From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 30A8D4FD29C; Thu, 17 Sep 2026 17:45:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789667157; cv=none; b=Z9gv3UfJ4sZkaaI5L2Vf0VxENUiCOf88HtMEiPoN5lLsAEGmEcZ8eiUBPd5YNRnSjNB7NQv4mvtjsIGI4fdM0+3Hsz+qk6iF9RcvNsHSucGqBfjGt1ocQz3pBsL+FgA6nSjexMexN8OFjw6OkEDz9u/31kQlqznrfVmmmWQCnOo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789667157; c=relaxed/simple; bh=Wajz/DAFosYoXndJnoLG0dlnJaJh4S3EskaiGibaicM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=lnkhoyo9IjXxvtUYUNBE1y4M43JTvgwrZvWqJcwDXjh3dWeAeYtI5Bl9Uw3Vwz/Bf/VvWmQW0SepNBBYz7zE8dUDC3G7aS06ULgb14OXBM9KE5gfPCYiVFh55tevKyzgZt/D2ZqEGMv27nCTyg9RLWHDqsxLAZ8QN19+M8eXT1Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=nGM8aUqh; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="nGM8aUqh" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 60F4E1F0089A; Thu, 17 Sep 2026 17:45:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789667155; bh=MYsk118QlVYhV6g6CujJesNIpIsXreUjPlJN1M49CpI=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=nGM8aUqhGu/wn4ax6wMxbVov/iI/HV63AxRAblKtG+AShvtBzefArIsYp+HRL9Nqr Bj3HtIJPfiqmX1RPqwxtZKF6Em7NbBIx7Xe7n4v5vEPKkJUtK0V+sw7sM5kQ/+Yno9 ptLMO/LbFVH5d1KCHGi/qdy+NfjNHKjKLR2Gc64k= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, =?UTF-8?q?Thomas=20Hellstr=C3=B6m?= , Christian Koenig , Huang Rui , Matthew Auld , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Matthew Brost , Sasha Levin Subject: [PATCH 6.18 1247/1250] drm/ttm: Drop tt->restore after successful restore Date: Thu, 17 Sep 2026 16:17:22 +0100 Message-ID: <20260917151626.101707354@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260917151551.901433442@linuxfoundation.org> References: <20260917151551.901433442@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Matthew Brost [ Upstream commit 941ac10529b3be5965a88d432a161ab459672ba8 ] ttm_pool_restore_and_alloc() can successfully complete the restore process via ttm_pool_restore_commit(), but tt->restore is not dropped afterward. As a result, subsequent backup/restore flows observe what appears to be a completed restore, while in reality shmem handles are still installed in tt->pages, leading to the stack trace below. Fix this by freeing and dropping tt->restore in ttm_pool_restore_and_alloc() upon successful completion of the restore. 20545 [  309.784531] RIP: 0010:sg_alloc_append_table_from_pages+0x38c/0x490 20547 [  309.809570] RSP: 0018:ffffc9000623b838 EFLAGS: 00010206 20548 [  309.814827] RAX: 0000000000001000 RBX: ffff88816e42a160 RCX: 0000000000000000 20549 [  309.821986] RDX: 0000000000002000 RSI: 0000000000000003 RDI: 0000000000001000 20550 [  309.829147] RBP: ffff88816e42a168 R08: 0000000000000002 R09: 000000007ffff000 20551 [  309.836310] R10: ffffc9000623b928 R11: 0000000000000000 R12: 000000007ffff000 20552 [  309.843471] R13: ffff88815ba5a100 R14: 0000000000000000 R15: 0000000000000001 20553 [  309.850634] FS:  00007f9ff305e700(0000) GS:ffff888276c94000(0000) knlGS:0000000000000000 20554 [  