[PATCH v2 31/40] tracing: Allow whitespace to surround hist trigger filter

[Tom Zanussi]

The existing code only allows for one space before and after the 'if'
specifying the filter for a hist trigger.  Add code to make that more
permissive as far as whitespace goes.

Signed-off-by: Tom Zanussi <tom.zanussi@xxxxxxxxxxxxxxx>
---
 kernel/trace/trace_events_hist.c | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 0a398f3..4f66f2e 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -4819,7 +4819,7 @@ static int event_hist_trigger_func(struct event_command *cmd_ops,
 	struct synth_event *se;
 	const char *se_name;
 	bool remove = false;
-	char *trigger;
+	char *trigger, *p;
 	int ret = 0;
 
 	if (!param)
@@ -4829,9 +4829,19 @@ static int event_hist_trigger_func(struct event_command *cmd_ops,
 		remove = true;
 
 	/* separate the trigger from the filter (k:v [if filter]) */
-	trigger = strsep(&param, " \t");
-	if (!trigger)
-		return -EINVAL;
+	trigger = param;
+	p = strstr(param, " if");
+	if (!p)
+		p = strstr(param, "\tif");
+	if (p) {
+		if (p == trigger)
+			return -EINVAL;
+		param = p + 1;
+		param = strstrip(param);
+		*p = '\0';
+		trigger = strstrip(trigger);
+	} else
+		param = NULL;
 
 	attrs = parse_hist_trigger_attrs(trigger);
 	if (IS_ERR(attrs))
@@ -4889,6 +4899,7 @@ static int event_hist_trigger_func(struct event_command *cmd_ops,
 	}
 
 	ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file);
+
 	/*
 	 * The above returns on success the # of triggers registered,
 	 * but if it didn't register any it returns zero.  Consider no
-- 
1.9.3