1 // SPDX-License-Identifier: GPL-2.0
2 #undef _GNU_SOURCE
3 #include <string.h>
4 #include <stdio.h>
5 #include <linux/string.h>
6 
7 /*
8  * The tools so far have been using the strerror_r() GNU variant, that returns
9  * a string, be it the buffer passed or something else.
10  *
11  * But that, besides being tricky in cases where we expect that the function
12  * using strerror_r() returns the error formatted in a provided buffer (we have
13  * to check if it returned something else and copy that instead), breaks the
14  * build on systems not using glibc, like Alpine Linux, where musl libc is
15  * used.
16  *
17  * So, introduce yet another wrapper, str_error_r(), that has the GNU
18  * interface, but uses the portable XSI variant of strerror_r(), so that users
19  * rest asured that the provided buffer is used and it is what is returned.
20  */
str_error_r(int errnum,char * buf,size_t buflen)21 char *str_error_r(int errnum, char *buf, size_t buflen)
22 {
23 	int err = strerror_r(errnum, buf, buflen);
24 	if (err)
25 		snprintf(buf, buflen, "INTERNAL ERROR: strerror_r(%d, [buf], %zd)=%d", errnum, buflen, err);
26 	return buf;
27 }
28