[PATCH] drm: add __user attribute to ptr_to_compat()

[Sean Paul]

On Fri, Mar 01, 2019 at 12:00:46PM +0000, Ben Dooks wrote:
> The ptr_to_compat() call takes a "void __user *", so cast
> the compat drm calls that use it to avoid the following
> warnings from sparse:
> 
> drivers/gpu/drm/drm_ioc32.c:188:39: warning: incorrect type in argument 1 (different address spaces)
> drivers/gpu/drm/drm_ioc32.c:188:39:    expected void [noderef] <asn:1>*uptr
> drivers/gpu/drm/drm_ioc32.c:188:39:    got void *[addressable] [assigned] handle
> drivers/gpu/drm/drm_ioc32.c:529:41: warning: incorrect type in argument 1 (different address spaces)
> drivers/gpu/drm/drm_ioc32.c:529:41:    expected void [noderef] <asn:1>*uptr
> drivers/gpu/drm/drm_ioc32.c:529:41:    got void *[addressable] [assigned] handle
> 
> Signed-off-by: Ben Dooks <ben.dooks at codethink.co.uk>

Thanks for your patch, I've applied it to drm-misc-next-fixes with cc: stable.

Sean

> ---
>  drivers/gpu/drm/drm_ioc32.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_ioc32.c b/drivers/gpu/drm/drm_ioc32.c
> index 67b1fca39aa6..0e3043e08c69 100644
> --- a/drivers/gpu/drm/drm_ioc32.c
> +++ b/drivers/gpu/drm/drm_ioc32.c
> @@ -185,7 +185,7 @@ static int compat_drm_getmap(struct file *file, unsigned int cmd,
>  	m32.size = map.size;
>  	m32.type = map.type;
>  	m32.flags = map.flags;
> -	m32.handle = ptr_to_compat(map.handle);
> +	m32.handle = ptr_to_compat((void __user *)map.handle);
>  	m32.mtrr = map.mtrr;
>  	if (copy_to_user(argp, &m32, sizeof(m32)))
>  		return -EFAULT;
> @@ -216,7 +216,7 @@ static int compat_drm_addmap(struct file *file, unsigned int cmd,
>  
>  	m32.offset = map.offset;
>  	m32.mtrr = map.mtrr;
> -	m32.handle = ptr_to_compat(map.handle);
> +	m32.handle = ptr_to_compat((void __user *)map.handle);
>  	if (map.handle != compat_ptr(m32.handle))
>  		pr_err_ratelimited("compat_drm_addmap truncated handle %p for type %d offset %x\n",
>  				   map.handle, m32.type, m32.offset);
> @@ -526,7 +526,7 @@ static int compat_drm_getsareactx(struct file *file, unsigned int cmd,
>  	if (err)
>  		return err;
>  
> -	req32.handle = ptr_to_compat(req.handle);
> +	req32.handle = ptr_to_compat((void __user *)req.handle);
>  	if (copy_to_user(argp, &req32, sizeof(req32)))
>  		return -EFAULT;
>  
> -- 
> 2.20.1
> 

-- 
Sean Paul, Software Engineer, Google / Chromium OS