Commit 6d2d73cd authored by Quentin Monnet's avatar Quentin Monnet Committed by Andrii Nakryiko
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libbpf: Return non-null error on failures in libbpf_find_prog_btf_id() 



Variable "err" is initialised to -EINVAL so that this error code is
returned when something goes wrong in libbpf_find_prog_btf_id().
However, a recent change in the function made use of the variable in
such a way that it is set to 0 if retrieving linear information on the
program is successful, and this 0 value remains if we error out on
failures at later stages.

Let's fix this by setting err to -EINVAL later in the function.

Fixes: e9fc3ce9 ("libbpf: Streamline error reporting for high-level APIs")
Signed-off-by: default avatarQuentin Monnet <quentin@isovalent.com>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210729162028.29512-2-quentin@isovalent.com
parent d3621642

tools/lib/bpf/libbpf.c

+3 −1
Original line number Diff line number Diff line
@@ -8317,7 +8317,7 @@ static int libbpf_find_prog_btf_id(const char *name, __u32 attach_prog_fd) 
	struct bpf_prog_info_linear *info_linear;

	struct bpf_prog_info *info;

	struct btf *btf = NULL;

	int err = -EINVAL;

	int err;



	info_linear = bpf_program__get_prog_info_linear(attach_prog_fd, 0);

	err = libbpf_get_error(info_linear);
@@ -8326,6 +8326,8 @@ static int libbpf_find_prog_btf_id(const char *name, __u32 attach_prog_fd) 
			attach_prog_fd);

		return err;

	}



	err = -EINVAL;

	info = &info_linear->info;

	if (!info->btf_id) {

		pr_warn("The target program doesn't have BTF\n");