From patchwork Wed Oct 4 21:20:03 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Garnier X-Patchwork-Id: 9985549 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 406F260586 for ; Wed, 4 Oct 2017 21:23:26 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2FE4728C2C for ; Wed, 4 Oct 2017 21:23:26 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2359628C30; Wed, 4 Oct 2017 21:23:26 +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=-4.1 required=2.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED, RCVD_IN_DNSWL_MED, T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 0918C28C2E for ; Wed, 4 Oct 2017 21:23:25 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1dzr6r-0003oB-DM; Wed, 04 Oct 2017 21:21:41 +0000 Received: from mail6.bemta5.messagelabs.com ([195.245.231.135]) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1dzr6p-0003ia-I5 for xen-devel@lists.xenproject.org; Wed, 04 Oct 2017 21:21:39 +0000 Received: from [85.158.139.211] by server-5.bemta-5.messagelabs.com id 50/82-02223-2E055D95; Wed, 04 Oct 2017 21:21:38 +0000 X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFtrJIsWRWlGSWpSXmKPExsXiVRtspPsw4Gq kwewFFhbft0xmcmD0OPzhCksAYxRrZl5SfkUCa0bjiR1sBZdtK9b+esnawLjJpIuRi0NIYAaj xO7t3YxdjJwcLAKvWCS+HwoFSUgI9LNK9M04xAaSkBDIkvje/Yq1i5EDyE6TeNBbDxGuluiZu o4dxBYSUJLYumEpM8TQv4wSV2fNButlE9CS2NMwnwkkISIwS0Ti1useNhCHWeAMk8TxvpOsIF XCAsESl7/eZoE4Q1Xi6prfzCA2r4ClxLKVuxkh1plIPDxyDayeEyh+5MQbZojVFhKtZ+4zTWA UXMDIsIpRozi1qCy1SNfISC+pKDM9oyQ3MTNH19DAVC83tbg4MT01JzGpWC85P3cTIzDo6hkY GHcw7mn3O8QoycGkJMq7yfdqpBBfUn5KZUZicUZ8UWlOavEhRhkODiUJ3of+QDnBotT01Iq0z Bxg+MOkJTh4lER4J4OkeYsLEnOLM9MhUqcYLTn27bn1h4nj0Y27QLLjJpAUYsnLz0uVEufdDN IgANKQUZoHNw4Wo5cYZaWEeRkZGBiEeApSi3IzS1DlXzGKczAqCfM+AJnCk5lXArf1FdBBTEA HzWm6AnJQSSJCSqqBsYhz14pls88WrUhKcDBdfWPCo3uWW8vbi8+/EREIM+YJqLw+eW2SHHP9 jdrTdx3eZPpMk3D8tW6h9dTyX4nddZHXzWfO4DFfO23hHK7tE5iW9XapcP+My+c/z8s780Dwn cs/BMOsP719vSJKrmrTtTSfyRnnvjTrl1qpSjJ+Tdr/8Kn8sZa2i0osxRmJhlrMRcWJAB8+3l 3MAgAA X-Env-Sender: thgarnie@google.com X-Msg-Ref: server-12.tower-206.messagelabs.com!1507152096!78325788!1 X-Originating-IP: [74.125.83.50] X-SpamReason: No, hits=0.5 required=7.0 tests=BODY_RANDOM_LONG X-StarScan-Received: X-StarScan-Version: 9.4.45; banners=-,-,- X-VirusChecked: Checked Received: (qmail 29781 invoked from network); 4 Oct 2017 21:21:37 -0000 Received: from mail-pg0-f50.google.com (HELO mail-pg0-f50.google.com) (74.125.83.50) by server-12.tower-206.messagelabs.com with AES128-GCM-SHA256 encrypted SMTP; 4 Oct 2017 21:21:37 -0000 Received: by mail-pg0-f50.google.com with SMTP id j70so7163995pgc.10 for ; Wed, 04 Oct 2017 14:21:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=1Q3KlexTuAFjPrkuzh5X/4nC1whLhjQYyVU2FoFbWKs=; b=dQCdJ3bfQm5ZN4rZxnlu8CLr6234biXBRmI1GOrj/tB5nyIaEAYLkFWlR6xBzjqhzz 0fDCwplV38ChXuKOQbLMUSH3ab5S/RhJpWGhNep92FJgJAS+it7kq2jnuq5TMQs4TyiN DY6enFxCrzSkSdlsN81Vc20lP5T05Uz5/365180W/8EtzVJ8ZKZFgmb4oTPd5AIExYAX iiR6rrg5MAkIHi7T4YfjbfCGM2d7IWl1B5iMdx2YrAjQjxiNpzu9LgVmiSrH1gtiya3D Fx55r869aXemQqaFUlObfb1s1lBUZ8KQCgJZYnZ9AGPGdhkpSI3i5B+jrqzW4i3RGD4W GnBw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=1Q3KlexTuAFjPrkuzh5X/4nC1whLhjQYyVU2FoFbWKs=; b=AXnFRmymCkYQrlDk10P7KUZ54haKkdxfiXGhJsw2n5rr/4qA/4Eqafa39If3AsBOZl Tq/Sf2DVbtzh+LJywkSfHyXIr7QDho0IoeblpVpyzPteAZKjX0gXk6YrffoJWuz1wN5I f//0lf5yEqGjvUm0UEq70VDSTw/JR1qNywk/MbEdM91H1zlajeMPu7SwTEhcc4hHAsoL 