From: Ravi Bangoria ravi.bangoria@linux.ibm.com
[ Upstream commit 913a90bc5a3a06b1f04c337320e9aeee2328dd77 ]
perf_event_open() limits the sample_period to 63 bits. See:
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.bangoria@linux.ibm.com Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Cc: Alexander Shishkin alexander.shishkin@linux.intel.com Cc: Arnaldo Carvalho de Melo acme@redhat.com Cc: Jiri Olsa jolsa@redhat.com Cc: Linus Torvalds torvalds@linux-foundation.org Cc: Peter Zijlstra peterz@infradead.org Cc: Stephane Eranian eranian@google.com Cc: Thomas Gleixner tglx@linutronix.de Cc: Vince Weaver vincent.weaver@maine.edu Cc: acme@kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: maddy@linux.vnet.ibm.com Cc: mpe@ellerman.id.au Fixes: 0819b2e30ccb ("perf: Limit perf_event_attr::sample_period to 63 bits") Link: https://lkml.kernel.org/r/20190604042953.914-1-ravi.bangoria@linux.ibm.com Signed-off-by: Ingo Molnar mingo@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- kernel/events/core.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/kernel/events/core.c b/kernel/events/core.c index 751888cbed5c..16af86ab24c4 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -5012,6 +5012,9 @@ 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;