Commit d1b4574a authored Nov 02, 2019 by Toke Høiland-Jørgensen Committed by Alexei Starovoitov Nov 02, 2019

libbpf: Fix error handling in bpf_map__reuse_fd()

bpf_map__reuse_fd() was calling close() in the error path before returning
an error value based on errno. However, close can change errno, so that can
lead to potentially misleading error messages. Instead, explicitly store
errno in the err variable before each goto.

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/157269297769.394725.12634985106772698611.stgit@toke.dk

parent 78db77fa

tools/lib/bpf/libbpf.c

+10 −4

Original line number	Diff line number	Diff line
		@@ -1917,16 +1917,22 @@ int bpf_map__reuse_fd(struct bpf_map *map, int fd)
		return -errno;

		new_fd = open("/", O_RDONLY \| O_CLOEXEC);
		if (new_fd < 0)
		if (new_fd < 0) {
		err = -errno;
		goto err_free_new_name;
		}

		new_fd = dup3(fd, new_fd, O_CLOEXEC);
		if (new_fd < 0)
		if (new_fd < 0) {
		err = -errno;
		goto err_close_new_fd;
		}

		err = zclose(map->fd);
		if (err)
		if (err) {
		err = -errno;
		goto err_close_new_fd;
		}
		free(map->name);

		map->fd = new_fd;
		@@ -1945,7 +1951,7 @@ err_close_new_fd:
		close(new_fd);
		err_free_new_name:
		free(new_name);
		return -errno;
		return err;
		}

		int bpf_map__resize(struct bpf_map *map, __u32 max_entries)