From patchwork Sun May 26 13:47:40 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandre Ghiti X-Patchwork-Id: 10961615 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 7DE6E13AD for ; Sun, 26 May 2019 13:57:10 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6804D28A86 for ; Sun, 26 May 2019 13:57:10 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 55B2828A7A; Sun, 26 May 2019 13:57:10 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BAD1E28A7A for ; Sun, 26 May 2019 13:57:09 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id E99FA6B0003; Sun, 26 May 2019 09:57:08 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id E49EA6B0005; Sun, 26 May 2019 09:57:08 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D12B66B0007; Sun, 26 May 2019 09:57:08 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from mail-ed1-f72.google.com (mail-ed1-f72.google.com [209.85.208.72]) by kanga.kvack.org (Postfix) with ESMTP id 840B86B0003 for ; Sun, 26 May 2019 09:57:08 -0400 (EDT) Received: by mail-ed1-f72.google.com with SMTP id d15so23333776edm.7 for ; Sun, 26 May 2019 06:57:08 -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:from:to:cc :subject:date:message-id:in-reply-to:references:mime-version :content-transfer-encoding; bh=k4gAy3Z0GohLZRHeMFIbFeMU/TQlVJcVgn+DpFBm95g=; b=LUAZ7Vwt2ksiFYbpw5W4CTO9PBTWqrmj9TowN188ne6B65dnMcSci0Ez8T2ExpF7Uf Fd/Va8evgssmVu17lNoPeva7CaKUYu7Olg1D+RHdfy2k09YLqBXuIEIE0EbjIm4qC6+U MaNrU9kUyvW+Z4JiCDG0Ae4RaZgVoDXry1w8RKAFzBKwexQUOyfepxxjgqdesk/XuwlB QelbhgjTEfr0ekySrJ4MKsagca7kB/PY/1cjeF3YS3r1zU3RWtp6CwwzFiRBrv/O2tuV rJ5jZqAVGkOHU/Y9sDZj14I3/pdmXWIpH7plDXanQq4RGQYSOQxsuD+zVl+nw3/CffL8 FDVQ== X-Original-Authentication-Results: mx.google.com; spf=neutral (google.com: 217.70.183.197 is neither permitted nor denied by best guess record for domain of alex@ghiti.fr) smtp.mailfrom=alex@ghiti.fr X-Gm-Message-State: APjAAAU0IjeogDDeGufm61A3BKR9RAtMR4gz2TZE6wCSYl8gyZ+mKTCC ouz237ZUgUaNS6hiHOkZG0woWP/jvSfFlRHkBQ9/nO/JClFLOyr3BsBFqM5GCm5A41qv531nOhc akuowEZ5OV8zAgA82/1aNHxYOowIeshnRwojrElWqKy2WN7wxLZvLdONOtj37F4g= X-Received: by 2002:a50:91cc:: with SMTP id h12mr116243475eda.3.1558879028028; Sun, 26 May 2019 06:57:08 -0700 (PDT) X-Google-Smtp-Source: APXvYqxgApBfPLUTy/7iECdVsQI/wtru241tgH6PA+5SlVLKsuWtxBGARbZPwYj0P56dIjf6TKIx X-Received: by 2002:a50:91cc:: with SMTP id h12mr116243384eda.3.1558879026676; Sun, 26 May 2019 06:57:06 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1558879026; cv=none; d=google.com; s=arc-20160816; b=oqIiJ7P8iORu8a/2Gs6lohkC2PFa5sHWgbTHr8bujGnlt+nzFW8hEaAMLyKVX1POuI M17fzDbbKTBNnlClp5Jp8ALhUTV6jkX0rzgtkNxB2+7+UM8jE1CRx5yf3vjuJMvfcmx4 aQPvTvfZypS/+p3GFkc8GYspZGrAjTJ4tdiY+Ij+rGaeIzny0BL5bIb8l/y3W9BTr4U7 XVIA+MsqaJuaguHp1uGDG3gmJe+OpA0uOQ6zobhSWMPbjOStb9NtV8N4HRVP5sjXgNSe 64Q0QX31NhV6rxcJiQgpJeY9aHZxCly/fac0LSm0BUJhZaK53rfWoEXUIfQ6TmKJiDu3 Ak1A== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from; bh=k4gAy3Z0GohLZRHeMFIbFeMU/TQlVJcVgn+DpFBm95g=; b=Lze2yAnXfM9O9fkNgAc7bSkEu9HFHad1F0jdE0jCKfDXJ9TarekENhX9eIK9+H6Wwr