Re: [PATCH] Input: gunze: replace deprecated APIs and fix warning style

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] Replacing simple_strtoul() with kstrtoul() breaks packet parsing by unconditionally returning an error, dropping all touch events.
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--- Patch [1]: [PATCH] Input: gunze: replace deprecated APIs and fix warning style ---
commit c6cb2e487b7cdb132629587d8da300e20e580c31
Author: Bivash Kumar Singh <bivashraj750@gmail.com>

Input: gunze: replace deprecated APIs and fix warning style

This commit replaces deprecated simple_strtoul() calls with kstrtoul() and
adds an early return on parsing failures. It also updates the printk warning
to use dev_warn() with the serio device.

> diff --git a/drivers/input/touchscreen/gunze.c b/drivers/input/touchscreen/gunze.c
> index 2baeb4f3b941c..38450cabdd113 100644
> --- a/drivers/input/touchscreen/gunze.c
> +++ b/drivers/input/touchscreen/gunze.c
> @@ -41,15 +41,19 @@ struct gunze {
>  static void gunze_process_packet(struct gunze *gunze)
>  {
[ ... ]
> -	input_report_abs(dev, ABS_X, simple_strtoul(gunze->data + 1, NULL, 10));
> -	input_report_abs(dev, ABS_Y, 1024 - simple_strtoul(gunze->data + 6, NULL, 10));
> +	if (kstrtoul(gunze->data + 1, 10, &x) || kstrtoul(gunze->data + 6, 10, &y))
> +		return;

[Severity: High]
Does this replacement break packet parsing by unconditionally returning an
error?

The kstrtoul() API strictly requires the parsed string to be NUL-terminated
and contain no trailing non-digit characters other than an optional newline.

Because the input data is a comma-separated string like "T1234,5678" and the
buffer is not NUL-terminated, kstrtoul() will encounter the comma when parsing
the X coordinate and return -EINVAL. It will also fail when parsing the Y
coordinate due to the missing NUL terminator.

This early return will unconditionally trigger on every valid touch event,
causing all packets to be dropped and rendering the touchscreen unusable.

> +
> +	input_report_abs(dev, ABS_X, x);
> +	input_report_abs(dev, ABS_Y, 1024 - y);
>  	input_report_key(dev, BTN_TOUCH, gunze->data[0] == 'T');
>  	input_sync(dev);
>  }

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Sashiko AI review · https://sashiko.dev/#/patchset/20260718190040.10613-1-bivashraj750@gmail.com?part=1