diff options
author | Thomas Gleixner <tglx@linutronix.de> | 2018-01-08 00:48:00 +0300 |
---|---|---|
committer | Thomas Gleixner <tglx@linutronix.de> | 2018-01-08 13:10:33 +0300 |
commit | 87590ce6e373d1a5401f6539f0c59ef92dd924a9 (patch) | |
tree | b3d5c8ca8fe62571842c3461956da2183957a61c | |
parent | 99c6fa2511d8a683e61468be91b83f85452115fa (diff) | |
download | linux-87590ce6e373d1a5401f6539f0c59ef92dd924a9.tar.xz |
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
-rw-r--r-- | Documentation/ABI/testing/sysfs-devices-system-cpu | 16 | ||||
-rw-r--r-- | drivers/base/Kconfig | 3 | ||||
-rw-r--r-- | drivers/base/cpu.c | 48 | ||||
-rw-r--r-- | include/linux/cpu.h | 7 |
4 files changed, 74 insertions, 0 deletions
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, |