[PATCH 4.19.y 09/13] tracing: Have the historgram use the result of str_has_prefix() for len of prefix

George Guo
2024-05-09T02:30:30Z

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

commit 036876fa56204ae0fa59045bd6bbb2691a060633 upstream.

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@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: George Guo <guodongtai@kylinos.cn>
---
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 95f5e328a98b..460b07d51dd6 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -4410,12 +4410,13 @@ 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)) {
@@ -4423,8 +4424,8 @@ 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)) {
--
2.34.1