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 <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-d4t42fnf48ytlk8rjxs822tf@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index 0201f661ccb8..2b222a7955c9 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -468,7 +468,7 @@ static struct debuginfo *open_debuginfo(const char *module, bool silent)
                 err = kernel_get_module_dso(module, &dso);
                 if (err < 0) {
                         if (!dso || dso->load_errno == 0) {
-                                if (!strerror_r(-err, reason, STRERR_BUFSIZE))
+                                if (!str_error_r(-err, reason, STRERR_BUFSIZE))
                                         strcpy(reason, "(unknown)");
                         } else
                                 dso__strerror_load(dso, reason, STRERR_BUFSIZE);
@@ -806,7 +806,7 @@ static int __show_one_line(FILE *fp, int l, bool skip, bool show_num)
 error:
         if (ferror(fp)) {
                 pr_warning("File read error: %s\n",
-                           strerror_r(errno, sbuf, sizeof(sbuf)));
+                           str_error_r(errno, sbuf, sizeof(sbuf)));
                 return -1;
         }
         return 0;
@@ -886,7 +886,7 @@ static int __show_line_range(struct line_range *lr, const char *module,
         fp = fopen(lr->path, "r");
         if (fp == NULL) {
                 pr_warning("Failed to open %s: %s\n", lr->path,
-                           strerror_r(errno, sbuf, sizeof(sbuf)));
+                           str_error_r(errno, sbuf, sizeof(sbuf)));
                 return -errno;
         }
         /* Skip to starting line number */