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 CAA71C4167B for ; Tue, 7 Nov 2023 12:42:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235303AbjKGMmG (ORCPT ); Tue, 7 Nov 2023 07:42:06 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44496 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235304AbjKGMlt (ORCPT ); Tue, 7 Nov 2023 07:41:49 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3C3592D67; Tue, 7 Nov 2023 04:29:46 -0800 (PST) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4FDF6C433C7; Tue, 7 Nov 2023 12:29:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1699360185; bh=RQBd2PXDrZbS8s6bkX523kM3pf4EKY4c7HeXttE7ZVE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=g7T7YBNjDZk1h8TW22AXdNGP/pZMC6FSTVVcQCOF9jpWgWVrZM0BF3brL656CEwdu DpUzbXWK47TixMZI+2jbSM9cvmi6rTKvF5v2rN+AWzfxt80AybXBkmCVERrffecVEj WvF9i42YC3thMZKG/+uFu6lmW7ZuFi2qol2vvwsnJqqKqPPKqPdS/IGzW4ulf40fTQ WrY9+YrMTy80XIwY+aNcJcnEDduWPMxJrLPXmQLBTfeK9IZDMLLqjqY4OPkVcPGYUz GoAURA1UKFPV+Bxk2Dd/imziaw6WHA6ncyfEgX9BfXMLJMisezrlBOi9wmGq0RP/2h eEcGXZV8tpaQw== 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 5.15 02/20] drm/amdkfd: Fix a race condition of vram buffer unref in svm code Date: Tue, 7 Nov 2023 07:28:56 -0500 Message-ID: <20231107122940.3762228-2-sashal@kernel.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231107122940.3762228-1-sashal@kernel.org> References: <20231107122940.3762228-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 5.15.137 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 22a70aaccf13c..b7d32a5062b6c 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c @@ -550,8 +550,15 @@ svm_range_vram_node_new(struct amdgpu_device *adev, 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 amdgpu_device * -- 2.42.0