1 files changed, 30 insertions, 0 deletions
diff --git a/lib/cpus/aarch64/wa_cve_2022_23960_bhb.S b/lib/cpus/aarch64/wa_cve_2022_23960_bhb.S
new file mode 100644
index 0000000..ceb93f1
--- /dev/null
+++ b/lib/cpus/aarch64/wa_cve_2022_23960_bhb.S
@@ -0,0 +1,30 @@
+/*
+ * Copyright (c) 2022, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <context.h>
+
+#if WORKAROUND_CVE_2022_23960
+	/*
+	 * This macro applies the mitigation for CVE-2022-23960.
+         * The macro saves x2 to the CPU context.
+         * SP should point to the CPU context.
+	 */
+	.macro	apply_cve_2022_23960_bhb_wa _bhb_loop_count
+	str	x2, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X2]
+
+	/* CVE-BHB-NUM loop count */
+	mov	x2, \_bhb_loop_count
+
+1:
+	/* b pc+4 part of the workaround */
+	b	2f
+2:
+	subs	x2, x2, #1
+	bne	1b
+	speculation_barrier
+	ldr	x2, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X2]
+	.endm
+#endif /* WORKAROUND_CVE_2022_23960 */