diff --git a/Documentation/arm64/cpu-feature-registers.rst b/Documentation/arm64/cpu-feature-registers.rst
index b86828f..c96c7df 100644
--- a/Documentation/arm64/cpu-feature-registers.rst
+++ b/Documentation/arm64/cpu-feature-registers.rst
@@ -174,6 +174,8 @@ infrastructure:
      +------------------------------+---------+---------+
      | SSBS                         | [7-4]   |    y    |
      +------------------------------+---------+---------+
+     | BT                           | [3-0]   |    y    |
+     +------------------------------+---------+---------+
 
 
   4) MIDR_EL1 - Main ID Register
diff --git a/Documentation/arm64/elf_hwcaps.rst b/Documentation/arm64/elf_hwcaps.rst
index 91f7952..296dcac 100644
--- a/Documentation/arm64/elf_hwcaps.rst
+++ b/Documentation/arm64/elf_hwcaps.rst
@@ -201,6 +201,10 @@ HWCAP2_FRINT
 
     Functionality implied by ID_AA64ISAR1_EL1.FRINTTS == 0b0001.
 
+HWCAP2_BTI
+
+    Functionality implied by ID_AA64PFR0_EL1.BT == 0b0001.
+
 
 4. Unused AT_HWCAP bits
 -----------------------
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 41a9b42..bb3189e 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -1410,6 +1410,34 @@ config ARM64_PTR_AUTH
 
 endmenu
 
+menu "ARMv8.5 architectural features"
+
+config ARM64_BTI
+	bool "Branch Target Identification support"
+	default y
+	depends on ARM64_PTR_AUTH
+	help
+	  Branch Target Identification (part of the ARMv8.5 Extensions)
+	  provides a mechanism to limit the set of locations to which computed
+	  branch instructions such as BR or BLR can jump.
+
+	  To make use of BTI on CPUs that support it, say Y.
+
+	  BTI is intended to provide complementary protection to other control
+	  flow integrity protection mechanisms, such as the Pointer
+	  authentication mechanism provided as part of the ARMv8.3 Extensions.
+	  For this reason, it does not make sense to enable this option without
+	  also enabling support for Pointer authentication.
+
+	  Thus, to enable this option you also need to select ARM64_PTR_AUTH=y.
+
+	  Userspace binaries must also be specifically compiled to make use of
+	  this mechanism.  If you say N here or the hardware does not support
+	  BTI, such binaries can still run, but you get no additional
+	  enforcement of branch destinations.
+
+endmenu
+
 config ARM64_SVE
 	bool "ARM Scalable Vector Extension support"
 	default y
diff --git a/arch/arm64/include/asm/cpucaps.h b/arch/arm64/include/asm/cpucaps.h
index f19fe4b..946165e 100644
--- a/arch/arm64/include/asm/cpucaps.h
+++ b/arch/arm64/include/asm/cpucaps.h
@@ -52,7 +52,8 @@
 #define ARM64_HAS_IRQ_PRIO_MASKING		42
 #define ARM64_HAS_DCPODP			43
 #define ARM64_WORKAROUND_1463225		44
+#define ARM64_BTI				45
 
-#define ARM64_NCAPS				45
+#define ARM64_NCAPS				46
 
 #endif /* __ASM_CPUCAPS_H */
diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h
index 9cde5d2..84fa48f 100644
--- a/arch/arm64/include/asm/cpufeature.h
+++ b/arch/arm64/include/asm/cpufeature.h
@@ -613,6 +613,12 @@ static inline bool system_has_prio_mask_debugging(void)
 	       system_uses_irq_prio_masking();
 }
 
+static inline bool system_supports_bti(void)
+{
+	return IS_ENABLED(CONFIG_ARM64_BTI) &&
+		cpus_have_const_cap(ARM64_BTI);
+}
+
 #define ARM64_BP_HARDEN_UNKNOWN		-1
 #define ARM64_BP_HARDEN_WA_NEEDED	0
 #define ARM64_BP_HARDEN_NOT_REQUIRED	1
diff --git a/arch/arm64/include/asm/esr.h b/arch/arm64/include/asm/esr.h
index cb29253..390b8ba 100644
--- a/arch/arm64/include/asm/esr.h
+++ b/arch/arm64/include/asm/esr.h
@@ -22,7 +22,7 @@
 #define ESR_ELx_EC_PAC		(0x09)	/* EL2 and above */
 /* Unallocated EC: 0x0A - 0x0B */
 #define ESR_ELx_EC_CP14_64	(0x0C)
-/* Unallocated EC: 0x0d */
+#define ESR_ELx_EC_BTI		(0x0D)
 #define ESR_ELx_EC_ILL		(0x0E)
 /* Unallocated EC: 0x0F - 0x10 */
 #define ESR_ELx_EC_SVC32	(0x11)
diff --git a/arch/arm64/include/asm/hwcap.h b/arch/arm64/include/asm/hwcap.h
index 3d2f247..f9e681d 100644
--- a/arch/arm64/include/asm/hwcap.h
+++ b/arch/arm64/include/asm/hwcap.h
@@ -86,6 +86,7 @@
 #define KERNEL_HWCAP_SVESM4		__khwcap2_feature(SVESM4)
 #define KERNEL_HWCAP_FLAGM2		__khwcap2_feature(FLAGM2)
 #define KERNEL_HWCAP_FRINT		__khwcap2_feature(FRINT)
+#define KERNEL_HWCAP_BTI		__khwcap2_feature(BTI)
 
