perf list: Fix max event string size

Recent stalled-cycles event names were larger than the 40 chars printout
used by perf list.

Extend that, make it robust for future extensions and also adjust alignments
in face of wider event names.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/n/tip-7y40wib8n009io7hjpn1dsrm@git.kernel.orgSigned-off-by: Ingo Molnar <mingo@elte.hu>

tools/perf/util/parse-events.c

@@ -929,7 +929,7 @@ void print_tracepoint_events(const char *subsys_glob, const char *event_glob)
 
 			snprintf(evt_path, MAXPATHLEN, "%s:%s",
 				 sys_dirent.d_name, evt_dirent.d_name);
-			printf("  %-42s [%s]\n", evt_path,
+			printf("  %-50s [%s]\n", evt_path,
 				event_type_descriptors[PERF_TYPE_TRACEPOINT]);
 		}
 		closedir(evt_dir);
@@ -994,7 +994,7 @@ void print_events_type(u8 type)
 		else
 			snprintf(name, sizeof(name), "%s", syms->symbol);
 
-		printf("  %-42s [%s]\n", name,
+		printf("  %-50s [%s]\n", name,
 			event_type_descriptors[type]);
 	}
 }
@@ -1012,11 +1012,10 @@ int print_hwcache_events(const char *event_glob)
 			for (i = 0; i < PERF_COUNT_HW_CACHE_RESULT_MAX; i++) {
 				char *name = event_cache_name(type, op, i);
 
-				if (event_glob != NULL && 
-				    !strglobmatch(name, event_glob))
+				if (event_glob != NULL && !strglobmatch(name, event_glob))
 					continue;
 
-				printf("  %-42s [%s]\n", name,
+				printf("  %-50s [%s]\n", name,
 					event_type_descriptors[PERF_TYPE_HW_CACHE]);
 				++printed;
 			}
@@ -1026,14 +1025,16 @@ int print_hwcache_events(const char *event_glob)
 	return printed;
 }
 
+#define MAX_NAME_LEN 100
+
 /*
  * Print the help text for the event symbols:
  */
 void print_events(const char *event_glob)
 {
-	struct event_symbol *syms = event_symbols;
 	unsigned int i, type, prev_type = -1, printed = 0, ntypes_printed = 0;
-	char name[40];
+	struct event_symbol *syms = event_symbols;
+	char name[MAX_NAME_LEN];
 
 	printf("\n");
 	printf("List of pre-defined events (to be used in -e):\n");
@@ -1053,10 +1054,10 @@ void print_events(const char *event_glob)
 			continue;
 
 		if (strlen(syms->alias))
-			sprintf(name, "%s OR %s", syms->symbol, syms->alias);
+			snprintf(name, MAX_NAME_LEN, "%s OR %s", syms->symbol, syms->alias);
 		else
-			strcpy(name, syms->symbol);
-		printf("  %-42s [%s]\n", name,
+			strncpy(name, syms->symbol, MAX_NAME_LEN);
+		printf("  %-50s [%s]\n", name,
 			event_type_descriptors[type]);
 
 		prev_type = type;
@@ -1073,12 +1074,12 @@ void print_events(const char *event_glob)
 		return;
 
 	printf("\n");
-	printf("  %-42s [%s]\n",
+	printf("  %-50s [%s]\n",
 		"rNNN (see 'perf list --help' on how to encode it)",
 	       event_type_descriptors[PERF_TYPE_RAW]);
 	printf("\n");
 
-	printf("  %-42s [%s]\n",
+	printf("  %-50s [%s]\n",
 			"mem:<addr>[:access]",
 			event_type_descriptors[PERF_TYPE_BREAKPOINT]);
 	printf("\n");