The current notifiers have the following error handling pattern all
over the place:

        int err, nr;

        err = __foo_notifier_call_chain(&chain, val_up, v, -1, &nr);
        if (err & NOTIFIER_STOP_MASK)
                __foo_notifier_call_chain(&chain, val_down, v, nr-1, NULL)

And aside from the endless repetition thereof, it is broken. Consider
blocking notifiers; both calls take and drop the rwsem, this means
that the notifier list can change in between the two calls, making @nr
meaningless.

Fix this by replacing all the __foo_notifier_call_chain() functions
with foo_notifier_call_chain_robust() that embeds the above pattern,
but ensures it is inside a single lock region.

Note: I switched atomic_notifier_call_chain_robust() to use
      the spinlock, since RCU cannot provide the guarantee
      required for the recovery.

Note: software_resume() error handling was broken afaict.

Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org>
Acked-by: Rafael J. Wysocki <rafael.j.wyso...@intel.com>
---
 include/linux/notifier.h           |   15 +--
 kernel/cpu_pm.c                    |   48 ++++--------
 kernel/notifier.c                  |  144 ++++++++++++++++++++++---------------
 kernel/power/hibernate.c           |   39 ++++------
 kernel/power/main.c                |    8 +-
 kernel/power/power.h               |    3 
 kernel/power/suspend.c             |   14 +--
 kernel/power/user.c                |   14 +--
 tools/power/pm-graph/sleepgraph.py |    2 
 9 files changed, 147 insertions(+), 140 deletions(-)

--- a/include/linux/notifier.h
+++ b/include/linux/notifier.h
@@ -161,20 +161,19 @@ extern int srcu_notifier_chain_unregiste
 
 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 */
--- a/kernel/cpu_pm.c
+++ b/kernel/cpu_pm.c
@@ -15,18 +15,28 @@
 
 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);
@@ -80,18 +90,7 @@ EXPORT_SYMBOL_GPL(cpu_pm_unregister_noti
  */
 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);
 
@@ -109,7 +108,7 @@ 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);
 
@@ -131,18 +130,7 @@ 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);
 
@@ -163,7 +151,7 @@ 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);
 
--- a/kernel/notifier.c
+++ b/kernel/notifier.c
@@ -94,6 +94,34 @@ static int notifier_call_chain(struct no
 }
 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).
@@ -144,13 +172,30 @@ int atomic_notifier_chain_unregister(str
 }
 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.
@@ -163,24 +208,16 @@ EXPORT_SYMBOL_GPL(atomic_notifier_chain_
  *     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);
@@ -250,13 +287,30 @@ int blocking_notifier_chain_unregister(s
 }
 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.
@@ -268,9 +322,8 @@ EXPORT_SYMBOL_GPL(blocking_notifier_chai
  *     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;
 
@@ -281,19 +334,11 @@ int __blocking_notifier_call_chain(struc
         */
        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);
 
 /*
@@ -335,13 +380,18 @@ int raw_notifier_chain_unregister(struct
 }
 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.
@@ -354,18 +404,10 @@ EXPORT_SYMBOL_GPL(raw_notifier_chain_unr
  *     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);
 
@@ -437,12 +479,10 @@ int srcu_notifier_chain_unregister(struc
 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.
@@ -454,25 +494,17 @@ EXPORT_SYMBOL_GPL(srcu_notifier_chain_un
  *     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);
 
 /**
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -706,8 +706,8 @@ static int load_image_and_restore(void)
  */
 int hibernate(void)
 {
-       int error, nr_calls = 0;
        bool snapshot_test = false;
+       int error;
 
        if (!hibernation_available()) {
                pm_pr_dbg("Hibernation not available.\n");
@@ -723,11 +723,9 @@ int hibernate(void)
 
        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();
 
@@ -785,7 +783,8 @@ int hibernate(void)
        /* 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:
@@ -804,7 +803,7 @@ int hibernate(void)
  */
 int hibernate_quiet_exec(int (*func)(void *data), void *data)
 {
-       int error, nr_calls = 0;
+       int error;
 
        lock_system_sleep();
 
@@ -815,11 +814,9 @@ int hibernate_quiet_exec(int (*func)(voi
 
        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)
@@ -880,8 +877,9 @@ int hibernate_quiet_exec(int (*func)(voi
        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();
@@ -910,7 +908,7 @@ EXPORT_SYMBOL_GPL(hibernate_quiet_exec);
  */
 static int software_resume(void)
 {
-       int error, nr_calls = 0;
+       int error;
 
        /*
         * If the user said "noresume".. bail out early.
@@ -997,11 +995,9 @@ static int software_resume(void)
 
