From patchwork Fri Oct 23 12:21:50 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Daniel Vetter X-Patchwork-Id: 11852981 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id C887F16BC for ; Fri, 23 Oct 2020 12:23:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9919524654 for ; Fri, 23 Oct 2020 12:23:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ffwll.ch header.i=@ffwll.ch header.b="URbjYqZv" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S463674AbgJWMXL (ORCPT ); Fri, 23 Oct 2020 08:23:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38060 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S463656AbgJWMXK (ORCPT ); Fri, 23 Oct 2020 08:23:10 -0400 Received: from mail-wm1-x342.google.com (mail-wm1-x342.google.com [IPv6:2a00:1450:4864:20::342]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CB62FC0613D2 for ; Fri, 23 Oct 2020 05:23:09 -0700 (PDT) Received: by mail-wm1-x342.google.com with SMTP id q5so1306684wmq.0 for ; Fri, 23 Oct 2020 05:23:09 -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=hp7lChw6Uow+58XPniSHemIeAoNErbB/sdK6im80Iug=; b=URbjYqZvij6vMp6zpIk/3WlniapSCelkh8qPhM9XSJmSi3JP0Pkq6JfYZq+gC0V2Ja Jq8vCQ4Ho/GAm6SQXrzJhiajzuA2XAwJXKB1Cll6tMyrVwJYz4NCmG2PdfE0KkUS7bh0 l5/AnqPDLrJU4JyaIv3jCsFac60g5JtxDcFVQ= 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=hp7lChw6Uow+58XPniSHemIeAoNErbB/sdK6im80Iug=; b=JPI4irHJ6jnmQ+OvUwTCZarjXZVwfyXZb+nsjFoXVcpPjCS1MjPDIuGxbFoEwZfqvJ FgzEA1rzbHKkf/gnfTvCXQAUmIoZ8B09wIsuOiftIaf7KpOrE+xOULeD4pKBfOI4KKpu Nbrb9WF+NcZVedlz4WAb0fq22D3FNLlmRh+w4GWnOOceB3O0PzoaQcsNKa7r0Z47g6CA NI9hLjGBvGczUjK6mhet5wFFjBZA714Pq1IdwfTAnIKEpQDe+4glqoISAx2HMaVcKCwW qBOHzc97/lYIUuAPBujvfG1DiO/JJwTYqJ5hBwICAQBPC62JIg+vLhlWLMCDPe/gLhNz yimA== X-Gm-Message-State: AOAM5303zGzwTy2BzgJas3wkAKpD2VTG399LXKHL5jKSU7rTz2NJLYBl +2TwssvD50v7N56x6xp5i7rEjg== X-Google-Smtp-Source: ABdhPJwqZWBmXRQ8vY8ZKJrjdPXGP2WILf15a1TrVl8Pgis8iT7Odd2hX51Nk7fKP5ClvyukHiQ2vg== X-Received: by 2002:a1c:4d05:: with SMTP id o5mr1994877wmh.94.1603455788583; Fri, 23 Oct 2020 05:23:08 -0700 (PDT) Received: from phenom.ffwll.local ([2a02:168:57f4:0:efd0:b9e5:5ae6:c2fa]) by smtp.gmail.com with ESMTPSA id y4sm3056484wrp.74.2020.10.23.05.23.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 23 Oct 2020 05:23:08 -0700 (PDT) From: Daniel Vetter To: DRI Development Cc: Intel Graphics Development , Daniel Vetter , Daniel Vetter , Jason Gunthorpe , Kees Cook , Dan Williams , Andrew Morton , John Hubbard , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , Jan Kara , linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, linux-media@vger.kernel.org, Alex Williamson , Cornelia Huck , kvm@vger.kernel.org Subject: [PATCH 39/65] vfio/type1: Mark follow_pfn as unsafe Date: Fri, 23 Oct 2020 14:21:50 +0200 Message-Id: <20201023122216.2373294-39-daniel.vetter@ffwll.ch> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201023122216.2373294-1-daniel.vetter@ffwll.ch> References: <20201021163242.1458885-1-daniel.vetter@ffwll.ch> <20201023122216.2373294-1-daniel.vetter@ffwll.ch> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-samsung-soc@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 5fbf0c1f7433..a4d53f3d0a35 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;