OfSB1IH02nIUootr7EPkyNsUrjyvaRZGoyRDGL2NQ50zulLfTfFcy+fSvjEkrKsxanBZ QEj0NOjaDQEFHcI+nJ7/7YJJUhmEMnzKjQ8aavQyRVlQ4X1EA0ray8RmBYp1vv1poqG1 ZZV3Zdt9h9XAP+Qm35lJ0JNqLyTVJKsv7Y0/vZnDTnb3zBmTbUuPtRV/QfXOBAmwXMPR FqR9UYN7l9gbGJUA6WZUGrQY4bzLIspyf+unMwA3rfhxKzYIPyeP4Z48ed2S2khUaB3p hGpQ== ARC-Authentication-Results: i=1; mx.google.com; spf=neutral (google.com: 217.70.183.197 is neither permitted nor denied by best guess record for domain of alex@ghiti.fr) smtp.mailfrom=alex@ghiti.fr Received: from relay5-d.mail.gandi.net (relay5-d.mail.gandi.net. [217.70.183.197]) by mx.google.com with ESMTPS id b26si6110929edw.334.2019.05.26.06.57.06 for (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Sun, 26 May 2019 06:57:06 -0700 (PDT) Received-SPF: neutral (google.com: 217.70.183.197 is neither permitted nor denied by best guess record for domain of alex@ghiti.fr) client-ip=217.70.183.197; Authentication-Results: mx.google.com; spf=neutral (google.com: 217.70.183.197 is neither permitted nor denied by best guess record for domain of alex@ghiti.fr) smtp.mailfrom=alex@ghiti.fr X-Originating-IP: 79.86.19.127 Received: from alex.numericable.fr (127.19.86.79.rev.sfr.net [79.86.19.127]) (Authenticated sender: alex@ghiti.fr) by relay5-d.mail.gandi.net (Postfix) with ESMTPSA id 572EE1C0003; Sun, 26 May 2019 13:57:00 +0000 (UTC) From: Alexandre Ghiti To: Andrew Morton Cc: Christoph Hellwig , Russell King , Catalin Marinas , Will Deacon , Ralf Baechle , Paul Burton , James Hogan , Palmer Dabbelt , Albert Ou , Alexander Viro , Luis Chamberlain , Kees Cook , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org, linux-riscv@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Alexandre Ghiti Subject: [PATCH v4 08/14] arm: Use generic mmap top-down layout and brk randomization Date: Sun, 26 May 2019 09:47:40 -0400 Message-Id: <20190526134746.9315-9-alex@ghiti.fr> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190526134746.9315-1-alex@ghiti.fr> References: <20190526134746.9315-1-alex@ghiti.fr> MIME-Version: 1.0 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: X-Virus-Scanned: ClamAV using ClamSMTP arm uses a top-down mmap layout by default that exactly fits the generic functions, so get rid of arch specific code and use the generic version by selecting ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT. As ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT selects ARCH_HAS_ELF_RANDOMIZE, use the generic version of arch_randomize_brk since it also fits. Note that this commit also removes the possibility for arm to have elf randomization and no MMU: without MMU, the security added by randomization is worth nothing. Signed-off-by: Alexandre Ghiti Acked-by: Kees Cook --- arch/arm/Kconfig | 2 +- arch/arm/include/asm/processor.h | 2 -- arch/arm/kernel/process.c | 5 --- arch/arm/mm/mmap.c | 62 -------------------------------- 4 files changed, 1 insertion(+), 70 deletions(-) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 8869742a85df..27687a8c9fb5 