309.858749] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033 20555 [  309.864519] CR2: 00007f9fca701000 CR3: 00000001565e2005 CR4: 0000000008f70ef0 20556 [  309.871678] PKRU: 55555558 20557 [  309.874403] Call Trace: 20558 [  309.876866]  20559 [  309.878988]  sg_alloc_table_from_pages_segment+0x60/0x100 20560 [  309.884415]  ? ttm_resource_manager_usage+0x36/0x60 [ttm] 20561 [  309.889845]  ? xe_tt_map_sg+0x7d/0xd0 [xe] 20562 [  309.894045]  xe_tt_map_sg+0x7d/0xd0 [xe] 20563 [  309.898037]  xe_bo_move+0x927/0xaa0 [xe] 20564 [  309.902029]  ttm_bo_handle_move_mem+0xba/0x170 [ttm] 20565 [  309.907022]  ttm_bo_validate+0xbe/0x190 [ttm] 20566 [  309.911405]  xe_bo_validate+0x9a/0x120 [xe] 20567 [  309.915663]  xe_gpuvm_validate+0xd9/0x140 [xe] 20568 [  309.920206]  drm_gpuvm_validate+0x2f0/0x5b0 [drm_gpuvm] 20569 [  309.925459]  ? drm_exec_lock_obj+0x63/0x210 [drm_exec] 20570 [  309.930627]  xe_vm_validate_rebind+0x46/0xb0 [xe] 20571 [  309.935428]  xe_exec_fn+0x20/0x40 [xe] 20572 [  309.939249]  drm_gpuvm_exec_lock+0x78/0xc0 [drm_gpuvm] 20573 [  309.944410]  xe_validation_exec_lock+0x5a/0xa0 [xe] 20574 [  309.949385]  xe_exec_ioctl+0x806/0xc30 [xe] 20575 [  309.953639]  ? ttwu_queue_wakelist+0xd9/0xf0 20576 [  309.957935]  ? __pfx_xe_exec_fn+0x10/0x10 [xe] 20577 [  309.962449]  ? __wake_up_common+0x73/0xa0 20578 [  309.966482]  ? __pfx_xe_exec_ioctl+0x10/0x10 [xe] 20579 [  309.971263]  drm_ioctl_kernel+0xa3/0x100 20580 [  309.975209]  drm_ioctl+0x213/0x440 20581 [  309.978637]  ? __pfx_xe_exec_ioctl+0x10/0x10 [xe] 20582 [  309.983415]  xe_drm_ioctl+0x67/0xd0 [xe] 20583 [  309.987408]  __x64_sys_ioctl+0x7f/0xd0 Cc: Thomas Hellström Cc: Christian Koenig Cc: Huang Rui Cc: Matthew Auld Cc: Maarten Lankhorst Cc: Maxime Ripard Cc: Thomas Zimmermann Cc: David Airlie Cc: Simona Vetter Cc: dri-devel@lists.freedesktop.org Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org Fixes: b63d715b8090 ("drm/ttm/pool, drm/ttm/tt: Provide a helper to shrink pages") Signed-off-by: Matthew Brost Reviewed-by: Thomas Hellström Link: https://patch.msgid.link/20260617015531.1164189-1-matthew.brost@intel.com Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/ttm/ttm_pool.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) --- a/drivers/gpu/drm/ttm/ttm_pool.c +++ b/drivers/gpu/drm/ttm/ttm_pool.c @@ -838,6 +838,7 @@ int ttm_pool_restore_and_alloc(struct tt { struct ttm_pool_tt_restore *restore = tt->restore; struct ttm_pool_alloc_state alloc; + int ret; if (WARN_ON(!ttm_tt_is_backed_up(tt))) return -EINVAL; @@ -861,14 +862,22 @@ int ttm_pool_restore_and_alloc(struct tt } else { alloc = restore->snapshot_alloc; if (ttm_pool_restore_valid(restore)) { - int ret = ttm_pool_restore_commit(restore, tt->backup, - ctx, &alloc); + ret = ttm_pool_restore_commit(restore, tt->backup, + ctx, &alloc); if (ret) return ret; } - if (!alloc.remaining_pages) + if (!alloc.remaining_pages) { + ret = ttm_pool_apply_caching(&alloc); + if (ret) + return ret; + + kfree(tt->restore); + tt->restore = NULL; + return 0; + } } return __ttm_pool_alloc(pool, tt, ctx, &alloc, restore);