Commit 47f661ec authored by Marco Elver's avatar Marco Elver Committed by Peter Zijlstra
Browse files

perf: Apply PERF_EVENT_IOC_MODIFY_ATTRIBUTES to children 



As with other ioctls (such as PERF_EVENT_IOC_{ENABLE,DISABLE}), fix up
handling of PERF_EVENT_IOC_MODIFY_ATTRIBUTES to also apply to children.

Suggested-by: default avatarDmitry Vyukov <dvyukov@google.com>
Signed-off-by: default avatarMarco Elver <elver@google.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: default avatarDmitry Vyukov <dvyukov@google.com>
Link: https://lkml.kernel.org/r/20210408103605.1676875-3-elver@google.com
parent ef54c1a4

kernel/events/core.c

+21 −1
Original line number Diff line number Diff line
@@ -3200,16 +3200,36 @@ static int perf_event_modify_breakpoint(struct perf_event *bp, 
static int perf_event_modify_attr(struct perf_event *event,

				  struct perf_event_attr *attr)

{

	int (*func)(struct perf_event *, struct perf_event_attr *);

	struct perf_event *child;

	int err;



	if (event->attr.type != attr->type)

		return -EINVAL;



	switch (event->attr.type) {

	case PERF_TYPE_BREAKPOINT:

		return perf_event_modify_breakpoint(event, attr);

		func = perf_event_modify_breakpoint;

		break;

	default:

		/* Place holder for future additions. */

		return -EOPNOTSUPP;

	}



	WARN_ON_ONCE(event->ctx->parent_ctx);



	mutex_lock(&event->child_mutex);

	err = func(event, attr);

	if (err)

		goto out;

	list_for_each_entry(child, &event->child_list, child_list) {

		err = func(child, attr);

		if (err)

			goto out;

	}

out:

	mutex_unlock(&event->child_mutex);

	return err;

}



static void ctx_sched_out(struct perf_event_context *ctx,