Re: 回复: Re: [PATCH] gpu/drm/radeon:Fix null pointer risk

[Christian König <christian.koenig@xxxxxxx>]

    Am 31.12.21 um 09:37 schrieb 温志伟:

   

Then the judgment in line 944 is needed. Are the possibilities of these two positions consistent.

Why keep this judgment？

    Because when mem is non-NULL bo_va->bo can't be NULL either.
    
    Regards,
    Christian.

Regards,

Wen Zhiwei.

   

----

       

主　题：Re: [PATCH] gpu/drm/radeon:Fix null pointer risk            
日　期：2021-12-31 00:36            
发件人：Christian König            
收件人：Wen Zhiweialexander.deucher@xxxxxxxxxxxxxxxxx@amd.comairlied@linux.iedaniel@xxxxxxxx                    

       

Am 28.12.21 um 08:31 schrieb Wen Zhiwei:
> If the null pointer is not judged in advance,
> there is a risk that the pointer will cross
> the boundary

As far as I can see that case is impossible, why do you want to add a
check for it?

Regards,
Christian.

>
> Signed-off-by: Wen Zhiwei
> ---
>   drivers/gpu/drm/radeon/radeon_vm.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/radeon/radeon_vm.c b/drivers/gpu/drm/radeon/radeon_vm.c
> index bb53016f3138..d3d342041adf 100644
> --- a/drivers/gpu/drm/radeon/radeon_vm.c
> +++ b/drivers/gpu/drm/radeon/radeon_vm.c
> @@ -951,7 +951,7 @@ int radeon_vm_bo_update(struct radeon_device *rdev,
>  
>   if (mem->mem_type == TTM_PL_TT) {
>   bo_va->flags |= RADEON_VM_PAGE_SYSTEM;
> - if (!(bo_va->bo->flags & (RADEON_GEM_GTT_WC | RADEON_GEM_GTT_UC)))
> + if (bo_va->bo && !(bo_va->bo->flags & (RADEON_GEM_GTT_WC | RADEON_GEM_GTT_UC)))
>   bo_va->flags |= RADEON_VM_PAGE_SNOOPED;
>  
>   } else {