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=-8.7 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_GIT autolearn=unavailable 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 D9A0CC43613 for ; Thu, 20 Jun 2019 05:12:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AFCEE206E0 for ; Thu, 20 Jun 2019 05:12:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731293AbfFTFM1 (ORCPT ); Thu, 20 Jun 2019 01:12:27 -0400 Received: from relay6-d.mail.gandi.net ([217.70.183.198]:45045 "EHLO relay6-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725857AbfFTFM0 (ORCPT ); Thu, 20 Jun 2019 01:12:26 -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 relay6-d.mail.gandi.net (Postfix) with ESMTPSA id B26EDC0005; Thu, 20 Jun 2019 05:12:17 +0000 (UTC) From: Alexandre Ghiti To: Andrew Morton Cc: "James E . J . Bottomley" , Helge Deller , Heiko Carstens , Vasily Gorbik , Christian Borntraeger , Yoshinori Sato , Rich Felker , "David S . Miller" , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H . Peter Anvin" , x86@kernel.org, Dave Hansen , Andy Lutomirski , Peter Zijlstra , linux-parisc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-mm@kvack.org, Alexandre Ghiti Subject: [PATCH RESEND 7/8] x86: Use mmap_*base, not mmap_*legacy_base, as low_limit for bottom-up mmap Date: Thu, 20 Jun 2019 01:03:27 -0400 Message-Id: <20190620050328.8942-8-alex@ghiti.fr> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190620050328.8942-1-alex@ghiti.fr> References: <20190620050328.8942-1-alex@ghiti.fr> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Bottom-up mmap scheme is used twice: - for legacy mode, in which mmap_legacy_base and mmap_compat_legacy_base are respectively equal to mmap_base and mmap_compat_base. - in case of mmap failure in top-down mode, where there is no need to go through the whole address space again for the bottom-up fallback: the goal of this fallback is to find, as a last resort, space between the top-down mmap base and the stack, which is the only place not covered by the top-down mmap. Then this commit removes the usage of mmap_legacy_base and mmap_compat_legacy_base fields from x86 code. Signed-off-by: Alexandre Ghiti --- arch/x86/include/asm/elf.h | 2 +- arch/x86/kernel/sys_x86_64.c | 4 ++-- arch/x86/mm/hugetlbpage.c | 4 ++-- arch/x86/mm/mmap.c | 20 +++++++++----------- 4 files changed, 14 insertions(+), 16 deletions(-) diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h index 69c0f892e310..bbfd81453250 100644 --- a/arch/x86/include/asm/elf.h +++ b/arch/x86/include/asm/elf.h @@ -307,7 +307,7 @@ static inline int mmap_is_ia32(void) extern unsigned long task_size_32bit(void); extern unsigned long task_size_64bit(int full_addr_space); -extern unsigned long get_mmap_base(int is_legacy); +extern unsigned long get_mmap_base(void); extern bool mmap_address_hint_valid(unsigned long addr, unsigned long len); #ifdef CONFIG_X86_32 diff --git a/arch/x86/kernel/sys_x86_64.c b/arch/x86/kernel/sys_x86_64.c index f7476ce23b6e..0bf8604bea5e 100644 --- a/arch/x86/kernel/sys_x86_64.c +++ b/arch/x86/kernel/sys_x86_64.c @@ -121,7 +121,7 @@ static void find_start_end(unsigned long addr, unsigned long flags, return; } - *begin = get_mmap_base(1); + *begin = get_mmap_base(); if (in_32bit_syscall()) *end = task_size_32bit(); else @@ -211,7 +211,7 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, info.flags = VM_UNMAPPED_AREA_TOPDOWN; info.length = len; info.low_limit = PAGE_SIZE; - info.high_limit = get_mmap_base(0); + info.high_limit = get_mmap_base(); /* * If hint address is above DEFAULT_MAP_WINDOW, look for unmapped area diff --git a/arch/x86/mm/hugetlbpage.c b/arch/x86/mm/hugetlbpage.c index 4b90339aef50..3a7f11e66114 100644 --- a/arch/x86/mm/hugetlbpage.c +++ b/arch/x86/mm/hugetlbpage.c @@ -86,7 +86,7 @@ static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *file, info.flags = 0; info.length = len; - info.low_limit = get_mmap_base(1); + info.low_limit = get_mmap_base(); /* * If hint address is above DEFAULT_MAP_WINDOW, look for unmapped area @@ -106,7 +106,7 @@ static unsigned long hugetlb_get_unmapped_area_topdown(struct file *file, { struct hstate *h = hstate_file(file); struct vm_unmapped_area_info info; - unsigned long mmap_base = get_mmap_base(0); + unsigned long mmap_base = get_mmap_base(); info.flags = VM_UNMAPPED_AREA_TOPDOWN; info.length = len; diff --git a/arch/x86/mm/mmap.c b/arch/x86/mm/mmap.c index aae9a933dfd4..54c9ff301323 100644 --- a/arch/x86/mm/mmap.c +++ b/arch/x86/mm/mmap.c @@ -113,13 +113,12 @@ static unsigned long mmap_legacy_base(unsigned long rnd, * This function, called very early during the creation of a new * process VM image, sets up which VM layout function to use: */ -static void arch_pick_mmap_base(unsigned long *base, unsigned long *legacy_base, +static void arch_pick_mmap_base(unsigned long *base, unsigned long random_factor, unsigned long task_size, struct rlimit *rlim_stack) { - *legacy_base = mmap_legacy_base(random_factor, task_size); if (mmap_is_legacy()) - *base = *legacy_base; + *base = mmap_legacy_base(random_factor, task_size); else *base = mmap_base(random_factor, task_size, rlim_stack); } @@ -131,7 +130,7 @@ void arch_pick_mmap_layout(struct mm_struct *mm, struct rlimit *rlim_stack) else mm->get_unmapped_area = arch_get_unmapped_area_topdown; - arch_pick_mmap_base(&mm->mmap_base, &mm->mmap_legacy_base, + arch_pick_mmap_base(&mm->mmap_base, arch_rnd(mmap64_rnd_bits), task_size_64bit(0), rlim_stack); @@ -142,23 +141,22 @@ void arch_pick_mmap_layout(struct mm_struct *mm, struct rlimit *rlim_stack) * applications and 32bit applications. The 64bit syscall uses * mmap_base, the compat syscall uses mmap_compat_base. */ - arch_pick_mmap_base(&mm->mmap_compat_base, &mm->mmap_compat_legacy_base, + arch_pick_mmap_base(&mm->mmap_compat_base, arch_rnd(mmap32_rnd_bits), task_size_32bit(), rlim_stack); #endif } -unsigned long get_mmap_base(int is_legacy) +unsigned long get_mmap_base(void) { struct mm_struct *mm = current->mm; #ifdef CONFIG_HAVE_ARCH_COMPAT_MMAP_BASES - if (in_32bit_syscall()) { - return is_legacy ? mm->mmap_compat_legacy_base - : mm->mmap_compat_base; - } + if (in_32bit_syscall()) + return mm->mmap_compat_base; #endif - return is_legacy ? mm->mmap_legacy_base : mm->mmap_base; + + return mm->mmap_base; } const char *arch_vma_name(struct vm_area_struct *vma) -- 2.20.1