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 X-Spam-Level: X-Spam-Status: No, score=-17.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EB039C433E6 for ; Wed, 17 Feb 2021 18:11:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B6BAE64E4B for ; Wed, 17 Feb 2021 18:11:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233634AbhBQSLM (ORCPT ); Wed, 17 Feb 2021 13:11:12 -0500 Received: from mail.kernel.org ([198.145.29.99]:44966 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233175AbhBQSKs (ORCPT ); Wed, 17 Feb 2021 13:10:48 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id EF80664E42; Wed, 17 Feb 2021 18:10:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1613585407; bh=0Z0WorCxaD7BP56hnkNMqdSiCglGFGlqAwsbSLCh6m8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=DomK4OPIHSzryzMWD5lTcExqL1chGXqVrXzu9LoLydAPrkFf74FsawJICKWnt1zWI q/KJDAtzBK0+DcQxYKC8mRmCTx/OdNROykkMOmkda4Pt0NX1x+J4uz4QfbMAFIyyyt /ldV/cm2fyYDcojGz4m2mitcaJknMpOXR66i4TBDaY+7hCMayTqa5tFicFYdsPRaEx aaCqO/zycLaUsiMFLcteS6hyBTRyZxwgfuFCkTPLbkT6yTcVSbT6aPeZ+t1fCxghBV HbpBcx4xDe+WnFP9gd2WEcFUm9g39+iVELWLsCMO1fDXQd6efesRCk7BD3IHzsE5W0 rtbd55DCpwibA== Date: Wed, 17 Feb 2021 18:10:02 +0000 From: Will Deacon To: Andrey Ryabinin Cc: Joerg Roedel , iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Qian Cai , valesini@yandex-team.ru, stable@vger.kernel.org Subject: Re: [PATCH] iommu/amd: Fix sleeping in atomic in increase_address_space() Message-ID: <20210217181002.GC4304@willie-the-truck> References: <20210217143004.19165-1-arbn@yandex-team.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210217143004.19165-1-arbn@yandex-team.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 17, 2021 at 05:30:04PM +0300, Andrey Ryabinin wrote: > increase_address_space() calls get_zeroed_page(gfp) under spin_lock with > disabled interrupts. gfp flags passed to increase_address_space() may allow > sleeping, so it comes to this: > > BUG: sleeping function called from invalid context at mm/page_alloc.c:4342 > in_atomic(): 1, irqs_disabled(): 1, pid: 21555, name: epdcbbf1qnhbsd8 > > Call Trace: > dump_stack+0x66/0x8b > ___might_sleep+0xec/0x110 > __alloc_pages_nodemask+0x104/0x300 > get_zeroed_page+0x15/0x40 > iommu_map_page+0xdd/0x3e0 > amd_iommu_map+0x50/0x70 > iommu_map+0x106/0x220 > vfio_iommu_type1_ioctl+0x76e/0x950 [vfio_iommu_type1] > do_vfs_ioctl+0xa3/0x6f0 > ksys_ioctl+0x66/0x70 > __x64_sys_ioctl+0x16/0x20 > do_syscall_64+0x4e/0x100 > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > Fix this by moving get_zeroed_page() out of spin_lock/unlock section. > > Fixes: 754265bcab ("iommu/amd: Fix race in increase_address_space()") > Signed-off-by: Andrey Ryabinin > Cc: > --- > drivers/iommu/amd/iommu.c | 10 ++++++---- > 1 file changed, 6 insertions(+), 4 deletions(-) Acked-by: Will Deacon Will