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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 1440BC31E40 for ; Fri, 9 Aug 2019 09:44:46 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id A32E321743 for ; Fri, 9 Aug 2019 09:44:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A32E321743 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ghiti.fr Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 52F6A6B0006; Fri, 9 Aug 2019 05:44:45 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 4DF686B0007; Fri, 9 Aug 2019 05:44:45 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3F5016B0008; Fri, 9 Aug 2019 05:44:45 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from mail-ed1-f71.google.com (mail-ed1-f71.google.com [209.85.208.71]) by kanga.kvack.org (Postfix) with ESMTP id E582D6B0006 for ; Fri, 9 Aug 2019 05:44:44 -0400 (EDT) Received: by mail-ed1-f71.google.com with SMTP id z2so990834ede.2 for ; Fri, 09 Aug 2019 02:44:44 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-original-authentication-results:x-gm-message-state:subject:to:cc :references:from:message-id:date:user-agent:mime-version:in-reply-to :content-transfer-encoding:content-language; bh=7Zz+dekQVz+t60cfPAWXHDt673zqelsbIxrG4v8rxXU=; b=PWUyyvPiWg43+178mY4Y0h+79yV7/v8rnEawctRQdDcBxAYCcZ3fIFESyrVIaefce5 +u2ad20rxFpZkSIj9MBHSRiuwmqg2uOScDwZy395HE69tQ4srLtwTTDaMTdNTW8wqEQK TN9yDCUoVhe8kltX5zfJHa3QH7BFa66TMZe9bJOC8I3MvXhM5zNUuEI76hS5D+sdPkcS k1VAmKYjbWM/je2yVL+PD4aMxvqpVcFT6t8MY9WkQA+7oCtqZeZi9OdvLe5iyjPOQQLX 9dBtTG9vE2y4iGvcUBL8IUYFQB22fZTV5ei4Ih0h8X1lkiQ7TNBG6Q/za0PC4vvlxY4T kaCw== X-Original-Authentication-Results: mx.google.com; spf=neutral (google.com: 217.70.183.195 is neither permitted nor denied by best guess record for domain of alex@ghiti.fr) smtp.mailfrom=alex@ghiti.fr X-Gm-Message-State: APjAAAWr7PLJFLnwvy3EJ20PcvLya4frtQ/M41Joq6X9e2UPRHI7TwE4 pCyt+SJ+6nZbX5sSMcz6DGCaImcVOJ+l4FKdhWDGpQVBf2zDU/mawNmiim+pUUB4SnqABc/1HoK D2xUI0W7wWYNtLvvh/bS5ZkNS0Nd2q1aoXHysrN2CVxUzYxW9/u9/ZpS08aHhd4M= X-Received: by 2002:a17:906:8409:: with SMTP id n9mr17274494ejx.128.1565343884486; Fri, 09 Aug 2019 02:44:44 -0700 (PDT) X-Google-Smtp-Source: APXvYqwTABTVR1Z1J01O+vViFpoNPTKBuhkAGeQcfuVv1cNNAC0DL1SEAmr1prZ7wBIRBPx2EzPD X-Received: by 2002:a17:906:8409:: with SMTP id n9mr17274452ejx.128.1565343883492; Fri, 09 Aug 2019 02:44:43 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1565343883; cv=none; d=google.com; s=arc-20160816; b=hFeQkxAr9aPznB1/3ousJxRMqKg2GxplrjKDvwQCTVAK59f5QSx1n/Vf2XCOWsprdP YsWNLIHFW6HKQXAEHYjsxpONl8rHfdTCoNO68jS0L9K461f2w6mwdG7eyCr8wMKfVOxT AuI8xuRLKH2IbCOwK4+ZMqaz7ELEFRMnLObwS9l1wmM+qMgWWIOopp043yHsfnETFHPh fnUSiwCMQgF6rFh3VoUHEPAXUTv5H5JFKzAyJuc0rT6nR8MvZmeD4spQnTZjHIdYjUSX sH7hRv01ytfbYUUk5bB11z+lmu/VZ1kDozbfBWEFCpQ2l5eg6mOgL3Hl0DtOXvEwF3E+ KR1A== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-language:content-transfer-encoding:in-reply-to:mime-version :user-agent:date:message-id:from:references:cc:to:subject; bh=7Zz+dekQVz+t60cfPAWXHDt673zqelsbIxrG4v8rxXU=; b=JZD1dKaB9yfaOmcUPqmam75Gn1qy0Urr1PF21VlRJPOueX22gbgR2Y3z9thqBKxrya AZEICW13SHz9RMYa5D6/HP3Cr6aFI313Z38cojn69KfVtXmcUHez2cPrmCImC7rCGKjK LeWZpgdtJhdVaXxhi5i51YviNB4wH5nZDnXFxS6D0xzglZeElpRBXZJhAgqpJCyGWsqc 5L+0RAWY1YbMcb3LptU1AI2D3PNkSpm0zTa1/ba3MhFn0Po4z38uJ5IE4i3Y5UP+d6kZ QANETBIHheSJlbyQv5DhBh7/B/mPGQ+Lc7YmfjBpClQyf1iumufLUEf71ivL1MMb4PCB EB8g== ARC-Authentication-Results: i=1; mx.google.com; spf=neutral (google.com: 217.70.183.195 is neither permitted nor denied by best guess record for domain of alex@ghiti.fr) smtp.mailfrom=alex@ghiti.fr Received: from relay3-d.mail.gandi.net (relay3-d.mail.gandi.net. [217.70.183.195]) by mx.google.com with ESMTPS id e42si38087869edd.289.2019.08.09.02.44.43 for (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Fri, 