From patchwork Thu Apr 4 05:51:24 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandre Ghiti X-Patchwork-Id: 10884971 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 7A3A7922 for ; Thu, 4 Apr 2019 05:52:48 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6713428A13 for ; Thu, 4 Apr 2019 05:52:48 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 5AEF628A21; Thu, 4 Apr 2019 05:52:48 +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=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E055028A1F for ; Thu, 4 Apr 2019 05:52:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725927AbfDDFwq (ORCPT ); Thu, 4 Apr 2019 01:52:46 -0400 Received: from relay5-d.mail.gandi.net ([217.70.183.197]:47993 "EHLO relay5-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725904AbfDDFwq (ORCPT ); Thu, 4 Apr 2019 01:52:46 -0400 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 867E61C000C; Thu, 4 Apr 2019 05:52:35 +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-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org, linux-riscv@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Alexandre Ghiti Subject: [PATCH v2 1/5] mm, fs: Move randomize_stack_top from fs to mm Date: Thu, 4 Apr 2019 01:51:24 -0400 Message-Id: <20190404055128.24330-2-alex@ghiti.fr> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190404055128.24330-1-alex@ghiti.fr> References: <20190404055128.24330-1-alex@ghiti.fr> MIME-Version: 1.0 Sender: linux-mips-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This preparatory commit moves this function so that further introduction of generic topdown mmap layout is contained only in mm/util.c. Signed-off-by: Alexandre Ghiti Reviewed-by: Christoph Hellwig --- fs/binfmt_elf.c | 20 -------------------- include/linux/mm.h | 2 ++ mm/util.c | 22 ++++++++++++++++++++++ 3 files changed, 24 insertions(+), 20 deletions(-) diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index 7d09d125f148..045f3b29d264 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -662,26 +662,6 @@ static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex, * libraries. There is no binary dependent code anywhere else. */ -#ifndef STACK_RND_MASK -#define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */ -#endif - -static unsigned long randomize_stack_top(unsigned long stack_top) -{ - unsigned long random_variable = 0; - - if (current->flags & PF_RANDOMIZE) { - random_variable = get_random_long(); - random_variable &= STACK_RND_MASK; - random_variable <<= PAGE_SHIFT; - } -#ifdef CONFIG_STACK_GROWSUP - return PAGE_ALIGN(stack_top) + random_variable; -#else - return PAGE_ALIGN(stack_top) - random_variable; -#endif -} - static int load_elf_binary(struct linux_binprm *bprm) { struct file *interpreter = NULL; /* to shut gcc up */ diff --git a/include/linux/mm.h b/include/linux/mm.h index 76769749b5a5..087824a5059f 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2312,6 +2312,8 @@ extern int install_special_mapping(struct mm_struct *mm, unsigned long addr, unsigned long len, unsigned long flags, struct page **pages); +unsigned long randomize_stack_top(unsigned long stack_top); + extern unsigned long get_unmapped_area(struct file *, unsigned long, unsigned long, unsigned long, unsigned long); extern unsigned long mmap_region(struct file *file, unsigned long addr, diff --git a/mm/util.c b/mm/util.c index d559bde497a9..a54afb9b4faa 100644 --- a/mm/util.c +++ b/mm/util.c @@ -14,6 +14,8 @@ #include #include #include +#include +#include #include @@ -291,6 +293,26 @@ int vma_is_stack_for_current(struct vm_area_struct *vma) return (vma->vm_start <= KSTK_ESP(t) && vma->vm_end >= KSTK_ESP(t)); } +#ifndef STACK_RND_MASK +#define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */ +#endif + +unsigned long randomize_stack_top(unsigned long stack_top) +{ + unsigned long random_variable = 0; + + if (current->flags & PF_RANDOMIZE) { + random_variable = get_random_long(); + random_variable &= STACK_RND_MASK; + random_variable <<= PAGE_SHIFT; + } +#ifdef CONFIG_STACK_GROWSUP + return PAGE_ALIGN(stack_top) + random_variable; +#else + return PAGE_ALIGN(stack_top) - random_variable; +#endif +} + #if defined(CONFIG_MMU) && !defined(HAVE_ARCH_PICK_MMAP_LAYOUT) void arch_pick_mmap_layout(struct mm_struct *mm, struct rlimit *rlim_stack) {