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| author | Will Deacon <will.deacon@arm.com> | 2012-03-06 17:34:50 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2012-03-07 10:40:49 +0100 |
| commit | f6f5a30c834135c9f2fa10400c59ebbdd9188567 (patch) | |
| tree | 208358216772eedab5998070878db55df5d4e772 /arch/arm/kernel/perf_event_v6.c | |
| parent | ARM: 7355/1: perf: clear overflow flag when disabling counter on ARMv7 PMU (diff) | |
| download | linux-f6f5a30c834135c9f2fa10400c59ebbdd9188567.tar.xz linux-f6f5a30c834135c9f2fa10400c59ebbdd9188567.zip | |
ARM: 7356/1: perf: check that we have an event in the PMU IRQ handlers
The PMU IRQ handlers in perf assume that if a counter has overflowed
then perf must be responsible. In the paranoid world of crazy hardware,
this could be false, so check that we do have a valid event before
attempting to dereference NULL in the interrupt path.
Cc: <stable@vger.kernel.org>
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/kernel/perf_event_v6.c')
| -rw-r--r-- | arch/arm/kernel/perf_event_v6.c | 20 |
1 files changed, 2 insertions, 18 deletions
diff --git a/arch/arm/kernel/perf_event_v6.c b/arch/arm/kernel/perf_event_v6.c index 88bf15253fbd..b78af0cc6ef3 100644 --- a/arch/arm/kernel/perf_event_v6.c +++ b/arch/arm/kernel/perf_event_v6.c @@ -467,23 +467,6 @@ armv6pmu_enable_event(struct hw_perf_event *hwc, raw_spin_unlock_irqrestore(&events->pmu_lock, flags); } -static int counter_is_active(unsigned long pmcr, int idx) -{ - unsigned long mask = 0; - if (idx == ARMV6_CYCLE_COUNTER) - mask = ARMV6_PMCR_CCOUNT_IEN; - else if (idx == ARMV6_COUNTER0) - mask = ARMV6_PMCR_COUNT0_IEN; - else if (idx == ARMV6_COUNTER1) - mask = ARMV6_PMCR_COUNT1_IEN; - - if (mask) - return pmcr & mask; - - WARN_ONCE(1, "invalid counter number (%d)\n", idx); - return 0; -} - static irqreturn_t armv6pmu_handle_irq(int irq_num, void *dev) @@ -513,7 +496,8 @@ armv6pmu_handle_irq(int irq_num, struct perf_event *event = cpuc->events[idx]; struct hw_perf_event *hwc; - if (!counter_is_active(pmcr, idx)) + /* Ignore if we don't have an event. */ + if (!event) continue; /* |