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7c7389df50
pve-kernel-qoup/patches/kernel/0190-x86-mm-pti-Add-infrastructure-for-page-table-isolati.patch
Fabian Grünbichler 7c7389df50 add Spectre PoC fix 
picked from https://patchwork.kernel.org/patch/10147679/
2018-01-06 15:15:39 +01:00

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From 384e4cfab1886f8abb94fe16abbad2a034612f78 Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@linutronix.de>
Date: Mon, 4 Dec 2017 15:07:36 +0100
Subject: [PATCH 190/232] x86/mm/pti: Add infrastructure for page table
isolation
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
CVE-2017-5754
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 <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
(backported from commit aa8c6248f8c75acfd610fe15d8cae23cf70d9d09)
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
(cherry picked from commit 50da124a01ed7a59f9b2c9551f622c5a27d1caec)
Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
---
Documentation/admin-guide/kernel-parameters.txt | 2 +
arch/x86/mm/Makefile | 7 ++-
arch/x86/entry/calling.h | 7 +++
arch/x86/include/asm/pti.h | 14 +++++
include/linux/pti.h | 11 ++++
arch/x86/boot/compressed/pagetable.c | 3 +
arch/x86/mm/init.c | 2 +
arch/x86/mm/pti.c | 84 +++++++++++++++++++++++++
init/main.c | 3 +
9 files changed, 130 insertions(+), 3 deletions(-)
create mode 100644 arch/x86/include/asm/pti.h
create mode 100644 include/linux/pti.h
create mode 100644 arch/x86/mm/pti.c
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 3510e255ef4c..e2a4608da5d2 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -2677,6 +2677,8 @@
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.
diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile
index 76f5399a8356..7aa68fc18abe 100644
--- a/arch/x86/mm/Makefile
+++ b/arch/x86/mm/Makefile
@@ -35,7 +35,8 @@ 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
diff --git a/arch/x86/entry/calling.h b/arch/x86/entry/calling.h
index dde6262be0a3..bb56f5346ae8 100644
--- a/arch/x86/entry/calling.h
+++ b/arch/x86/entry/calling.h
@@ -204,18 +204,23 @@ For 32-bit we have the following conventions - kernel is built with
.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
/*
@@ -232,11 +237,13 @@ For 32-bit we have the following conventions - kernel is built with
.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: */
diff --git a/arch/x86/include/asm/pti.h b/arch/x86/include/asm/pti.h
new file mode 100644
index 000000000000..0b5ef05b2d2d
--- /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 */
diff --git a/include/linux/pti.h b/include/linux/pti.h
new file mode 100644
index 000000000000..0174883a935a
--- /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 <asm/pti.h>
+#else
+static inline void pti_init(void) { }
+#endif
+
+#endif
diff --git a/arch/x86/boot/compressed/pagetable.c b/arch/x86/boot/compressed/pagetable.c
index 28029be47fbb..21d8839cdaa7 100644
--- a/arch/x86/boot/compressed/pagetable.c
+++ b/arch/x86/boot/compressed/pagetable.c
@@ -15,6 +15,9 @@
#define __pa(x) ((unsigned long)(x))
#define __va(x) ((void *)((unsigned long)(x)))
+/* 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. */
diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index 020223420308..af75069fb116 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -20,6 +20,7 @@
#include <asm/kaslr.h>
#include <asm/hypervisor.h>
#include <asm/cpufeature.h>
+#include <asm/pti.h>
/*
* 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();
diff --git a/arch/x86/mm/pti.c b/arch/x86/mm/pti.c
new file mode 100644
index 000000000000..375f23a758bc
--- /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 <richard.fellner@student.tugraz.at>
+ * Signed-off-by: Moritz Lipp <moritz.lipp@iaik.tugraz.at>
+ * Signed-off-by: Daniel Gruss <daniel.gruss@iaik.tugraz.at>
+ * Signed-off-by: Michael Schwarz <michael.schwarz@iaik.tugraz.at>
+ *
+ * Major changes to the original code by: Dave Hansen <dave.hansen@intel.com>
+ * Mostly rewritten by Thomas Gleixner <tglx@linutronix.de> and
+ * Andy Lutomirsky <luto@amacapital.net>
+ */
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/bug.h>
+#include <linux/init.h>
+#include <linux/spinlock.h>
+#include <linux/mm.h>
+#include <linux/uaccess.h>
+
+#include <asm/cpufeature.h>
+#include <asm/hypervisor.h>
+#include <asm/cmdline.h>
+#include <asm/pti.h>
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
+#include <asm/tlbflush.h>
+#include <asm/desc.h>
+
+#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");
+}
diff --git a/init/main.c b/init/main.c
index de1c495da782..bb0896c24c08 100644
--- a/init/main.c
+++ b/init/main.c
@@ -75,6 +75,7 @@
#include <linux/slab.h>
#include <linux/perf_event.h>
#include <linux/ptrace.h>
+#include <linux/pti.h>
#include <linux/blkdev.h>
#include <linux/elevator.h>
#include <linux/sched_clock.h>
@@ -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)
--
2.14.2
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