Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754186AbeAAOka (ORCPT + 1 other); Mon, 1 Jan 2018 09:40:30 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:45054 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754151AbeAAOkZ (ORCPT ); Mon, 1 Jan 2018 09:40:25 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Thomas Gleixner , Borislav Petkov , Andy Lutomirski , Boris Ostrovsky , Borislav Petkov , Brian Gerst , Dave Hansen , David Laight , Denys Vlasenko , Eduardo Valentin , "H. Peter Anvin" , Josh Poimboeuf , Juergen Gross , Linus Torvalds , Peter Zijlstra , Will Deacon , aliguori@amazon.com, daniel.gruss@iaik.tugraz.at, hughd@google.com, keescook@google.com, Ingo Molnar Subject: [PATCH 4.14 007/146] x86/mm/pti: Add infrastructure for page table isolation Date: Mon, 1 Jan 2018 15:36:38 +0100 Message-Id: <20180101140124.853158062@linuxfoundation.org> X-Mailer: git-send-email 2.15.1 In-Reply-To: <20180101140123.743014891@linuxfoundation.org> References: <20180101140123.743014891@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Thomas Gleixner commit aa8c6248f8c75acfd610fe15d8cae23cf70d9d09 upstream. Add the initial files for kernel page table isolation, with a minimal init function and the boot time detection for this misfeature. Signed-off-by: Thomas Gleixner Reviewed-by: Borislav Petkov Cc: Andy Lutomirski Cc: Boris Ostrovsky Cc: Borislav Petkov Cc: Brian Gerst Cc: Dave Hansen Cc: David Laight Cc: Denys Vlasenko Cc: Eduardo Valentin Cc: Greg KH Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Juergen Gross Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Will Deacon Cc: aliguori@amazon.com Cc: daniel.gruss@iaik.tugraz.at Cc: hughd@google.com Cc: keescook@google.com Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- Documentation/admin-guide/kernel-parameters.txt | 2 arch/x86/boot/compressed/pagetable.c | 3 arch/x86/entry/calling.h | 7 ++ arch/x86/include/asm/pti.h | 14 ++++ arch/x86/mm/Makefile | 7 +- arch/x86/mm/init.c | 2 arch/x86/mm/pti.c | 84 ++++++++++++++++++++++++ include/linux/pti.h | 11 +++ init/main.c | 3 9 files changed, 130 insertions(+), 3 deletions(-) --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -2685,6 +2685,8 @@ steal time is computed, but won't influence scheduler behaviour + nopti [X86-64] Disable kernel page table isolation + nolapic [X86-32,APIC] Do not enable or use the local APIC. nolapic_timer [X86-32,APIC] Do not use the local APIC timer. --- a/arch/x86/boot/compressed/pagetable.c +++ b/arch/x86/boot/compressed/pagetable.c @@ -23,6 +23,9 @@ */ #undef CONFIG_AMD_MEM_ENCRYPT +/* No PAGE_TABLE_ISOLATION support needed either: */ +#undef CONFIG_PAGE_TABLE_ISOLATION + #include "misc.h" /* These actually do the work of building the kernel identity maps. */ --- a/arch/x86/entry/calling.h +++ b/arch/x86/entry/calling.h @@ -205,18 +205,23 @@ For 32-bit we have the following convent .endm .macro SWITCH_TO_KERNEL_CR3 scratch_reg:req + ALTERNATIVE "jmp .Lend_\@", "", X86_FEATURE_PTI mov %cr3, \scratch_reg ADJUST_KERNEL_CR3 \scratch_reg mov \scratch_reg, %cr3 +.Lend_\@: .endm .macro SWITCH_TO_USER_CR3 scratch_reg:req + ALTERNATIVE "jmp .Lend_\@", "", X86_FEATURE_PTI mov %cr3, \scratch_reg ADJUST_USER_CR3 \scratch_reg mov \scratch_reg, %cr3 +.Lend_\@: .endm .macro SAVE_AND_SWITCH_TO_KERNEL_CR3 scratch_reg:req save_reg:req + ALTERNATIVE "jmp .Ldone_\@", "", X86_FEATURE_PTI movq %cr3, \scratch_reg movq \scratch_reg, \save_reg /* @@ -233,11 +238,13 @@ For 32-bit we have the following convent .endm .macro RESTORE_CR3 save_reg:req + ALTERNATIVE "jmp .Lend_\@", "", X86_FEATURE_PTI /* * The CR3 write could be avoided when not changing its value, * but would require a CR3 read *and* a scratch register. */ movq \save_reg, %cr3 +.Lend_\@: .endm #else /* CONFIG_PAGE_TABLE_ISOLATION=n: */ --- /dev/null +++ b/arch/x86/include/asm/pti.h @@ -0,0 +1,14 @@ +// SPDX-License-Identifier: GPL-2.0 +#ifndef _ASM_X86_PTI_H +#define _ASM_X86_PTI_H +#ifndef __ASSEMBLY__ + +#ifdef CONFIG_PAGE_TABLE_ISOLATION +extern void pti_init(void); +extern void pti_check_boottime_disable(void); +#else +static inline void pti_check_boottime_disable(void) { } +#endif + +#endif /* __ASSEMBLY__ */ +#endif /* _ASM_X86_PTI_H */ --- a/arch/x86/mm/Makefile +++ b/arch/x86/mm/Makefile @@ -43,9 +43,10 @@ obj-$(CONFIG_AMD_NUMA) += amdtopology.o obj-$(CONFIG_ACPI_NUMA) += srat.o obj-$(CONFIG_NUMA_EMU) += numa_emulation.o -obj-$(CONFIG_X86_INTEL_MPX) += mpx.o -obj-$(CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS) += pkeys.o -obj-$(CONFIG_RANDOMIZE_MEMORY) += kaslr.o +obj-$(CONFIG_X86_INTEL_MPX) += mpx.o +obj-$(CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS) += pkeys.o +obj-$(CONFIG_RANDOMIZE_MEMORY) += kaslr.o +obj-$(CONFIG_PAGE_TABLE_ISOLATION) += pti.o obj-$(CONFIG_AMD_MEM_ENCRYPT) += mem_encrypt.o obj-$(CONFIG_AMD_MEM_ENCRYPT) += mem_encrypt_boot.o --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -20,6 +20,7 @@ #include #include #include +#include /* * We need to define the tracepoints somewhere, and tlb.c @@ -630,6 +631,7 @@ void __init init_mem_mapping(void) { unsigned long end; + pti_check_boottime_disable(); probe_page_size_mask(); setup_pcid(); --- /dev/null +++ b/arch/x86/mm/pti.c @@ -0,0 +1,84 @@ +/* + * Copyright(c) 2017 Intel Corporation. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of version 2 of the GNU General Public License as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * This code is based in part on work published here: + * + * https://github.com/IAIK/KAISER + * + * The original work was written by and and signed off by for the Linux + * kernel by: + * + * Signed-off-by: Richard Fellner + * Signed-off-by: Moritz Lipp + * Signed-off-by: Daniel Gruss + * Signed-off-by: Michael Schwarz + * + * Major changes to the original code by: Dave Hansen + * Mostly rewritten by Thomas Gleixner and + * Andy Lutomirsky + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include +#include +#include + +#undef pr_fmt +#define pr_fmt(fmt) "Kernel/User page tables isolation: " fmt + +static void __init pti_print_if_insecure(const char *reason) +{ + if (boot_cpu_has_bug(X86_BUG_CPU_INSECURE)) + pr_info("%s\n", reason); +} + +void __init pti_check_boottime_disable(void) +{ + if (hypervisor_is_type(X86_HYPER_XEN_PV)) { + pti_print_if_insecure("disabled on XEN PV."); + return; + } + + if (cmdline_find_option_bool(boot_command_line, "nopti")) { + pti_print_if_insecure("disabled on command line."); + return; + } + + if (!boot_cpu_has_bug(X86_BUG_CPU_INSECURE)) + return; + + setup_force_cpu_cap(X86_FEATURE_PTI); +} + +/* + * Initialize kernel page table isolation + */ +void __init pti_init(void) +{ + if (!static_cpu_has(X86_FEATURE_PTI)) + return; + + pr_info("enabled\n"); +} --- /dev/null +++ b/include/linux/pti.h @@ -0,0 +1,11 @@ +// SPDX-License-Identifier: GPL-2.0 +#ifndef _INCLUDE_PTI_H +#define _INCLUDE_PTI_H + +#ifdef CONFIG_PAGE_TABLE_ISOLATION +#include +#else +static inline void pti_init(void) { } +#endif + +#endif --- a/init/main.c +++ b/init/main.c @@ -75,6 +75,7 @@ #include #include #include +#include #include #include #include @@ -506,6 +507,8 @@ static void __init mm_init(void) ioremap_huge_init(); /* Should be run before the first non-init thread is created */ init_espfix_bsp(); + /* Should be run after espfix64 is set up. */ + pti_init(); } asmlinkage __visible void __init start_kernel(void)