linux-kernel - [PATCH] vboxvideo: Fix incorrect type in assignment sparse warning

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20180106142053.GA28369@box1>
Date:   Sat, 6 Jan 2018 16:20:53 +0200
From:   Alexander Kapshuk <alexander.kapshuk@...il.com>
To:     gregkh@...uxfoundation.org, hdegoede@...hat.com,
        michael.thayer@...cle.com, dri-devel@...ts.freedesktop.org
Cc:     peda@...ntia.se, daniel.vetter@...ll.ch, cakturk@...il.com,
        seanpaul@...omium.org, linux-kernel@...r.kernel.org,
        alexander.kapshuk@...il.com
Subject: [PATCH] vboxvideo: Fix incorrect type in assignment sparse warning

On Mon, Dec 25, 2017 at 04:42:59PM +0200, Alexander Kapshuk wrote:
> Sparse emitted the following warning:
> ../drivers/staging/vboxvideo/vbox_fb.c:173:27: warning: incorrect type in assignment (different address spaces)
> ../drivers/staging/vboxvideo/vbox_fb.c:173:27:    expected char [noderef] <asn:2>*screen_base
> ../drivers/staging/vboxvideo/vbox_fb.c:173:27:    got void *virtual
> 
> The vbox_bo buffer object kernel mapping is handled by a call
> to ttm_bo_kmap() prior to the assignment of bo->kmap.virtual to
> info->screen_base of type char __iomem*.
> Casting bo->kmap.virtual to char __iomem* in this assignment fixes
> the warning.
> 
> vboxvideo: Fix address space of expression removal sparse warning
> 
> Sparse emitted the following warning:
> ../drivers/staging/vboxvideo/vbox_main.c:64:25: warning: cast removes address space of expression
> 
> vbox->vbva_buffers iomapping is handled by calling vbox_accel_init()
> from vbox_hw_init().
> __force attribute is used in assignment to vbva to fix the warning.
> 
> Signed-off-by: Alexander Kapshuk <alexander.kapshuk@...il.com>
> ---
>  drivers/staging/vboxvideo/vbox_fb.c   | 2 +-
>  drivers/staging/vboxvideo/vbox_main.c | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/staging/vboxvideo/vbox_fb.c b/drivers/staging/vboxvideo/vbox_fb.c
> index 8aed248db6e2..43c39eca4ae1 100644
> --- a/drivers/staging/vboxvideo/vbox_fb.c
> +++ b/drivers/staging/vboxvideo/vbox_fb.c
> @@ -170,7 +170,7 @@ static int vboxfb_create(struct drm_fb_helper *helper,
>  	drm_fb_helper_fill_var(info, &fbdev->helper, sizes->fb_width,
>  			       sizes->fb_height);
> 
> -	info->screen_base = bo->kmap.virtual;
> +	info->screen_base = (char __iomem *)bo->kmap.virtual;
>  	info->screen_size = size;
> 
>  #ifdef CONFIG_DRM_KMS_FB_HELPER
> diff --git a/drivers/staging/vboxvideo/vbox_main.c b/drivers/staging/vboxvideo/vbox_main.c
> index 80bd039fa08e..973b3bcc04b1 100644
> --- a/drivers/staging/vboxvideo/vbox_main.c
> +++ b/drivers/staging/vboxvideo/vbox_main.c
> @@ -61,7 +61,7 @@ void vbox_enable_accel(struct vbox_private *vbox)
>  		if (vbox->vbva_info[i].vbva)
>  			continue;
> 
> -		vbva = (void *)vbox->vbva_buffers + i * VBVA_MIN_BUFFER_SIZE;
> +		vbva = (void __force *)vbox->vbva_buffers + i * VBVA_MIN_BUFFER_SIZE;
>  		if (!vbva_enable(&vbox->vbva_info[i],
>  				 vbox->guest_pool, vbva, i)) {
>  			/* very old host or driver error. */
> --
> 2.13.6
> 
Ping.

Could someone please comment on the patch above?

Thanks.