The patch titled
percpu_counter: fix CPU unplug race in percpu_counter_destroy()
has been added to the -mm tree. Its filename is
percpu_counter-fix-cpu-unplug-race-in-percpu_counter_destroy.patch
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------------------------------------------------------
Subject: percpu_counter: fix CPU unplug race in percpu_counter_destroy()
From: Eric Dumazet <dada1@xxxxxxxxxxxxx>
We should first delete the counter from percpu_counters list
before freeing memory, or a percpu_counter_hotcpu_callback()
could dereference a NULL pointer.
Signed-off-by: Eric Dumazet <dada1@xxxxxxxxxxxxx>
Acked-by: David S. Miller <davem@xxxxxxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Mingming Cao <cmm@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
lib/percpu_counter.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff -puN lib/percpu_counter.c~percpu_counter-fix-cpu-unplug-race-in-percpu_counter_destroy lib/percpu_counter.c
--- a/lib/percpu_counter.c~percpu_counter-fix-cpu-unplug-race-in-percpu_counter_destroy
+++ a/lib/percpu_counter.c
@@ -104,13 +104,13 @@ void percpu_counter_destroy(struct percp
if (!fbc->counters)
return;
- free_percpu(fbc->counters);
- fbc->counters = NULL;
#ifdef CONFIG_HOTPLUG_CPU
mutex_lock(&percpu_counters_lock);
list_del(&fbc->list);
mutex_unlock(&percpu_counters_lock);
#endif
+ free_percpu(fbc->counters);
+ fbc->counters = NULL;
}
EXPORT_SYMBOL(percpu_counter_destroy);
_
Patches currently in -mm which might be from dada1@xxxxxxxxxxxxx are
origin.patch
linux-next.patch
percpu_counter-fix-cpu-unplug-race-in-percpu_counter_destroy.patch
percpu_counter-fix-__percpu_counter_sum.patch
softirq-introduce-statistics-for-softirq.patch
proc-export-statistics-for-softirq-to-proc.patch
proc-update-document-for-proc-softirqs-and-proc-stat.patch
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