tools lib traceevent: Separate out tep_strerror() for strerror_r() issues

While working on having PowerTop use libtracevent as a shared object
library, Tzvetomir hit "str_error_r not defined". This was added by commit
c3cec9e68f12d ("tools lib traceevent: Use str_error_r()") because
strerror_r() has two definitions, where one is GNU specific, and the other
is XSI complient. The strerror_r() is in a wrapper str_error_r() to keep the
code from having to worry about which compiler is being used.

The problem is that str_error_r() is external to libtraceevent, and not part
of the library. If it is used as a shared object then the tools using it
will need to define that function. I do not want that function defined in
libtraceevent itself, as it is out of scope for that library.

As there's only a single instance of this call, and its in the traceevent
library's own tep_strerror() function, we can copy what was done in perf,
and create yet another external file that undefs _GNU_SOURCE to use the more
portable version of the function. We don't need to worry about the errors
that strerror_r() returns. If the buffer isn't big enough, we simply
truncate it.

Reported-by: Tzvetomir Stoyanov <tstoyanov@vmware.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
Cc: linux trace devel <linux-trace-devel@vger.kernel.org>
Link: http://lkml.kernel.org/r/20181005121816.484e654f@gandalf.local.home
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 0 insertions, 30 deletions

diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c
index 7980fc6c3bac..233179a712d6 100644
--- a/tools/lib/traceevent/event-parse.c
+++ b/tools/lib/traceevent/event-parse.c
@@ -18,7 +18,6 @@
 #include <errno.h>
 #include <stdint.h>
 #include <limits.h>
-#include <linux/string.h>
 #include <linux/time64.h>
 
 #include <netinet/in.h>
@@ -6201,35 +6200,6 @@ enum tep_errno tep_parse_event(struct tep_handle *pevent, const char *buf,
 	return __parse_event(pevent, &event, buf, size, sys);
 }
 
-#undef _PE
-#define _PE(code, str) str
-static const char * const tep_error_str[] = {
-	TEP_ERRORS
-};
-#undef _PE
-
-int tep_strerror(struct tep_handle *pevent __maybe_unused,
-		 enum tep_errno errnum, char *buf, size_t buflen)
-{
-	int idx;
-	const char *msg;
-
-	if (errnum >= 0) {
-		str_error_r(errnum, buf, buflen);
-		return 0;
-	}
-
-	if (errnum <= __TEP_ERRNO__START ||
-	    errnum >= __TEP_ERRNO__END)
-		return -1;
-
-	idx = errnum - __TEP_ERRNO__START - 1;
-	msg = tep_error_str[idx];
-	snprintf(buf, buflen, "%s", msg);
-
-	return 0;
-}
-
 int get_field_val(struct trace_seq *s, struct tep_format_field *field,
 		  const char *name, struct tep_record *record,
 		  unsigned long long *val, int err)