From: Quentin Monnet quentin@isovalent.com
mainline inclusion from mainline-5.15-rc1 commit 6d2d73cdd673d493f9f3751188757129b1d23fb7 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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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 (cherry picked from commit 6d2d73cdd673d493f9f3751188757129b1d23fb7) Signed-off-by: Wang Yufen wangyufen@huawei.com --- 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 75fdc19e85c1..21bf1f5f45ec 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -8324,7 +8324,7 @@ 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); @@ -8333,6 +8333,8 @@ 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");