perf core: Return error pointer if inherit_event() fails to find pmu_ctx

Ravi Bangoria · Peter Zijlstra · commit e2d371484653 · 2022-12-27T12:44:00.000+01:00
inherit_event() returns NULL only when it finds orphaned events otherwise it returns either valid child_event pointer or an error pointer. Follow the same when it fails to find pmu_ctx. Fixes: bd27568 ("perf: Rewrite core context handling") Reported-by: Dan Carpenter <error27@gmail.com> Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20221118051539.820-1-ravi.bangoria@amd.com
diff --git a/kernel/events/core.c b/kernel/events/core.c
@@ -13231,7 +13231,7 @@ inherit_event(struct perf_event *parent_event,
 	pmu_ctx = find_get_pmu_context(child_event->pmu, child_ctx, child_event);
 	if (IS_ERR(pmu_ctx)) {
 		free_event(child_event);
-		return NULL;
+		return ERR_CAST(pmu_ctx);
 	}
 	child_event->pmu_ctx = pmu_ctx;
 

Original file line number	Diff line number	Diff line change
`@@ -13231,7 +13231,7 @@ inherit_event(struct perf_event *parent_event,`
`13231`	`13231`	`pmu_ctx = find_get_pmu_context(child_event->pmu, child_ctx, child_event);`
`13232`	`13232`	`if (IS_ERR(pmu_ctx)) {`
`13233`	`13233`	`free_event(child_event);`
`13234`		`- return NULL;`
	`13234`	`+ return ERR_CAST(pmu_ctx);`
`13235`	`13235`	`}`
`13236`	`13236`	`child_event->pmu_ctx = pmu_ctx;`
`13237`	`13237`