perf target: Simplify handling of strerror_r return

To deal with forwarding the strerror_r (GNU) return we need to check if
the returned value is the buffer we passed or maybe some constant
(unknown error), simplify that action by using scnprintf, that will do
all the buflen size checks, trimming if needed.

Acked-by: Jiri Olsa <jolsa@redhat.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-d0ik6i5gjew56j0qphql28ou@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/target.c b/tools/perf/util/target.c
index e74c5963dc7a9db7038e4ad3f5f7de1ed490f20f..a53603b27e525864eeb328e934ba696dc3ea7e6e 100644 (file)
--- a/tools/perf/util/target.c
+++ b/tools/perf/util/target.c
@@ -123,11 +123,8 @@ int target__strerror(struct target *target, int errnum,
        if (errnum >= 0) {
                const char *err = strerror_r(errnum, buf, buflen);
 
-               if (err != buf) {
-                       size_t len = strlen(err);
-                       memcpy(buf, err, min(buflen - 1, len));
-                       *(buf + min(buflen - 1, len)) = '\0';
-               }
+               if (err != buf)
+                       scnprintf(buf, buflen, "%s", err);
 
                return 0;
        }