3.2-stable review patch. If anyone has any objections, please let me know.
------------------ From: Will Deacon <[email protected]> commit 99c1745b9c76910e195889044f914b4898b7c9a5 upstream. When disabling a counter on an ARMv7 PMU, we should also clear the overflow flag in case an overflow occurred whilst stopping the counter. This prevents a spurious overflow being picked up later and leading to either false accounting or a NULL dereference. Reported-by: Ming Lei <[email protected]> Signed-off-by: Will Deacon <[email protected]> Signed-off-by: Russell King <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- arch/arm/kernel/perf_event_v7.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/arch/arm/kernel/perf_event_v7.c +++ b/arch/arm/kernel/perf_event_v7.c @@ -878,6 +878,11 @@ static inline int armv7_pmnc_disable_int counter = ARMV7_IDX_TO_COUNTER(idx); asm volatile("mcr p15, 0, %0, c9, c14, 2" : : "r" (BIT(counter))); + isb(); + /* Clear the overflow flag in case an interrupt is pending. */ + asm volatile("mcr p15, 0, %0, c9, c12, 3" : : "r" (BIT(counter))); + isb(); + return idx; } -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
