6.6-stable review patch. If anyone has any objections, please let me know.
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From: Chun-Tse Shao ctshao@google.com
[ Upstream commit 02a55f2743012a8089f09f6867220c3d57f16564 ]
Same as https://lore.kernel.org/all/20240514180050.182454-1-namhyung@kernel.org/, we should skip `for_each_sibling_event()` for group leader since it doesn't have the ctx yet.
Fixes: f3c0eba28704 ("perf: Add a few assertions") Reported-by: Greg Thelen gthelen@google.com Cc: Namhyung Kim namhyung@kernel.org Cc: Robin Murphy robin.murphy@arm.com Cc: Tuan Phan tuanphan@os.amperecomputing.com Signed-off-by: Chun-Tse Shao ctshao@google.com Acked-by: Will Deacon will@kernel.org Link: https://lore.kernel.org/r/20241108050806.3730811-1-ctshao@google.com Signed-off-by: Catalin Marinas catalin.marinas@arm.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/perf/arm_smmuv3_pmu.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-)
diff --git a/drivers/perf/arm_smmuv3_pmu.c b/drivers/perf/arm_smmuv3_pmu.c index 6303b82566f98..31e491e7f2065 100644 --- a/drivers/perf/arm_smmuv3_pmu.c +++ b/drivers/perf/arm_smmuv3_pmu.c @@ -431,6 +431,17 @@ static int smmu_pmu_event_init(struct perf_event *event) return -EINVAL; }
+ /* + * Ensure all events are on the same cpu so all events are in the + * same cpu context, to avoid races on pmu_enable etc. + */ + event->cpu = smmu_pmu->on_cpu; + + hwc->idx = -1; + + if (event->group_leader == event) + return 0; + for_each_sibling_event(sibling, event->group_leader) { if (is_software_event(sibling)) continue; @@ -442,14 +453,6 @@ static int smmu_pmu_event_init(struct perf_event *event) return -EINVAL; }
- hwc->idx = -1; - - /* - * Ensure all events are on the same cpu so all events are in the - * same cpu context, to avoid races on pmu_enable etc. - */ - event->cpu = smmu_pmu->on_cpu; - return 0; }