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=-12.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT 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 A6B95C64E8A for ; Fri, 30 Oct 2020 10:09:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 49AD422228 for ; Fri, 30 Oct 2020 10:09:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ffwll.ch header.i=@ffwll.ch header.b="ddb3ur1/" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726602AbgJ3KJu (ORCPT ); Fri, 30 Oct 2020 06:09:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50384 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726444AbgJ3KIz (ORCPT ); Fri, 30 Oct 2020 06:08:55 -0400 Received: from mail-wm1-x341.google.com (mail-wm1-x341.google.com [IPv6:2a00:1450:4864:20::341]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6B083C0613D2 for ; Fri, 30 Oct 2020 03:08:53 -0700 (PDT) Received: by mail-wm1-x341.google.com with SMTP id w23so2302384wmi.4 for ; Fri, 30 Oct 2020 03:08:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=oGBzVmmcnUwoCpcjwMRu//j69ndtXtCP0NS2ElhXzwU=; b=ddb3ur1/6UNkfQr4L91EGkmgAJ2WFlh64b3krQrxHdXICPqGD1U7KSjV8mliOcYT2T IQK1rF0Fay6IRnqi6Z1rjQW4mkT8UrxQsAja5X4I4Zb0BD7E8rZgI9L3j1sWoJXQiFP2 XQzGN/xa46QCrVP1PNnx5Jw7AGsn+9JT27UuU= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=oGBzVmmcnUwoCpcjwMRu//j69ndtXtCP0NS2ElhXzwU=; b=tTJuxC0IJ3eP03vARGf2jy97rHB2Xn5tbOCF02XLzRLCc6hObTwxnDWVCGD1j5Qcax jt8+Jp26+Za/3M/jKenAyQERJUertpvbFsX0FZWHrklOg70AZUjLVjllZ2o7rQBv7ixe 9FPHhUVOFYYm9d287YMmuOGkHBsoOAZyWVtbM/1Wg4N2WYx+PsInf6cvpVZFj/qcVJei 9XWeLVsRGRic6RqMix5GDYlWQ17jf9CLDcEdQuOBKAeZPql2iIv+52hpehfF9utW9kvd RQx2866q6pwhLFDWrR2O0xcKCotoogdZB9RKtWbF0Z9lj6QDWairpLPARcOdMZzo6CUe YSTQ== X-Gm-Message-State: AOAM530XJ9HUnBPaUh77f0+YgI8ueYgeAVhNuGWQNVMkIt+2GyjS5mZW YL0aEALj8OYdH8qe5lDQMugjXA== X-Google-Smtp-Source: ABdhPJwf6UH/CcQRHOKUtt59ycYpiu3snU7M2hjeYaaPa8vODJopyC6lafOLMLKP7+MR3NDzcDgM5Q== X-Received: by 2002:a7b:c309:: with SMTP id k9mr1632728wmj.125.1604052532224; Fri, 30 Oct 2020 03:08:52 -0700 (PDT) Received: from phenom.ffwll.local ([2a02:168:57f4:0:efd0:b9e5:5ae6:c2fa]) by smtp.gmail.com with ESMTPSA id v189sm4430947wmg.14.2020.10.30.03.08.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 30 Oct 2020 03:08:51 -0700 (PDT) From: Daniel Vetter To: DRI Development , LKML Cc: kvm@vger.kernel.org, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, linux-media@vger.kernel.org, Daniel Vetter , Daniel Vetter , Jason Gunthorpe , Kees Cook , Dan Williams , Andrew Morton , John Hubbard , =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= , Jan Kara , Alex Williamson , Cornelia Huck Subject: [PATCH v5 10/15] vfio/type1: Mark follow_pfn as unsafe Date: Fri, 30 Oct 2020 11:08:10 +0100 Message-Id: <20201030100815.2269-11-daniel.vetter@ffwll.ch> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201030100815.2269-1-daniel.vetter@ffwll.ch> References: <20201030100815.2269-1-daniel.vetter@ffwll.ch> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The code seems to stuff these pfns into iommu pts (or something like that, I didn't follow), but there's no mmu_notifier to ensure that access is synchronized with pte updates. Hence mark these as unsafe. This means that with CONFIG_STRICT_FOLLOW_PFN, these will be rejected. Real fix is to wire up an mmu_notifier ... somehow. Probably means any invalidate is a fatal fault for this vfio device, but then this shouldn't ever happen if userspace is reasonable. Signed-off-by: Daniel Vetter Cc: Jason Gunthorpe Cc: Kees Cook Cc: Dan Williams Cc: Andrew Morton Cc: John Hubbard Cc: Jérôme Glisse Cc: Jan Kara Cc: Dan Williams Cc: linux-mm@kvack.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-samsung-soc@vger.kernel.org Cc: linux-media@vger.kernel.org Cc: Alex Williamson Cc: Cornelia Huck Cc: kvm@vger.kernel.org Signed-off-by: Daniel Vetter --- drivers/vfio/vfio_iommu_type1.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c index bb2684cc245e..eccfee900033 100644 --- a/drivers/vfio/vfio_iommu_type1.c +++ b/drivers/vfio/vfio_iommu_type1.c @@ -421,7 +421,7 @@ static int follow_fault_pfn(struct vm_area_struct *vma, struct mm_struct *mm, { int ret; - ret = follow_pfn(vma, vaddr, pfn); + ret = unsafe_follow_pfn(vma, vaddr, pfn); if (ret) { bool unlocked = false; @@ -435,7 +435,7 @@ static int follow_fault_pfn(struct vm_area_struct *vma, struct mm_struct *mm, if (ret) return ret; - ret = follow_pfn(vma, vaddr, pfn); + ret = unsafe_follow_pfn(vma, vaddr, pfn); } return ret; -- 2.28.0