x86/cpu: Implement CPU vulnerabilites sysfs functions

[pandora-kernel.git] / arch / x86 / kernel / cpu / bugs.c

diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 46674fb..1455cab 100644 (file)
--- 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 +17,10 @@
 #include <asm/msr.h>
 #include <asm/paravirt.h>
 #include <asm/alternative.h>
+#include <asm/pgtable.h>
+#include <asm/cacheflush.h>
+
+#ifdef CONFIG_X86_32
 
 static int __init no_halt(char *s)
 {
@@ -156,14 +161,26 @@ static void __init check_config(void)
 #endif
 }
 
+#endif /* CONFIG_X86_32 */
 
 void __init check_bugs(void)
 {
-       identify_boot_cpu();
-#ifndef CONFIG_SMP
-       printk(KERN_INFO "CPU: ");
-       print_cpu_info(&boot_cpu_data);
+#ifdef CONFIG_X86_32
+       /*
+        * Regardless of whether PCID is enumerated, the SDM says
+        * that it can't be enabled in 32-bit mode.
+        */
+       setup_clear_cpu_cap(X86_FEATURE_PCID);
 #endif
+
+       identify_boot_cpu();
+
+       if (!IS_ENABLED(CONFIG_SMP)) {
+               pr_info("CPU: ");
+               print_cpu_info(&boot_cpu_data);
+       }
+
+#ifdef CONFIG_X86_32
        check_config();
        check_fpu();
        check_hlt();
@@ -171,4 +188,46 @@ void __init check_bugs(void)
        init_utsname()->machine[1] =
                '0' + (boot_cpu_data.x86 > 6 ? 6 : boot_cpu_data.x86);
        alternative_instructions();
+#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 sysdev_class *dev,
+                         struct sysdev_class_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 sysdev_class *dev,
+                           struct sysdev_class_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 sysdev_class *dev,
+                           struct sysdev_class_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