tracing/filters: allow user input integer to be oct or hex

Before patch:

 # echo 'parent_pid == 0x10' > events/sched/sched_process_fork/filter
 # cat sched/sched_process_fork/filter
 parent_pid == 0

After patch:

 # cat sched/sched_process_fork/filter
 parent_pid == 16

Also check the input more strictly.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Tom Zanussi <tzanussi@gmail.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <49E04C53.4010600@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

kernel/trace/trace_events_filter.c

@@ -419,12 +419,13 @@ int filter_parse(char **pbuf, struct filter_pred *pred)
 	if (!pred->field_name)
 		return -ENOMEM;
 
-	pred->val = simple_strtoull(val_str, &tmp, 10);
+	pred->val = simple_strtoull(val_str, &tmp, 0);
 	if (tmp == val_str) {
 		pred->str_val = kstrdup(val_str, GFP_KERNEL);
 		if (!pred->str_val)
 			return -ENOMEM;
-	}
+	} else if (*tmp != '\0')
+		return -EINVAL;
 
 	return 0;
 }