[PATCH v3 1/1] drm/ttm: Fix COW check
Christian König
ckoenig.leichtzumerken at gmail.com
Fri Jul 23 08:33:48 UTC 2021
Am 23.07.21 um 10:21 schrieb Daniel Vetter:
> On Wed, Jul 14, 2021 at 10:51 AM Christian König
> <christian.koenig at amd.com> wrote:
>>
>>
>> Am 13.07.21 um 17:28 schrieb Alex Deucher:
>>> On Tue, Jul 13, 2021 at 2:57 AM Christian König
>>> <ckoenig.leichtzumerken at gmail.com> wrote:
>>>>
>>>> Am 13.07.21 um 00:06 schrieb Felix Kuehling:
>>>>> KFD Thunk maps invisible VRAM BOs with PROT_NONE, MAP_PRIVATE.
>>>>> is_cow_mapping returns true for these mappings. Add a check for
>>>>> vm_flags & VM_WRITE to avoid mmap failures on private read-only or
>>>>> PROT_NONE mappings.
>>>>>
>>>>> v2: protect against mprotect making a mapping writable after the fact
>>>>> v3: update driver-specific vm_operations_structs
>>>>>
>>>>> Fixes: f91142c62161 ("drm/ttm: nuke VM_MIXEDMAP on BO mappings v3")
>>>>> Signed-off-by: Felix Kuehling <Felix.Kuehling at amd.com>
>>>>> Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
>>>> Reviewed-by: Christian König <christian.koenig at amd.com>
>>> Are you planning to push this to drm-misc?
>> Yes, just didn't found time yesterday.
> This is pushed to the wrong tree drm-misc-next-fixes, should have been
> in drm-misc-fixes. Please be careful with that because every time that
> goes wrong the script gets confused about which the current tree is,
> and pushes the wrong tree to linux-next branches.
>
> I'm going to hard-reset drm-misc-next-fixes now and hope that's good
> enough to fix things up (since Thomas is not around all the time for
> this merge window).
STOP! I'm about to push a revert for this patch.
And yes that was pushed to the wrong branch, but it turned out that this
was fortunate since the patch doesn't work correctly.
Christian.
> -Daniel
>
>
>> Christian.
>>
>>> Alex
>>>
>>>>> ---
>>>>> drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c | 3 ++-
>>>>> drivers/gpu/drm/nouveau/nouveau_gem.c | 3 ++-
>>>>> drivers/gpu/drm/radeon/radeon_gem.c | 3 ++-
>>>>> drivers/gpu/drm/ttm/ttm_bo_vm.c | 14 +++++++++++++-
>>>>> drivers/gpu/drm/vmwgfx/vmwgfx_ttm_glue.c | 1 +
>>>>> include/drm/ttm/ttm_bo_api.h | 4 ++++
>>>>> 6 files changed, 24 insertions(+), 4 deletions(-)
>>>>>
>>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
>>>>> index b3404c43a911..1aa750a6a5d2 100644
>>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
>>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
>>>>> @@ -79,7 +79,8 @@ static const struct vm_operations_struct amdgpu_gem_vm_ops = {
>>>>> .fault = amdgpu_gem_fault,
>>>>> .open = ttm_bo_vm_open,
>>>>> .close = ttm_bo_vm_close,
>>>>> - .access = ttm_bo_vm_access
>>>>> + .access = ttm_bo_vm_access,
>>>>> + .mprotect = ttm_bo_vm_mprotect
>>>>> };
>>>>>
>>>>> static void amdgpu_gem_object_free(struct drm_gem_object *gobj)
>>>>> diff --git a/drivers/gpu/drm/nouveau/nouveau_gem.c b/drivers/gpu/drm/nouveau/nouveau_gem.c
>>>>> index 5b27845075a1..164ea564bb7a 100644
>>>>> --- a/drivers/gpu/drm/nouveau/nouveau_gem.c
>>>>> +++ b/drivers/gpu/drm/nouveau/nouveau_gem.c
>>>>> @@ -70,7 +70,8 @@ static const struct vm_operations_struct nouveau_ttm_vm_ops = {
>>>>> .fault = nouveau_ttm_fault,
>>>>> .open = ttm_bo_vm_open,
>>>>> .close = ttm_bo_vm_close,
>>>>> - .access = ttm_bo_vm_access
>>>>> + .access = ttm_bo_vm_access,
>>>>> + .mprotect = ttm_bo_vm_mprotect