1cUPMiuVpajRlniBsqMMSCZjfN05DhuDVoG8lrKOr3M5QhXJ3Wiu9ym7BIYo8FRcjhhP eZGPGWGdlVR0pDpQF18W8mxSNP4ICKC5o9pvHmnsvRNpdo3OMBvld3Ak9s785VESQN3f XIYQ== X-Gm-Message-State: AMCzsaUiEzarH3odBHXvnNH/RKzOvwbG/hKGbZW/nAd8yWtIhbyV1lCP tvqxpX71kjrAGQ1z2piug5qLCw== X-Google-Smtp-Source: AOwi7QC5m8/+t24qpBVWkHAf/kuWK7tVtfn18+yXBx15BIP/FmUhxpag0153FDgVPzHqrhPPk9DYYw== X-Received: by 10.99.139.195 with SMTP id j186mr7485233pge.231.1507152095386; Wed, 04 Oct 2017 14:21:35 -0700 (PDT) Received: from skynet.sea.corp.google.com ([172.31.92.33]) by smtp.gmail.com with ESMTPSA id s68sm30204019pfd.72.2017.10.04.14.21.33 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 04 Oct 2017 14:21:34 -0700 (PDT) From: Thomas Garnier To: Herbert Xu , "David S . Miller" , Thomas Gleixner , Ingo Molnar , "H . Peter Anvin" , Peter Zijlstra , Josh Poimboeuf , Thomas Garnier , Arnd Bergmann , Kees Cook , Matthias Kaehlcke , Tom Lendacky , Andy Lutomirski , "Kirill A . Shutemov" , Borislav Petkov , "Rafael J . Wysocki" , Len Brown , Pavel Machek , Juergen Gross , Chris Wright , Alok Kataria , Rusty Russell , Tejun Heo , Christoph Lameter , Boris Ostrovsky , Alexey Dobriyan , Andrew Morton , Paul Gortmaker , Chris Metcalf , "Paul E . McKenney" , Nicolas Pitre , Borislav Petkov , "Luis R . Rodriguez" , Greg Kroah-Hartman , Christopher Li , Steven Rostedt , Jason Baron , Dou Liyang , "Rafael J . Wysocki" , Mika Westerberg , Lukas Wunner , Masahiro Yamada , Alexei Starovoitov , Daniel Borkmann , Markus Trippelsdorf , Paolo Bonzini , =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= , Joerg Roedel , Rik van Riel , David Howells , Ard Biesheuvel , Waiman Long , Kyle Huey , Andrey Ryabinin , Jonathan Corbet , Matthew Wilcox , Michal Hocko , Peter Foley , Paul Bolle , Jiri Kosina , Rob Landley , "H . J . Lu" , Baoquan He , =?UTF-8?q?Jan=20H=20=2E=20Sch=C3=B6nherr?= , Daniel Micay Date: Wed, 4 Oct 2017 14:20:03 -0700 Message-Id: <20171004212003.28296-28-thgarnie@google.com> X-Mailer: git-send-email 2.14.2.920.gcf0c67979c-goog In-Reply-To: <20171004212003.28296-1-thgarnie@google.com> References: <20171004212003.28296-1-thgarnie@google.com> Cc: linux-arch@vger.kernel.org, kvm@vger.kernel.org, linux-pm@vger.kernel.org, x86@kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-sparse@vger.kernel.org, linux-crypto@vger.kernel.org, kernel-hardening@lists.openwall.com, xen-devel@lists.xenproject.org Subject: [Xen-devel] [RFC v3 27/27] x86/kaslr: Add option to extend KASLR range from 1GB to 3GB X-BeenThere: xen-devel@lists.xen.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: xen-devel-bounces@lists.xen.org Sender: "Xen-devel" X-Virus-Scanned: ClamAV using ClamSMTP Add a new CONFIG_RANDOMIZE_BASE_LARGE option to benefit from PIE support. It increases the KASLR range from 1GB to 3GB. The new range stars at 0xffffffff00000000 just above the EFI memory region. This option is off by default. The boot code is adapted to create the appropriate page table spanning three PUD pages. The relocation table uses 64-bit integers generated with the updated relocation tool with the large-reloc option. Signed-off-by: Thomas Garnier --- arch/x86/Kconfig | 21 +++++++++++++++++++++ arch/x86/boot/compressed/Makefile | 5 +++++ arch/x86/boot/compressed/misc.c | 10 +++++++++- arch/x86/include/asm/page_64_types.h | 9 +++++++++ arch/x86/kernel/head64.c | 15 ++++++++++++--- arch/x86/kernel/head_64.S | 11 ++++++++++- 6 files changed, 66 insertions(+), 5 deletions(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index b92f96923712..81f4512549d1 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -2149,6 +2149,27 @@ config X86_PIE select MODULE_REL_CRCS if MODVERSIONS select X86_GLOBAL_STACKPROTECTOR if CC_STACKPROTECTOR +config RANDOMIZE_BASE_LARGE + bool "Increase the randomization range of the kernel image" + depends on X86_64 && RANDOMIZE_BASE + select X86_PIE + select X86_MODULE_PLTS if MODULES + default n + ---help--- + Build the kernel as a Position Independent Executable (PIE) and + increase the available randomization range from 1GB to 3GB. + + This option impacts performance on kernel CPU intensive workloads up + to 10% due to PIE generated code. Impact on user-mode processes and + typical usage would be significantly less (0.50% when you build the + kernel). + + The kernel and modules will generate slightly more assembly (1 to 2% + increase on the .text sections). The vmlinux binary will be + significantly smaller due to less relocations. + + If unsure say N + config HOTPLUG_CPU bool "Support for hot-pluggable CPUs" depends on SMP diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile index 8a958274b54c..94dfee5a7cd2 100644 --- a/arch/x86/boot/compressed/Makefile +++ b/arch/x86/boot/compressed/Makefile @@ -112,7 +112,12 @@ $(obj)/vmlinux.bin: vmlinux FORCE targets += $(patsubst $(obj)/%,%,$(vmlinux-objs-y)) vmlinux.bin.all vmlinux.relocs +# Large randomization require bigger relocation table +ifeq ($(CONFIG_RANDOMIZE_BASE_LARGE),y) +CMD_RELOCS = arch/x86/tools/relocs --large-reloc +else CMD_RELOCS = arch/x86/tools/relocs +endif quiet_cmd_relocs = RELOCS $@ cmd_relocs = $(CMD_RELOCS) $< > $@;$(CMD_RELOCS) --abs-relocs $< $(obj)/vmlinux.relocs: vmlinux FORCE diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c index c14217cd0155..c1ac9f2e283d 100644 --- a/arch/x86/boot/compressed/misc.c +++ b/arch/x86/boot/compressed/misc.c @@ -169,10 +169,18 @@ void __puthex(unsigned long value) } #if CONFIG_X86_NEED_RELOCS + +/* Large randomization go lower than -2G and use large relocation table */ +#ifdef CONFIG_RANDOMIZE_BASE_LARGE +typedef long rel_t; +#else +typedef int rel_t; +#endif + static void handle_relocations(void *output, unsigned long output_len, unsigned long virt_addr) { - int *reloc; + rel_t *reloc; unsigned long delta, map, ptr; unsigned long min_addr = (unsigned long)output; unsigned long max_addr = min_addr + (VO___bss_start - VO__text); diff --git a/arch/x86/include/asm/page_64_types.h b/arch/x86/include/asm/page_64_types.h index 3f5f08b010d0..6b65f846dd64 100644 --- a/arch/x86/include/asm/page_64_types.h +++ b/arch/x86/include/asm/page_64_types.h @@ -48,7 +48,11 @@ #define __PAGE_OFFSET __PAGE_OFFSET_BASE #endif /* CONFIG_RANDOMIZE_MEMORY */ +#ifdef CONFIG_RANDOMIZE_BASE_LARGE +#define __START_KERNEL_map _AC(0xffffffff00000000, UL) +#else #define __START_KERNEL_map _AC(0xffffffff80000000, UL) +#endif /* CONFIG_RANDOMIZE_BASE_LARGE */ /* See Documentation/x86/x86_64/mm.txt for a description of the memory map. */ #ifdef CONFIG_X86_5LEVEL @@ -65,9 +69,14 @@ * 512MiB by default, leaving 1.5GiB for modules once the page tables * are fully set up. If kernel ASLR is configured, it can extend the * kernel page table mapping, reducing the size of the modules area. + * On PIE, we relocate the binary 