diff options
| author | Zack Rusin <zackr@vmware.com> | 2023-02-11 00:05:14 -0500 |
|---|---|---|
| committer | Zack Rusin <zackr@vmware.com> | 2023-02-14 22:06:19 -0500 |
| commit | 9ef8d83e8e25d5f1811b3a38eb1484f85f64296c (patch) | |
| tree | ca8d16299d928f82612f5e301a2ec6c435d55943 /drivers/gpu/drm/vmwgfx/vmwgfx_surface.c | |
| parent | 36d421e632e9a0e8375eaed0143551a34d81a7e3 (diff) | |
drm/vmwgfx: Do not drop the reference to the handle too soon
v3: Fix vmw_user_bo_lookup which was also dropping the gem reference
before the kernel was done with buffer depending on userspace doing
the right thing. Same bug, different spot.
It is possible for userspace to predict the next buffer handle and
to destroy the buffer while it's still used by the kernel. Delay
dropping the internal reference on the buffers until kernel is done
with them.
Instead of immediately dropping the gem reference in vmw_user_bo_lookup
and vmw_gem_object_create_with_handle let the callers decide when they're
ready give the control back to userspace.
Also fixes the second usage of vmw_gem_object_create_with_handle in
vmwgfx_surface.c which wasn't grabbing an explicit reference
to the gem object which could have been destroyed by the userspace
on the owning surface at any point.
Signed-off-by: Zack Rusin <zackr@vmware.com>
Fixes: 8afa13a0583f ("drm/vmwgfx: Implement DRIVER_GEM")
Reviewed-by: Martin Krastev <krastevm@vmware.com>
Reviewed-by: Maaz Mombasawala <mombasawalam@vmware.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230211050514.2431155-1-zack@kde.org
Diffstat (limited to 'drivers/gpu/drm/vmwgfx/vmwgfx_surface.c')
| -rw-r--r-- | drivers/gpu/drm/vmwgfx/vmwgfx_surface.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c index 9d4ae9623a00..5db403ee8261 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c @@ -686,7 +686,7 @@ static void vmw_user_surface_base_release(struct ttm_base_object **p_base) container_of(base, struct vmw_user_surface, prime.base); struct vmw_resource *res = &user_srf->srf.res; - if (base->shareable && res && res->guest_memory_bo) + if (res->guest_memory_bo) drm_gem_object_put(&res->guest_memory_bo->tbo.base); *p_base = NULL; @@ -867,7 +867,11 @@ int vmw_surface_define_ioctl(struct drm_device *dev, void *data, goto out_unlock; } vmw_bo_reference(res->guest_memory_bo); - drm_gem_object_get(&res->guest_memory_bo->tbo.base); + /* + * We don't expose the handle to the userspace and surface + * already holds a gem reference + */ + drm_gem_handle_delete(file_priv, backup_handle); } tmp = vmw_resource_reference(&srf->res); @@ -1571,8 +1575,6 @@ vmw_gb_surface_define_internal(struct drm_device *dev, drm_vma_node_offset_addr(&res->guest_memory_bo->tbo.base.vma_node); rep->buffer_size = res->guest_memory_bo->tbo.base.size; rep->buffer_handle = backup_handle; - if (user_srf->prime.base.shareable) - drm_gem_object_get(&res->guest_memory_bo->tbo.base); } else { rep->buffer_map_handle = 0; rep->buffer_size = 0; |