perf tools: Use sscanf for parsing /proc/pid/maps

When reading those files to synthesize MMAP events.  It makes the code
shorter and cleaner.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1352643651-13891-1-git-send-email-namhyung@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/event.c

@@ -193,41 +193,30 @@ static int perf_event__synthesize_mmap_events(struct perf_tool *tool,
 	event->header.misc = PERF_RECORD_MISC_USER;
 
 	while (1) {
-		char bf[BUFSIZ], *pbf = bf;
-		int n;
+		char bf[BUFSIZ];
+		char prot[5];
+		char execname[PATH_MAX];
+		char anonstr[] = "//anon";
 		size_t size;
+
 		if (fgets(bf, sizeof(bf), fp) == NULL)
 			break;
 
-		/* 00400000-0040c000 r-xp 00000000 fd:01 41038  /bin/cat */
-		n = hex2u64(pbf, &event->mmap.start);
-		if (n < 0)
-			continue;
-		pbf += n + 1;
-		n = hex2u64(pbf, &event->mmap.len);
-		if (n < 0)
-			continue;
-		pbf += n + 3;
-		if (*pbf == 'x') { /* vm_exec */
-			char anonstr[] = "//anon\n";
-			char *execname = strchr(bf, '/');
-
-			/* Catch VDSO */
-			if (execname == NULL)
-				execname = strstr(bf, "[vdso]");
+		/* ensure null termination since stack will be reused. */
+		strcpy(execname, "");
 
-			/* Catch anonymous mmaps */
-			if ((execname == NULL) && !strstr(bf, "["))
-				execname = anonstr;
+		/* 00400000-0040c000 r-xp 00000000 fd:01 41038  /bin/cat */
+		sscanf(bf, "%"PRIx64"-%"PRIx64" %s %"PRIx64" %*x:%*x %*u %s\n",
+		       &event->mmap.start, &event->mmap.len, prot,
+		       &event->mmap.pgoff, execname);
 
-			if (execname == NULL)
+		if (prot[2] != 'x')
 			continue;
 
-			pbf += 3;
-			n = hex2u64(pbf, &event->mmap.pgoff);
+		if (!strcmp(execname, ""))
+			strcpy(execname, anonstr);
 
-			size = strlen(execname);
-			execname[size - 1] = '\0'; /* Remove \n */
+		size = strlen(execname) + 1;
 		memcpy(event->mmap.filename, execname, size);
 		size = PERF_ALIGN(size, sizeof(u64));
 		event->mmap.len -= event->mmap.start;
@@ -243,7 +232,6 @@ static int perf_event__synthesize_mmap_events(struct perf_tool *tool,
 			break;
 		}
 	}
-	}
 
 	fclose(fp);
 	return rc;