09 Aug 2019 02:44:43 -0700 (PDT) Received-SPF: neutral (google.com: 217.70.183.195 is neither permitted nor denied by best guess record for domain of alex@ghiti.fr) client-ip=217.70.183.195; Authentication-Results: mx.google.com; spf=neutral (google.com: 217.70.183.195 is neither permitted nor denied by best guess record for domain of alex@ghiti.fr) smtp.mailfrom=alex@ghiti.fr X-Originating-IP: 81.250.144.103 Received: from [10.30.1.20] (lneuilly-657-1-5-103.w81-250.abo.wanadoo.fr [81.250.144.103]) (Authenticated sender: alex@ghiti.fr) by relay3-d.mail.gandi.net (Postfix) with ESMTPSA id 5865C6000D; Fri, 9 Aug 2019 09:44:39 +0000 (UTC) Subject: Re: [PATCH v6 09/14] mips: Properly account for stack randomization and stack guard gap To: Sergei Shtylyov , Andrew Morton Cc: Albert Ou , Kees Cook , linux-mm@kvack.org, Catalin Marinas , Palmer Dabbelt , Will Deacon , Russell King , Ralf Baechle , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Luis Chamberlain , Paul Burton , Paul Walmsley , James Hogan , linux-riscv@lists.infradead.org, linux-mips@vger.kernel.org, Christoph Hellwig , linux-arm-kernel@lists.infradead.org, Alexander Viro References: <20190808061756.19712-1-alex@ghiti.fr> <20190808061756.19712-10-alex@ghiti.fr> From: Alexandre Ghiti Message-ID: <91e31484-b268-2c90-1dd1-98cec349af6c@ghiti.fr> Date: Fri, 9 Aug 2019 11:44:38 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: fr 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: On 8/8/19 11:16 AM, Sergei Shtylyov wrote: > Hello! > > On 08.08.2019 9:17, Alexandre Ghiti wrote: > >> This commit takes care of stack randomization and stack guard gap when >> computing mmap base address and checks if the task asked for >> randomization. >> >> This fixes the problem uncovered and not fixed for arm here: >> https://lkml.kernel.org/r/20170622200033.25714-1-riel@redhat.com >> >> Signed-off-by: Alexandre Ghiti >> Acked-by: Kees Cook >> Acked-by: Paul Burton >> Reviewed-by: Luis Chamberlain >> --- >>   arch/mips/mm/mmap.c | 14 ++++++++++++-- >>   1 file changed, 12 insertions(+), 2 deletions(-) >> >> diff --git a/arch/mips/mm/mmap.c b/arch/mips/mm/mmap.c >> index d79f2b432318..f5c778113384 100644 >> --- a/arch/mips/mm/mmap.c >> +++ b/arch/mips/mm/mmap.c >> @@ -21,8 +21,9 @@ unsigned long shm_align_mask = PAGE_SIZE - 1;    /* >> Sane caches */ >>   EXPORT_SYMBOL(shm_align_mask); >>     /* gap between mmap and stack */ >> -#define MIN_GAP (128*1024*1024UL) >> -#define MAX_GAP ((TASK_SIZE)/6*5) >> +#define MIN_GAP        (128*1024*1024UL) >> +#define MAX_GAP        ((TASK_SIZE)/6*5) > >    Could add spaces around *, while touching this anyway? And parens > around TASK_SIZE shouldn't be needed... > I did not fix checkpatch warnings here since this code gets removed afterwards. >> +#define STACK_RND_MASK    (0x7ff >> (PAGE_SHIFT - 12)) >>     static int mmap_is_legacy(struct rlimit *rlim_stack) >>   { >> @@ -38,6 +39,15 @@ static int mmap_is_legacy(struct rlimit *rlim_stack) >>   static unsigned long mmap_base(unsigned long rnd, struct rlimit >> *rlim_stack) >>   { >>       unsigned long gap = rlim_stack->rlim_cur; >> +    unsigned long pad = stack_guard_gap; >> + >> +    /* Account for stack randomization if necessary */ >> +    if (current->flags & PF_RANDOMIZE) >> +        pad += (STACK_RND_MASK << PAGE_SHIFT); > >    Parens not needed here. Belt and braces approach here as I'm never sure about priorities. Thanks for your time, Alex > >> + >> +    /* Values close to RLIM_INFINITY can overflow. */ >> +    if (gap + pad > gap) >> +        gap += pad; >>         if (gap < MIN_GAP) >>           gap = MIN_GAP; >> > > > _______________________________________________ > linux-riscv mailing list > linux-riscv@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-riscv