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| 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 /tools/power | |
| parent | f75aef392f869018f78cfedf3c320a6b3fcfda6b (diff) | |
| download | linux-70d932985757fbe978024db313001218e9f8fe5c.tar.bz2 | |
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 'tools/power')
| -rwxr-xr-x | tools/power/pm-graph/sleepgraph.py | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/tools/power/pm-graph/sleepgraph.py b/tools/power/pm-graph/sleepgraph.py index 46ff97e909c6..1bc36a1db14f 100755 --- a/tools/power/pm-graph/sleepgraph.py +++ b/tools/power/pm-graph/sleepgraph.py @@ -171,7 +171,7 @@ class SystemValues: tracefuncs = { 'sys_sync': {}, 'ksys_sync': {}, - '__pm_notifier_call_chain': {}, + 'pm_notifier_call_chain_robust': {}, 'pm_prepare_console': {}, 'pm_notifier_call_chain': {}, 'freeze_processes': {}, |