From patchwork Wed Jul 24 05:58:40 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandre Ghiti X-Patchwork-Id: 11056009 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 68B59912 for ; Wed, 24 Jul 2019 06:03:32 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5961D2875F for ; Wed, 24 Jul 2019 06:03:32 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4C6A32876C; Wed, 24 Jul 2019 06:03:32 +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=unavailable 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 073AA28768 for ; Wed, 24 Jul 2019 06:03:29 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 08AEF6B0003; Wed, 24 Jul 2019 02:03:29 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 039956B0008; Wed, 24 Jul 2019 02:03:28 -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 E6CCB8E0002; Wed, 24 Jul 2019 02:03:28 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from mail-ed1-f71.google.com (mail-ed1-f71.google.com [209.85.208.71]) by kanga.kvack.org (Postfix) with ESMTP id 9794B6B0003 for ; Wed, 24 Jul 2019 02:03:28 -0400 (EDT) Received: by mail-ed1-f71.google.com with SMTP id c31so29573030ede.5 for ; Tue, 23 Jul 2019 23:03:28 -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=0PoVlhP/B7SmAW4NwkDAl9x9/d/JAFrQTHRVEkNR7AM=; b=jCDDopKK3wzwYaO8XrWBWcLYQLBcm4hAmlBbypEC7y5veM8HCa4p88e/YzI68HctNF Po4D022kPb479R5G9UwX5q2kTz2gUO5Y2WHyzhAeDeTWMKYs8KBXJFd2yGamX8zqh7e3 2GPkP6izpFShETyuqVwl1drytUgDjyPK0S2wjelpKukss9w1s10rWXd1+qJj6BBl/Npz oEzLXI0zuCAp3Ya3A3sPvzGdAkTAlR2DfDVxUVvZjJZcXwDBoqrzgqM7nr6rVdlo9/99 gXOFrDei4MbdfUY5cJI23H7T1kKOPrdZBGFsv+pdLnUKqBdgrC54/VIZ/m7nw4XEcbzz JlpA== X-Original-Authentication-Results: mx.google.com; spf=neutral (google.com: 217.70.183.199 is neither permitted nor denied by best guess record for domain of alex@ghiti.fr) smtp.mailfrom=alex@ghiti.fr X-Gm-Message-State: APjAAAVNUT3w/0glzRmit6S3YwlcQGcvvEZzoA+37qAvxnlW8hOh2JGd 7YyWtutusVhDtoNsMztm4l+M0zlVu6svjCIKbNDz9GI5N3UzxwR4sLfbz22Ef/nnkD6qcHinYbI mr9S43wpWkS9/XkD+0ZhlxfxMCIGQDZRCw55Jm+1kSV3bSq+2FaK62RP+eCaO45o= X-Received: by 2002:a17:906:c802:: with SMTP id cx2mr51710127ejb.114.1563948208142; Tue, 23 Jul 2019 23:03:28 -0700 (PDT) X-Google-Smtp-Source: APXvYqx9+R+71mT+WLdMNe+sOOgsV+bFLrsE8U+XHiTkeY5a0k91NVg7M4gu6YCvveaNiBXGRP82 X-Received: by 2002:a17:906:c802:: with SMTP id cx2mr51710043ejb.114.1563948206608; Tue, 23 Jul 2019 23:03:26 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1563948206; cv=none; d=google.com; s=arc-20160816; b=0lHjYRB5qFoVlDqkU7AuxLflARjhbQ5WET829kVcoOoYxCgK527qvTYFaTY1cGdDUT kNWhxlCGArzjQW0Swd8bmP85V0PONFZXwDtMNjL/YkZiks5Ti9SIjEvqAQhJj+5SvDha ccHZ+3PQV1p5geVXiYjbnjjw2LOYccwcRLdQM6s/83zu1SlWZwIHhgUDv5vEmcOBPQd9 KwPKw7zMdyULf2PWywvtpmke/5uWiBaOpDDqs4Yn7X496/sMJwQ+GBDUXTHRdmAqkyGv wS4zaMVkWHNHzjVP0nUmD6EizEUpzvP6e4dzMsN6Axyxnklp0NUWLrdt5QcQ1HS08zuY 5fDw== 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=0PoVlhP/B7SmAW4NwkDAl9x9/d/JAFrQTHRVEkNR7AM=; b=DIdTaZ2JB1lhz6XKTH4IxamglfN/0kjb1vAvghkXWkcTnUlC4w0boqBJtH2gWRhzC6 6TS/qZ1IlW/X/astA5SeAQzUl2wGq68hd9B+bD2fjjuht996YGiHjhDLAlA9wt5utcxP CgK3CfM17klFGx+fG4SE4KlCcVLUdTSzQi2HERNfe9DtbMFc1yH/PRf6yr51VUK0gCs2 DO8J0w2VlksP0h13D6RDUW8x66I1+RQmEgwrOJy5dJbaRws9hXpJy4TxWJSFH/W5L+OG iRdIFLR6Vr+MjthF1sGNwFouFZPMLYvDaeJmUoWHXqPj0ewHiudhmkjuzt69DdpV1dMG yofQ== ARC-Authentication-Results: i=1; mx.google.com; spf=neutral (google.com: 