UBUNTU: SAUCE: claim mitigation via observable speculation barrier

CVE-2017-5753 (Spectre v1 Intel)
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

arch/x86/kernel/cpu/bugs.c

@@ -227,11 +227,19 @@ ssize_t cpu_show_meltdown(struct device *dev,
 	return sprintf(buf, "Vulnerable\n");
 }
 
+#ifndef osb
+#define osb_is_enabled 	(0)
+#endif
+#ifndef osb_is_enabled
+#define osb_is_enabled	(1)
+#endif
 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");
+	if (osb_is_enabled)
+		return sprintf(buf, "Mitigation: OSB (observable speculation barrier, Intel v6)\n");
 	return sprintf(buf, "Vulnerable\n");
 }