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -6,7 +6,6 @@ config ARM select ARCH_CLOCKSOURCE_DATA select ARCH_HAS_DEBUG_VIRTUAL if MMU select ARCH_HAS_DEVMEM_IS_ALLOWED - select ARCH_HAS_ELF_RANDOMIZE select ARCH_HAS_FORTIFY_SOURCE select ARCH_HAS_KEEPINITRD select ARCH_HAS_KCOV @@ -29,6 +28,7 @@ config ARM select ARCH_SUPPORTS_ATOMIC_RMW select ARCH_USE_BUILTIN_BSWAP select ARCH_USE_CMPXCHG_LOCKREF + select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU select ARCH_WANT_IPC_PARSE_VERSION select BUILDTIME_EXTABLE_SORT if MMU select CLONE_BACKWARDS diff --git a/arch/arm/include/asm/processor.h b/arch/arm/include/asm/processor.h index 5d06f75ffad4..95b7688341c5 100644 --- a/arch/arm/include/asm/processor.h +++ b/arch/arm/include/asm/processor.h @@ -143,8 +143,6 @@ static inline void prefetchw(const void *ptr) #endif #endif -#define HAVE_ARCH_PICK_MMAP_LAYOUT - #endif #endif /* __ASM_ARM_PROCESSOR_H */ diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c index 72cc0862a30e..19a765db5f7f 100644 --- a/arch/arm/kernel/process.c +++ b/arch/arm/kernel/process.c @@ -322,11 +322,6 @@ unsigned long get_wchan(struct task_struct *p) return 0; } -unsigned long arch_randomize_brk(struct mm_struct *mm) -{ - return randomize_page(mm->brk, 0x02000000); -} - #ifdef CONFIG_MMU #ifdef CONFIG_KUSER_HELPERS /* diff --git a/arch/arm/mm/mmap.c b/arch/arm/mm/mmap.c index 0b94b674aa91..b8d912ac9e61 100644 --- a/arch/arm/mm/mmap.c +++ b/arch/arm/mm/mmap.c @@ -17,43 +17,6 @@ ((((addr)+SHMLBA-1)&~(SHMLBA-1)) + \ (((pgoff)<> (PAGE_SHIFT - 12)) - -static int mmap_is_legacy(struct rlimit *rlim_stack) -{ - if (current->personality & ADDR_COMPAT_LAYOUT) - return 1; - - if (rlim_stack->rlim_cur == RLIM_INFINITY) - return 1; - - return sysctl_legacy_va_layout; -} - -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); - - /* Values close to RLIM_INFINITY can overflow. */ - if (gap + pad > gap) - gap += pad; - - if (gap < MIN_GAP) - gap = MIN_GAP; - else if (gap > MAX_GAP) - gap = MAX_GAP; - - return PAGE_ALIGN(STACK_TOP - gap - rnd); -} - /* * We need to ensure that shared mappings are correctly aligned to * avoid aliasing issues with VIPT caches. We need to ensure that @@ -181,31 +144,6 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, return addr; } -unsigned long arch_mmap_rnd(void) -{ - unsigned long rnd; - - rnd = get_random_long() & ((1UL << mmap_rnd_bits) - 1); - - return rnd << PAGE_SHIFT; -} - -void arch_pick_mmap_layout(struct mm_struct *mm, struct rlimit *rlim_stack) -{ - unsigned long random_factor = 0UL; - - if (current->flags & PF_RANDOMIZE) - random_factor = arch_mmap_rnd(); - - if (mmap_is_legacy(rlim_stack)) { - mm->mmap_base = TASK_UNMAPPED_BASE + random_factor; - mm->get_unmapped_area = arch_get_unmapped_area; - } else { - mm->mmap_base = mmap_base(random_factor, rlim_stack); - mm->get_unmapped_area = arch_get_unmapped_area_topdown; - } -} - /* * You really shouldn't be using read() or write() on /dev/mem. This * might go away in the future.