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=-9.5 required=3.0 tests=DKIM_ADSP_CUSTOM_MED, DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,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 3263DC4360C for ; Sat, 12 Oct 2019 12:29:58 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id D9B512089C for ; Sat, 12 Oct 2019 12:29:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ZEe0bJ+1" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D9B512089C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 84C228E0005; Sat, 12 Oct 2019 08:29:57 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 7FA0A8E0001; Sat, 12 Oct 2019 08:29:57 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7101E8E0005; Sat, 12 Oct 2019 08:29:57 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0086.hostedemail.com [216.40.44.86]) by kanga.kvack.org (Postfix) with ESMTP id 4FDAF8E0001 for ; Sat, 12 Oct 2019 08:29:57 -0400 (EDT) Received: from smtpin23.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with SMTP id E7BB2181AEF32 for ; Sat, 12 Oct 2019 12:29:56 +0000 (UTC) X-FDA: 76035064392.23.tramp57_39b6b2b8c0b48 X-HE-Tag: tramp57_39b6b2b8c0b48 X-Filterd-Recvd-Size: 4464 Received: from mail-pl1-f193.google.com (mail-pl1-f193.google.com [209.85.214.193]) by imf10.hostedemail.com (Postfix) with ESMTP for ; Sat, 12 Oct 2019 12:29:56 +0000 (UTC) Received: by mail-pl1-f193.google.com with SMTP id u20so5758101plq.4 for ; Sat, 12 Oct 2019 05:29:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=CUVTcUa5b8bKD7FsmBN2tFeSI1tiWWw4BFpLw9k7yCs=; b=ZEe0bJ+1FUWHAd7hQeuzlNX/YuaFs6XETmII7Fd2roFyVU7ZxUZYSJZhvRfCSh+oHF r8e8KobZ2Zq4aJTgsCnVidrK+K/dMHb5sBZjt10nA6Q9jNReWqzoN5bfqw4nUYd7fxQA Y1zLqclmF7IIT8xZCXLaBwjHUzcAUQXayGM1/rlc58V1KcjSqPQrLVs45eA2ylNa6LCp YbrrnOQxWJIi5GLbiiv2MhgkrevEbQMHw0FwbzryLbL/cYAqRlLMGBF0JQ5jDsS7cs38 Swn1LU0gK6Uywm6QOej3PSgbkqGk8NUU9DofCGqnR4mvK/O31ju8G/C9VulR78+z3ElB IGjg== 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:mime-version :content-transfer-encoding; bh=CUVTcUa5b8bKD7FsmBN2tFeSI1tiWWw4BFpLw9k7yCs=; b=Vv+Sr6qtueSfTBcCFj0CBGM907JvhF7PNgujKHsAd4kTHdLvJw1ckNudiaC0DZZSNk DTMvphVvoHsFgISR5qEZBuu1LZF9D2CzX4Cvwp4t8PH+UeGX/bsSmp0feuZzjFjdJ96O p2jv6cUJmNvlC4Azcbh+jks8ItAp9S4Bh9N9Vey6wD1oongPwJQQ2W07jbqpASIWeq8Z 54cu96eLFGeNL5fGc/CYWDMbV1wJs4pUNGSTnIcILX4UjvPttymLwPyi1GKsBRLmdQN6 EPDnOdlNNXLu2g4rsOq6QyNigTFQqdo4cmLGYhBg5k2/+rAn2Kb/ZCx5BX8S6fAPisy7 xujw== X-Gm-Message-State: APjAAAWtnI3JDluvc9HSl4Uu/GLAzeoakqKbUqekDJ4UawLRp73U77Xm nRejLqZhsznyWCGI8+/+WbY= X-Google-Smtp-Source: APXvYqyoYkM83GDHs5E3PNlXmZYrHsdzyiSKwuZ0dy6B4Pl7gdC+716gQxKin/hT8FITw6cUNd+2Dw== X-Received: by 2002:a17:902:144:: with SMTP id 62mr20399568plb.100.1570883395203; Sat, 12 Oct 2019 05:29:55 -0700 (PDT) Received: from localhost.localdomain ([2402:3a80:95a:fd75:24a6:4bd:55a6:4f65]) by smtp.gmail.com with ESMTPSA id v8sm33708697pje.6.2019.10.12.05.29.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 12 Oct 2019 05:29:54 -0700 (PDT) From: Shyam Saini To: kernel-hardening@lists.openwall.com Cc: iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Shyam Saini , Christoph Hellwig , Marek Szyprowski , Robin Murphy , Matthew Wilcox , Christopher Lameter , Kees Cook Subject: [PATCH] kernel: dma: Make CMA boot parameters __ro_after_init Date: Sat, 12 Oct 2019 17:59:18 +0530 Message-Id: <20191012122918.8066-1-mayhs11saini@gmail.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: This parameters are not changed after early boot. By making them __ro_after_init will reduce any attack surface in the kernel. Link: https://lwn.net/Articles/676145/ Cc: Christoph Hellwig Cc: Marek Szyprowski Cc: Robin Murphy Cc: Matthew Wilcox Cc: Christopher Lameter Cc: Kees Cook Signed-off-by: Shyam Saini --- kernel/dma/contiguous.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/kernel/dma/contiguous.c b/kernel/dma/contiguous.c index 69cfb4345388..1b689b1303cd 100644 --- a/kernel/dma/contiguous.c +++ b/kernel/dma/contiguous.c @@ -42,10 +42,10 @@ struct cma *dma_contiguous_default_area; * Users, who want to set the size of global CMA area for their system * should use cma=3D kernel parameter. */ -static const phys_addr_t size_bytes =3D (phys_addr_t)CMA_SIZE_MBYTES * S= Z_1M; -static phys_addr_t size_cmdline =3D -1; -static phys_addr_t base_cmdline; -static phys_addr_t limit_cmdline; +static const phys_addr_t __ro_after_init size_bytes =3D (phys_addr_t)CMA= _SIZE_MBYTES * SZ_1M; +static phys_addr_t __ro_after_init size_cmdline =3D -1; +static phys_addr_t __ro_after_init base_cmdline; +static phys_addr_t __ro_after_init limit_cmdline; =20 static int __init early_cma(char *p) { --=20 2.20.1