Am 05.08.2014 um 19:39 schrieb Jerome Glisse:
> On Tue, Aug 05, 2014 at 06:05:29PM +0200, Christian K?nig wrote:
>> From: Christian K?nig <christian.koenig at amd.com>
>>
>> Avoid problems with writeback by limiting userptr to anonymous memory.
>>
>> v2: add commit and code comments
> I guess, i have not expressed myself clearly. This is bogus, you pretend
> you want to avoid writeback issue but you still allow userspace to map
> file backed pages (which by the way might be a regular bo object from
> another device for instance and that would be fun).
>
> So this patch is a no go and i would rather see that this userptr to
> be restricted to anon vma only no matter what. No flags here.
Mapping of non anonymous memory (e.g. everything get_user_pages won't
fail with) is restricted to read only access by the GPU.
I'm fine with making it a hard requirement for all mappings if you say
it's a must have.
Christian.
>
> Cheers,
> J?r?me
>
>> Signed-off-by: Christian K?nig <christian.koenig at amd.com>
>> ---
>> drivers/gpu/drm/radeon/radeon_gem.c | 3 ++-
>> drivers/gpu/drm/radeon/radeon_ttm.c | 10 ++++++++++
>> include/uapi/drm/radeon_drm.h | 1 +
>> 3 files changed, 13 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/radeon/radeon_gem.c
>> b/drivers/gpu/drm/radeon/radeon_gem.c
>> index 993ab22..032736b 100644
>> --- a/drivers/gpu/drm/radeon/radeon_gem.c
>> +++ b/drivers/gpu/drm/radeon/radeon_gem.c
>> @@ -290,7 +290,8 @@ int radeon_gem_userptr_ioctl(struct drm_device *dev,
>> void *data,
>> return -EACCES;
>>
>> /* reject unknown flag values */
>> - if (args->flags & ~RADEON_GEM_USERPTR_READONLY)
>> + if (args->flags & ~(RADEON_GEM_USERPTR_READONLY |
>> + RADEON_GEM_USERPTR_ANONONLY))
>> return -EINVAL;
>>
>> /* readonly pages not tested on older hardware */
>> diff --git a/drivers/gpu/drm/radeon/radeon_ttm.c
>> b/drivers/gpu/drm/radeon/radeon_ttm.c
>> index 0109090..54eb7bc 100644
>> --- a/drivers/gpu/drm/radeon/radeon_ttm.c
>> +++ b/drivers/gpu/drm/radeon/radeon_ttm.c
>> @@ -542,6 +542,16 @@ static int radeon_ttm_tt_pin_userptr(struct ttm_tt *ttm)
>> ttm->num_pages * PAGE_SIZE))
>> return -EFAULT;
>>
>> + if (gtt->userflags & RADEON_GEM_USERPTR_ANONONLY) {
>> + /* check that we only pin down anonymous memory
>> + to prevent problems with writeback */
>> + unsigned long end = gtt->userptr + ttm->num_pages * PAGE_SIZE;
>> + struct vm_area_struct *vma;
>> + vma = find_vma(gtt->usermm, gtt->userptr);
>> + if (!vma || vma->vm_file || vma->vm_end < end)
>> + return -EPERM;
>> + }
>> +
>> do {
>> unsigned num_pages = ttm->num_pages - pinned;
>> uint64_t userptr = gtt->userptr + pinned * PAGE_SIZE;
>> diff --git a/include/uapi/drm/radeon_drm.h b/include/uapi/drm/radeon_drm.h
>> index 3a9f209..9720e1a 100644
>> --- a/include/uapi/drm/radeon_drm.h
>> +++ b/include/uapi/drm/radeon_drm.h
>> @@ -816,6 +816,7 @@ struct drm_radeon_gem_create {
>> * perform any operation.
>> */
>> #define RADEON_GEM_USERPTR_READONLY (1 << 0)
>> +#define RADEON_GEM_USERPTR_ANONONLY (1 << 1)
>>
>> struct drm_radeon_gem_userptr {
>> uint64_t addr;
>> --
>> 1.9.1
>>
>> _______________________________________________
>> dri-devel mailing list
>> dri-devel at lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/dri-devel
