On Fri, 2024-07-12 at 18:14 +0800, Geliang Tang wrote:
> From: Geliang Tang <tanggeliang@xxxxxxxxxx>
>
> The errno 95 (ENOTSUP or EOPNOTSUPP) can be recognized by
> strerror_r(),
> but 524 (ENOTSUPP) can't:
>
> prog 'basic_alloc3': BPF program load failed: Operation not
> supported
> prog 'basic_alloc3': failed to load: -95
> failed to load object 'verifier_arena'
> FAIL:unexpected_load_failure unexpected error: -95 (errno 95)
>
> prog 'inner_map': BPF program load failed: unknown error (-524)
> prog 'inner_map': failed to load: -524
> failed to load object 'bloom_filter_map'
> failed to load BPF skeleton 'bloom_filter_map': -524
> FAIL:bloom_filter_map__open_and_load unexpected error: -524
>
> This patch fixes this by handling ENOTSUPP in libbpf_strerror_r().
> With
> this change, the new error string looks like:
>
> prog 'inner_map': BPF program load failed: Operation not supported
> (-524)
>
> Signed-off-by: Geliang Tang <tanggeliang@xxxxxxxxxx>
> ---
> tools/lib/bpf/str_error.c | 11 +++++++----
> tools/lib/bpf/str_error.h | 4 ++++
> 2 files changed, 11 insertions(+), 4 deletions(-)
>
> diff --git a/tools/lib/bpf/str_error.c b/tools/lib/bpf/str_error.c
> index 5e6a1e27ddf9..10597d5124cd 100644
> --- a/tools/lib/bpf/str_error.c
> +++ b/tools/lib/bpf/str_error.c
> @@ -23,10 +23,13 @@ char *libbpf_strerror_r(int err, char *dst, int
> len)
> if (ret == -1)
> ret = errno;
> if (ret) {
> - if (ret == EINVAL)
> - /* strerror_r() doesn't recognize this
> specific error */
> - snprintf(dst, len, "unknown error (%d)", err
> < 0 ? err : -err);
> - else
> + if (ret == EINVAL) {
> + if (err == ENOTSUPP)
Shouldn't use "err" directly here, should use "err < 0 ? -err : err"
instead. I prefer to add an unsigned variable "no" in v2:
unsigned int no = err < 0 ? -err : err;
And use "switch-case" for future expansion:
switch (no) {
case ENOTSUPP:
> + snprintf(dst, len, "Operation not
> supported (%d)", -err);
No need to use "Operation not supported (-524)" here, just "Operation
not supported" is better.
snprintf(dst, len, "Operation not supported");
> + else
> + /* strerror_r() doesn't recognize
> this specific error */
> + snprintf(dst, len, "unknown error
> (%d)", err < 0 ? err : -err);
Then here:
snprintf(dst, len, "unknown error (-%u)", no);
Changes Requested.
Will send a v2 soon.
Thanks,
-Geliang
> + } else
> snprintf(dst, len, "ERROR:
> strerror_r(%d)=%d", err, ret);
> }
> return dst;
> diff --git a/tools/lib/bpf/str_error.h b/tools/lib/bpf/str_error.h
> index 626d7ffb03d6..c41f6ba133cf 100644
> --- a/tools/lib/bpf/str_error.h
> +++ b/tools/lib/bpf/str_error.h
> @@ -4,6 +4,10 @@
>
> #define STRERR_BUFSIZE 128
>
> +#ifndef ENOTSUPP
> +#define ENOTSUPP 524
> +#endif
> +
> char *libbpf_strerror_r(int err, char *dst, int len);
>
> #endif /* __LIBBPF_STR_ERROR_H */
