trace_kprobes: Don't output zero offset

"symbol_name+0" is not so friendly.
It makes the output longer.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4B0CEBCB.7080309@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

kernel/trace/trace_kprobe.c

@@ -243,7 +243,11 @@ static int probe_arg_string(char *buf, size_t n, struct fetch_func *ff)
 		ret = snprintf(buf, n, "@0x%p", ff->data);
 	else if (ff->func == fetch_symbol) {
 		struct symbol_cache *sc = ff->data;
-		ret = snprintf(buf, n, "@%s%+ld", sc->symbol, sc->offset);
+		if (sc->offset)
+			ret = snprintf(buf, n, "@%s%+ld", sc->symbol,
+					sc->offset);
+		else
+			ret = snprintf(buf, n, "@%s", sc->symbol);
 	} else if (ff->func == fetch_retvalue)
 		ret = snprintf(buf, n, "$retval");
 	else if (ff->func == fetch_stack_address)
@@ -762,10 +766,12 @@ static int probes_seq_show(struct seq_file *m, void *v)
 	seq_printf(m, "%c", probe_is_return(tp) ? 'r' : 'p');
 	seq_printf(m, ":%s/%s", tp->call.system, tp->call.name);
 
-	if (tp->symbol)
+	if (!tp->symbol)
+		seq_printf(m, " 0x%p", tp->rp.kp.addr);
+	else if (tp->rp.kp.offset)
 		seq_printf(m, " %s+%u", probe_symbol(tp), tp->rp.kp.offset);
 	else
-		seq_printf(m, " 0x%p", tp->rp.kp.addr);
+		seq_printf(m, " %s", probe_symbol(tp));
 
 	for (i = 0; i < tp->nr_args; i++) {
 		ret = probe_arg_string(buf, MAX_ARGSTR_LEN, &tp->args[i].fetch);