xref: /arm-trusted-firmware/lib/cpus/aarch64/wa_cve_2022_23960_bhb.S (revision 91f16700b400a8c0651d24a598fc48ee2997a0d7)
1*91f16700Schasinglulu/*
2*91f16700Schasinglulu * Copyright (c) 2022, Arm Limited and Contributors. All rights reserved.
3*91f16700Schasinglulu *
4*91f16700Schasinglulu * SPDX-License-Identifier: BSD-3-Clause
5*91f16700Schasinglulu */
6*91f16700Schasinglulu
7*91f16700Schasinglulu#include <context.h>
8*91f16700Schasinglulu
9*91f16700Schasinglulu#if WORKAROUND_CVE_2022_23960
10*91f16700Schasinglulu	/*
11*91f16700Schasinglulu	 * This macro applies the mitigation for CVE-2022-23960.
12*91f16700Schasinglulu         * The macro saves x2 to the CPU context.
13*91f16700Schasinglulu         * SP should point to the CPU context.
14*91f16700Schasinglulu	 */
15*91f16700Schasinglulu	.macro	apply_cve_2022_23960_bhb_wa _bhb_loop_count
16*91f16700Schasinglulu	str	x2, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X2]
17*91f16700Schasinglulu
18*91f16700Schasinglulu	/* CVE-BHB-NUM loop count */
19*91f16700Schasinglulu	mov	x2, \_bhb_loop_count
20*91f16700Schasinglulu
21*91f16700Schasinglulu1:
22*91f16700Schasinglulu	/* b pc+4 part of the workaround */
23*91f16700Schasinglulu	b	2f
24*91f16700Schasinglulu2:
25*91f16700Schasinglulu	subs	x2, x2, #1
26*91f16700Schasinglulu	bne	1b
27*91f16700Schasinglulu	speculation_barrier
28*91f16700Schasinglulu	ldr	x2, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X2]
29*91f16700Schasinglulu	.endm
30*91f16700Schasinglulu#endif /* WORKAROUND_CVE_2022_23960 */
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