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 0E008C4167B for ; Fri, 23 Dec 2022 10:24:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235840AbiLWKYa (ORCPT ); Fri, 23 Dec 2022 05:24:30 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52796 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229734AbiLWKY2 (ORCPT ); Fri, 23 Dec 2022 05:24:28 -0500 Received: from mail-wm1-x330.google.com (mail-wm1-x330.google.com [IPv6:2a00:1450:4864:20::330]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E729C1FFB9; Fri, 23 Dec 2022 02:24:27 -0800 (PST) Received: by mail-wm1-x330.google.com with SMTP id v124-20020a1cac82000000b003cf7a4ea2caso5844559wme.5; Fri, 23 Dec 2022 02:24:27 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=CRuUJZVOpUtgPvjJSw65Ev7JgBrVcaaYMlRw59e9HHo=; b=aKDfNpRXZ27jsLjGo3FBvyZVLAnFXagcPNocTyT8aZNnWT5jO3bG9yr+ZtkR3R+XQB rwB35v6+Oo4WigU65Z+wI/bekDZ2yxSCox341aiSxK5S6iyTfgCNGuvFX3H2ulB58IM/ qppT5/mM4+jUO4B/15KM8irHnM7SVwf7dl9mKm15Q/1feN1QPZIPDE+Ex352sLWYnDNr zvwE+jGsjnHqrQ/87Yxost4XxnWU+8r38zNrapRMJzx18Mm1WzWR+/xJ/h8dJ+6TmmhU ZhwZyzKC4DSyj8R45zXrbkHiKoA7ebU7eopWFpiIi/AcQw+nJbEwctHFfQAzQ4oB81+M 2cQw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=CRuUJZVOpUtgPvjJSw65Ev7JgBrVcaaYMlRw59e9HHo=; b=q/iKd1ZjM3NfwhwiudLvs1HjGnF2FdNJfLmhHXN5svL65Hu4vubwZKsY+z4zQd8o+j H2MmwJNSnuGQTf5SkgA1ia/XISr6HGCddRAG+U6yyjAerTxnxlQ7yXIhMqYpZYkBqOfp DWBqclL8o7n/2rf3b82I/xnOEUd0VHlM5p0RXvXlfLFHF780dQoTnZqkWsF68zKQf2hu gyder/DnDiewt16/j786CXWZsETLkD6ytbm0XNaJCoEAkJQ3nhSfOgalLG/SFCSogBfk e2FPv+/3QZ1RaCwD1OeKRroskxOxL1akx8cVbpcPNhGnzNwO/5+vTbPd0ELP+qVaMHDl 7D+Q== X-Gm-Message-State: AFqh2kqV/tyHr2SuzCltuK647OtP5l9dp44Dd97I49V5BuVbzU6kpz3d TcXREF3MTL0IDYNXJD7WUVw= X-Google-Smtp-Source: AMrXdXuqkbabnF7DzHU0Ej1s4hVLvQJ+bsyuWTyXaxsjS1VNZXTjdjD4EiZQnf6FSm8KN1A3U8ddKQ== X-Received: by 2002:a05:600c:a4f:b0:3d3:5c35:8919 with SMTP id c15-20020a05600c0a4f00b003d35c358919mr6783088wmq.30.1671791066352; Fri, 23 Dec 2022 02:24:26 -0800 (PST) Received: from localhost ([2a00:23c5:dc8c:8701:1663:9a35:5a7b:1d76]) by smtp.gmail.com with ESMTPSA id f1-20020a5d5681000000b002714b3d2348sm2880136wrv.25.2022.12.23.02.24.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 23 Dec 2022 02:24:25 -0800 (PST) Date: Fri, 23 Dec 2022 10:24:25 +0000 From: Lorenzo Stoakes To: Christoph Hellwig Cc: Andy Gross , Bjorn Andersson , Konrad Dybcio , Mathieu Poirier , Andrew Morton , Uladzislau Rezki , linux-arm-msm@vger.kernel.org, linux-remoteproc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, iommu@lists.linux.dev Subject: Re: [PATCH 2/2] vmalloc: reject vmap with VM_FLUSH_RESET_PERMS Message-ID: References: <20221223092703.61927-1-hch@lst.de> <20221223092703.61927-3-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221223092703.61927-3-hch@lst.de> Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org On Fri, Dec 23, 2022 at 10:27:03AM +0100, Christoph Hellwig wrote: > VM_FLUSH_RESET_PERMS is just for use with vmalloc as it is tied to freeing > the underlying pages. > > Signed-off-by: Christoph Hellwig > --- > mm/vmalloc.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > index 9e30f0b3920325..88a644cde9fb12 100644 > --- a/mm/vmalloc.c > +++ b/mm/vmalloc.c > @@ -2849,6 +2849,9 @@ void *vmap(struct page **pages, unsigned int count, > > might_sleep(); > > + if (WARN_ON_ONCE(flags & VM_FLUSH_RESET_PERMS)) > + return NULL; > + Might it be worth adding a specific vmap mask that explicitly indicates what flags are permissible on vmap()? Then this could become e.g.:- if (WARN_ON_ONCE(flags & ~VM_VMAP_PERMITTED_MASK)) return NULL; And would be self-documenting as to why we are disallowing flags (i.e. they are not part of the permitted vmap mask).