drm/xe: skip eviction of a BO with no resource

Browse source

xe_evict_flags() switches on tbo->resource->mem_type to choose an
eviction placement. An xe BO can reach eviction with no ttm.resource,
e.g. an imported dma-buf BO whose resource was freed during teardown
while its attachment is still live: the exporter then invalidates it via
xe_dma_buf_move_notify() -> xe_bo_evict(), and the switch dereferences a
NULL resource and faults.

A BO with no resource has nothing placed or mapped, so there is nothing
to evict. Return an empty placement (num_placement = 0), mirroring the
handling already used for non-xe scatter-gather BOs just above;
ttm_bo_validate() then takes the pipeline-gutting path and returns 0.

Without the fix the xe_dma_buf@xe_test_dmabuf_move_notify_no_resource
dynamic live selftest will fail with below stack.

BUG: kernel NULL pointer dereference, address: 0000000000000010
RIP: 0010:xe_evict_flags+0xf4/0x140 [xe]
Call Trace:
 <TASK>
 xe_bo_evict+0x40/0xa0 [xe]
 ? ttm_bo_pipeline_gutting+0x71/0x180 [ttm]
 xe_test_dmabuf_move_notify_no_resource+0x182/0x440 [xe]
 xe_dma_buf_kunit+0x387/0x580 [xe]

v2: Add Fixes tag and failure info in commit text (Matt Brost)

Fixes: dd08ebf6c3 ("drm/xe: Introduce a new DRM driver for Intel GPUs")
Assisted-by: GitHub-Copilot:claude-opus-4.8
Signed-off-by: Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>
Reviewed-by: Tejas Upadhyay <tejas.upadhyay@intel.com>
Link: https://patch.msgid.link/20261012215014.1495677-5-niranjana.vishwanathapura@intel.com
(cherry picked from commit dbcfaac6331f1fcb0c2fe3ad3e9adb1e5d43ec0c)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

...

This commit is contained in:

Niranjana Vishwanathapura 2026-10-12 14:50:14 -07:00 • committed by Rodrigo Vivi

parent ffbfd3f98f

commit 448e76cbdc

No known key found for this signature in database

GPG key ID: FA625F640EEB13CA

1 changed files with 6 additions and 0 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

6

drivers/gpu/drm/xe/xe_bo.c

View file