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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9B7C1C433EF for ; Thu, 25 Nov 2021 08:38:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1352289AbhKYIlN (ORCPT ); Thu, 25 Nov 2021 03:41:13 -0500 Received: from pegase2.c-s.fr ([93.17.235.10]:38011 "EHLO pegase2.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1352552AbhKYIjM (ORCPT ); Thu, 25 Nov 2021 03:39:12 -0500 Received: from localhost (mailhub3.si.c-s.fr [172.26.127.67]) by localhost (Postfix) with ESMTP id 4J09rV0cw5z9sSs; Thu, 25 Nov 2021 09:23:54 +0100 (CET) X-Virus-Scanned: amavisd-new at c-s.fr Received: from pegase2.c-s.fr ([172.26.127.65]) by localhost (pegase2.c-s.fr [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id UhTo96FhZmbx; Thu, 25 Nov 2021 09:23:54 +0100 (CET) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase2.c-s.fr (Postfix) with ESMTP id 4J09rM692Kz9sT2; Thu, 25 Nov 2021 09:23:47 +0100 (CET) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id C369E8B77E; Thu, 25 Nov 2021 09:23:47 +0100 (CET) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id XJ4T76QF9Q8h; Thu, 25 Nov 2021 09:23:47 +0100 (CET) Received: from PO20335.IDSI0.si.c-s.fr (unknown [192.168.203.227]) by messagerie.si.c-s.fr (Postfix) with ESMTP id E583F8B77C; Thu, 25 Nov 2021 09:23:46 +0100 (CET) Received: from PO20335.IDSI0.si.c-s.fr (localhost [127.0.0.1]) by PO20335.IDSI0.si.c-s.fr (8.17.1/8.16.1) with ESMTPS id 1AP8NcC8086372 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Thu, 25 Nov 2021 09:23:38 +0100 Received: (from chleroy@localhost) by PO20335.IDSI0.si.c-s.fr (8.17.1/8.17.1/Submit) id 1AP8NcDf086371; Thu, 25 Nov 2021 09:23:38 +0100 X-Authentication-Warning: PO20335.IDSI0.si.c-s.fr: chleroy set sender to christophe.leroy@csgroup.eu using -f From: Christophe Leroy To: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , alex@ghiti.fr Cc: Christophe Leroy , linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-mm@kvack.org Subject: [PATCH v2 7/9] powerpc/mm: Convert to default topdown mmap layout Date: Thu, 25 Nov 2021 09:23:29 +0100 Message-Id: <4b6f05b1bc4b3e07920e87e692961de9ea5dd2e6.1637828367.git.christophe.leroy@csgroup.eu> X-Mailer: git-send-email 2.33.1 In-Reply-To: References: MIME-Version: 1.0 X-Developer-Signature: v=1; a=ed25519-sha256; t=1637828609; l=5473; s=20211009; h=from:subject:message-id; bh=mL8gpT9ntkhU5TH9ZSa2DX4HYBqV4Ob2fppAal1lP3g=; b=Idb7QgJRp5yZfMUTdNeaVkEFBh9BF8B9vuSRgTIqGTroElSqUmQFRjjRfmPt49+7FShQAMEzJmLt IhKOCwbfCQPvyCLhKuNn02LJaMGRbIM773Nq9wE4h5eBJQn6xffO X-Developer-Key: i=christophe.leroy@csgroup.eu; a=ed25519; pk=HIzTzUj91asvincQGOFx6+ZF5AoUuP9GdOtQChs7Mm0= Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Select CONFIG_ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT and remove arch/powerpc/mm/mmap.c This change provides standard randomisation of mmaps. See commit 8b8addf891de ("x86/mm/32: Enable full randomization on i386 and X86_32") for all the benefits of mmap randomisation. Signed-off-by: Christophe Leroy --- v2: Also remove selection of ARCH_HAS_ELF_RANDOMIZE as it is already selected by CONFIG_ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT --- arch/powerpc/Kconfig | 2 +- arch/powerpc/include/asm/processor.h | 2 - arch/powerpc/mm/Makefile | 2 +- arch/powerpc/mm/mmap.c | 105 --------------------------- 4 files changed, 2 insertions(+), 109 deletions(-) delete mode 100644 arch/powerpc/mm/mmap.c diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index dea74d7717c0..f2d02d462558 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -122,7 +122,6 @@ config PPC select ARCH_HAS_DEBUG_WX if STRICT_KERNEL_RWX select ARCH_HAS_DEVMEM_IS_ALLOWED select ARCH_HAS_DMA_MAP_DIRECT if PPC_PSERIES - select ARCH_HAS_ELF_RANDOMIZE select ARCH_HAS_FORTIFY_SOURCE select ARCH_HAS_GCOV_PROFILE_ALL select ARCH_HAS_HUGEPD if HUGETLB_PAGE @@ -158,6 +157,7 @@ config PPC select ARCH_USE_MEMTEST select ARCH_USE_QUEUED_RWLOCKS if PPC_QUEUED_SPINLOCKS select ARCH_USE_QUEUED_SPINLOCKS if PPC_QUEUED_SPINLOCKS + select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT select ARCH_WANT_IPC_PARSE_VERSION select ARCH_WANT_IRQS_OFF_ACTIVATE_MM select ARCH_WANT_LD_ORPHAN_WARN diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h index e39bd0ff69f3..d906b14dd599 100644 --- a/arch/powerpc/include/asm/processor.h +++ b/arch/powerpc/include/asm/processor.h @@ -378,8 +378,6 @@ static inline void prefetchw(const void *x) #define spin_lock_prefetch(x) prefetchw(x) -#define HAVE_ARCH_PICK_MMAP_LAYOUT - /* asm stubs */ extern unsigned long isa300_idle_stop_noloss(unsigned long psscr_val); extern unsigned long isa300_idle_stop_mayloss(unsigned long psscr_val); diff --git a/arch/powerpc/mm/Makefile b/arch/powerpc/mm/Makefile index d4c20484dad9..503a6e249940 100644 --- a/arch/powerpc/mm/Makefile +++ b/arch/powerpc/mm/Makefile @@ -5,7 +5,7 @@ ccflags-$(CONFIG_PPC64) := $(NO_MINIMAL_TOC) -obj-y := fault.o mem.o pgtable.o mmap.o maccess.o pageattr.o \ +obj-y := fault.o mem.o pgtable.o maccess.o pageattr.o \ init_$(BITS).o pgtable_$(BITS).o \ pgtable-frag.o ioremap.o ioremap_$(BITS).o \ init-common.o mmu_context.o drmem.o \ diff --git a/arch/powerpc/mm/mmap.c b/arch/powerpc/mm/mmap.c deleted file mode 100644 index 5972d619d274..000000000000 --- a/arch/powerpc/mm/mmap.c +++ /dev/null @@ -1,105 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-or-later -/* - * flexible mmap layout support - * - * Copyright 2003-2004 Red Hat Inc., Durham, North Carolina. - * All Rights Reserved. - * - * Started by Ingo Molnar - */ - -#include -#include -#include -#include -#include -#include -#include -#include - -/* - * Top of mmap area (just below the process stack). - * - * Leave at least a ~128 MB hole. - */ -#define MIN_GAP (128*1024*1024) -#define MAX_GAP (TASK_SIZE/6*5) - -static inline 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; -} - -unsigned long arch_mmap_rnd(void) -{ - unsigned long shift, rnd; - - shift = mmap_rnd_bits; -#ifdef CONFIG_COMPAT - if (is_32bit_task()) - shift = mmap_rnd_compat_bits; -#endif - rnd = get_random_long() % (1ul << shift); - - return rnd << PAGE_SHIFT; -} - -static inline unsigned long stack_maxrandom_size(void) -{ - if (!(current->flags & PF_RANDOMIZE)) - return 0; - - /* 8MB for 32bit, 1GB for 64bit */ - if (is_32bit_task()) - return (1<<23); - else - return (1<<30); -} - -static inline unsigned long mmap_base(unsigned long rnd, - struct rlimit *rlim_stack) -{ - unsigned long gap = rlim_stack->rlim_cur; - unsigned long pad = stack_maxrandom_size() + stack_guard_gap; - - /* 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(DEFAULT_MAP_WINDOW - gap - rnd); -} - -/* - * This function, called very early during the creation of a new - * process VM image, sets up which VM layout function to use: - */ -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(); - - /* - * Fall back to the standard layout if the personality - * bit is set, or if the expected stack growth is unlimited: - */ - if (mmap_is_legacy(rlim_stack)) { - mm->mmap_base = TASK_UNMAPPED_BASE; - 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; - } -} -- 2.33.1