diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2014-05-15 20:23:48 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-06-11 12:03:21 -0700 |
| commit | 95090e8a573c7743a2b0d800c4c52fac581e5bbe (patch) | |
| tree | bea7d960de3286872e8fa13c6b967818c1ecbb1a /kernel | |
| parent | 266166041bd6195b0d1ecbb1c4753aa00569112f (diff) | |
perf: Limit perf_event_attr::sample_period to 63 bits
commit 0819b2e30ccb93edf04876237b6205eef84ec8d2 upstream.
Vince reported that using a large sample_period (one with bit 63 set)
results in wreckage since while the sample_period is fundamentally
unsigned (negative periods don't make sense) the way we implement
things very much rely on signed logic.
So limit sample_period to 63 bits to avoid tripping over this.
Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-p25fhunibl4y3qi0zuqmyf4b@git.kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/events/core.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index 0a29beef35f1..a130e4a1d500 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -6590,6 +6590,9 @@ SYSCALL_DEFINE5(perf_event_open, if (attr.freq) { if (attr.sample_freq > sysctl_perf_event_sample_rate) return -EINVAL; + } else { + if (attr.sample_period & (1ULL << 63)) + return -EINVAL; } /* |