[PATCH v2] drm/ttm: Fix ttm_bo_move_memcpy() for subclassed struct ttm_resource

[PATCH v2] drm/ttm: Fix ttm_bo_move_memcpy() for subclassed struct ttm_resource

[Thomas Hellström]

The code was making a copy of a struct ttm_resource. However,
recently the struct ttm_resources were allowed to be subclassed and
also were allowed to be malloced, hence the driver could end up assuming
the copy we handed it was subclassed and worse, the original could have
been freed at this point.

Fix this by using the original struct ttm_resource before it is
potentially freed in ttm_bo_move_sync_cleanup()

v2: Base on drm-misc-next-fixes rather than drm-tip.

Reported-by: Ben Skeggs <skeggsb@gmail.com>
Reported-by: Dave Airlie <airlied@gmail.com>
Cc: Christian König <christian.koenig@amd.com>
Fixes: 3bf3710e3718 ("drm/ttm: Add a generic TTM memcpy move for page-based iomem")
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Ben Skeggs <bskeggs@redhat.com>
---
 drivers/gpu/drm/ttm/ttm_bo_util.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c
index 763fa6f4e07d..1c5ffe2935af 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_util.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
@@ -143,7 +143,6 @@ int ttm_bo_move_memcpy(struct ttm_buffer_object *bo,
 	struct ttm_resource *src_mem = bo->resource;
 	struct ttm_resource_manager *src_man =
 		ttm_manager_type(bdev, src_mem->mem_type);
-	struct ttm_resource src_copy = *src_mem;
 	union {
 		struct ttm_kmap_iter_tt tt;
 		struct ttm_kmap_iter_linear_io io;
@@ -173,11 +172,11 @@ int ttm_bo_move_memcpy(struct ttm_buffer_object *bo,
 	}
 
 	ttm_move_memcpy(bo, dst_mem->num_pages, dst_iter, src_iter);
-	src_copy = *src_mem;
-	ttm_bo_move_sync_cleanup(bo, dst_mem);
 
 	if (!src_iter->ops->maps_tt)
-		ttm_kmap_iter_linear_io_fini(&_src_iter.io, bdev, &src_copy);
+		ttm_kmap_iter_linear_io_fini(&_src_iter.io, bdev, src_mem);
+	ttm_bo_move_sync_cleanup(bo, dst_mem);
+
 out_src_iter:
 	if (!dst_iter->ops->maps_tt)
 		ttm_kmap_iter_linear_io_fini(&_dst_iter.io, bdev, dst_mem);
-- 
2.31.1

[Intel-gfx] [PATCH v2] drm/ttm: Fix ttm_bo_move_memcpy() for subclassed struct ttm_resource

[Thomas Hellström]

The code was making a copy of a struct ttm_resource. However,
recently the struct ttm_resources were allowed to be subclassed and
also were allowed to be malloced, hence the driver could end up assuming
the copy we handed it was subclassed and worse, the original could have
been freed at this point.

Fix this by using the original struct ttm_resource before it is
potentially freed in ttm_bo_move_sync_cleanup()

v2: Base on drm-misc-next-fixes rather than drm-tip.

Reported-by: Ben Skeggs <skeggsb@gmail.com>
Reported-by: Dave Airlie <airlied@gmail.com>
Cc: Christian König <christian.koenig@amd.com>
Fixes: 3bf3710e3718 ("drm/ttm: Add a generic TTM memcpy move for page-based iomem")
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Ben Skeggs <bskeggs@redhat.com>
---
 drivers/gpu/drm/ttm/ttm_bo_util.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c
index 763fa6f4e07d..1c5ffe2935af 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_util.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
@@ -143,7 +143,6 @@ int ttm_bo_move_memcpy(struct ttm_buffer_object *bo,
 	struct ttm_resource *src_mem = bo->resource;
 	struct ttm_resource_manager *src_man =
 		ttm_manager_type(bdev, src_mem->mem_type);
-	struct ttm_resource src_copy = *src_mem;
 	union {
 		struct ttm_kmap_iter_tt tt;
 		struct ttm_kmap_iter_linear_io io;
@@ -173,11 +172,11 @@ int ttm_bo_move_memcpy(struct ttm_buffer_object *bo,
 	}
 
 	ttm_move_memcpy(bo, dst_mem->num_pages, dst_iter, src_iter);
-	src_copy = *src_mem;
-	ttm_bo_move_sync_cleanup(bo, dst_mem);
 
 	if (!src_iter->ops->maps_tt)
-		ttm_kmap_iter_linear_io_fini(&_src_iter.io, bdev, &src_copy);
+		ttm_kmap_iter_linear_io_fini(&_src_iter.io, bdev, src_mem);
+	ttm_bo_move_sync_cleanup(bo, dst_mem);
+
 out_src_iter:
 	if (!dst_iter->ops->maps_tt)
 		ttm_kmap_iter_linear_io_fini(&_dst_iter.io, bdev, dst_mem);
-- 
2.31.1

[Intel-gfx] ✗ Fi.CI.BUILD: failure for drm/ttm: Fix ttm_bo_move_memcpy() for subclassed struct ttm_resource (rev2)

[Patchwork]

== Series Details ==

Series: drm/ttm: Fix ttm_bo_move_memcpy() for subclassed struct ttm_resource (rev2)
URL   : https://patchwork.freedesktop.org/series/94154/
State : failure

== Summary ==

Applying: drm/ttm: Fix ttm_bo_move_memcpy() for subclassed struct ttm_resource
Using index info to reconstruct a base tree...
M	drivers/gpu/drm/ttm/ttm_bo_util.c
Falling back to patching base and 3-way merge...
Auto-merging drivers/gpu/drm/ttm/ttm_bo_util.c
CONFLICT (content): Merge conflict in drivers/gpu/drm/ttm/ttm_bo_util.c
error: Failed to merge in the changes.
hint: Use 'git am --show-current-patch=diff' to see the failed patch
Patch failed at 0001 drm/ttm: Fix ttm_bo_move_memcpy() for subclassed struct ttm_resource
When you have resolved this problem, run "git am --continue".
If you prefer to skip this patch, run "git am --skip" instead.
To restore the original branch and stop patching, run "git am --abort".