path: root/tools/power/pm-graph
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authorPeter Zijlstra <peterz@infradead.org>2020-08-18 15:57:36 +0200
committerIngo Molnar <mingo@kernel.org>2020-09-01 09:58:03 +0200
commit70d932985757fbe978024db313001218e9f8fe5c (patch)
tree66e9c13a3877d35009421dd0aa19a13d2d06450a /tools/power/pm-graph
parentLinux 5.9-rc3 (diff)
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/pm-graph')
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': {},