aboutsummaryrefslogtreecommitdiffstats
path: root/common/recipes-kernel/linux/linux-yocto-4.9.21/0053-sysfs-cpu-Add-vulnerability-folder.patch
diff options
context:
space:
mode:
Diffstat (limited to 'common/recipes-kernel/linux/linux-yocto-4.9.21/0053-sysfs-cpu-Add-vulnerability-folder.patch')
-rw-r--r--common/recipes-kernel/linux/linux-yocto-4.9.21/0053-sysfs-cpu-Add-vulnerability-folder.patch157
1 files changed, 157 insertions, 0 deletions
diff --git a/common/recipes-kernel/linux/linux-yocto-4.9.21/0053-sysfs-cpu-Add-vulnerability-folder.patch b/common/recipes-kernel/linux/linux-yocto-4.9.21/0053-sysfs-cpu-Add-vulnerability-folder.patch
new file mode 100644
index 00000000..117c98ae
--- /dev/null
+++ b/common/recipes-kernel/linux/linux-yocto-4.9.21/0053-sysfs-cpu-Add-vulnerability-folder.patch
@@ -0,0 +1,157 @@
+From e288c57f82b662d0bc2d8fcf64e78e23c4c77919 Mon Sep 17 00:00:00 2001
+From: Thomas Gleixner <tglx@linutronix.de>
+Date: Sun, 7 Jan 2018 22:48:00 +0100
+Subject: [PATCH 053/102] sysfs/cpu: Add vulnerability folder
+
+commit 87590ce6e373d1a5401f6539f0c59ef92dd924a9 upstream.
+
+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
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ 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 4987417..8b30a48 100644
+--- a/Documentation/ABI/testing/sysfs-devices-system-cpu
++++ b/Documentation/ABI/testing/sysfs-devices-system-cpu
+@@ -350,3 +350,19 @@ Contact: Linux ARM Kernel Mailing list <linux-arm-kernel@lists.infradead.org>
+ Description: AArch64 CPU registers
+ 'identification' directory exposes the CPU ID registers for
+ identifying model and revision of the 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 d02e7c0..0651010 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
+
+diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
+index 4c28e1a..56b6c85 100644
+--- a/drivers/base/cpu.c
++++ b/drivers/base/cpu.c
+@@ -499,10 +499,58 @@ 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 e571128..2f475ad 100644
+--- a/include/linux/cpu.h
++++ b/include/linux/cpu.h
+@@ -44,6 +44,13 @@ 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,
+--
+2.7.4
+