x86/bugs: Concentrate bug reporting into a separate function

Those SysFS functions have a similar preamble, as such make common
code to handle them.

Suggested-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
CVE-2018-3639 (x86)

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index bfca937bdcc36ce8d9523f03dcc92e93d3c39d5c..ad613f73d0713f9a284d1b22f96f013212ec830a 100644 (file)
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -314,30 +314,48 @@ retpoline_auto:
 #undef pr_fmt
 
 #ifdef CONFIG_SYSFS
-ssize_t cpu_show_meltdown(struct device *dev, struct device_attribute *attr, char *buf)
+
+ssize_t cpu_show_common(struct device *dev, struct device_attribute *attr,
+                       char *buf, unsigned int bug)
 {
-       if (!boot_cpu_has_bug(X86_BUG_CPU_MELTDOWN))
+       if (!boot_cpu_has_bug(bug))
                return sprintf(buf, "Not affected\n");
-       if (boot_cpu_has(X86_FEATURE_PTI))
-               return sprintf(buf, "Mitigation: PTI\n");
+
+       switch (bug) {
+       case X86_BUG_CPU_MELTDOWN:
+               if (boot_cpu_has(X86_FEATURE_PTI))
+                       return sprintf(buf, "Mitigation: PTI\n");
+
+               break;
+
+       case X86_BUG_SPECTRE_V1:
+               return sprintf(buf, "Mitigation: __user pointer sanitization\n");
+
+       case X86_BUG_SPECTRE_V2:
+               return sprintf(buf, "%s%s%s%s\n", spectre_v2_strings[spectre_v2_enabled],
+                              boot_cpu_has(X86_FEATURE_USE_IBPB) ? ", IBPB" : "",
+                              boot_cpu_has(X86_FEATURE_USE_IBRS_FW) ? ", IBRS_FW" : "",
+                              spectre_v2_module_string());
+
+       default:
+               break;
+       }
+
        return sprintf(buf, "Vulnerable\n");
 }
 
+ssize_t cpu_show_meltdown(struct device *dev, struct device_attribute *attr, char *buf)
+{
+       return cpu_show_common(dev, attr, buf, X86_BUG_CPU_MELTDOWN);
+}
+
 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, "Mitigation: __user pointer sanitization\n");
+       return cpu_show_common(dev, attr, buf, X86_BUG_SPECTRE_V1);
 }
 
 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, "%s%s%s%s\n", spectre_v2_strings[spectre_v2_enabled],
-                      boot_cpu_has(X86_FEATURE_USE_IBPB) ? ", IBPB" : "",
-                      boot_cpu_has(X86_FEATURE_USE_IBRS_FW) ? ", IBRS_FW" : "",
-                      spectre_v2_module_string());
+       return cpu_show_common(dev, attr, buf, X86_BUG_SPECTRE_V2);
 }
 #endif