Initial retpoline patches for Spectre v2

0002-sysfs-cpu-Add-vulnerability-folder.patch

@@ -0,0 +1,154 @@
+From 87590ce6e373d1a5401f6539f0c59ef92dd924a9 Mon Sep 17 00:00:00 2001
+From: Thomas Gleixner <tglx@linutronix.de>
+Date: Sun, 7 Jan 2018 22:48:00 +0100
+Subject: [PATCH 2/2] sysfs/cpu: Add vulnerability folder
+
+As the meltdown/spectre problem affects several CPU architectures, it makes
+sense to have common way to express whether a system is affected by a
+particular vulnerability or not. If affected the way to express the
+mitigation should be common as well.
+
+Create /sys/devices/system/cpu/vulnerabilities folder and files for
+meltdown, spectre_v1 and spectre_v2.
+
+Allow architectures to override the show function.
+
+Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
+Cc: Peter Zijlstra <peterz@infradead.org>
+Cc: Will Deacon <will.deacon@arm.com>
+Cc: Dave Hansen <dave.hansen@intel.com>
+Cc: Linus Torvalds <torvalds@linuxfoundation.org>
+Cc: Borislav Petkov <bp@alien8.de>
+Cc: David Woodhouse <dwmw@amazon.co.uk>
+Link: https://lkml.kernel.org/r/20180107214913.096657732@linutronix.de
+---
+ Documentation/ABI/testing/sysfs-devices-system-cpu | 16 ++++++++
+ drivers/base/Kconfig                               |  3 ++
+ drivers/base/cpu.c                                 | 48 ++++++++++++++++++++++
+ include/linux/cpu.h                                |  7 ++++
+ 4 files changed, 74 insertions(+)
+
+diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu
+index f3d5817c4ef0..bd3a88e16d8b 100644
+--- a/Documentation/ABI/testing/sysfs-devices-system-cpu
++++ b/Documentation/ABI/testing/sysfs-devices-system-cpu
+@@ -373,3 +373,19 @@ Contact:	Linux kernel mailing list <linux-kernel@vger.kernel.org>
+ Description:	information about CPUs heterogeneity.
+
+ 		cpu_capacity: capacity of cpu#.
++
++What:		/sys/devices/system/cpu/vulnerabilities
++		/sys/devices/system/cpu/vulnerabilities/meltdown
++		/sys/devices/system/cpu/vulnerabilities/spectre_v1
++		/sys/devices/system/cpu/vulnerabilities/spectre_v2
++Date:		Januar 2018
++Contact:	Linux kernel mailing list <linux-kernel@vger.kernel.org>
++Description:	Information about CPU vulnerabilities
++
++		The files are named after the code names of CPU
++		vulnerabilities. The output of those files reflects the
++		state of the CPUs in the system. Possible output values:
++
++		"Not affected"	  CPU is not affected by the vulnerability
++		"Vulnerable"	  CPU is affected and no mitigation in effect
++		"Mitigation: $M"  CPU is affetcted and mitigation $M is in effect
+diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig
+index 2f6614c9a229..37a71fd9043f 100644
+--- a/drivers/base/Kconfig
++++ b/drivers/base/Kconfig
+@@ -235,6 +235,9 @@ config GENERIC_CPU_DEVICES
+ config GENERIC_CPU_AUTOPROBE
+ 	bool
+
++config GENERIC_CPU_VULNERABILITIES
++	bool
++
+ config SOC_BUS
+ 	bool
+ 	select GLOB
+diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
+index 321cd7b4d817..825964efda1d 100644
+--- a/drivers/base/cpu.c
++++ b/drivers/base/cpu.c
+@@ -501,10 +501,58 @@ static void __init cpu_dev_register_generic(void)
+ #endif
+ }
+
++#ifdef CONFIG_GENERIC_CPU_VULNERABILITIES
++
++ssize_t __weak cpu_show_meltdown(struct device *dev,
++				 struct device_attribute *attr, char *buf)
++{
++	return sprintf(buf, "Not affected\n");
++}
++
++ssize_t __weak cpu_show_spectre_v1(struct device *dev,
++				   struct device_attribute *attr, char *buf)
++{
++	return sprintf(buf, "Not affected\n");
++}
++
++ssize_t __weak cpu_show_spectre_v2(struct device *dev,
++				   struct device_attribute *attr, char *buf)
++{
++	return sprintf(buf, "Not affected\n");
++}
++
++static DEVICE_ATTR(meltdown, 0444, cpu_show_meltdown, NULL);
++static DEVICE_ATTR(spectre_v1, 0444, cpu_show_spectre_v1, NULL);
++static DEVICE_ATTR(spectre_v2, 0444, cpu_show_spectre_v2, NULL);
++
++static struct attribute *cpu_root_vulnerabilities_attrs[] = {
++	&dev_attr_meltdown.attr,
++	&dev_attr_spectre_v1.attr,
++	&dev_attr_spectre_v2.attr,
++	NULL
++};
++
++static const struct attribute_group cpu_root_vulnerabilities_group = {
++	.name  = "vulnerabilities",
++	.attrs = cpu_root_vulnerabilities_attrs,
++};
++
++static void __init cpu_register_vulnerabilities(void)
++{
++	if (sysfs_create_group(&cpu_subsys.dev_root->kobj,
++			       &cpu_root_vulnerabilities_group))
++		pr_err("Unable to register CPU vulnerabilities\n");
++}
++
++#else
++static inline void cpu_register_vulnerabilities(void) { }
++#endif
++
+ void __init cpu_dev_init(void)
+ {
+ 	if (subsys_system_register(&cpu_subsys, cpu_root_attr_groups))
+ 		panic("Failed to register CPU subsystem");
+
+ 	cpu_dev_register_generic();
++	cpu_register_vulnerabilities();
+ }
+diff --git a/include/linux/cpu.h b/include/linux/cpu.h
+index 938ea8ae0ba4..c816e6f2730c 100644
+--- a/include/linux/cpu.h
++++ b/include/linux/cpu.h
+@@ -47,6 +47,13 @@ extern void cpu_remove_dev_attr(struct device_attribute *attr);
+ extern int cpu_add_dev_attr_group(struct attribute_group *attrs);
+ extern void cpu_remove_dev_attr_group(struct attribute_group *attrs);
+
++extern ssize_t cpu_show_meltdown(struct device *dev,
++				 struct device_attribute *attr, char *buf);
++extern ssize_t cpu_show_spectre_v1(struct device *dev,
++				   struct device_attribute *attr, char *buf);
++extern ssize_t cpu_show_spectre_v2(struct device *dev,
++				   struct device_attribute *attr, char *buf);
++
+ extern __printf(4, 5)
+ struct device *cpu_device_create(struct device *parent, void *drvdata,
+ 				 const struct attribute_group **groups,
+-- 
+2.14.3
+