[PATCH v3 1/1] drm/ttm: Fix COW check
Christian König
ckoenig.leichtzumerken at gmail.com
Fri Jul 23 09:09:05 UTC 2021
Am 23.07.21 um 11:00 schrieb Daniel Vetter:
> On Fri, Jul 23, 2021 at 10:33:48AM +0200, Christian König wrote:
>>
>> 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.
> Well I just hard-reset, so you can push the right patch to the right
> branch now. The trouble is that outside of the merge window no one is
> allowed to push to drm-misc-next-fixes. If you do, then dim pushes
> drm-misc-next-fixes to for-linux-next instead of drm-misc-next, and we
> have bad surprises.
Could we then make the branch read-only for that time?
> Which unfortunately happens like every merge window a few times and always
> takes a few days/weeks to get caught.
Yeah, at least to me it's absolutely not obvious when the merge windows
for a certain version start/end.
Christian.
> -Danie
>
>> 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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