[PATCH 1/2] watchdog: use kstrtouint to parse softlockup_panic=

[PATCH 1/2] watchdog: use kstrtouint to parse softlockup_panic=

[林濬哲]

simple_strtoul() is deprecated. Replace it with kstrtouint(), which
also reports parse errors back to the boot process instead of
silently accepting garbage.

Signed-off-by: 林濬哲 <m18667909625@163.com>
Assisted-by: AI coding assistant (disclosed per kernel AI guidelines)
---
 kernel/watchdog.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index e5134ad7b663..420f08140713 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -17,6 +17,7 @@
 #include <linux/irq.h>
 #include <linux/irqdesc.h>
 #include <linux/kernel_stat.h>
+#include <linux/kstrtox.h>
 #include <linux/kvm_para.h>
 #include <linux/math64.h>
 #include <linux/mm.h>
@@ -422,8 +423,10 @@ static unsigned long soft_lockup_nmi_warn;
 
 static int __init softlockup_panic_setup(char *str)
 {
-	softlockup_panic = simple_strtoul(str, NULL, 0);
-	return 1;
+	int ret;
+
+	ret = kstrtouint(str, 0, &softlockup_panic);
+	return ret ? ret : 1;
 }
 __setup("softlockup_panic=", softlockup_panic_setup);
 
-- 
2.53.0

Re: [PATCH 1/2] watchdog: use kstrtouint to parse softlockup_panic=

[Guenter Roeck]

On Mon, Sep 21, 2026 at 02:41:43PM +0800, 林濬哲 wrote:
> simple_strtoul() is deprecated. Replace it with kstrtouint(), which
> also reports parse errors back to the boot process instead of
> silently accepting garbage.
> 
> Signed-off-by: 林濬哲 <m18667909625@163.com>
> Assisted-by: AI coding assistant (disclosed per kernel AI guidelines)
> ---
>  kernel/watchdog.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/kernel/watchdog.c b/kernel/watchdog.c
> index e5134ad7b663..420f08140713 100644
> --- a/kernel/watchdog.c
> +++ b/kernel/watchdog.c
> @@ -17,6 +17,7 @@
>  #include <linux/irq.h>
>  #include <linux/irqdesc.h>
>  #include <linux/kernel_stat.h>
> +#include <linux/kstrtox.h>
>  #include <linux/kvm_para.h>
>  #include <linux/math64.h>
>  #include <linux/mm.h>
> @@ -422,8 +423,10 @@ static unsigned long soft_lockup_nmi_warn;
>  
>  static int __init softlockup_panic_setup(char *str)
>  {
> -	softlockup_panic = simple_strtoul(str, NULL, 0);
> -	return 1;
> +	int ret;
> +
> +	ret = kstrtouint(str, 0, &softlockup_panic);
> +	return ret ? ret : 1;

Please read the documentation (or ask your AI to do it).

/*
 * NOTE: __setup functions return values:
 * @fn returns 1 (or non-zero) if the option argument is "handled"
 * and returns 0 if the option argument is "not handled".
 */

There is no means to "reports parse errors back to the boot process"
from __setup functions.

Guenter

[PATCH v2 2/2] PM: hibernate: use kstrtouint to parse resume= device numbers

[林濬哲]

simple_strtoul() is deprecated. Replace the base-16 parse with
kstrtouint(); the explicit trailing-character check the old code
needed is provided by kstrtouint() itself. As a side effect, values
wider than 32 bits are now rejected instead of being silently
truncated before the dev_t conversion.

Signed-off-by: Lin Junzhe <m18667909625@163.com>
Assisted-by: AI coding assistant (disclosed per kernel AI guidelines)
---
 kernel/power/hibernate.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index d2479c69d71a..74f2d20518cc 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -14,6 +14,7 @@
 #include <crypto/acompress.h>
 #include <linux/blkdev.h>
 #include <linux/export.h>
+#include <linux/kstrtox.h>
 #include <linux/suspend.h>
 #include <linux/reboot.h>
 #include <linux/string.h>
@@ -1278,7 +1279,7 @@ static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
 	error = lookup_bdev(name, &dev);
 	if (error) {
 		unsigned maj, min, offset;
-		char *p, dummy;
+		char dummy;
 
 		error = 0;
 		if (sscanf(name, "%u:%u%c", &maj, &min, &dummy) == 2 ||
@@ -1288,9 +1289,12 @@ static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
 			if (maj != MAJOR(dev) || min != MINOR(dev))
 				error = -EINVAL;
 		} else {
-			dev = new_decode_dev(simple_strtoul(name, &p, 16));
-			if (*p)
+			unsigned int val;
+
+			if (kstrtouint(name, 16, &val))
 				error = -EINVAL;
+			else
+				dev = new_decode_dev(val);
 		}
 	}
 	kfree(name);
-- 
2.54.0.windows.1

