From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C4E3CC0018C for ; Tue, 7 Nov 2023 12:29:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234627AbjKGM3P (ORCPT ); Tue, 7 Nov 2023 07:29:15 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36870 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234655AbjKGM25 (ORCPT ); Tue, 7 Nov 2023 07:28:57 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 82C1734892; Tue, 7 Nov 2023 04:19:52 -0800 (PST) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5ECB1C433C9; Tue, 7 Nov 2023 12:19:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1699359575; bh=pHZF4xAPU87lfR/eyN0VX1XeTc37LcaLDLgqJaK+C+Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FqFT6Pyt8o0y/vIjqBqVh6iKby4WiLnALDSYWhykGnZGH6qpGPN75G78SNvClrwOk 7t9UnV37/g1NAxqh3GziZgwGyZdd5+wYYKxtT+9X72jS4bmNzCAwOyJXEw640sqm0d 40a15SAaJgoKc6WU/ewaFcfZqI6jLMIULP5iyc6u8AE9RoC3jmfOPV6b2QRRckOt6V RYbg2GvNjNKKm0T1dh9l+3fnJZs5WaSRn2NnkbXqEWO0hTbKwfKcDcDDh0C9em37ki NFnhG4hrTqk6NL9aJtRXr1MtG5Ycl1pr4NazKJUYu5UWQMAcREDBEpyDTHFkYq//D+ Sg1bn6w3SG0Ew== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Xiaogang Chen , Philip Yang , Jesse Zhang , Alex Deucher , Sasha Levin , Felix.Kuehling@amd.com, christian.koenig@amd.com, Xinhui.Pan@amd.com, airlied@gmail.com, daniel@ffwll.ch, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org Subject: [PATCH AUTOSEL 6.6 10/40] drm/amdkfd: Fix a race condition of vram buffer unref in svm code Date: Tue, 7 Nov 2023 07:16:12 -0500 Message-ID: <20231107121837.3759358-10-sashal@kernel.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231107121837.3759358-1-sashal@kernel.org> References: <20231107121837.3759358-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.6 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Xiaogang Chen [ Upstream commit 709c348261618da7ed89d6c303e2ceb9e453ba74 ] prange->svm_bo unref can happen in both mmu callback and a callback after migrate to system ram. Both are async call in different tasks. Sync svm_bo unref operation to avoid random "use-after-free". Signed-off-by: Xiaogang Chen Reviewed-by: Philip Yang Reviewed-by: Jesse Zhang Tested-by: Jesse Zhang Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin --- drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c index bb16b795d1bc2..175090be3760c 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c @@ -628,8 +628,15 @@ svm_range_vram_node_new(struct kfd_node *node, struct svm_range *prange, void svm_range_vram_node_free(struct svm_range *prange) { - svm_range_bo_unref(prange->svm_bo); - prange->ttm_res = NULL; + /* serialize prange->svm_bo unref */ + mutex_lock(&prange->lock); + /* prange->svm_bo has not been unref */ + if (prange->ttm_res) { + prange->ttm_res = NULL; + mutex_unlock(&prange->lock); + svm_range_bo_unref(prange->svm_bo); + } else + mutex_unlock(&prange->lock); } struct kfd_node * -- 2.42.0