[for-next][PATCH 4/5] tracing: Have the historgram use the result of str_has_prefix() for len of prefix

From: Steven Rostedt
Date: Sat Dec 22 2018 - 11:47:26 EST


From: "Steven Rostedt (VMware)" <rostedt@xxxxxxxxxxx>

As str_has_prefix() returns the length on match, we can use that for the
updating of the string pointer instead of recalculating the prefix size.

Cc: Tom Zanussi <zanussi@xxxxxxxxxx>
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
---
kernel/trace/trace_events_hist.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 0d878dcd1e4b..449d90cfa151 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -4342,12 +4342,13 @@ static int parse_actions(struct hist_trigger_data *hist_data)
unsigned int i;
int ret = 0;
char *str;
+ int len;

for (i = 0; i < hist_data->attrs->n_actions; i++) {
str = hist_data->attrs->action_str[i];

- if (str_has_prefix(str, "onmatch(")) {
- char *action_str = str + sizeof("onmatch(") - 1;
+ if ((len = str_has_prefix(str, "onmatch("))) {
+ char *action_str = str + len;

data = onmatch_parse(tr, action_str);
if (IS_ERR(data)) {
@@ -4355,8 +4356,8 @@ static int parse_actions(struct hist_trigger_data *hist_data)
break;
}
data->fn = action_trace;
- } else if (str_has_prefix(str, "onmax(")) {
- char *action_str = str + sizeof("onmax(") - 1;
+ } else if ((len = str_has_prefix(str, "onmax("))) {
+ char *action_str = str + len;

data = onmax_parse(action_str);
if (IS_ERR(data)) {
--
2.19.2