xref: /openbmc/linux/tools/lib/str_error_r.c (revision f3539c12)
1 #undef _GNU_SOURCE
2 #include <string.h>
3 #include <stdio.h>
4 #include <linux/string.h>
5 
6 /*
7  * The tools so far have been using the strerror_r() GNU variant, that returns
8  * a string, be it the buffer passed or something else.
9  *
10  * But that, besides being tricky in cases where we expect that the function
11  * using strerror_r() returns the error formatted in a provided buffer (we have
12  * to check if it returned something else and copy that instead), breaks the
13  * build on systems not using glibc, like Alpine Linux, where musl libc is
14  * used.
15  *
16  * So, introduce yet another wrapper, str_error_r(), that has the GNU
17  * interface, but uses the portable XSI variant of strerror_r(), so that users
18  * rest asured that the provided buffer is used and it is what is returned.
19  */
20 char *str_error_r(int errnum, char *buf, size_t buflen)
21 {
22 	int err = strerror_r(errnum, buf, buflen);
23 	if (err)
24 		snprintf(buf, buflen, "INTERNAL ERROR: strerror_r(%d, %p, %zd)=%d", errnum, buf, buflen, err);
25 	return buf;
26 }
27