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authorChuhong Yuan <hslester96@gmail.com>2019-08-09 10:10:34 +0300
committerPetr Mladek <pmladek@suse.com>2019-08-16 10:54:08 +0300
commit35c35493b0e3343522256f6054516f4e2161a6d4 (patch)
tree44d06154bcf3d4b1fa7b2cfb09c4f0e6ed04183d /kernel/printk
parent8ebea6ea1a7ed5d67ecbb2a493c716a2a89c0be2 (diff)
downloadlinux-35c35493b0e3343522256f6054516f4e2161a6d4.tar.xz
printk: Replace strncmp() with str_has_prefix()
strncmp(str, const, len) is error-prone because len is easy to have typo. An example is the hard-coded len has counting error or sizeof(const) forgets - 1. So we prefer using newly introduced str_has_prefix() to substitute such strncmp() to make code better. Link: http://lkml.kernel.org/r/20190809071034.17279-1-hslester96@gmail.com Cc: "Steven Rostedt" <rostedt@goodmis.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Chuhong Yuan <hslester96@gmail.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> [pmladek@suse.com: Slightly updated and reformatted the commit message.] Signed-off-by: Petr Mladek <pmladek@suse.com>
Diffstat (limited to 'kernel/printk')
-rw-r--r--kernel/printk/braille.c15
-rw-r--r--kernel/printk/printk.c22
2 files changed, 27 insertions, 10 deletions
diff --git a/kernel/printk/braille.c b/kernel/printk/braille.c
index 1d21ebacfdb8..17a9591e54ff 100644
--- a/kernel/printk/braille.c
+++ b/kernel/printk/braille.c
@@ -11,11 +11,18 @@
int _braille_console_setup(char **str, char **brl_options)
{
- if (!strncmp(*str, "brl,", 4)) {
+ size_t len;
+
+ len = str_has_prefix(*str, "brl,");
+ if (len) {
*brl_options = "";
- *str += 4;
- } else if (!strncmp(*str, "brl=", 4)) {
- *brl_options = *str + 4;
+ *str += len;
+ return 0;
+ }
+
+ len = str_has_prefix(*str, "brl=");
+ if (len) {
+ *brl_options = *str + len;
*str = strchr(*brl_options, ',');
if (!*str) {
pr_err("need port name after brl=\n");
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 1888f6a3b694..43a31015ec93 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -118,19 +118,29 @@ static unsigned int __read_mostly devkmsg_log = DEVKMSG_LOG_MASK_DEFAULT;
static int __control_devkmsg(char *str)
{
+ size_t len;
+
if (!str)
return -EINVAL;
- if (!strncmp(str, "on", 2)) {
+ len = str_has_prefix(str, "on");
+ if (len) {
devkmsg_log = DEVKMSG_LOG_MASK_ON;
- return 2;
- } else if (!strncmp(str, "off", 3)) {
+ return len;
+ }
+
+ len = str_has_prefix(str, "off");
+ if (len) {
devkmsg_log = DEVKMSG_LOG_MASK_OFF;
- return 3;
- } else if (!strncmp(str, "ratelimit", 9)) {
+ return len;
+ }
+
+ len = str_has_prefix(str, "ratelimit");
+ if (len) {
devkmsg_log = DEVKMSG_LOG_MASK_DEFAULT;
- return 9;
+ return len;
}
+
return -EINVAL;
}