public inbox for stable@vger.kernel.org
 help / color / mirror / Atom feed
From: George Guo <dongtai.guo@linux.dev>
To: gregkh@linuxfoundation.org, rostedt@goodmis.org,
	mhiramat@kernel.org, tom.zanussi@linux.intel.com
Cc: stable@vger.kernel.org, Namhyung Kim <namhyung@kernel.org>,
	George Guo <guodongtai@kylinos.cn>
Subject: [PATCH 4.19.y 07/13] tracing: Use str_has_prefix() helper for histogram code
Date: Thu,  9 May 2024 10:29:25 +0800	[thread overview]
Message-ID: <20240509022931.3513365-8-dongtai.guo@linux.dev> (raw)
In-Reply-To: <20240509022931.3513365-1-dongtai.guo@linux.dev>

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

commit 754481e6954cbef53f8bc4412ad48dde611e21d3 upstream.

The tracing histogram code contains a lot of instances of the construct:

 strncmp(str, "const", sizeof("const") - 1)

This can be prone to bugs due to typos or bad cut and paste. Use the
str_has_prefix() helper macro instead that removes the need for having two
copies of the constant string.

Cc: Tom Zanussi <tom.zanussi@linux.intel.com>
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 | 32 ++++++++++++++++----------------
 1 file changed, 16 insertions(+), 16 deletions(-)

diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 1139075a6395..1441c3934cbf 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -1878,8 +1878,8 @@ static int parse_action(char *str, struct hist_trigger_attrs *attrs)
 	if (attrs->n_actions >= HIST_ACTIONS_MAX)
 		return ret;
 
-	if ((strncmp(str, "onmatch(", strlen("onmatch(")) == 0) ||
-	    (strncmp(str, "onmax(", strlen("onmax(")) == 0)) {
+	if ((str_has_prefix(str, "onmatch(")) ||
+	    (str_has_prefix(str, "onmax("))) {
 		attrs->action_str[attrs->n_actions] = kstrdup(str, GFP_KERNEL);
 		if (!attrs->action_str[attrs->n_actions]) {
 			ret = -ENOMEM;
@@ -1896,34 +1896,34 @@ static int parse_assignment(char *str, struct hist_trigger_attrs *attrs)
 {
 	int ret = 0;
 
-	if ((strncmp(str, "key=", strlen("key=")) == 0) ||
-	    (strncmp(str, "keys=", strlen("keys=")) == 0)) {
+	if ((str_has_prefix(str, "key=")) ||
+	    (str_has_prefix(str, "keys="))) {
 		attrs->keys_str = kstrdup(str, GFP_KERNEL);
 		if (!attrs->keys_str) {
 			ret = -ENOMEM;
 			goto out;
 		}
-	} else if ((strncmp(str, "val=", strlen("val=")) == 0) ||
-		 (strncmp(str, "vals=", strlen("vals=")) == 0) ||
-		 (strncmp(str, "values=", strlen("values=")) == 0)) {
+	} else if ((str_has_prefix(str, "val=")) ||
+		   (str_has_prefix(str, "vals=")) ||
+		   (str_has_prefix(str, "values="))) {
 		attrs->vals_str = kstrdup(str, GFP_KERNEL);
 		if (!attrs->vals_str) {
 			ret = -ENOMEM;
 			goto out;
 		}
-	} else if (strncmp(str, "sort=", strlen("sort=")) == 0) {
+	} else if (str_has_prefix(str, "sort=")) {
 		attrs->sort_key_str = kstrdup(str, GFP_KERNEL);
 		if (!attrs->sort_key_str) {
 			ret = -ENOMEM;
 			goto out;
 		}
-	} else if (strncmp(str, "name=", strlen("name=")) == 0) {
+	} else if (str_has_prefix(str, "name=")) {
 		attrs->name = kstrdup(str, GFP_KERNEL);
 		if (!attrs->name) {
 			ret = -ENOMEM;
 			goto out;
 		}
-	} else if (strncmp(str, "clock=", strlen("clock=")) == 0) {
+	} else if (str_has_prefix(str, "clock=")) {
 		strsep(&str, "=");
 		if (!str) {
 			ret = -EINVAL;
@@ -1936,7 +1936,7 @@ static int parse_assignment(char *str, struct hist_trigger_attrs *attrs)
 			ret = -ENOMEM;
 			goto out;
 		}
-	} else if (strncmp(str, "size=", strlen("size=")) == 0) {
+	} else if (str_has_prefix(str, "size=")) {
 		int map_bits = parse_map_size(str);
 
 		if (map_bits < 0) {
@@ -3623,7 +3623,7 @@ static struct action_data *onmax_parse(char *str)
 	if (!onmax_fn_name || !str)
 		goto free;
 
