85 lines
2.3 KiB
C
85 lines
2.3 KiB
C
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/*
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* Copyright(c) 2017 Intel Corporation. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of version 2 of the GNU General Public License as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* This code is based in part on work published here:
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*
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* https://github.com/IAIK/KAISER
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*
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* The original work was written by and and signed off by for the Linux
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* kernel by:
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*
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* Signed-off-by: Richard Fellner <richard.fellner@student.tugraz.at>
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* Signed-off-by: Moritz Lipp <moritz.lipp@iaik.tugraz.at>
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* Signed-off-by: Daniel Gruss <daniel.gruss@iaik.tugraz.at>
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* Signed-off-by: Michael Schwarz <michael.schwarz@iaik.tugraz.at>
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*
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* Major changes to the original code by: Dave Hansen <dave.hansen@intel.com>
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* Mostly rewritten by Thomas Gleixner <tglx@linutronix.de> and
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* Andy Lutomirsky <luto@amacapital.net>
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*/
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#include <linux/kernel.h>
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#include <linux/errno.h>
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#include <linux/string.h>
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#include <linux/types.h>
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#include <linux/bug.h>
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#include <linux/init.h>
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#include <linux/spinlock.h>
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#include <linux/mm.h>
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#include <linux/uaccess.h>
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#include <asm/cpufeature.h>
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#include <asm/hypervisor.h>
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#include <asm/cmdline.h>
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#include <asm/pti.h>
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#include <asm/pgtable.h>
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#include <asm/pgalloc.h>
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#include <asm/tlbflush.h>
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#include <asm/desc.h>
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#undef pr_fmt
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#define pr_fmt(fmt) "Kernel/User page tables isolation: " fmt
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static void __init pti_print_if_insecure(const char *reason)
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{
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if (boot_cpu_has_bug(X86_BUG_CPU_INSECURE))
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pr_info("%s\n", reason);
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}
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void __init pti_check_boottime_disable(void)
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{
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if (hypervisor_is_type(X86_HYPER_XEN_PV)) {
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pti_print_if_insecure("disabled on XEN PV.");
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return;
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}
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if (cmdline_find_option_bool(boot_command_line, "nopti")) {
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pti_print_if_insecure("disabled on command line.");
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return;
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}
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if (!boot_cpu_has_bug(X86_BUG_CPU_INSECURE))
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return;
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setup_force_cpu_cap(X86_FEATURE_PTI);
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}
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/*
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* Initialize kernel page table isolation
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*/
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void __init pti_init(void)
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{
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if (!static_cpu_has(X86_FEATURE_PTI))
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return;
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pr_info("enabled\n");
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}
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