From c8b5f2c96d1bf6cefcbe12f67dce0b892fe20512 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Wed, 6 Jul 2016 11:56:20 -0300 Subject: tools: Introduce str_error_r() The tools so far have been using the strerror_r() GNU variant, that returns a string, be it the buffer passed or something else. But that, besides being tricky in cases where we expect that the function using strerror_r() returns the error formatted in a provided buffer (we have to check if it returned something else and copy that instead), breaks the build on systems not using glibc, like Alpine Linux, where musl libc is used. So, introduce yet another wrapper, str_error_r(), that has the GNU interface, but uses the portable XSI variant of strerror_r(), so that users rest asured that the provided buffer is used and it is what is returned. Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-d4t42fnf48ytlk8rjxs822tf@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/lib/str_error_r.c | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) create mode 100644 tools/lib/str_error_r.c (limited to 'tools/lib') diff --git a/tools/lib/str_error_r.c b/tools/lib/str_error_r.c new file mode 100644 index 000000000000..503ae072244c --- /dev/null +++ b/tools/lib/str_error_r.c @@ -0,0 +1,26 @@ +#undef _GNU_SOURCE +#include +#include +#include + +/* + * The tools so far have been using the strerror_r() GNU variant, that returns + * a string, be it the buffer passed or something else. + * + * But that, besides being tricky in cases where we expect that the function + * using strerror_r() returns the error formatted in a provided buffer (we have + * to check if it returned something else and copy that instead), breaks the + * build on systems not using glibc, like Alpine Linux, where musl libc is + * used. + * + * So, introduce yet another wrapper, str_error_r(), that has the GNU + * interface, but uses the portable XSI variant of strerror_r(), so that users + * rest asured that the provided buffer is used and it is what is returned. + */ +char *str_error_r(int errnum, char *buf, size_t buflen) +{ + int err = strerror_r(errnum, buf, buflen); + if (err) + snprintf(buf, buflen, "INTERNAL ERROR: strerror_r(%d, %p, %zd)=%d", errnum, buf, buflen, err); + return buf; +} -- cgit v1.2.3