Re: [PATCH] drm/modes: Replace deprecated simple_strtol with kstrtol

From: Jani Nikula
Date: Thu Feb 01 2024 - 05:03:33 EST


On Thu, 01 Feb 2024, Cong Liu <liucong2@xxxxxxxxxx> wrote:
> This patch replaces the use of the deprecated simple_strtol [1] function
> in the drm_modes.c file with the recommended kstrtol function. This change
> improves error handling and boundary checks.
>
> [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#simple-strtol-simple-strtoll-simple-strtoul-simple-strtoull
>
> Signed-off-by: Cong Liu <liucong2@xxxxxxxxxx>

This is completely wrong, and obviously not tested at all.

The recommended replacements are *not* drop-in replacements. Look into
the documentation of the functions.

BR,
Jani.

> ---
> drivers/gpu/drm/drm_modes.c | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c
> index 893f52ee4926..fce0fb1df9b2 100644
> --- a/drivers/gpu/drm/drm_modes.c
> +++ b/drivers/gpu/drm/drm_modes.c
> @@ -1942,7 +1942,7 @@ static int drm_mode_parse_cmdline_bpp(const char *str, char **end_ptr,
> return -EINVAL;
>
> str++;
> - bpp = simple_strtol(str, end_ptr, 10);
> + bpp = kstrtol(str, end_ptr, 10);
> if (*end_ptr == str)
> return -EINVAL;
>
> @@ -1961,7 +1961,7 @@ static int drm_mode_parse_cmdline_refresh(const char *str, char **end_ptr,
> return -EINVAL;
>
> str++;
> - refresh = simple_strtol(str, end_ptr, 10);
> + refresh = kstrtol(str, end_ptr, 10);
> if (*end_ptr == str)
> return -EINVAL;
>
> @@ -2033,7 +2033,7 @@ static int drm_mode_parse_cmdline_res_mode(const char *str, unsigned int length,
> int remaining, i;
> char *end_ptr;
>
> - xres = simple_strtol(str, &end_ptr, 10);
> + xres = kstrtol(str, &end_ptr, 10);
> if (end_ptr == str)
> return -EINVAL;
>
> @@ -2042,7 +2042,7 @@ static int drm_mode_parse_cmdline_res_mode(const char *str, unsigned int length,
> end_ptr++;
>
> str = end_ptr;
> - yres = simple_strtol(str, &end_ptr, 10);
> + yres = kstrtol(str, &end_ptr, 10);
> if (end_ptr == str)
> return -EINVAL;
>
> @@ -2100,7 +2100,7 @@ static int drm_mode_parse_cmdline_int(const char *delim, unsigned int *int_ret)
> return -EINVAL;
>
> value = delim + 1;
> - *int_ret = simple_strtol(value, &endp, 10);
> + *int_ret = kstrtol(value, &endp, 10);
>
> /* Make sure we have parsed something */
> if (endp == value)

--
Jani Nikula, Intel