diff options
Diffstat (limited to 'arch/x86/kernel/cpu/bugs.c')
| -rw-r--r-- | arch/x86/kernel/cpu/bugs.c | 55 |
1 files changed, 51 insertions, 4 deletions
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index 0b6124315441..cd46f9039119 100644 --- 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> @@ -16,6 +17,8 @@ #include <asm/msr.h> #include <asm/paravirt.h> #include <asm/alternative.h> +#include <asm/pgtable.h> +#include <asm/cacheflush.h> void __init check_bugs(void) { @@ -28,11 +31,13 @@ void __init check_bugs(void) #endif identify_boot_cpu(); -#ifndef CONFIG_SMP - pr_info("CPU: "); - print_cpu_info(&boot_cpu_data); -#endif + if (!IS_ENABLED(CONFIG_SMP)) { + pr_info("CPU: "); + print_cpu_info(&boot_cpu_data); + } + +#ifdef CONFIG_X86_32 /* * Check whether we are able to run this kernel safely on SMP. * @@ -48,4 +53,46 @@ void __init check_bugs(void) alternative_instructions(); fpu__init_check_bugs(); +#else /* CONFIG_X86_64 */ + alternative_instructions(); + + /* + * Make sure the first 2MB area is not mapped by huge pages + * There are typically fixed size MTRRs in there and overlapping + * MTRRs into large pages causes slow downs. + * + * Right now we don't do that with gbpages because there seems + * very little benefit for that case. + */ + if (!direct_gbpages) + set_memory_4k((unsigned long)__va(0), 1); +#endif } + +#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_KAISER)) + 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 |