 /*
  * This yields a mask that user programs can use to figure out what
diff --git a/arch/arm64/include/asm/mman.h b/arch/arm64/include/asm/mman.h
new file mode 100644
index 0000000..081ec8d
--- /dev/null
+++ b/arch/arm64/include/asm/mman.h
@@ -0,0 +1,37 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_MMAN_H__
+#define __ASM_MMAN_H__
+
+#include <linux/compiler.h>
+#include <linux/types.h>
+#include <uapi/asm/mman.h>
+
+static inline unsigned long arch_calc_vm_prot_bits(unsigned long prot,
+	unsigned long pkey __always_unused)
+{
+	if (system_supports_bti() && (prot & PROT_BTI))
+		return VM_ARM64_BTI;
+
+	return 0;
+}
+#define arch_calc_vm_prot_bits(prot, pkey) arch_calc_vm_prot_bits(prot, pkey)
+
+static inline pgprot_t arch_vm_get_page_prot(unsigned long vm_flags)
+{
+	return (vm_flags & VM_ARM64_BTI) ? __pgprot(PTE_GP) : __pgprot(0);
+}
+#define arch_vm_get_page_prot(vm_flags) arch_vm_get_page_prot(vm_flags)
+
+static inline bool arch_validate_prot(unsigned long prot,
+	unsigned long addr __always_unused)
+{
+	unsigned long supported = PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM;
+
+	if (system_supports_bti())
+		supported |= PROT_BTI;
+
+	return (prot & ~supported) == 0;
+}
+#define arch_validate_prot(prot, addr) arch_validate_prot(prot, addr)
+
+#endif /* ! __ASM_MMAN_H__ */
diff --git a/arch/arm64/include/asm/pgtable-hwdef.h b/arch/arm64/include/asm/pgtable-hwdef.h
index 3df60f9..f85d1fc 100644
--- a/arch/arm64/include/asm/pgtable-hwdef.h
+++ b/arch/arm64/include/asm/pgtable-hwdef.h
@@ -150,6 +150,7 @@
 #define PTE_SHARED		(_AT(pteval_t, 3) << 8)		/* SH[1:0], inner shareable */
 #define PTE_AF			(_AT(pteval_t, 1) << 10)	/* Access Flag */
 #define PTE_NG			(_AT(pteval_t, 1) << 11)	/* nG */
+#define PTE_GP			(_AT(pteval_t, 1) << 50)	/* BTI guarded */
 #define PTE_DBM			(_AT(pteval_t, 1) << 51)	/* Dirty Bit Management */
 #define PTE_CONT		(_AT(pteval_t, 1) << 52)	/* Contiguous range */
 #define PTE_PXN			(_AT(pteval_t, 1) << 53)	/* Privileged XN */
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 7576df0..a7b5a81 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -679,7 +679,7 @@ static inline phys_addr_t pgd_page_paddr(pgd_t pgd)
 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 {
 	const pteval_t mask = PTE_USER | PTE_PXN | PTE_UXN | PTE_RDONLY |
-			      PTE_PROT_NONE | PTE_VALID | PTE_WRITE;
+			      PTE_PROT_NONE | PTE_VALID | PTE_WRITE | PTE_GP;
 	/* preserve the hardware dirty information */
 	if (pte_hw_dirty(pte))
 		pte = pte_mkdirty(pte);
diff --git a/arch/arm64/include/asm/ptrace.h b/arch/arm64/include/asm/ptrace.h
index fbebb41..212bba1 100644
--- a/arch/arm64/include/asm/ptrace.h
+++ b/arch/arm64/include/asm/ptrace.h
@@ -35,8 +35,16 @@
 #define GIC_PRIO_PSR_I_SET		(1 << 4)
 
 /* Additional SPSR bits not exposed in the UABI */
+#define PSR_BTYPE_SHIFT		10
+
 #define PSR_IL_BIT		(1 << 20)
 
+/* Convenience names for the values of PSTATE.BTYPE */
+#define PSR_BTYPE_NONE		(0b00 << PSR_BTYPE_SHIFT)
+#define PSR_BTYPE_JC		(0b01 << PSR_BTYPE_SHIFT)
+#define PSR_BTYPE_C		(0b10 << PSR_BTYPE_SHIFT)
+#define PSR_BTYPE_J		(0b11 << PSR_BTYPE_SHIFT)
+
 /* AArch32-specific ptrace requests */
 #define COMPAT_PTRACE_GETREGS		12
 #define COMPAT_PTRACE_SETREGS		13
diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
index 972d196..58a5e5e 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h
@@ -510,6 +510,8 @@
 #endif
 
