diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2020-08-18 15:57:36 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2020-09-01 09:58:03 +0200 |
| commit | 70d932985757fbe978024db313001218e9f8fe5c (patch) | |
| tree | 66e9c13a3877d35009421dd0aa19a13d2d06450a /kernel/power/power.h | |
| parent | Linux 5.9-rc3 (diff) | |
| download | linux-70d932985757fbe978024db313001218e9f8fe5c.tar.xz linux-70d932985757fbe978024db313001218e9f8fe5c.zip | |
notifier: Fix broken error handling pattern
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) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20200818135804.325626653@infradead.org
Diffstat (limited to 'kernel/power/power.h')
| -rw-r--r-- | kernel/power/power.h | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/kernel/power/power.h b/kernel/power/power.h index 32fc89ac96c3..24f12d534515 100644 --- a/kernel/power/power.h +++ b/kernel/power/power.h @@ -210,8 +210,7 @@ static inline void suspend_test_finish(const char *label) {} #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 |