perf_event_open() limits the sample_period to 63 bits. See commit 0819b2e30ccb ("perf: Limit perf_event_attr::sample_period to 63 bits"). Make ioctl() consistent with it.
Also on powerpc, negative sample_period could cause a recursive PMIs leading to a hang (reported when running perf-fuzzer). Signed-off-by: Ravi Bangoria <ravi.bango...@linux.ibm.com> --- kernel/events/core.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/events/core.c b/kernel/events/core.c index abbd4b3b96c2..e44c90378940 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -5005,6 +5005,9 @@ static int perf_event_period(struct perf_event *event, u64 __user *arg) if (perf_event_check_period(event, value)) return -EINVAL; + if (!event->attr.freq && (value & (1ULL << 63))) + return -EINVAL; + event_function_call(event, __perf_event_period, &value); return 0; -- 2.20.1