Merge tag 'perf-urgent-2026-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf fixes from Ingo Molnar:

 - Fix a PMU driver crash on AMD EPYC systems, caused by
   a race condition in x86_pmu_enable()

 - Fix a possible counter-initialization bug in x86_pmu_enable()

 - Fix a counter inheritance bug in inherit_event() and
   __perf_event_read()

 - Fix an Intel PMU driver branch constraints handling bug
   found by UBSAN

 - Fix the Intel PMU driver's new Off-Module Response (OMR)
   support code for Diamond Rapids / Nova lake, to fix a snoop
   information parsing bug

* tag 'perf-urgent-2026-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/intel: Fix OMR snoop information parsing issues
  perf/x86/intel: Add missing branch counters constraint apply
  perf: Make sure to use pmu_ctx->pmu for groups
  x86/perf: Make sure to program the counter value for stopped events on migration
  perf/x86: Move event pointer setup earlier in x86_pmu_enable()

1 files changed, 8 insertions, 11 deletions

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 1f5699b339ec..89b40e439717 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -4813,7 +4813,7 @@ static void __perf_event_read(void *info)
 	struct perf_event *sub, *event = data->event;
 	struct perf_event_context *ctx = event->ctx;
 	struct perf_cpu_context *cpuctx = this_cpu_ptr(&perf_cpu_context);
-	struct pmu *pmu = event->pmu;
+	struct pmu *pmu;
 
 	/*
 	 * If this is a task context, we need to check whether it is
@@ -4825,7 +4825,7 @@ static void __perf_event_read(void *info)
 	if (ctx->task && cpuctx->task_ctx != ctx)
 		return;
 
-	raw_spin_lock(&ctx->lock);
+	guard(raw_spinlock)(&ctx->lock);
 	ctx_time_update_event(ctx, event);
 
 	perf_event_update_time(event);
@@ -4833,25 +4833,22 @@ static void __perf_event_read(void *info)
 		perf_event_update_sibling_time(event);
 
 	if (event->state != PERF_EVENT_STATE_ACTIVE)
-		goto unlock;
+		return;
 
 	if (!data->group) {
-		pmu->read(event);
+		perf_pmu_read(event);
 		data->ret = 0;
-		goto unlock;
+		return;
 	}
 
+	pmu = event->pmu_ctx->pmu;
 	pmu->start_txn(pmu, PERF_PMU_TXN_READ);
 
-	pmu->read(event);
-
+	perf_pmu_read(event);
 	for_each_sibling_event(sub, event)
 		perf_pmu_read(sub);
 
 	data->ret = pmu->commit_txn(pmu);
-
-unlock:
-	raw_spin_unlock(&ctx->lock);
 }
 
 static inline u64 perf_event_count(struct perf_event *event, bool self)
@@ -14744,7 +14741,7 @@ inherit_event(struct perf_event *parent_event,
 	get_ctx(child_ctx);
 	child_event->ctx = child_ctx;
 
-	pmu_ctx = find_get_pmu_context(child_event->pmu, child_ctx, child_event);
+	pmu_ctx = find_get_pmu_context(parent_event->pmu_ctx->pmu, child_ctx, child_event);
 	if (IS_ERR(pmu_ctx)) {
 		free_event(child_event);
 		return ERR_CAST(pmu_ctx);