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 B4B0532ED40; Sat, 12 Sep 2026 14:34:22 +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=1789223664; cv=none; b=hUHAT5Ym11Jdv2uqEsO7iXm54fppofDoAEOtn33QrOwAXb8BZRK8Kfw7Eg745SzMpDsU9xE1rhIUFw/VNQ/x12lbJcSowq2dUV2yahaRGYQLbzafALoQT1MbZ/MLQ0lsTTs7G1bN3mDMGrY26jeyloQv3i2Dlx1vJMxjrFgGhA4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789223664; c=relaxed/simple; bh=5KGAjaKRiqURBTU9apOiwO77RImCsqSWROMJiDiU5jQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=EmPwIEcxh7tn31I9VS463s9elIFor1lzOtzATrJ+l15tfz0dYYC5lDa8uK4M9jKfh9mkOVtpJlyVX03NXme/GvykTrdXEpKMd7hkDImQOL2XLhVdYT5ADoLchBrV8/unqkwSE8/Jz3lNjAeccJHj5k2mNWahvNjHoEso7dJF/ZU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ZUw5Spy8; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ZUw5Spy8" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3C5AB1F00893; Sat, 12 Sep 2026 14:34:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789223662; bh=50MDlKeHzZptqeNiSQueD/W5VPcD18X/x07MiohJnng=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=ZUw5Spy8wX111O0I03cVMQ7Hph35U/QYuuIwsIvra6Q1UojaG3tcaux0kSI94Upzs qPX9/Godts6I/WkxXRyMXmMtLSHFCuAL6N45gyVUCu1nkMu2UyhJ6nAhe0ELw18HdR z5d4EX6ivln7k7BdyzlarzbGANCxYIb4WKV1yJwpSvVFwy/GFtnwKrmZJGmPNTCKSn xiq5WhXaV0M9nfGWf7TmgTk3GuAMRz9ziqX6AGFQ2k8uIaFU1YP6i9lgxdFCQsd2oX YJSfLGCF8aQSqlkvx/yy0+Vfz5XvD/HCkQX1xc4IVSGn/LXL0GXPcXPUKIERvpvz1z TXl5OtpuQrL+w== From: Sasha Levin To: stable@vger.kernel.org Cc: Matthew Brost , =?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, Sasha Levin Subject: [PATCH 6.18.y 2/2] drm/ttm: Drop tt->restore after successful restore Date: Sat, 12 Sep 2026 10:34:18 -0400 Message-ID: <20260912143418.2961430-2-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260912143418.2961430-1-sashal@kernel.org> References: <2026090936-stew-difficult-cba0@gregkh> <20260912143418.2961430-1-sashal@kernel.org> 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 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 --- drivers/gpu/drm/ttm/ttm_pool.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/ttm/ttm_pool.c b/drivers/gpu/drm/ttm/ttm_pool.c index 1f52a1f59d7b7..dd5666eb4692b 100644 --- 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 ttm_pool *pool, struct ttm_tt *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 ttm_pool *pool, struct ttm_tt *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); -- 2.53.0