diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2022-10-02 09:41:27 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-10-02 09:41:27 -0700 |
| commit | febae48afe6063105a0fad83d8e12a6addda7c6a (patch) | |
| tree | 5ef5fb278958c19339b8d4c1957d4b83d6207a72 /kernel | |
| parent | 534b0abc627a4034ecaf177e780b1680e61b37f4 (diff) | |
| parent | 6b959ba22d34ca793ffdb15b5715457c78e38b1a (diff) | |
Merge tag 'perf-urgent-2022-10-02' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull misc perf fixes from Ingo Molnar:
- Fix a PMU enumeration/initialization bug on Intel Alder Lake CPUs
- Fix KVM guest PEBS register handling
- Fix race/reentry bug in perf_output_read_group() reading of PMU
counters
* tag 'perf-urgent-2022-10-02' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/core: Fix reentry problem in perf_output_read_group()
perf/x86/core: Completely disable guest PEBS via guest's global_ctrl
perf/x86/intel: Fix unchecked MSR access error for Alder Lake N
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/events/core.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index 2621fd24ad26..ff4bffc502c6 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -6893,9 +6893,16 @@ static void perf_output_read_group(struct perf_output_handle *handle, { struct perf_event *leader = event->group_leader, *sub; u64 read_format = event->attr.read_format; + unsigned long flags; u64 values[6]; int n = 0; + /* + * Disabling interrupts avoids all counter scheduling + * (context switches, timer based rotation and IPIs). + */ + local_irq_save(flags); + values[n++] = 1 + leader->nr_siblings; if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) @@ -6931,6 +6938,8 @@ static void perf_output_read_group(struct perf_output_handle *handle, __output_copy(handle, values, n * sizeof(u64)); } + + local_irq_restore(flags); } #define PERF_FORMAT_TOTAL_TIMES (PERF_FORMAT_TOTAL_TIME_ENABLED|\ |