2013/3/17 Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>:
> On Mon, Mar 18, 2013 at 07:42:58AM +1000, Dave Airlie wrote:
>> On Mon, Mar 18, 2013 at 7:40 AM, Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> wrote:
>> > On Sun, Mar 17, 2013 at 08:50:03PM +0100, Daniel Vetter wrote:
>> >> On Sat, Mar 16, 2013 at 11:19 AM, Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> wrote:
>> >> > If *userspace* doesn't request either IOC_IN | IOC_OUT in their ioctl
>> >> > command (which are seperate from the ioctl number), then kdata is set to
>> >> > NULL.
>> >>
>> >> Doesn't that mean that we need these checks everywhere? Or at least a
>> >> fixup in drm core proper?
>> >
>> > That's my conclusion. We either add a flag to ask drm_ioctl to prevent
>> > passing NULL pointers (as the existing behaviour may be useful
>> > somewhere, and I have not checked all callees) or saturate our callbacks
>> > with NULL checks.
>>
>> Do we have the kernel's expected IOC_IN/IOC_OUT flags at that point as well?
>>
>> we could check them and block NULL in that case.
>
> Yes. For the core ioctls, we use drm_ioctls[nr].cmd rather than the
> value passed in by userspace for the IOC_IN|IN_OUT bits. So:
Thanks, trinity can indeed set the in/out bits randomly, in a way that
does not match the driver ioctl definition.
Your patch almost fixes this. For the driver ioctls we will want to
grab the cmd from cmd_drv. So the patch should be:
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index 25f91cd..5210f33 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -408,6 +408,7 @@ long drm_ioctl(struct file *filp,
usize = asize = _IOC_SIZE(cmd);
if (drv_size > asize)
asize = drv_size;
+ cmd = ioctl->cmd_drv;
}
else if ((nr >= DRM_COMMAND_END) || (nr < DRM_COMMAND_BASE)) {
ioctl = &drm_ioctls[nr];
Can you please submit this officially?
> diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
> index 25f91cd..79b8bd1 100644
> --- a/drivers/gpu/drm/drm_drv.c
> +++ b/drivers/gpu/drm/drm_drv.c
> @@ -408,6 +408,7 @@ long drm_ioctl(struct file *filp,
> usize = asize = _IOC_SIZE(cmd);
> if (drv_size > asize)
> asize = drv_size;
> + cmd = ioctl->cmd;
> }
> else if ((nr >= DRM_COMMAND_END) || (nr < DRM_COMMAND_BASE)) {
> ioctl = &drm_ioctls[nr];
>
>
> --
> Chris Wilson, Intel Open Source Technology Centre
_______________________________________________
dri-devel mailing list
dri-devel@xxxxxxxxxxxxxxxxxxxxx
http://lists.freedesktop.org/mailman/listinfo/dri-devel