>>>>> };
>>>>>
>>>>> void
>>>>> diff --git a/drivers/gpu/drm/radeon/radeon_gem.c b/drivers/gpu/drm/radeon/radeon_gem.c
>>>>> index 458f92a70887..c19ad07eb7b5 100644
>>>>> --- a/drivers/gpu/drm/radeon/radeon_gem.c
>>>>> +++ b/drivers/gpu/drm/radeon/radeon_gem.c
>>>>> @@ -77,7 +77,8 @@ static const struct vm_operations_struct radeon_gem_vm_ops = {
>>>>> .fault = radeon_gem_fault,
>>>>> .open = ttm_bo_vm_open,
>>>>> .close = ttm_bo_vm_close,
>>>>> - .access = ttm_bo_vm_access
>>>>> + .access = ttm_bo_vm_access,
>>>>> + .mprotect = ttm_bo_vm_mprotect
>>>>> };
>>>>>
>>>>> static void radeon_gem_object_free(struct drm_gem_object *gobj)
>>>>> diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c
>>>>> index f56be5bc0861..fb325bad5db6 100644
>>>>> --- a/drivers/gpu/drm/ttm/ttm_bo_vm.c
>>>>> +++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c
>>>>> @@ -542,17 +542,29 @@ int ttm_bo_vm_access(struct vm_area_struct *vma, unsigned long addr,
>>>>> }
>>>>> EXPORT_SYMBOL(ttm_bo_vm_access);
>>>>>
>>>>> +int ttm_bo_vm_mprotect(struct vm_area_struct *vma, unsigned long start,
>>>>> + unsigned long end, unsigned long newflags)
>>>>> +{
>>>>> + /* Enforce no COW since would have really strange behavior with it. */
>>>>> + if (is_cow_mapping(newflags) && (newflags & VM_WRITE))
>>>>> + return -EINVAL;
>>>>> +
>>>>> + return 0;
>>>>> +}
>>>>> +EXPORT_SYMBOL(ttm_bo_vm_mprotect);
>>>>> +
>>>>> static const struct vm_operations_struct ttm_bo_vm_ops = {
>>>>> .fault = ttm_bo_vm_fault,
>>>>> .open = ttm_bo_vm_open,
>>>>> .close = ttm_bo_vm_close,
>>>>> .access = ttm_bo_vm_access,
>>>>> + .mprotect = ttm_bo_vm_mprotect,
>>>>> };
>>>>>
>>>>> int ttm_bo_mmap_obj(struct vm_area_struct *vma, struct ttm_buffer_object *bo)
>>>>> {
>>>>> /* Enforce no COW since would have really strange behavior with it. */
>>>>> - if (is_cow_mapping(vma->vm_flags))
>>>>> + if (is_cow_mapping(vma->vm_flags) && (vma->vm_flags & VM_WRITE))
>>>>> return -EINVAL;
>>>>>
>>>>> ttm_bo_get(bo);
>>>>> diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_glue.c b/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_glue.c
>>>>> index e6b1f98ec99f..e4bf7dc99320 100644
>>>>> --- a/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_glue.c
>>>>> +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_glue.c
>>>>> @@ -61,6 +61,7 @@ int vmw_mmap(struct file *filp, struct vm_area_struct *vma)
>>>>> .fault = vmw_bo_vm_fault,
>>>>> .open = ttm_bo_vm_open,
>>>>> .close = ttm_bo_vm_close,
>>>>> + .mprotect = ttm_bo_vm_mprotect,
>>>>> #ifdef CONFIG_TRANSPARENT_HUGEPAGE
>>>>> .huge_fault = vmw_bo_vm_huge_fault,
>>>>> #endif
>>>>> diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h
>>>>> index f681bbdbc698..40eb95875355 100644
>>>>> --- a/include/drm/ttm/ttm_bo_api.h
>>>>> +++ b/include/drm/ttm/ttm_bo_api.h
>>>>> @@ -605,6 +605,10 @@ void ttm_bo_vm_close(struct vm_area_struct *vma);
>>>>>
>>>>> int ttm_bo_vm_access(struct vm_area_struct *vma, unsigned long addr,
>>>>> void *buf, int len, int write);
>>>>> +
>>>>> +int ttm_bo_vm_mprotect(struct vm_area_struct *vma, unsigned long start,
>>>>> + unsigned long end, unsigned long newflags);
>>>>> +
>>>>> bool ttm_bo_delayed_delete(struct ttm_device *bdev, bool remove_all);
>>>>>
>>>>> vm_fault_t ttm_bo_vm_dummy_page(struct vm_fault *vmf, pgprot_t prot);
>
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