1 files changed, 28 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 709acab25f3c..03bd73f16d74 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -517,6 +517,34 @@ static __init int setup_disable_pku(char *arg)
 __setup("nopku", setup_disable_pku);
 #endif /* CONFIG_X86_64 */
 
+#ifdef CONFIG_X86_KERNEL_IBT
+
+__noendbr u64 ibt_save(void)
+{
+	u64 msr = 0;
+
+	if (cpu_feature_enabled(X86_FEATURE_IBT)) {
+		rdmsrl(MSR_IA32_S_CET, msr);
+		wrmsrl(MSR_IA32_S_CET, msr & ~CET_ENDBR_EN);
+	}
+
+	return msr;
+}
+
+__noendbr void ibt_restore(u64 save)
+{
+	u64 msr;
+
+	if (cpu_feature_enabled(X86_FEATURE_IBT)) {
+		rdmsrl(MSR_IA32_S_CET, msr);
+		msr &= ~CET_ENDBR_EN;
+		msr |= (save & CET_ENDBR_EN);
+		wrmsrl(MSR_IA32_S_CET, msr);
+	}
+}
+
+#endif
+
 static __always_inline void setup_cet(struct cpuinfo_x86 *c)
 {
 	u64 msr = CET_ENDBR_EN;