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authorPeter Zijlstra <peterz@infradead.org>2023-06-09 12:34:46 +0200
committerIngo Molnar <mingo@kernel.org>2023-11-15 04:18:31 +0100
commit889c58b3155ff4c8e8671c95daef63d6fabbb6b1 (patch)
treeb3e5e03a84f667fcae07cab2b64a26afaff2ab1e /include/linux/perf_event.h
parentb85ea95d086471afb4ad062012a4d73cd328fa86 (diff)
perf/core: Fix cpuctx refcounting
Audit of the refcounting turned up that perf_pmu_migrate_context() fails to migrate the ctx refcount. Fixes: bd2756811766 ("perf: Rewrite core context handling") Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lkml.kernel.org/r/20230612093539.085862001@infradead.org Cc: <stable@vger.kernel.org>
Diffstat (limited to 'include/linux/perf_event.h')
-rw-r--r--include/linux/perf_event.h13
1 files changed, 8 insertions, 5 deletions
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index afb028c54f33..5547ba68e6e4 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -843,11 +843,11 @@ struct perf_event {
};
/*
- * ,-----------------------[1:n]----------------------.
- * V V
- * perf_event_context <-[1:n]-> perf_event_pmu_context <--- perf_event
- * ^ ^ | |
- * `--------[1:n]---------' `-[n:1]-> pmu <-[1:n]-'
+ * ,-----------------------[1:n]------------------------.
+ * V V
+ * perf_event_context <-[1:n]-> perf_event_pmu_context <-[1:n]- perf_event
+ * | |
+ * `--[n:1]-> pmu <-[1:n]--'
*
*
* struct perf_event_pmu_context lifetime is refcount based and RCU freed
@@ -865,6 +865,9 @@ struct perf_event {
* ctx->mutex pinning the configuration. Since we hold a reference on
* group_leader (through the filedesc) it can't go away, therefore it's
* associated pmu_ctx must exist and cannot change due to ctx->mutex.
+ *
+ * perf_event holds a refcount on perf_event_context
+ * perf_event holds a refcount on perf_event_pmu_context
*/
struct perf_event_pmu_context {
struct pmu *pmu;