From patchwork Mon Jun 25 22:39:10 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Garnier X-Patchwork-Id: 10488311 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id B03D7602B3 for ; Tue, 26 Jun 2018 08:45:11 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9A985287E2 for ; Tue, 26 Jun 2018 08:45:11 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8A447287E7; Tue, 26 Jun 2018 08:45:11 +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=-12.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED, USER_IN_DEF_DKIM_WL autolearn=ham version=3.3.1 Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.wl.linuxfoundation.org (Postfix) with SMTP id 5B273287E2 for ; Tue, 26 Jun 2018 08:45:10 +0000 (UTC) Received: (qmail 30234 invoked by uid 550); 26 Jun 2018 08:40:08 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Delivered-To: mailing list kernel-hardening@lists.openwall.com Delivered-To: moderator for kernel-hardening@lists.openwall.com Received: (qmail 13320 invoked from network); 25 Jun 2018 22:42:44 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:date:in-reply-to:message-id:references:subject:from:to :cc; bh=tANS2lc9/Sh68sJhsCX5qG1RCeLj+qbifMvYUS14SXw=; b=MIKPBeNyAUivtuOBErWOT6xMIpCguOjiOwVYN4gEjsxPFnPuaeavwLyyK/Re7lrB6+ 5hK+yO6gpML8zEC4llnS/H/oJo57vjUg7dWTsN3gV7hsjx0HHkZpXyB1o/+l3iUPk5CR 8x4G7ep+t30PwUvZ4EwoMh1gKMAt09aMIx/s2ekUAe2KbUnpX+oxIrNsSZiNgK8K0EFv s/W9mEOHMAxSdj/juei66DO2pnR2wjAzIkiyIqzHcl2xx/PVPbduQ15lAEPIWuSa19s7 ZvbsTr2La/cUCVzn8GzwiE86yx7UWCF8idK3MsIL5NDwr4Tk9GdSWX6eFVaZcswxnPzD ktmg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:date:in-reply-to:message-id :references:subject:from:to:cc; bh=tANS2lc9/Sh68sJhsCX5qG1RCeLj+qbifMvYUS14SXw=; b=bIR3CCvvk0YKB5OQNUlDE5tuh+IDDeFOLC6W/PCKDljzrcL9J1QTFnyV2OQ5jgJBLT x79Ps7m7FP/PtjlZ2DbnOJ3+w+O9lT6UYzwPOAHb765U9UXLNr5pNtfssjJaBU52NUoJ D8V9+jv2K8Ose8FnK+b2h8atyn6PEEkWOx8FyLbHW6g5umn5Ze3nPJ/URDbKogGmqfF/ 5O8c0GSfUUsSAuV/9yIoT0iqrlQ7ITpxlIMFeVXevb9gxjN51syKaQ15BLtBCxrALM/5 gAr2jafVJVxPsRxnPVU7ao6Tm/ccIIvkeItqR1kl9UI07OTrzwPgtGGZk05ZEnzMwJ6T WdCg== X-Gm-Message-State: APt69E2Ekh2NRZ3c/GS2oTUzZDCcuz1ZPHAiE16Sr74px+q3m2VznDUl bGQ9/yrj7NxoajlccOdj8X8tkZNJgwF0eFzMG51o1YKI3xMdYapQNMY16vL6avZ/4Fu0CkUe2ie qwt1CdWbdrKxXPwgeVk9rmz8I/jsfAW4EX0Rb8DfP85655qm8JjbQQsDoOPXU0BvKw40Ka+wFzo ZEymvLtQqz X-Google-Smtp-Source: ADUXVKLOUL2lonFJULrlVFwRLr1xvIP2xywc4GJ+6dsQSMBMsoAwis+Su78h+obQ5704IyyLbYgT0KPBvLLjhA== MIME-Version: 1.0 X-Received: by 2002:ac8:28dd:: with SMTP id j29-v6mr8141842qtj.31.1529966552405; Mon, 25 Jun 2018 15:42:32 -0700 (PDT) Date: Mon, 25 Jun 2018 15:39:10 -0700 In-Reply-To: <20180625224014.134829-1-thgarnie@google.com> Message-Id: <20180625224014.134829-23-thgarnie@google.com> References: <20180625224014.134829-1-thgarnie@google.com> X-Mailer: git-send-email 2.18.0.rc2.346.g013aa6912e-goog Subject: [PATCH v5 22/27] x86/modules: Add option to start module section after kernel From: Thomas Garnier To: kernel-hardening@lists.openwall.com Cc: Thomas Garnier , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, Jonathan Corbet , Andy Lutomirski , Andrey Ryabinin , "Kirill A. Shutemov" , Tom Lendacky , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Add an option so the module section is just after the mapped kernel. It will ensure position independent modules are always at the right distance from the kernel and do not require mcmodule=large. It also optimize the available size for modules by getting rid of the empty space on kernel randomization range. Signed-off-by: Thomas Garnier --- Documentation/x86/x86_64/mm.txt | 3 +++ arch/x86/Kconfig | 4 ++++ arch/x86/include/asm/pgtable_64_types.h | 6 ++++++ arch/x86/kernel/head64.c | 5 ++++- arch/x86/mm/dump_pagetables.c | 3 ++- 5 files changed, 19 insertions(+), 2 deletions(-) diff --git a/Documentation/x86/x86_64/mm.txt