[PATCH 25/32] tracing: Allow whitespace to surround hist trigger filter

Tom Zanussi
2017-06-26T22:54:06Z

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@linux.intel.com>
---
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 d191f1a..53a0634 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -4632,7 +4632,7 @@ static int event_hist_trigger_func(struct event_command *cmd_ops,
struct event_trigger_ops *trigger_ops;
struct hist_trigger_data *hist_data;
bool remove = false;
- char *trigger;
+ char *trigger, *p;
int ret = 0;

if (!param)
@@ -4642,9 +4642,19 @@ 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))
@@ -4694,6 +4704,7 @@ 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