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08 September 2024, 02:26:05 UTC
Revision 12ca6ad2e3a896256f086497a7c7406a547ee373 authored by Peter Zijlstra on 15 December 2015, 12:49:05 UTC, committed by Ingo Molnar on 06 January 2016, 09:52:39 UTC 
perf: Fix race in swevent hash
 
There's a race on CPU unplug where we free the swevent hash array
while it can still have events on. This will result in a
use-after-free which is BAD.

Simply do not free the hash array on unplug. This leaves the thing
around and no use-after-free takes place.

When the last swevent dies, we do a for_each_possible_cpu() iteration
anyway to clean these up, at which time we'll free it, so no leakage
will occur.

Reported-by: Sasha Levin <sasha.levin@oracle.com>
Tested-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
1 parent c127449
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Tip revision: 12ca6ad2e3a896256f086497a7c7406a547ee373 authored by Peter Zijlstra on 15 December 2015, 12:49:05 UTC
perf: Fix race in swevent hash
Tip revision: 12ca6ad
locking-selftest-hardirq.h 
#undef IRQ_DISABLE
#undef IRQ_ENABLE
#undef IRQ_ENTER
#undef IRQ_EXIT

#define IRQ_ENABLE		HARDIRQ_ENABLE
#define IRQ_DISABLE		HARDIRQ_DISABLE
#define IRQ_ENTER		HARDIRQ_ENTER
#define IRQ_EXIT		HARDIRQ_EXIT
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