perfcounters: fix refcounting bug, take 2 (4bcf349a) · Commits · 戴 / test

Only free child_counter if it has a parent; if it doesn't, then it has a file pointing to it and we'll free it in perf_release. Signed-off-by:

kernel/perf_counter.c

+4 −5

Original line number	Diff line number	Diff line
		@@ -1958,15 +1958,14 @@ __perf_counter_exit_task(struct task_struct *child,
		sync_child_counter(child_counter, parent_counter);
		list_for_each_entry_safe(sub, tmp, &child_counter->sibling_list,
		list_entry) {
		if (sub->parent)
		if (sub->parent) {
		sync_child_counter(sub, sub->parent);
		kfree(sub);
		}
		}

		if (!child_counter->filp \|\| !atomic_long_read(&child_counter->filp->f_count))
		kfree(child_counter);
		}
		}

		/*
		* When a child task exits, feed back counter values to parent counters.