-	if (strncmp(onmax_fn_name, "save", strlen("save")) == 0) {
+	if (str_has_prefix(onmax_fn_name, "save")) {
 		char *params = strsep(&str, ")");
 
 		if (!params) {
@@ -4414,8 +4414,8 @@ static int parse_actions(struct hist_trigger_data *hist_data)
 	for (i = 0; i < hist_data->attrs->n_actions; i++) {
 		str = hist_data->attrs->action_str[i];
 
-		if (strncmp(str, "onmatch(", strlen("onmatch(")) == 0) {
-			char *action_str = str + strlen("onmatch(");
+		if (str_has_prefix(str, "onmatch(")) {
+			char *action_str = str + sizeof("onmatch(") - 1;
 
 			data = onmatch_parse(tr, action_str);
 			if (IS_ERR(data)) {
@@ -4423,8 +4423,8 @@ static int parse_actions(struct hist_trigger_data *hist_data)
 				break;
 			}
 			data->fn = action_trace;
-		} else if (strncmp(str, "onmax(", strlen("onmax(")) == 0) {
-			char *action_str = str + strlen("onmax(");
+		} else if (str_has_prefix(str, "onmax(")) {
+			char *action_str = str + sizeof("onmax(") - 1;
 
 			data = onmax_parse(action_str);
 			if (IS_ERR(data)) {
-- 
2.34.1


  parent reply	other threads:[~2024-05-09  2:30 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-05-09  2:29 [PATCH 4.19.y 00/13] fix double-free bug causing by destroy_hist_field(data->onmax.var, 0) George Guo
2024-05-09  2:29 ` [PATCH 4.19.y 01/13] tracing: Simplify creation and deletion of synthetic events George Guo
2024-05-09  2:29 ` [PATCH 4.19.y 02/13] tracing: Add unified dynamic event framework George Guo
2024-05-09  2:29 ` [PATCH 4.19.y 03/13] tracing: Use dyn_event framework for synthetic events George Guo
2024-05-09  2:29 ` [PATCH 4.19.y 04/13] tracing: Remove unneeded synth_event_mutex George Guo
2024-05-09  2:29 ` [PATCH 4.19.y 05/13] tracing: Consolidate trace_add/remove_event_call back to the nolock functions George Guo
2024-05-09  2:29 ` [PATCH 4.19.y 06/13] string.h: Add str_has_prefix() helper function George Guo
2024-05-09  2:29 ` George Guo [this message]
2024-05-09  2:29 ` [PATCH 4.19.y 08/13] tracing: Use str_has_prefix() instead of using fixed sizes George Guo
2024-05-09  2:29 ` [PATCH 4.19.y 09/13] tracing: Have the historgram use the result of str_has_prefix() for len of prefix George Guo
2024-05-09  2:29 ` [PATCH 4.19.y 10/13] tracing: Refactor hist trigger action code George Guo
2024-05-09  2:29 ` [PATCH 4.19.y 11/13] tracing: Split up onmatch action data George Guo
2024-05-09  2:29 ` [PATCH 4.19.y 12/13] tracing: Generalize hist trigger onmax and save action George Guo
2024-05-09  2:29 ` [PATCH 4.19.y 13/13] tracing: Remove unnecessary var_ref destroy in track_data_destroy() George Guo
2024-05-23 12:09 ` [PATCH 4.19.y 00/13] fix double-free bug causing by destroy_hist_field(data->onmax.var, 0) Greg KH

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20240509022931.3513365-8-dongtai.guo@linux.dev \
    --to=dongtai.guo@linux.dev \
    --cc=gregkh@linuxfoundation.org \
    --cc=guodongtai@kylinos.cn \
    --cc=mhiramat@kernel.org \
    --cc=namhyung@kernel.org \
    --cc=rostedt@goodmis.org \
    --cc=stable@vger.kernel.org \
    --cc=tom.zanussi@linux.intel.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox