Commit 170a7e3e authored by Sean Young's avatar Sean Young Committed by Daniel Borkmann
Browse files

bpf: bpf_prog_array_copy() should return -ENOENT if exclude_prog not found 



This makes is it possible for bpf prog detach to return -ENOENT.

Acked-by: default avatarYonghong Song <yhs@fb.com>
Signed-off-by: default avatarSean Young <sean@mess.org>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
parent 9ce64f19

kernel/bpf/core.c

+9 −2
Original line number Diff line number Diff line
@@ -1616,6 +1616,7 @@ int bpf_prog_array_copy(struct bpf_prog_array __rcu *old_array, 
	int new_prog_cnt, carry_prog_cnt = 0;

	struct bpf_prog **existing_prog;

	struct bpf_prog_array *array;

	bool found_exclude = false;

	int new_prog_idx = 0;



	/* Figure out how many existing progs we need to carry over to
@@ -1624,14 +1625,20 @@ int bpf_prog_array_copy(struct bpf_prog_array __rcu *old_array, 
	if (old_array) {

		existing_prog = old_array->progs;

		for (; *existing_prog; existing_prog++) {

			if (*existing_prog != exclude_prog &&

			    *existing_prog != &dummy_bpf_prog.prog)

			if (*existing_prog == exclude_prog) {

				found_exclude = true;

				continue;

			}

			if (*existing_prog != &dummy_bpf_prog.prog)

				carry_prog_cnt++;

			if (*existing_prog == include_prog)

				return -EEXIST;

		}

	}



	if (exclude_prog && !found_exclude)

		return -ENOENT;



	/* How many progs (not NULL) will be in the new array? */

	new_prog_cnt = carry_prog_cnt;

	if (include_prog)

kernel/trace/bpf_trace.c

+2 −0
Original line number Diff line number Diff line
@@ -1006,6 +1006,8 @@ void perf_event_detach_bpf_prog(struct perf_event *event) 


	old_array = event->tp_event->prog_array;

	ret = bpf_prog_array_copy(old_array, event->prog, NULL, &new_array);

	if (ret == -ENOENT)

		goto unlock;

	if (ret < 0) {

		bpf_prog_array_delete_safe(old_array, event->prog);

	} else {