diff options
| author | Kan Liang <kan.liang@linux.intel.com> | 2025-01-17 07:19:12 -0800 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2025-02-25 14:54:14 +0100 |
| commit | 0d39844150546fa1415127c5fbae26db64070dd3 (patch) | |
| tree | 4ec6b68c342a4323b226c1758094210a3b26224f | |
| parent | 88ec7eedbbd21cad38707620ad6c48a4e9a87c18 (diff) | |
perf/core: Fix low freq setting via IOC_PERIOD
A low attr::freq value cannot be set via IOC_PERIOD on some platforms.
The perf_event_check_period() introduced in:
81ec3f3c4c4d ("perf/x86: Add check_period PMU callback")
was intended to check the period, rather than the frequency.
A low frequency may be mistakenly rejected by limit_period().
Fix it.
Fixes: 81ec3f3c4c4d ("perf/x86: Add check_period PMU callback")
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20250117151913.3043942-2-kan.liang@linux.intel.com
Closes: https://lore.kernel.org/lkml/20250115154949.3147-1-ravi.bangoria@amd.com/
| -rw-r--r-- | kernel/events/core.c | 17 |
1 files changed, 9 insertions, 8 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index 086d46d09696..6364319e2f88 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -5969,14 +5969,15 @@ static int _perf_event_period(struct perf_event *event, u64 value) if (!value) return -EINVAL; - if (event->attr.freq && value > sysctl_perf_event_sample_rate) - return -EINVAL; - - if (perf_event_check_period(event, value)) - return -EINVAL; - - if (!event->attr.freq && (value & (1ULL << 63))) - return -EINVAL; + if (event->attr.freq) { + if (value > sysctl_perf_event_sample_rate) + return -EINVAL; + } else { + if (perf_event_check_period(event, value)) + return -EINVAL; + if (value & (1ULL << 63)) + return -EINVAL; + } event_function_call(event, __perf_event_period, &value); |