b/Documentation/x86/x86_64/mm.txt index 5432a96d31ff..334ab458c82d 100644 --- a/Documentation/x86/x86_64/mm.txt +++ b/Documentation/x86/x86_64/mm.txt @@ -77,3 +77,6 @@ Their order is preserved but their base will be offset early at boot time. Be very careful vs. KASLR when changing anything here. The KASLR address range must not overlap with anything except the KASAN shadow area, which is correct as KASAN disables KASLR. + +If CONFIG_DYNAMIC_MODULE_BASE is enabled, the module section follows the end of +the mapped kernel. diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index f49725df7109..f98a47662023 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -2212,6 +2212,10 @@ config RANDOMIZE_MEMORY_PHYSICAL_PADDING If unsure, leave at the default value. +# Module section starts just after the end of the kernel module +config DYNAMIC_MODULE_BASE + bool + config X86_GLOBAL_STACKPROTECTOR bool "Stack cookie using a global variable" depends on CC_STACKPROTECTOR_AUTO diff --git a/arch/x86/include/asm/pgtable_64_types.h b/arch/x86/include/asm/pgtable_64_types.h index 054765ab2da2..faaab159ed54 100644 --- a/arch/x86/include/asm/pgtable_64_types.h +++ b/arch/x86/include/asm/pgtable_64_types.h @@ -7,6 +7,7 @@ #ifndef __ASSEMBLY__ #include #include +#include /* * These are used to make use of C type-checking.. @@ -137,7 +138,12 @@ extern unsigned int ptrs_per_p4d; #define VMALLOC_END (VMALLOC_START + (VMALLOC_SIZE_TB << 40) - 1) +#ifdef CONFIG_DYNAMIC_MODULE_BASE +#define MODULES_VADDR ALIGN(((unsigned long)_end + PAGE_SIZE), PMD_SIZE) +#else #define MODULES_VADDR (__START_KERNEL_map + KERNEL_IMAGE_SIZE) +#endif + /* The module sections ends with the start of the fixmap */ #define MODULES_END _AC(0xffffffffff000000, UL) #define MODULES_LEN (MODULES_END - MODULES_VADDR) diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c index 49df0386098c..14bbbe592772 100644 --- a/arch/x86/kernel/head64.c +++ b/arch/x86/kernel/head64.c @@ -393,12 +393,15 @@ asmlinkage __visible void __init x86_64_start_kernel(char * real_mode_data) * Build-time sanity checks on the kernel image and module * area mappings. (these are purely build-time and produce no code) */ +#ifndef CONFIG_DYNAMIC_MODULE_BASE BUILD_BUG_ON(MODULES_VADDR < __START_KERNEL_map); BUILD_BUG_ON(MODULES_VADDR - __START_KERNEL_map < KERNEL_IMAGE_SIZE); - BUILD_BUG_ON(MODULES_LEN + KERNEL_IMAGE_SIZE > 2*PUD_SIZE); + BUILD_BUG_ON(!IS_ENABLED(CONFIG_RANDOMIZE_BASE_LARGE) && + MODULES_LEN + KERNEL_IMAGE_SIZE > 2*PUD_SIZE); BUILD_BUG_ON((__START_KERNEL_map & ~PMD_MASK) != 0); BUILD_BUG_ON((MODULES_VADDR & ~PMD_MASK) != 0); BUILD_BUG_ON(!(MODULES_VADDR > __START_KERNEL)); +#endif MAYBE_BUILD_BUG_ON(!(((MODULES_END - 1) & PGDIR_MASK) == (__START_KERNEL & PGDIR_MASK))); BUILD_BUG_ON(__fix_to_virt(__end_of_fixed_addresses) <= MODULES_END); diff --git a/arch/x86/mm/dump_pagetables.c b/arch/x86/mm/dump_pagetables.c index 2f3c9196b834..537884e5d092 100644 --- a/arch/x86/mm/dump_pagetables.c +++ b/arch/x86/mm/dump_pagetables.c @@ -105,7 +105,7 @@ static struct addr_marker address_markers[] = { [EFI_END_NR] = { EFI_VA_END, "EFI Runtime Services" }, #endif [HIGH_KERNEL_NR] = { __START_KERNEL_map, "High Kernel Mapping" }, - [MODULES_VADDR_NR] = { MODULES_VADDR, "Modules" }, + [MODULES_VADDR_NR] = { 0/*MODULES_VADDR*/, "Modules" }, [MODULES_END_NR] = { MODULES_END, "End Modules" }, [FIXADDR_START_NR] = { FIXADDR_START, "Fixmap Area" }, [END_OF_SPACE_NR] = { -1, NULL } @@ -600,6 +600,7 @@ static int __init pt_dump_init(void) address_markers[KASAN_SHADOW_START_NR].start_address = KASAN_SHADOW_START; address_markers[KASAN_SHADOW_END_NR].start_address = KASAN_SHADOW_END; #endif + address_markers[MODULES_VADDR_NR].start_address = MODULES_VADDR; #endif #ifdef CONFIG_X86_32 address_markers[VMALLOC_START_NR].start_address = VMALLOC_START;