2G lower so add this extra space. */ #if defined(CONFIG_RANDOMIZE_BASE) +#ifdef CONFIG_RANDOMIZE_BASE_LARGE +#define KERNEL_IMAGE_SIZE (_AC(3, UL) * 1024 * 1024 * 1024) +#else #define KERNEL_IMAGE_SIZE (1024 * 1024 * 1024) +#endif #else #define KERNEL_IMAGE_SIZE (512 * 1024 * 1024) #endif diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c index b6363f0d11a7..d603d0f5a40a 100644 --- a/arch/x86/kernel/head64.c +++ b/arch/x86/kernel/head64.c @@ -39,6 +39,7 @@ static unsigned int __initdata next_early_pgt; pmdval_t early_pmd_flags = __PAGE_KERNEL_LARGE & ~(_PAGE_GLOBAL | _PAGE_NX); #define __head __section(.head.text) +#define pud_count(x) (((x + (PUD_SIZE - 1)) & ~(PUD_SIZE - 1)) >> PUD_SHIFT) static void __head *fixup_pointer(void *ptr, unsigned long physaddr) { @@ -56,6 +57,8 @@ unsigned long __head notrace __startup_64(unsigned long physaddr, { unsigned long load_delta, *p; unsigned long pgtable_flags; + unsigned long level3_kernel_start, level3_kernel_count; + unsigned long level3_fixmap_start; pgdval_t *pgd; p4dval_t *p4d; pudval_t *pud; @@ -83,6 +86,11 @@ unsigned long __head notrace __startup_64(unsigned long physaddr, /* Include the SME encryption mask in the fixup value */ load_delta += sme_get_me_mask(); + /* Look at the randomization spread to adapt page table used */ + level3_kernel_start = pud_index(__START_KERNEL_map); + level3_kernel_count = pud_count(KERNEL_IMAGE_SIZE); + level3_fixmap_start = level3_kernel_start + level3_kernel_count; + /* Fixup the physical addresses in the page table */ pgd = fixup_pointer(&early_top_pgt, physaddr); @@ -94,8 +102,9 @@ unsigned long __head notrace __startup_64(unsigned long physaddr, } pud = fixup_pointer(&level3_kernel_pgt, physaddr); - pud[510] += load_delta; - pud[511] += load_delta; + for (i = 0; i < level3_kernel_count; i++) + pud[level3_kernel_start + i] += load_delta; + pud[level3_fixmap_start] += load_delta; pmd = fixup_pointer(level2_fixmap_pgt, physaddr); pmd[506] += load_delta; @@ -150,7 +159,7 @@ unsigned long __head notrace __startup_64(unsigned long physaddr, */ pmd = fixup_pointer(level2_kernel_pgt, physaddr); - for (i = 0; i < PTRS_PER_PMD; i++) { + for (i = 0; i < PTRS_PER_PMD * level3_kernel_count; i++) { if (pmd[i] & _PAGE_PRESENT) pmd[i] += load_delta; } diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index df5198e310fc..7918ffefc9c9 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -39,11 +39,15 @@ #define p4d_index(x) (((x) >> P4D_SHIFT) & (PTRS_PER_P4D-1)) #define pud_index(x) (((x) >> PUD_SHIFT) & (PTRS_PER_PUD-1)) +#define pud_count(x) (((x + (PUD_SIZE - 1)) & ~(PUD_SIZE - 1)) >> PUD_SHIFT) PGD_PAGE_OFFSET = pgd_index(__PAGE_OFFSET_BASE) PGD_START_KERNEL = pgd_index(__START_KERNEL_map) L3_START_KERNEL = pud_index(__START_KERNEL_map) +/* Adapt page table L3 space based on range of randomization */ +L3_KERNEL_ENTRY_COUNT = pud_count(KERNEL_IMAGE_SIZE) + .text __HEAD .code64 @@ -413,7 +417,12 @@ NEXT_PAGE(level4_kernel_pgt) NEXT_PAGE(level3_kernel_pgt) .fill L3_START_KERNEL,8,0 /* (2^48-(2*1024*1024*1024)-((2^39)*511))/(2^30) = 510 */ - .quad level2_kernel_pgt - __START_KERNEL_map + _KERNPG_TABLE_NOENC + i = 0 + .rept L3_KERNEL_ENTRY_COUNT + .quad level2_kernel_pgt - __START_KERNEL_map + _KERNPG_TABLE_NOENC \ + + PAGE_SIZE*i + i = i + 1 + .endr .quad level2_fixmap_pgt - __START_KERNEL_map + _PAGE_TABLE_NOENC NEXT_PAGE(level2_kernel_pgt)