[PATCH v2 1/2] watchdog: use kstrtouint to parse softlockup_panic=

[林濬哲]

simple_strtoul() is deprecated. Replace it with kstrtouint(). A bad
value now leaves the variable unchanged and produces a warning,
instead of being silently clamped.

__setup() handlers return whether they handled the option; there is
no way to propagate parse errors, so the handler simply returns 1.

v2: warn on a bad value and return 1 instead of returning the parse
    error, which __setup() handlers cannot do (Guenter Roeck).

Signed-off-by: Lin Junzhe <m18667909625@163.com>
Assisted-by: AI coding assistant (disclosed per kernel AI guidelines)
---
 kernel/watchdog.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index e5134ad7b663..7f8c904554a9 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -17,6 +17,7 @@
 #include <linux/irq.h>
 #include <linux/irqdesc.h>
 #include <linux/kernel_stat.h>
+#include <linux/kstrtox.h>
 #include <linux/kvm_para.h>
 #include <linux/math64.h>
 #include <linux/mm.h>
@@ -422,7 +423,11 @@ static unsigned long soft_lockup_nmi_warn;
 
 static int __init softlockup_panic_setup(char *str)
 {
-	softlockup_panic = simple_strtoul(str, NULL, 0);
+	int ret;
+
+	ret = kstrtouint(str, 0, &softlockup_panic);
+	if (ret)
+		pr_warn("softlockup_panic: bad option string '%s'\n", str);
 	return 1;
 }
 __setup("softlockup_panic=", softlockup_panic_setup);
-- 
2.54.0.windows.1

Re: [PATCH v2 1/2] watchdog: use kstrtouint to parse softlockup_panic=

[Guenter Roeck]

On Tue, Sep 22, 2026 at 01:50:40PM +0800, 林濬哲 wrote:
> 
> simple_strtoul() is deprecated. Replace it with kstrtouint(). A bad
> value now leaves the variable unchanged and produces a warning,
> instead of being silently clamped.
> 
> __setup() handlers return whether they handled the option; there is
> no way to propagate parse errors, so the handler simply returns 1.
> 
> v2: warn on a bad value and return 1 instead of returning the parse
>     error, which __setup() handlers cannot do (Guenter Roeck).
> 
> Signed-off-by: Lin Junzhe <m18667909625@163.com>
> Assisted-by: AI coding assistant (disclosed per kernel AI guidelines)
> ---
>  kernel/watchdog.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/kernel/watchdog.c b/kernel/watchdog.c
> index e5134ad7b663..7f8c904554a9 100644
> --- a/kernel/watchdog.c
> +++ b/kernel/watchdog.c
> @@ -17,6 +17,7 @@
>  #include <linux/irq.h>
>  #include <linux/irqdesc.h>
>  #include <linux/kernel_stat.h>
> +#include <linux/kstrtox.h>
>  #include <linux/kvm_para.h>
>  #include <linux/math64.h>
>  #include <linux/mm.h>
> @@ -422,7 +423,11 @@ static unsigned long soft_lockup_nmi_warn;
>  
>  static int __init softlockup_panic_setup(char *str)
>  {
> -	softlockup_panic = simple_strtoul(str, NULL, 0);
> +	int ret;
> +
> +	ret = kstrtouint(str, 0, &softlockup_panic);
> +	if (ret)
> +		pr_warn("softlockup_panic: bad option string '%s'\n", str);

Hardly any other __setup function warns here, and I do not see the point
adding it here.

Guenter

>  	return 1;
>  }
>  __setup("softlockup_panic=", softlockup_panic_setup);
> -- 
> 2.54.0.windows.1
> 
>