Messages in this thread | | | From | Michael Ellerman <> | Subject | Re: [PATCH v2] perf ioctl: Add check for the sample_period value | Date | Tue, 18 Jun 2019 22:28:19 +1000 |
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Ravi Bangoria <ravi.bangoria@linux.ibm.com> writes: > Peter / mpe, > > Is the v2 looks good? If so, can anyone of you please pick this up.
I usually wouldn't take it, it's generic perf code. Unless peter/ingo/acme tell me otherwise.
It's sort of a bug fix for 0819b2e30ccb, should it have a fixes and/or stable tag?
Fixes: 0819b2e30ccb ("perf: Limit perf_event_attr::sample_period to 63 bits") Cc: stable@vger.kernel.org # v3.15+
cheers
> On 6/4/19 9:59 AM, Ravi Bangoria wrote: >> 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.bangoria@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; >>
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