[PATCH 2/2] ubi: build: replace simple_strtoul with kstrtoul in bytes_str_to_int()

[Zhihao Cheng]

在 2026/5/7 11:23, haoyu.lu 写道:
> From: Haoyu Lu <hechushiguitu666 at gmail.com>
> 
> Replace the deprecated simple_strtoul() with kstrtoul() in the
> bytes_str_to_int() helper function. Since kstrtoul() rejects trailing
> non-numeric characters (such as the G/M/K suffixes), the numeric prefix
> is first extracted with strspn() and then parsed separately before
> handling the suffix.
> 
> This provides proper error handling through the kstrto* family while
> preserving the existing suffix semantics for byte count parameters.
> 
> Note: the original simple_strtoul() with base=0 accepted hexadecimal
> (0x prefix) and octal (0 prefix) formats, while kstrtoul() with base=10
> only supports decimal. This is not a practical concern since MTD byte
> count parameters are always specified as decimal values in boot
> parameters.
The ubi could be loaded by module insertion, many vendors set param 
'vid_hdr_offs' to save space. We cannot make the assumption that all 
users use the decimal system.
> 
> Signed-off-by: Haoyu Lu <hechushiguitu666 at gmail.com>
> ---
>   drivers/mtd/ubi/build.c | 19 +++++++++++++++----
>   1 file changed, 15 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c
> index 03ef195dc25c..7cb6ba4a3840 100644
> --- a/drivers/mtd/ubi/build.c
> +++ b/drivers/mtd/ubi/build.c
> @@ -1426,16 +1426,27 @@ module_exit(ubi_exit);
>    */
>   static int bytes_str_to_int(const char *str)
>   {
> -	char *endp;
>   	unsigned long result;
> +	unsigned int num_len;
> +	char num_buf[32];
>   
> -	result = simple_strtoul(str, &endp, 0);
> -	if (str == endp || result >= INT_MAX) {
> +	/* Find the length of the numeric prefix */
> +	num_len = strspn(str, "0123456789");
> +	if (num_len == 0 || num_len >= sizeof(num_buf)) {
>   		pr_err("UBI error: incorrect bytes count: \"%s\"\n", str);
>   		return -EINVAL;
>   	}
>   
> -	switch (*endp) {
> +	/* Parse the numeric part */
> +	memcpy(num_buf, str, num_len);
> +	num_buf[num_len] = '\0';
> +	if (kstrtoul(num_buf, 10, &result) < 0 || result >= INT_MAX) {
> +		pr_err("UBI error: incorrect bytes count: \"%s\"\n", str);
> +		return -EINVAL;
> +	}
> +
> +	/* Handle suffix */
> +	switch (str[num_len]) {
>   	case 'G':
>   		result *= 1024;
>   		fallthrough;
>