Commit 23ab656b authored by Toke Høiland-Jørgensen's avatar Toke Høiland-Jørgensen Committed by Daniel Borkmann
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libbpf: Prevent overriding errno when logging errors 



Turns out there were a few more instances where libbpf didn't save the
errno before writing an error message, causing errno to be overridden by
the printf() return and the error disappearing if logging is enabled.

Signed-off-by: default avatarToke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarAndrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200813142905.160381-1-toke@redhat.com
parent b33164f2

tools/lib/bpf/libbpf.c

+7 −5
Original line number Diff line number Diff line
@@ -3478,10 +3478,11 @@ bpf_object__probe_global_data(struct bpf_object *obj) 


	map = bpf_create_map_xattr(&map_attr);

	if (map < 0) {

		cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));

		ret = -errno;

		cp = libbpf_strerror_r(ret, errmsg, sizeof(errmsg));

		pr_warn("Error in %s():%s(%d). Couldn't create simple array map.\n",

			__func__, cp, errno);

		return -errno;

			__func__, cp, -ret);

		return ret;

	}



	insns[0].imm = map;
@@ -6012,9 +6013,10 @@ int bpf_program__pin_instance(struct bpf_program *prog, const char *path, 
	}



	if (bpf_obj_pin(prog->instances.fds[instance], path)) {

		cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));

		err = -errno;

		cp = libbpf_strerror_r(err, errmsg, sizeof(errmsg));

		pr_warn("failed to pin program: %s\n", cp);

		return -errno;

		return err;

	}

	pr_debug("pinned program '%s'\n", path);