4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Thomas Gleixner tglx@linutronix.de
commit 61dc0f555b5c761cdafb0ba5bd41ecf22d68a4c4 upstream.
Implement the CPU vulnerabilty show functions for meltdown, spectre_v1 and spectre_v2.
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/20180107214913.177414879@linutronix.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/x86/Kconfig | 1 + arch/x86/kernel/cpu/bugs.c | 29 +++++++++++++++++++++++++++++ 2 files changed, 30 insertions(+)
--- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -62,6 +62,7 @@ config X86 select GENERIC_CLOCKEVENTS_MIN_ADJUST select GENERIC_CMOS_UPDATE select GENERIC_CPU_AUTOPROBE + select GENERIC_CPU_VULNERABILITIES select GENERIC_EARLY_IOREMAP select GENERIC_FIND_FIRST_BIT select GENERIC_IOMAP --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -9,6 +9,7 @@ */ #include <linux/init.h> #include <linux/utsname.h> +#include <linux/cpu.h> #include <asm/bugs.h> #include <asm/processor.h> #include <asm/processor-flags.h> @@ -49,3 +50,31 @@ void __init check_bugs(void)
fpu__init_check_bugs(); } + +#ifdef CONFIG_SYSFS +ssize_t cpu_show_meltdown(struct device *dev, + struct device_attribute *attr, char *buf) +{ + if (!boot_cpu_has_bug(X86_BUG_CPU_MELTDOWN)) + return sprintf(buf, "Not affected\n"); + if (boot_cpu_has(X86_FEATURE_PTI)) + return sprintf(buf, "Mitigation: PTI\n"); + return sprintf(buf, "Vulnerable\n"); +} + +ssize_t cpu_show_spectre_v1(struct device *dev, + struct device_attribute *attr, char *buf) +{ + if (!boot_cpu_has_bug(X86_BUG_SPECTRE_V1)) + return sprintf(buf, "Not affected\n"); + return sprintf(buf, "Vulnerable\n"); +} + +ssize_t cpu_show_spectre_v2(struct device *dev, + struct device_attribute *attr, char *buf) +{ + if (!boot_cpu_has_bug(X86_BUG_SPECTRE_V2)) + return sprintf(buf, "Not affected\n"); + return sprintf(buf, "Vulnerable\n"); +} +#endif