perf tools: Stop reading the kallsyms data from perf.data

As it is not used anymore, since 'perf script' switched to asking
libtraceevent to use tools/perf's symbol resolution routines.
Acked-by: David Ahern <dsahern@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/n/tip-4ilhofz4b7o8yokvutjt9yzz@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/trace-event-parse.c

@@ -135,36 +135,6 @@ void event_format__print(struct event_format *event,
 	return event_format__fprintf(event, cpu, data, size, stdout);
 }
 
-void parse_proc_kallsyms(struct pevent *pevent,
-			 char *file, unsigned int size __maybe_unused)
-{
-	unsigned long long addr;
-	char *func;
-	char *line;
-	char *next = NULL;
-	char *addr_str;
-	char *mod;
-	char *fmt = NULL;
-
-	line = strtok_r(file, "\n", &next);
-	while (line) {
-		mod = NULL;
-		addr_str = strtok_r(line, " ", &fmt);
-		addr = strtoull(addr_str, NULL, 16);
-		/* skip character */
-		strtok_r(NULL, " ", &fmt);
-		func = strtok_r(NULL, "\t", &fmt);
-		mod = strtok_r(NULL, "]", &fmt);
-		/* truncate the extra '[' */
-		if (mod)
-			mod = mod + 1;
-
-		pevent_register_function(pevent, func, addr, mod);
-
-		line = strtok_r(NULL, "\n", &next);
-	}
-}
-
 void parse_ftrace_printk(struct pevent *pevent,
 			 char *file, unsigned int size __maybe_unused)
 {

tools/perf/util/trace-event-read.c

@@ -162,25 +162,23 @@ static char *read_string(void)
 static int read_proc_kallsyms(struct pevent *pevent)
 {
 	unsigned int size;
-	char *buf;
 
 	size = read4(pevent);
 	if (!size)
 		return 0;
-
-	buf = malloc(size + 1);
-	if (buf == NULL)
-		return -1;
-
-	if (do_read(buf, size) < 0) {
-		free(buf);
-		return -1;
-	}
-	buf[size] = '\0';
-
-	parse_proc_kallsyms(pevent, buf, size);
-
-	free(buf);
+	/*
+	 * Just skip it, now that we configure libtraceevent to use the
+	 * tools/perf/ symbol resolver.
+	 *
+	 * We need to skip it so that we can continue parsing old perf.data
+	 * files, that contains this /proc/kallsyms payload.
+	 *
+	 * Newer perf.data files will have just the 4-bytes zeros "kallsyms
+	 * payload", so that older tools can continue reading it and interpret
+	 * it as "no kallsyms payload is present".
+	 */
+	lseek(input_fd, size, SEEK_CUR);
+	trace_data_size += size;
 	return 0;
 }