_notifier_call_chain(struct blocking_notifier_head *nh,
- unsigned long val, void *v)
-{
- return __blocking_notifier_call_chain(nh, val, v, -1, NULL);
-}
EXPORT_SYMBOL_GPL(blocking_notifier_call_chain);
/*
}
EXPORT_SYMBOL_GPL(raw_notifier_chain_unregister);
+int raw_notifier_call_chain_robust(struct raw_notifier_head *nh,
+ unsigned long val_up, unsigned long val_down, void *v)
+{
+ return notifier_call_chain_robust(&nh->head, val_up, val_down, v);
+}
+EXPORT_SYMBOL_GPL(raw_notifier_call_chain_robust);
+
/**
- * __raw_notifier_call_chain - Call functions in a raw notifier chain
+ * raw_notifier_call_chain - Call functions in a raw notifier chain
* @nh: Pointer to head of the raw notifier chain
* @val: Value passed unmodified to notifier function
* @v: Pointer passed unmodified to notifier function
- * @nr_to_call: See comment for notifier_call_chain.
- * @nr_calls: See comment for notifier_call_chain
*
* Calls each function in a notifier chain in turn. The functions
* run in an undefined context.
* Otherwise the return value is the return value
* of the last notifier function called.
*/
-int __raw_notifier_call_chain(struct raw_notifier_head *nh,
- unsigned long val, void *v,
- int nr_to_call, int *nr_calls)
-{
- return notifier_call_chain(&nh->head, val, v, nr_to_call, nr_calls);
-}
-EXPORT_SYMBOL_GPL(__raw_notifier_call_chain);
-
int raw_notifier_call_chain(struct raw_notifier_head *nh,
unsigned long val, void *v)
{
- return __raw_notifier_call_chain(nh, val, v, -1, NULL);
+ return notifier_call_chain(&nh->head, val, v, -1, NULL);
}
EXPORT_SYMBOL_GPL(raw_notifier_call_chain);
EXPORT_SYMBOL_GPL(srcu_notifier_chain_unregister);
/**
- * __srcu_notifier_call_chain - Call functions in an SRCU notifier chain
+ * srcu_notifier_call_chain - Call functions in an SRCU notifier chain
* @nh: Pointer to head of the SRCU notifier chain
* @val: Value passed unmodified to notifier function
* @v: Pointer passed unmodified to notifier function
- * @nr_to_call: See comment for notifier_call_chain.
- * @nr_calls: See comment for notifier_call_chain
*
* Calls each function in a notifier chain in turn. The functions
* run in a process context, so they are allowed to block.
* Otherwise the return value is the return value
* of the last notifier function called.
*/
-int __srcu_notifier_call_chain(struct srcu_notifier_head *nh,
- unsigned long val, void *v,
- int nr_to_call, int *nr_calls)
+int srcu_notifier_call_chain(struct srcu_notifier_head *nh,
+ unsigned long val, void *v)
{
int ret;
int idx;
idx = srcu_read_lock(&nh->srcu);
- ret = notifier_call_chain(&nh->head, val, v, nr_to_call, nr_calls);
+ ret = notifier_call_chain(&nh->head, val, v, -1, NULL);
srcu_read_unlock(&nh->srcu, idx);
return ret;
}
-EXPORT_SYMBOL_GPL(__srcu_notifier_call_chain);
-
-int srcu_notifier_call_chain(struct srcu_notifier_head *nh,
- unsigned long val, void *v)
-{
- return __srcu_notifier_call_chain(nh, val, v, -1, NULL);
-}
EXPORT_SYMBOL_GPL(srcu_notifier_call_chain);
/**
*/
int hibernate(void)
{
- int error, nr_calls = 0;
bool snapshot_test = false;
+ int error;
if (!hibernation_available()) {
pm_pr_dbg("Hibernation not available.\n");
pr_info("hibernation entry\n");
pm_prepare_console();
- error = __pm_notifier_call_chain(PM_HIBERNATION_PREPARE, -1, &nr_calls);
- if (error) {
- nr_calls--;
- goto Exit;
- }
+ error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION);
+ if (error)
+ goto Restore;
ksys_sync_helper();
/* Don't bother checking whether freezer_test_done is true */
freezer_test_done = false;
Exit:
- __pm_notifier_call_chain(PM_POST_HIBERNATION, nr_calls, NULL);
+ pm_notifier_call_chain(PM_POST_HIBERNATION);
+ Restore:
pm_restore_console();
hibernate_release();
Unlock:
*/
int hibernate_quiet_exec(int (*func)(void *data), void *data)
{
- int error, nr_calls = 0;
+ int error;
lock_system_sleep();
pm_prepare_console();
- error = __pm_notifier_call_chain(PM_HIBERNATION_PREPARE, -1, &nr_calls);
- if (error) {
- nr_calls--;
- goto exit;
- }
+ error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION);
+ if (error)
+ goto restore;
error = freeze_processes();
if (error)
thaw_processes();
exit:
- __pm_notifier_call_chain(PM_POST_HIBERNATION, nr_calls, NULL);
+ pm_notifier_call_chain(PM_POST_HIBERNATION);
+restore:
pm_restore_console();
hibernate_release();
*/
static int software_resume(void)
{
- int error, nr_calls = 0;
+ int error;
/*
* If the user said "noresume".. bail out early.
pr_info("resume from hibernation\n");
pm_prepare_console();
- error = __pm_notifier_call_chain(PM_RESTORE_PREPARE, -1, &nr_calls);
- if (error) {
- nr_calls--;
- goto Close_Finish;
- }
+ error = pm_notifier_call_chain_robust(PM_RESTORE_PREPARE, PM_POST_RESTORE);
+ if (error)
+ goto Restore;
pm_pr_dbg("Preparing processes for hibernation restore.\n");
error = freeze_processes();
error = load_image_and_restore();
thaw_processes();
Finish:
- __pm_notifier_call_chain(PM_POST_RESTORE, nr_calls, NULL);
+ pm_notifier_call_chain(PM_POST_RESTORE);
+ Restore:
pm_restore_console();
pr_info("resume failed (%d)\n", error);
hibernate_release();