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

[Steven Rostedt]

From: "Steven Rostedt (VMware)" <rost...@goodmis.org>

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  <zanu...@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rost...@goodmis.org>
---
 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