[PATCH RESEND 1/2] stm class: Replace kmalloc + copy_from_user with memdup_user

[Thorsten Blum]

Gentle ping?

On Thu, Apr 02, 2026 at 06:59:35PM +0200, Thorsten Blum wrote:
> Replace kmalloc() followed by copy_from_user() with memdup_user() to
> simplify and improve stm_char_write().
> 
> Allocate and copy only 'count' bytes instead of 'count + 1' since the
> extra byte is unused.
> 
> Signed-off-by: Thorsten Blum <thorsten.blum at linux.dev>
> ---
>  drivers/hwtracing/stm/core.c | 12 +++---------
>  1 file changed, 3 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/hwtracing/stm/core.c b/drivers/hwtracing/stm/core.c
> index 37584e786bb5..49791024bb86 100644
> --- a/drivers/hwtracing/stm/core.c
> +++ b/drivers/hwtracing/stm/core.c
> @@ -645,15 +645,9 @@ static ssize_t stm_char_write(struct file *file, const char __user *buf,
>  			return err;
>  	}
>  
> -	kbuf = kmalloc(count + 1, GFP_KERNEL);
> -	if (!kbuf)
> -		return -ENOMEM;
> -
> -	err = copy_from_user(kbuf, buf, count);
> -	if (err) {
> -		kfree(kbuf);
> -		return -EFAULT;
> -	}
> +	kbuf = memdup_user(buf, count);
> +	if (IS_ERR(kbuf))
> +		return PTR_ERR(kbuf);
>  
>  	pm_runtime_get_sync(&stm->dev);
>