| From 82f4ea0be74c07f9803dc8a188889d1573924791 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Thu, 29 Jul 2021 17:20:21 +0100 |
| Subject: libbpf: Return non-null error on failures in |
| libbpf_find_prog_btf_id() |
| |
| From: Quentin Monnet <quentin@isovalent.com> |
| |
| [ Upstream commit 6d2d73cdd673d493f9f3751188757129b1d23fb7 ] |
| |
| 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: e9fc3ce99b34 ("libbpf: Streamline error reporting for high-level APIs") |
| Signed-off-by: Quentin Monnet <quentin@isovalent.com> |
| Signed-off-by: Andrii Nakryiko <andrii@kernel.org> |
| Link: https://lore.kernel.org/bpf/20210729162028.29512-2-quentin@isovalent.com |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| tools/lib/bpf/libbpf.c | 4 +++- |
| 1 file changed, 3 insertions(+), 1 deletion(-) |
| |
| diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c |
| index aa5ad6fc5f40..2234d5c33177 100644 |
| --- a/tools/lib/bpf/libbpf.c |
| +++ b/tools/lib/bpf/libbpf.c |
| @@ -9515,7 +9515,7 @@ 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); |
| @@ -9524,6 +9524,8 @@ 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"); |
| -- |
| 2.30.2 |
| |