Patch "drm/ttm: Fix ttm_bo_shrink() infinite LRU walk on backup failure" has been added to the 7.0-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    drm/ttm: Fix ttm_bo_shrink() infinite LRU walk on backup failure

to the 7.0-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     drm-ttm-fix-ttm_bo_shrink-infinite-lru-walk-on-backup-failure.patch
and it can be found in the queue-7.0 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


From 1d59f36e95f7f7134db0e313c9d787cb0adb2153 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thomas=20Hellstr=C3=B6m?= <thomas.hellstrom@linux.intel.com>
Date: Mon, 11 May 2026 18:24:43 +0200
Subject: drm/ttm: Fix ttm_bo_shrink() infinite LRU walk on backup failure
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

From: Thomas Hellström <thomas.hellstrom@linux.intel.com>

commit 1d59f36e95f7f7134db0e313c9d787cb0adb2153 upstream.

Apply the same fix as b2ed01e7ad ("drm/ttm: Fix ttm_bo_swapout()
infinite LRU walk on swapout failure") to the ttm_bo_shrink() path.

Move del_bulk_move from before the backup to after success only,
using ttm_resource_del_bulk_move_unevictable() since the resource
is now unevictable once fully backed up.

Fixes: 70d645deac98 ("drm/ttm: Add helpers for shrinking")
Cc: Christian König <christian.koenig@amd.com>
Cc: Huang Rui <ray.huang@amd.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: dri-devel@lists.freedesktop.org
Cc: stable@vger.kernel.org # v6.15+
Assisted-by: GitHub_Copilot:claude-opus-4.6
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patch.msgid.link/20260511162443.24352-1-thomas.hellstrom@linux.intel.com
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/gpu/drm/ttm/ttm_bo_util.c |   11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

--- a/drivers/gpu/drm/ttm/ttm_bo_util.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
@@ -1112,19 +1112,14 @@ long ttm_bo_shrink(struct ttm_operation_
 	if (lret < 0)
 		return lret;
 
-	if (bo->bulk_move) {
-		spin_lock(&bdev->lru_lock);
-		ttm_resource_del_bulk_move(bo->resource, bo);
-		spin_unlock(&bdev->lru_lock);
-	}
-
 	lret = ttm_tt_backup(bdev, bo->ttm, (struct ttm_backup_flags)
 			     {.purge = flags.purge,
 			      .writeback = flags.writeback});
 
-	if (lret <= 0 && bo->bulk_move) {
+	if (lret > 0) {
 		spin_lock(&bdev->lru_lock);
-		ttm_resource_add_bulk_move(bo->resource, bo);
+		ttm_resource_del_bulk_move_unevictable(bo->resource, bo);
+		ttm_resource_move_to_lru_tail(bo->resource);
 		spin_unlock(&bdev->lru_lock);
 	}
 


Patches currently in stable-queue which might be from thomas.hellstrom@linux.intel.com are

queue-7.0/drm-xe-dma-buf-fix-uaf-with-retry-loop.patch
queue-7.0/drm-ttm-fix-ttm_bo_shrink-infinite-lru-walk-on-backup-failure.patch
queue-7.0/drm-ttm-fix-ttm_bo_swapout-infinite-lru-walk-on-swapout-failure.patch
queue-7.0/drm-gpusvm-fix-unbalanced-unlock-in-drm_gpusvm_scan_.patch
queue-7.0/drm-xe-xelp-fix-wa_18022495364.patch
queue-7.0/drm-xe-dma-buf-handle-empty-bo-and-uaf-races.patch
queue-7.0/drm-ttm-convert-eagain-from-dmem_cgroup_try_charge-to-enospc.patch