[34/54] tracing: Allow whitespace to surround hist trigger filter
diff mbox series

Message ID TY1PR01MB1692184ED8E747455A0CABFA96090@TY1PR01MB1692.jpnprd01.prod.outlook.com
State New
Headers show
Series
  • [01/54] tracing: Remove redundant unread variable ret
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Commit Message

Motai.Hirotaka@aj.MitsubishiElectric.co.jp Aug. 29, 2018, 12:17 p.m. UTC
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.  Specifically, we want to allow
spaces in the trigger itself now that we have additional syntax
(onmatch/onmax) where spaces are more natural e.g. spaces after commas
in param lists.

Link: http://lkml.kernel.org/r/1053090c3c308d4f431accdeb59dff4b511d4554.1516069914.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
(cherry picked from commit ec5ce0987541087dbea5af346bdb85eb04b0f0a2)
Signed-off-by: Hirotaka MOTAI <Motai.Hirotaka@aj.MitsubishiElectric.co.jp>
---
 kernel/trace/trace_events_hist.c | 37 +++++++++++++++++++++++++++-----
 1 file changed, 32 insertions(+), 5 deletions(-)

Patch
diff mbox series

diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 7bcc32a7..7e88daae 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -5157,29 +5157,56 @@  static int event_hist_trigger_func(struct event_command *cmd_ops,
 	unsigned int hist_trigger_bits = TRACING_MAP_BITS_DEFAULT;
 	struct event_trigger_data *trigger_data;
 	struct hist_trigger_attrs *attrs;
 	struct event_trigger_ops *trigger_ops;
 	struct hist_trigger_data *hist_data;
 	struct synth_event *se;
 	const char *se_name;
 	bool remove = false;
-	char *trigger;
+	char *trigger, *p;
 	int ret = 0;
 
 	if (!param)
 		return -EINVAL;
 
 	if (glob[0] == '!')
 		remove = true;
 
-	/* separate the trigger from the filter (k:v [if filter]) */
-	trigger = strsep(&param, " \t");
-	if (!trigger)
-		return -EINVAL;
+	/*
+	 * separate the trigger from the filter (k:v [if filter])
+	 * allowing for whitespace in the trigger
+	 */
+	p = trigger = param;
+	do {
+		p = strstr(p, "if");
+		if (!p)
+			break;
+		if (p == param)
+			return -EINVAL;
+		if (*(p - 1) != ' ' && *(p - 1) != '\t') {
+			p++;
+			continue;
+		}
+		if (p >= param + strlen(param) - strlen("if") - 1)
+			return -EINVAL;
+		if (*(p + strlen("if")) != ' ' && *(p + strlen("if")) != '\t') {
+			p++;
+			continue;
+		}
+		break;
+	} while (p);
+
+	if (!p)
+		param = NULL;
+	else {
+		*(p - 1) = '\0';
+		param = strstrip(p);
+		trigger = strstrip(trigger);
+	}
 
 	attrs = parse_hist_trigger_attrs(trigger);
 	if (IS_ERR(attrs))
 		return PTR_ERR(attrs);
 
 	if (attrs->map_bits)
 		hist_trigger_bits = attrs->map_bits;