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=-6.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 78502C43381 for ; Mon, 18 Feb 2019 13:49:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4880F21906 for ; Mon, 18 Feb 2019 13:49:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1550497788; bh=NfaN7F6t25SlYgna6NxJ8RtcJ1RA1pR+gfI7QybJHd4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=1CyRWQElWaHvVKrbSRF6o5jfajOLVQBFzgTuCsuuGdyN8KthZFBZ4SXQdbSXAooGi RWuKrHyqUi68qQ7G4hjDwjtKUnUZmiNqo8w+adR+ooEIOxr3oh8OsF1RjMXmzNvCDI i4QnGyzR+HzKAi7d0RRRQ6FLz9nPJ552iE5XnCSU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731740AbfBRNtq (ORCPT ); Mon, 18 Feb 2019 08:49:46 -0500 Received: from mail.kernel.org ([198.145.29.99]:57004 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732056AbfBRNtj (ORCPT ); Mon, 18 Feb 2019 08:49:39 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 554FE21908; Mon, 18 Feb 2019 13:49:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1550497778; bh=NfaN7F6t25SlYgna6NxJ8RtcJ1RA1pR+gfI7QybJHd4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=uBICLoJQm4SrIKU88NOtxu9Cn9nDXQx5ySGeaYXHSiEoC+vTaDnDqhApfM9w1jcyA o2oi39SFiV34PAxs9ub0jtmX7PaSQQajvG/+/ZuvmgfRcB4s2ebe2i03aBcmNy6I+6 TTJ2d9obNENVzRzXhNtX5QrKsslRqjxbMyGjvCgE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Adam Zabrocki , Linus Torvalds , Joonas Lahtinen , Akash Goel , Chris Wilson , Tvrtko Ursulin , Jani Nikula , Tvrtko Ursulin Subject: [PATCH 4.20 92/92] drm/i915: Prevent a race during I915_GEM_MMAP ioctl with WC set Date: Mon, 18 Feb 2019 14:43:35 +0100 Message-Id: <20190218133503.923376832@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190218133454.668268457@linuxfoundation.org> References: <20190218133454.668268457@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.20-stable review patch. If anyone has any objections, please let me know. ------------------ From: Joonas Lahtinen commit 2e7bd10e05afb866b5fb13eda25095c35d7a27cc upstream. Make sure the underlying VMA in the process address space is the same as it was during vm_mmap to avoid applying WC to wrong VMA. A more long-term solution would be to have vm_mmap_locked variant in linux/mmap.h for when caller wants to hold mmap_sem for an extended duration. v2: - Refactor the compare function Fixes: 1816f9236303 ("drm/i915: Support creation of unbound wc user mappings for objects") Reported-by: Adam Zabrocki Suggested-by: Linus Torvalds Signed-off-by: Joonas Lahtinen Cc: # v4.0+ Cc: Akash Goel Cc: Chris Wilson Cc: Tvrtko Ursulin Cc: Adam Zabrocki Reviewed-by: Chris Wilson Reviewed-by: Tvrtko Ursulin #v1 Link: https://patchwork.freedesktop.org/patch/msgid/20190207085454.10598-1-joonas.lahtinen@linux.intel.com (cherry picked from commit 5c4604e757ba9b193b09768d75a7d2105a5b883f) Signed-off-by: Jani Nikula Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/i915/i915_gem.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -1826,6 +1826,16 @@ i915_gem_sw_finish_ioctl(struct drm_devi return 0; } +static inline bool +__vma_matches(struct vm_area_struct *vma, struct file *filp, + unsigned long addr, unsigned long size) +{ + if (vma->vm_file != filp) + return false; + + return vma->vm_start == addr && (vma->vm_end - vma->vm_start) == size; +} + /** * i915_gem_mmap_ioctl - Maps the contents of an object, returning the address * it is mapped to. @@ -1884,7 +1894,7 @@ i915_gem_mmap_ioctl(struct drm_device *d return -EINTR; } vma = find_vma(mm, addr); - if (vma) + if (vma && __vma_matches(vma, obj->base.filp, addr, args->size)) vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags)); else