        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();
@@ -1017,7 +1013,8 @@ static int software_resume(void)
        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();
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -80,18 +80,18 @@ int unregister_pm_notifier(struct notifi
 }
 EXPORT_SYMBOL_GPL(unregister_pm_notifier);
 
-int __pm_notifier_call_chain(unsigned long val, int nr_to_call, int *nr_calls)
+int pm_notifier_call_chain_robust(unsigned long val_up, unsigned long val_down)
 {
        int ret;
 
-       ret = __blocking_notifier_call_chain(&pm_chain_head, val, NULL,
-                                               nr_to_call, nr_calls);
+       ret = blocking_notifier_call_chain_robust(&pm_chain_head, val_up, 
val_down, NULL);
 
        return notifier_to_errno(ret);
 }
+
 int pm_notifier_call_chain(unsigned long val)
 {
-       return __pm_notifier_call_chain(val, -1, NULL);
+       return blocking_notifier_call_chain(&pm_chain_head, val, NULL);
 }
 
 /* If set, devices may be suspended and resumed asynchronously. */
--- a/kernel/power/power.h
+++ b/kernel/power/power.h
@@ -210,8 +210,7 @@ static inline void suspend_test_finish(c
 
 #ifdef CONFIG_PM_SLEEP
 /* kernel/power/main.c */
-extern int __pm_notifier_call_chain(unsigned long val, int nr_to_call,
-                                   int *nr_calls);
+extern int pm_notifier_call_chain_robust(unsigned long val_up, unsigned long 
val_down);
 extern int pm_notifier_call_chain(unsigned long val);
 #endif
 
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -342,18 +342,16 @@ static int suspend_test(int level)
  */
 static int suspend_prepare(suspend_state_t state)
 {
-       int error, nr_calls = 0;
+       int error;
 
        if (!sleep_state_supported(state))
                return -EPERM;
 
        pm_prepare_console();
 
-       error = __pm_notifier_call_chain(PM_SUSPEND_PREPARE, -1, &nr_calls);
-       if (error) {
-               nr_calls--;
-               goto Finish;
-       }
+       error = pm_notifier_call_chain_robust(PM_SUSPEND_PREPARE, 
PM_POST_SUSPEND);
+       if (error)
+               goto Restore;
 
        trace_suspend_resume(TPS("freeze_processes"), 0, true);
        error = suspend_freeze_processes();
@@ -363,8 +361,8 @@ static int suspend_prepare(suspend_state
 
        suspend_stats.failed_freeze++;
        dpm_save_failed_step(SUSPEND_FREEZE);
- Finish:
-       __pm_notifier_call_chain(PM_POST_SUSPEND, nr_calls, NULL);
+       pm_notifier_call_chain(PM_POST_SUSPEND);
+ Restore:
        pm_restore_console();
        return error;
 }
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -46,7 +46,7 @@ int is_hibernate_resume_dev(const struct
 static int snapshot_open(struct inode *inode, struct file *filp)
 {
        struct snapshot_data *data;
-       int error, nr_calls = 0;
+       int error;
 
        if (!hibernation_available())
                return -EPERM;
@@ -73,9 +73,7 @@ static int snapshot_open(struct inode *i
                        swap_type_of(swsusp_resume_device, 0, NULL) : -1;
                data->mode = O_RDONLY;
                data->free_bitmaps = false;
-               error = __pm_notifier_call_chain(PM_HIBERNATION_PREPARE, -1, 
&nr_calls);
-               if (error)
-                       __pm_notifier_call_chain(PM_POST_HIBERNATION, 
--nr_calls, NULL);
+               error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, 
PM_POST_HIBERNATION);
        } else {
                /*
                 * Resuming.  We may need to wait for the image device to
@@ -85,15 +83,11 @@ static int snapshot_open(struct inode *i
 
                data->swap = -1;
                data->mode = O_WRONLY;
-               error = __pm_notifier_call_chain(PM_RESTORE_PREPARE, -1, 
&nr_calls);
+               error = pm_notifier_call_chain_robust(PM_RESTORE_PREPARE, 
PM_POST_RESTORE);
                if (!error) {
                        error = create_basic_memory_bitmaps();
                        data->free_bitmaps = !error;
-               } else
-                       nr_calls--;
-
-               if (error)
-                       __pm_notifier_call_chain(PM_POST_RESTORE, nr_calls, 
NULL);
+               }
        }
        if (error)
                hibernate_release();
--- a/tools/power/pm-graph/sleepgraph.py
+++ b/tools/power/pm-graph/sleepgraph.py
@@ -171,7 +171,7 @@ import base64
        tracefuncs = {
                'sys_sync': {},
                'ksys_sync': {},
-               '__pm_notifier_call_chain': {},
+               'pm_notifier_call_chain_robust': {},
                'pm_prepare_console': {},
                'pm_notifier_call_chain': {},
                'freeze_processes': {},


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