diff options
| author | Andrii Nakryiko <andrii@kernel.org> | 2024-05-06 17:13:32 -0700 |
|---|---|---|
| committer | Martin KaFai Lau <martin.lau@kernel.org> | 2024-05-07 16:21:59 -0700 |
| commit | 548c2ede0dc81cb8c86f3a72c1c63fe1c179cbfe (patch) | |
| tree | 7b7d7cdb28f3dd005ebaeb22fc423a70a25edfb0 /tools/lib/bpf | |
| parent | 9d66d60e968d85742569d025a2fb509cb57333bb (diff) | |
libbpf: fix libbpf_strerror_r() handling unknown errors
strerror_r(), used from libbpf-specific libbpf_strerror_r() wrapper is
documented to return error in two different ways, depending on glibc
version. Take that into account when handling strerror_r()'s own errors,
which happens when we pass some non-standard (internal) kernel error to
it. Before this patch we'd have "ERROR: strerror_r(524)=22", which is
quite confusing. Now for the same situation we'll see a bit less
visually scary "unknown error (-524)".
At least we won't confuse user with irrelevant EINVAL (22).
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240507001335.1445325-5-andrii@kernel.org
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Diffstat (limited to 'tools/lib/bpf')
| -rw-r--r-- | tools/lib/bpf/str_error.c | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/tools/lib/bpf/str_error.c b/tools/lib/bpf/str_error.c index 146da01979c7..5e6a1e27ddf9 100644 --- a/tools/lib/bpf/str_error.c +++ b/tools/lib/bpf/str_error.c @@ -2,6 +2,7 @@ #undef _GNU_SOURCE #include <string.h> #include <stdio.h> +#include <errno.h> #include "str_error.h" /* make sure libbpf doesn't use kernel-only integer typedefs */ @@ -15,7 +16,18 @@ char *libbpf_strerror_r(int err, char *dst, int len) { int ret = strerror_r(err < 0 ? -err : err, dst, len); - if (ret) - snprintf(dst, len, "ERROR: strerror_r(%d)=%d", err, ret); + /* on glibc <2.13, ret == -1 and errno is set, if strerror_r() can't + * handle the error, on glibc >=2.13 *positive* (errno-like) error + * code is returned directly + */ + 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 + snprintf(dst, len, "ERROR: strerror_r(%d)=%d", err, ret); + } return dst; } |