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 11:54:08 -0700 |
| commit | 23d92064081ba10489b7a654b97255d8dfcfa6f4 (patch) | |
| tree | b03cc6c918a735b2b7d0fb1e2f7e687fab0861b9 /kernel/events | |
| parent | d4558852c75896249de3f3e70fa60befa4da4305 (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/events')
| -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 e80611f1f8a3..e75617186877 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -7025,6 +7025,9 @@ 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; } /* |