On Sun, Jan 07, 2018 at 10:48:00PM +0100, Thomas Gleixner wrote:
> 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 <t...@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(+)
>
> --- 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 <linu
> 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
s/Januar/January/
and with that
Reviewed-by: Konrad Rzeszutek Wilk <konrad.w...@oracle.com>
Thank you!
> +#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();
> }
> --- a/include/linux/cpu.h
> +++ b/include/linux/cpu.h
> @@ -47,6 +47,13 @@ extern void cpu_remove_dev_attr(struct d
> 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,
>
>
