Commit b437b8f7 authored by Boris Brezillon's avatar Boris Brezillon
Browse files

drm/panthor: Don't create a file offset for NO_MMAP BOs 



Right now the DRM_PANTHOR_BO_NO_MMAP flag is ignored by
panthor_ioctl_bo_mmap_offset(), meaning BOs with this flag set can
have a file offset but can't be mapped anyway, because
panthor_gem_mmap() will filter them out.

If we error out at mmap_offset creation time, we can get rid of
panthor_gem_mmap() and call drm_gem_shmem_object_mmap directly, and
we get rid of this inconsistency of having an mmap offset for a
BO that can never be mmap-ed.

Changes in v2:
- Get rid of panthor_gem_mmap()
- Get rid of the Fixes tag and adjust the commit message accordingly
- Return ENOPERM instead of EINVAL

Changes in v3:
- Don't leak the BO ref
- Add R-bs

Reviewed-by: default avatarSteven Price <steven.price@arm.com>
Reviewed-by: default avatarLiviu Dudau <liviu.dudau@arm.com>
Reviewed-by: default avatarAdrián Larumbe <adrian.larumbe@collabora.com>
Link: https://lore.kernel.org/r/20250417121942.3574111-1-boris.brezillon@collabora.com


Signed-off-by: default avatarBoris Brezillon <boris.brezillon@collabora.com>
parent e1eb7293

drivers/gpu/drm/panthor/panthor_drv.c

+7 −0
Original line number Diff line number Diff line
@@ -940,6 +940,7 @@ static int panthor_ioctl_bo_mmap_offset(struct drm_device *ddev, void *data, 
					struct drm_file *file)

{

	struct drm_panthor_bo_mmap_offset *args = data;

	struct panthor_gem_object *bo;

	struct drm_gem_object *obj;

	int ret;
@@ -950,6 +951,12 @@ static int panthor_ioctl_bo_mmap_offset(struct drm_device *ddev, void *data, 
	if (!obj)

		return -ENOENT;



	bo = to_panthor_bo(obj);

	if (bo->flags & DRM_PANTHOR_BO_NO_MMAP) {

		ret = -EPERM;

		goto out;

	}



	ret = drm_gem_create_mmap_offset(obj);

	if (ret)

		goto out;

drivers/gpu/drm/panthor/panthor_gem.c

+1 −12
Original line number Diff line number Diff line
@@ -129,17 +129,6 @@ panthor_kernel_bo_create(struct panthor_device *ptdev, struct panthor_vm *vm, 
	return ERR_PTR(ret);

}



static int panthor_gem_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma)

{

	struct panthor_gem_object *bo = to_panthor_bo(obj);



	/* Don't allow mmap on objects that have the NO_MMAP flag set. */

	if (bo->flags & DRM_PANTHOR_BO_NO_MMAP)

		return -EINVAL;



	return drm_gem_shmem_object_mmap(obj, vma);

}



static struct dma_buf *

panthor_gem_prime_export(struct drm_gem_object *obj, int flags)

{
@@ -169,7 +158,7 @@ static const struct drm_gem_object_funcs panthor_gem_funcs = { 
	.get_sg_table = drm_gem_shmem_object_get_sg_table,

	.vmap = drm_gem_shmem_object_vmap,

	.vunmap = drm_gem_shmem_object_vunmap,

	.mmap = panthor_gem_mmap,

	.mmap = drm_gem_shmem_object_mmap,

	.status = panthor_gem_status,

	.export = panthor_gem_prime_export,

	.vm_ops = &drm_gem_shmem_vm_ops,