xref: /linux/tools/lib/bpf/str_error.c (revision 3f41368fbfe1b3d5922d317fe1a0a0cab6846802)
1 // SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
2 #undef _GNU_SOURCE
3 #include <string.h>
4 #include <stdio.h>
5 #include <errno.h>
6 #include "str_error.h"
7 
8 /* make sure libbpf doesn't use kernel-only integer typedefs */
9 #pragma GCC poison u8 u16 u32 u64 s8 s16 s32 s64
10 
11 /*
12  * Wrapper to allow for building in non-GNU systems such as Alpine Linux's musl
13  * libc, while checking strerror_r() return to avoid having to check this in
14  * all places calling it.
15  */
16 char *libbpf_strerror_r(int err, char *dst, int len)
17 {
18 	int ret = strerror_r(err < 0 ? -err : err, dst, len);
19 	/* on glibc <2.13, ret == -1 and errno is set, if strerror_r() can't
20 	 * handle the error, on glibc >=2.13 *positive* (errno-like) error
21 	 * code is returned directly
22 	 */
23 	if (ret == -1)
24 		ret = errno;
25 	if (ret) {
26 		if (ret == EINVAL)
27 			/* strerror_r() doesn't recognize this specific error */
28 			snprintf(dst, len, "unknown error (%d)", err < 0 ? err : -err);
29 		else
30 			snprintf(dst, len, "ERROR: strerror_r(%d)=%d", err, ret);
31 	}
32 	return dst;
33 }
34