From patchwork Mon Nov 22 08:48:27 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christophe Leroy X-Patchwork-Id: 12631441 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3E995C433EF for ; Mon, 22 Nov 2021 08:51:48 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id AB29A6B0078; Mon, 22 Nov 2021 03:49:15 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id A62D06B007B; Mon, 22 Nov 2021 03:49:15 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 92A716B007D; Mon, 22 Nov 2021 03:49:15 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0070.hostedemail.com [216.40.44.70]) by kanga.kvack.org (Postfix) with ESMTP id 852C66B0078 for ; Mon, 22 Nov 2021 03:49:15 -0500 (EST) Received: from smtpin15.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 4601D18136851 for ; Mon, 22 Nov 2021 08:49:05 +0000 (UTC) X-FDA: 78835941450.15.3682B90 Received: from pegase2.c-s.fr (pegase2.c-s.fr [93.17.235.10]) by imf29.hostedemail.com (Postfix) with ESMTP id 87E519001A91 for ; Mon, 22 Nov 2021 08:49:02 +0000 (UTC) Received: from localhost (mailhub3.si.c-s.fr [172.26.127.67]) by localhost (Postfix) with ESMTP id 4HyLXj2Q6dz9sSZ; Mon, 22 Nov 2021 09:48:53 +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 WylMaZ_oXXeG; Mon, 22 Nov 2021 09:48:53 +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 4HyLXc1Klqz9sSp; Mon, 22 Nov 2021 09:48:48 +0100 (CET) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 1704B8B765; Mon, 22 Nov 2021 09:48:48 +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 gtie3yuamvMT; Mon, 22 Nov 2021 09:48:47 +0100 (CET) Received: from PO20335.IDSI0.si.c-s.fr (unknown [172.25.230.108]) by messagerie.si.c-s.fr (Postfix) with ESMTP id A10998B778; Mon, 22 Nov 2021 09:48:47 +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 1AM8meEq631736 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Mon, 22 Nov 2021 09:48:40 +0100 Received: (from chleroy@localhost) by PO20335.IDSI0.si.c-s.fr (8.17.1/8.17.1/Submit) id 1AM8memW631735; Mon, 22 Nov 2021 09:48:40 +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 7/8] powerpc/mm: Convert to default topdown mmap layout Date: Mon, 22 Nov 2021 09:48:27 +0100 Message-Id: <49d4ee53eb28ac76bc6c4979c735c4b1c7e45548.1637570556.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=1637570906; l=5023; s=20211009; h=from:subject:message-id; bh=tK6qNg9t0+26MFuTrnCae4Ffx33oTJnm6+vMdPreY6s=; b=jCuVpkkKoFx1318rjb62AgscrBDJqgpAus42sPuqv22A3aFR+82yd63TjdbTmlmKfFppoNNqZfmG /JACpinnCvCLAnyKExJCRy888/c2fXGmymELabZOnIx7jtmHYW0I X-Developer-Key: i=christophe.leroy@csgroup.eu; a=ed25519; pk=HIzTzUj91asvincQGOFx6+ZF5AoUuP9GdOtQChs7Mm0= X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: 87E519001A91 X-Stat-Signature: wm4nftzdg7cggcodsfy6s3txo3bjboah Authentication-Results: imf29.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf29.hostedemail.com: domain of christophe.leroy@csgroup.eu designates 93.17.235.10 as permitted sender) smtp.mailfrom=christophe.leroy@csgroup.eu X-HE-Tag: 1637570942-403896 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: 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 --- arch/powerpc/Kconfig | 1 + arch/powerpc/include/asm/processor.h | 2 - arch/powerpc/mm/Makefile | 2 +- arch/powerpc/mm/mmap.c | 105 --------------------------- 4 files changed, 2 insertions(+), 108 deletions(-) delete mode 100644 arch/powerpc/mm/mmap.c diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index dea74d7717c0..05ddcf99cb34 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -158,6 +158,7 @@ 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; - } -}