ARM: kvm: replace open coded VA->PA calculations with adr_l call

mainline inclusion
from mainline-5.11-rc1
commit aaac3733
category: bugfix
bugzilla: 46882
CVE: NA

-------------------------------------------------
Replace the open coded calculations of the actual physical address
of the KVM stub vector table with a single adr_l invocation.
Reviewed-by: NNicolas Pitre <nico@fluxnic.net>
Signed-off-by: NArd Biesheuvel <ardb@kernel.org>
(cherry picked from commit aaac3733)
Signed-off-by: NZhao Hongjiang <zhaohongjiang@huawei.com>
Acked-by: NXie XiuQi <xiexiuqi@huawei.com>

arch/arm/boot/compressed/head.S

@@ -468,15 +468,10 @@ dtb_check_done:
 
 		/*
 		 * Compute the address of the hyp vectors after relocation.
-		 * This requires some arithmetic since we cannot directly
-		 * reference __hyp_stub_vectors in a PC-relative way.
 		 * Call __hyp_set_vectors with the new address so that we
 		 * can HVC again after the copy.
 		 */
-0:		adr	r0, 0b
-		movw	r1, #:lower16:__hyp_stub_vectors - 0b
-		movt	r1, #:upper16:__hyp_stub_vectors - 0b
-		add	r0, r0, r1
+		adr_l	r0, __hyp_stub_vectors
 		sub	r0, r0, r5
 		add	r0, r0, r10
 		bl	__hyp_set_vectors
@@ -627,17 +622,11 @@ not_relocated:	mov	r0, #0
 		cmp	r0, #HYP_MODE		@ if not booted in HYP mode...
 		bne	__enter_kernel		@ boot kernel directly
 
-		adr	r12, .L__hyp_reentry_vectors_offset
-		ldr	r0, [r12]
-		add	r0, r0, r12
-
+		adr_l	r0, __hyp_reentry_vectors
 		bl	__hyp_set_vectors
 		__HVC(0)			@ otherwise bounce to hyp mode
 
 		b	.			@ should never be reached
-
-		.align	2
-.L__hyp_reentry_vectors_offset:	.long	__hyp_reentry_vectors - .
 #else
 		b	__enter_kernel
 #endif

arch/arm/kernel/hyp-stub.S

@@ -24,41 +24,38 @@ ENTRY(__boot_cpu_mode)
 .text
 
 	/*
-	 * Save the primary CPU boot mode. Requires 3 scratch registers.
+	 * Save the primary CPU boot mode. Requires 2 scratch registers.
 	 */
-	.macro	store_primary_cpu_mode	reg1, reg2, reg3
+	.macro	store_primary_cpu_mode	reg1, reg2
 	mrs	\reg1, cpsr
 	and	\reg1, \reg1, #MODE_MASK
-	adr	\reg2, .L__boot_cpu_mode_offset
-	ldr	\reg3, [\reg2]
-	str	\reg1, [\reg2, \reg3]
+	str_l	\reg1, __boot_cpu_mode, \reg2
 	.endm
 
 	/*
 	 * Compare the current mode with the one saved on the primary CPU.
 	 * If they don't match, record that fact. The Z bit indicates
 	 * if there's a match or not.
-	 * Requires 3 additionnal scratch registers.
+	 * Requires 2 additional scratch registers.
 	 */
-	.macro	compare_cpu_mode_with_primary mode, reg1, reg2, reg3
-	adr	\reg2, .L__boot_cpu_mode_offset
-	ldr	\reg3, [\reg2]
-	ldr	\reg1, [\reg2, \reg3]
+	.macro	compare_cpu_mode_with_primary mode, reg1, reg2
+	adr_l	\reg2, __boot_cpu_mode
+	ldr	\reg1, [\reg2]
 	cmp	\mode, \reg1		@ matches primary CPU boot mode?
 	orrne	\reg1, \reg1, #BOOT_CPU_MODE_MISMATCH
-	strne	\reg1, [\reg2, \reg3]	@ record what happened and give up
+	strne	\reg1, [\reg2]		@ record what happened and give up
 	.endm
 
 #else	/* ZIMAGE */
 
-	.macro	store_primary_cpu_mode	reg1:req, reg2:req, reg3:req
+	.macro	store_primary_cpu_mode	reg1:req, reg2:req
 	.endm
 
 /*
  * The zImage loader only runs on one CPU, so we don't bother with mult-CPU
  * consistency checking:
  */
-	.macro	compare_cpu_mode_with_primary mode, reg1, reg2, reg3
+	.macro	compare_cpu_mode_with_primary mode, reg1, reg2
 	cmp	\mode, \mode
 	.endm
 
@@ -73,7 +70,7 @@ ENTRY(__boot_cpu_mode)
  */
 @ Call this from the primary CPU
 ENTRY(__hyp_stub_install)
-	store_primary_cpu_mode	r4, r5, r6
+	store_primary_cpu_mode	r4, r5
 ENDPROC(__hyp_stub_install)
 
 	@ fall through...
@@ -87,7 +84,7 @@ ENTRY(__hyp_stub_install_secondary)
 	 * If the secondary has booted with a different mode, give up
 	 * immediately.
 	 */
-	compare_cpu_mode_with_primary	r4, r5, r6, r7
+	compare_cpu_mode_with_primary	r4, r5, r6
 	retne	lr
 
 	/*