[Intel-xe] [PATCH] drm/xe: Fix overflow in vram manager

[Matthew Auld]

On 14/03/2023 08:27, Matthew Auld wrote:
> On 14/03/2023 04:48, Riana Tauro wrote:
>> Cc:Matthew Auld <matthew.auld at intel.com>
>>
>> On 3/9/2023 10:21 PM, Dixit, Ashutosh wrote:
>>> On Thu, 09 Mar 2023 05:18:56 -0800, Riana Tauro wrote:
>>>>
>>>> The overflow caused xe_bo_restore_kernel to return an error
>>>> Fix overflow in vram manager alloc function.
>>>>
>>>> Signed-off-by: Riana Tauro <riana.tauro at intel.com>
>>>> ---
>>>>   drivers/gpu/drm/xe/xe_ttm_vram_mgr.c | 2 +-
>>>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>>>
>>>> diff --git a/drivers/gpu/drm/xe/xe_ttm_vram_mgr.c 
>>>> b/drivers/gpu/drm/xe/xe_ttm_vram_mgr.c
>>>> index 643365b18bc7..159ca7105df1 100644
>>>> --- a/drivers/gpu/drm/xe/xe_ttm_vram_mgr.c
>>>> +++ b/drivers/gpu/drm/xe/xe_ttm_vram_mgr.c
>>>> @@ -118,7 +118,7 @@ static int xe_ttm_vram_mgr_new(struct 
>>>> ttm_resource_manager *man,
>>>>
>>>>         cur_size = size;
>>>>
>>>> -        if (fpfn + size != place->lpfn << PAGE_SHIFT) {
>>>> +        if (fpfn + size != (u64)place->lpfn << PAGE_SHIFT) {
>>>
>>> Looks ok but not sure if it should just be lpfn computed above? 
> 
> Yes, that looks correct. place->lpfn should for now only be set when we 
> want to place something at a specific offset. AFAICT this is heavily 
> used for pinned kernel objects (as well as setting ALLOC_CONTIG), and 
> incorrectly applying the roundup_power_of_two() might break stuff when 
> restoring those objects (the roundup might smash into other pinned 
> kernel objects).
> 
> Reviewed-by: Matthew Auld <matthew.auld at intel.com>

Pushed to drm-xe-next.

> 
> fwiw the plan is to replace all of this with the i915 version, which 
> also fixes this:
> https://patchwork.freedesktop.org/patch/525697/?series=114521&rev=3
> 
>>> Copying Matt.
>>>
>>>>             /*
>>>>              * Except for actual range allocation, modify the size and
>>>>              * min_block_size conforming to continuous flag enablement
>>>> -- 
>>>> 2.39.1
>>>>