--- zzzz-none-000/linux-4.1.52/arch/arm/kernel/entry-header.S	2018-05-28 02:26:45.000000000 +0000
+++ bcm63-7530ax-731/linux-4.1.52/arch/arm/kernel/entry-header.S	2022-03-02 11:37:12.000000000 +0000
@@ -385,6 +385,33 @@
 #endif
 	.endm
 
+#if defined(CONFIG_BCM_KF_SPECTRE_PATCH) && defined(CONFIG_BCM_SPECTRE_PATCH_ENABLE)
+	.macro	invoke_syscall, table, nr, tmp, ret, reload=0
+#ifdef CONFIG_CPU_SPECTRE
+	mov	\tmp, \nr
+	cmp	\tmp, #NR_syscalls		@ check upper syscall limit
+	movcs	\tmp, #0
+	csdb
+	badr	lr, \ret			@ return address
+	.if	\reload
+	add	r1, sp, #S_R0 + S_OFF		@ pointer to regs
+	ldmccia	r1, {r0 - r6}			@ reload r0-r6
+	stmccia	sp, {r4, r5}			@ update stack arguments
+	.endif
+	ldrcc	pc, [\table, \tmp, lsl #2]	@ call sys_* routine
+#else
+	cmp	\nr, #NR_syscalls		@ check upper syscall limit
+	badr	lr, \ret			@ return address
+	.if	\reload
+	add	r1, sp, #S_R0 + S_OFF		@ pointer to regs
+	ldmccia	r1, {r0 - r6}			@ reload r0-r6
+	stmccia	sp, {r4, r5}			@ update stack arguments
+	.endif
+	ldrcc	pc, [\table, \nr, lsl #2]	@ call sys_* routine
+#endif
+	.endm
+#endif /* CONFIG_BCM_KF_SPECTRE_PATCH && CONFIG_BCM_SPECTRE_PATCH_ENABLE */
+
 /*
  * These are the registers used in the syscall handler, and allow us to
  * have in theory up to 7 arguments to a function - r0 to r6.