Commit 913a90bc authored by Ravi Bangoria's avatar Ravi Bangoria Committed by Ingo Molnar

perf/ioctl: Add check for the sample_period value

perf_event_open() limits the sample_period to 63 bits. See:

  0819b2e3 ("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: default avatarRavi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: default avatarPeter 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: 0819b2e3 ("perf: Limit perf_event_attr::sample_period to 63 bits")
Link: https://lkml.kernel.org/r/20190604042953.914-1-ravi.bangoria@linux.ibm.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 085ebfe9
...@@ -5005,6 +5005,9 @@ static int perf_event_period(struct perf_event *event, u64 __user *arg) ...@@ -5005,6 +5005,9 @@ static int perf_event_period(struct perf_event *event, u64 __user *arg)
if (perf_event_check_period(event, value)) if (perf_event_check_period(event, value))
return -EINVAL; return -EINVAL;
if (!event->attr.freq && (value & (1ULL << 63)))
return -EINVAL;
event_function_call(event, __perf_event_period, &value); event_function_call(event, __perf_event_period, &value);
return 0; return 0;
......
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