kernel_optimize_test/kernel/power
Peter Zijlstra 70d9329857 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
2020-09-01 09:58:03 +02:00
..
autosleep.c PM / wakeup: Show wakeup sources stats in sysfs 2019-08-21 00:20:40 +02:00
console.c
energy_model.c PM / EM: remove em_register_perf_domain 2020-06-24 17:16:42 +02:00
hibernate.c notifier: Fix broken error handling pattern 2020-09-01 09:58:03 +02:00
Kconfig treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
main.c notifier: Fix broken error handling pattern 2020-09-01 09:58:03 +02:00
Makefile PM: hibernate: Split off snapshot dev option 2020-05-19 17:48:08 +02:00
power.h notifier: Fix broken error handling pattern 2020-09-01 09:58:03 +02:00
poweroff.c kernel/power: constify sysrq_key_op 2020-05-15 14:53:20 +02:00
process.c PM / sleep: Show freezing tasks that caused a suspend abort 2018-09-10 12:09:10 +02:00
qos.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
snapshot.c mm: memcg: convert vmstat slab counters to bytes 2020-08-07 11:33:24 -07:00
suspend_test.c PM: sleep: Switch to rtc_time64_to_tm()/rtc_tm_to_time64() 2019-12-20 09:58:08 +01:00
suspend.c notifier: Fix broken error handling pattern 2020-09-01 09:58:03 +02:00
swap.c PM: hibernate: Add __init annotation to swsusp_header_init() 2020-06-05 13:52:38 +02:00
user.c notifier: Fix broken error handling pattern 2020-09-01 09:58:03 +02:00
wakelock.c PM / wakeup: Show wakeup sources stats in sysfs 2019-08-21 00:20:40 +02:00