Commit d7de7267 authored Jan 15, 2020 by Martin KaFai Lau Committed by Alexei Starovoitov Jan 15, 2020

bpftool: Fix a leak of btf object



When testing a map has btf or not, maps_have_btf() tests it by actually
getting a btf_fd from sys_bpf(BPF_BTF_GET_FD_BY_ID). However, it
forgot to btf__free() it.

In maps_have_btf() stage, there is no need to test it by really
calling sys_bpf(BPF_BTF_GET_FD_BY_ID). Testing non zero
info.btf_id is good enough.

Also, the err_close case is unnecessary, and also causes double
close() because the calling func do_dump() will close() all fds again.

Fixes: 99f9863a ("bpftool: Match maps by name")
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Cc: Paul Chaignon <paul.chaignon@orange.com>
Link: https://lore.kernel.org/bpf/20200115230019.1101352-1-kafai@fb.com

parent 990bca1f

tools/bpf/bpftool/map.c

+2 −14

Original line number	Diff line number	Diff line
		@@ -915,32 +915,20 @@ static int maps_have_btf(int *fds, int nb_fds)
		{
		struct bpf_map_info info = {};
		__u32 len = sizeof(info);
		struct btf *btf = NULL;
		int err, i;

		for (i = 0; i < nb_fds; i++) {
		err = bpf_obj_get_info_by_fd(fds[i], &info, &len);
		if (err) {
		p_err("can't get map info: %s", strerror(errno));
		goto err_close;
		}

		err = btf__get_from_id(info.btf_id, &btf);
		if (err) {
		p_err("failed to get btf");
		goto err_close;
		return -1;
		}

		if (!btf)
		if (!info.btf_id)
		return 0;
		}

		return 1;

		err_close:
		for (; i < nb_fds; i++)
		close(fds[i]);
		return -1;
		}

		static int