217.70.183.199 is neither permitted nor denied by best guess record for domain of alex@ghiti.fr) smtp.mailfrom=alex@ghiti.fr Received: from relay9-d.mail.gandi.net (relay9-d.mail.gandi.net. [217.70.183.199]) by mx.google.com with ESMTPS id m32si7816912edm.415.2019.07.23.23.03.26 for (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 23 Jul 2019 23:03:26 -0700 (PDT) Received-SPF: neutral (google.com: 217.70.183.199 is neither permitted nor denied by best guess record for domain of alex@ghiti.fr) client-ip=217.70.183.199; Authentication-Results: mx.google.com; spf=neutral (google.com: 217.70.183.199 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 relay9-d.mail.gandi.net (Postfix) with ESMTPSA id 4F010FF808; Wed, 24 Jul 2019 06:03:20 +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 , Christoph Hellwig Subject: [PATCH REBASE v4 04/14] arm64, mm: Move generic mmap layout functions to mm Date: Wed, 24 Jul 2019 01:58:40 -0400 Message-Id: <20190724055850.6232-5-alex@ghiti.fr> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190724055850.6232-1-alex@ghiti.fr> References: <20190724055850.6232-1-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 arm64 handles top-down mmap layout in a way that can be easily reused by other architectures, so make it available in mm. It then introduces a new config ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT that can be set by other architectures to benefit from those functions. Note that this new config depends on MMU being enabled, if selected without MMU support, a warning will be thrown. Suggested-by: Christoph Hellwig Signed-off-by: Alexandre Ghiti Acked-by: Catalin Marinas Acked-by: Kees Cook Reviewed-by: Christoph Hellwig --- arch/Kconfig | 10 ++++ arch/arm64/Kconfig | 1 + arch/arm64/include/asm/processor.h | 2 - arch/arm64/mm/mmap.c | 76 ----------------------------- kernel/sysctl.c | 6 ++- mm/util.c | 78 +++++++++++++++++++++++++++++- 6 files changed, 92 insertions(+), 81 deletions(-) diff --git a/arch/Kconfig b/arch/Kconfig index a7b57dd42c26..a0bb6fa4d381 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -696,6 +696,16 @@ config HAVE_ARCH_COMPAT_MMAP_BASES and vice-versa 32-bit applications to call 64-bit mmap(). Required for applications doing different bitness syscalls. +# This allows to use a set of generic functions to determine mmap base +# address by giving priority to top-down scheme only if the process +# is not in legacy mode (compat task, unlimited stack size or +# sysctl_legacy_va_layout). +# Architecture that selects this option can provide its own version of: +# - STACK_RND_MASK +config ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT + bool + depends on MMU + config HAVE_COPY_THREAD_TLS bool help diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 3adcec05b1f6..14a194e63458 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -72,6 +72,7 @@ config ARM64 select ARCH_SUPPORTS_INT128 if GCC_VERSION >= 50000 || CC_IS_CLANG select ARCH_SUPPORTS_NUMA_BALANCING select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT + select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT select ARCH_WANT_FRAME_POINTERS select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36) select ARCH_HAS_UBSAN_SANITIZE_ALL diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h index fd5b1a4efc70..7b8d448363f7 100644 --- a/arch/arm64/include/asm/processor.h +++ b/arch/arm64/include/asm/processor.h @@ -271,8 +271,6 @@ static inline void spin_lock_prefetch(const void *ptr) "nop") : : "p" (ptr)); } -#define HAVE_ARCH_PICK_MMAP_LAYOUT - #endif extern unsigned long __ro_after_init signal_minsigstksz; /* sigframe size */ diff --git a/arch/arm64/mm/mmap.c b/arch/arm64/mm/mmap.c index e4acaead67de..3028bacbc4e9 100644 --- a/arch/arm64/mm/mmap.c +++ b/arch/arm64/mm/mmap.c @@ -20,82 +20,6 @@ #include -/* - * Leave enough space between the mmap area and the stack to honour ulimit in - * the face of randomisation. - */ -#define MIN_GAP (SZ_128M) -#define MAX_GAP (STACK_TOP/6*5) - -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; -} - -unsigned long arch_mmap_rnd(void) -{ - unsigned long rnd; - -#ifdef CONFIG_COMPAT - if (is_compat_task()) - rnd = get_random_long() & ((1UL << mmap_rnd_compat_bits) - 1); - else -#endif - rnd = get_random_long() & ((1UL << mmap_rnd_bits) - 1); - return rnd << PAGE_SHIFT; -} - -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); -} - -/* - * 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 + 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. diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 078950d9605b..00fcea236eba 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -264,7 +264,8 @@ extern struct ctl_table epoll_table[]; extern struct ctl_table firmware_config_table[]; #endif -#ifdef HAVE_ARCH_PICK_MMAP_LAYOUT +#if defined(HAVE_ARCH_PICK_MMAP_LAYOUT) || \ + defined(CONFIG_ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT) int sysctl_legacy_va_layout; #endif @@ -1573,7 +1574,8 @@ static struct ctl_table vm_table[] = { .proc_handler = proc_dointvec, .extra1 = SYSCTL_ZERO, }, -#ifdef HAVE_ARCH_PICK_MMAP_LAYOUT +#if defined(HAVE_ARCH_PICK_MMAP_LAYOUT) || \ + defined(CONFIG_ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT) { .procname = "legacy_va_layout", .data = &sysctl_legacy_va_layout, diff --git a/mm/util.c b/mm/util.c index 15a4fb0f5473..0781e5575cb3 100644 --- a/mm/util.c +++ b/mm/util.c @@ -17,7 +17,12 @@ #include #include #include +#include +#include #include +#include +#include +#include #include @@ -315,7 +320,78 @@ unsigned long randomize_stack_top(unsigned long stack_top) #endif } -#if defined(CONFIG_MMU) && !defined(HAVE_ARCH_PICK_MMAP_LAYOUT) +#ifdef CONFIG_ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT +#ifdef CONFIG_ARCH_HAS_ELF_RANDOMIZE +unsigned long arch_mmap_rnd(void) +{ + unsigned long rnd; + +#ifdef CONFIG_HAVE_ARCH_MMAP_RND_COMPAT_BITS + if (is_compat_task()) + rnd = get_random_long() & ((1UL << mmap_rnd_compat_bits) - 1); + else +#endif /* CONFIG_HAVE_ARCH_MMAP_RND_COMPAT_BITS */ + rnd = get_random_long() & ((1UL << mmap_rnd_bits) - 1); + + return rnd << PAGE_SHIFT; +} +#endif /* CONFIG_ARCH_HAS_ELF_RANDOMIZE */ + +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; +} + +/* + * Leave enough space between the mmap area and the stack to honour ulimit in + * the face of randomisation. + */ +#define MIN_GAP (SZ_128M) +#define MAX_GAP (STACK_TOP / 6 * 5) + +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); +} + +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; + } +} +#elif defined(CONFIG_MMU) && !defined(HAVE_ARCH_PICK_MMAP_LAYOUT) void arch_pick_mmap_layout(struct mm_struct *mm, struct rlimit *rlim_stack) { mm->mmap_base = TASK_UNMAPPED_BASE;