Commit-ID: 0819b2e30ccb93edf04876237b6205eef84ec8d2 Gitweb: http://git.kernel.org/tip/0819b2e30ccb93edf04876237b6205eef84ec8d2 Author: Peter Zijlstra <pet...@infradead.org> AuthorDate: Thu, 15 May 2014 20:23:48 +0200 Committer: Thomas Gleixner <t...@linutronix.de> CommitDate: Mon, 19 May 2014 21:44:55 +0900
perf: Limit perf_event_attr::sample_period to 63 bits 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.wea...@maine.edu> Signed-off-by: Peter Zijlstra <pet...@infradead.org> Cc: sta...@vger.kernel.org Link: http://lkml.kernel.org/n/tip-p25fhunibl4y3qi0zuqmy...@git.kernel.org Signed-off-by: Thomas Gleixner <t...@linutronix.de> --- kernel/events/core.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/events/core.c b/kernel/events/core.c index 7123284..1d1ec64 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -7029,6 +7029,9 @@ 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; } /* -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/