 /* SCTLR_EL1 specific flags. */
+#define SCTLR_EL1_BT1		(BIT(36))
+#define SCTLR_EL1_BT0		(BIT(35))
 #define SCTLR_EL1_UCI		(BIT(26))
 #define SCTLR_EL1_E0E		(BIT(24))
 #define SCTLR_EL1_SPAN		(BIT(23))
@@ -599,10 +601,12 @@
 
 /* id_aa64pfr1 */
 #define ID_AA64PFR1_SSBS_SHIFT		4
+#define ID_AA64PFR1_BT_SHIFT		0
 
 #define ID_AA64PFR1_SSBS_PSTATE_NI	0
 #define ID_AA64PFR1_SSBS_PSTATE_ONLY	1
 #define ID_AA64PFR1_SSBS_PSTATE_INSNS	2
+#define ID_AA64PFR1_BT_BTI		0x1
 
 /* id_aa64zfr0 */
 #define ID_AA64ZFR0_SM4_SHIFT		40
diff --git a/arch/arm64/include/uapi/asm/hwcap.h b/arch/arm64/include/uapi/asm/hwcap.h
index a1e7288..363f569 100644
--- a/arch/arm64/include/uapi/asm/hwcap.h
+++ b/arch/arm64/include/uapi/asm/hwcap.h
@@ -65,5 +65,6 @@
 #define HWCAP2_SVESM4		(1 << 6)
 #define HWCAP2_FLAGM2		(1 << 7)
 #define HWCAP2_FRINT		(1 << 8)
+#define HWCAP2_BTI		(1 << 9)
 
 #endif /* _UAPI__ASM_HWCAP_H */
diff --git a/arch/arm64/include/uapi/asm/mman.h b/arch/arm64/include/uapi/asm/mman.h
new file mode 100644
index 0000000..6fdd71e
--- /dev/null
+++ b/arch/arm64/include/uapi/asm/mman.h
@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef _UAPI__ASM_MMAN_H
+#define _UAPI__ASM_MMAN_H
+
+#include <asm-generic/mman.h>
+
+#define PROT_BTI	0x10		/* BTI guarded page */
+
+#endif /* ! _UAPI__ASM_MMAN_H */
diff --git a/arch/arm64/include/uapi/asm/ptrace.h b/arch/arm64/include/uapi/asm/ptrace.h
index 7ed9294..09e66fa 100644
--- a/arch/arm64/include/uapi/asm/ptrace.h
+++ b/arch/arm64/include/uapi/asm/ptrace.h
@@ -46,6 +46,7 @@
 #define PSR_I_BIT	0x00000080
 #define PSR_A_BIT	0x00000100
 #define PSR_D_BIT	0x00000200
+#define PSR_BTYPE_MASK	0x00000c00
 #define PSR_SSBS_BIT	0x00001000
 #define PSR_PAN_BIT	0x00400000
 #define PSR_UAO_BIT	0x00800000
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 9323bcc..4bab6e7 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -171,6 +171,8 @@ static const struct arm64_ftr_bits ftr_id_aa64pfr0[] = {
 
 static const struct arm64_ftr_bits ftr_id_aa64pfr1[] = {
 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_SSBS_SHIFT, 4, ID_AA64PFR1_SSBS_PSTATE_NI),
+	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_BTI),
+				    FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_BT_SHIFT, 4, 0),
 	ARM64_FTR_END,
 };
 
@@ -1260,6 +1262,21 @@ static bool can_use_gic_priorities(const struct arm64_cpu_capabilities *entry,
 }
 #endif
 
+#ifdef CONFIG_ARM64_BTI
+static void bti_enable(const struct arm64_cpu_capabilities *__unused)
+{
+	/*
+	 * Use of X16/X17 for tail-calls and trampolines that jump to
+	 * function entry points using BR is a requirement for
+	 * marking binaries with GNU_PROPERTY_AARCH64_FEATURE_1_BTI.
+	 * So, be strict and forbid other BRs using other registers to
+	 * jump onto a PACIxSP instruction:
+	 */
+	sysreg_clear_set(sctlr_el1, 0, SCTLR_EL1_BT0 | SCTLR_EL1_BT1);
+	isb();
+}
+#endif /* CONFIG_ARM64_BTI */
+
 static const struct arm64_cpu_capabilities arm64_features[] = {
 	{
 		.desc = "GIC system register CPU interface",
@@ -1560,6 +1577,19 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
 		.min_field_value = 1,
 	},
 #endif
+#ifdef CONFIG_ARM64_BTI
+	{
+		.desc = "Branch Target Identification",
+		.capability = ARM64_BTI,
+		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
+		.matches = has_cpuid_feature,
+		.cpu_enable = bti_enable,
+		.sys_reg = SYS_ID_AA64PFR1_EL1,
+		.field_pos = ID_AA64PFR1_BT_SHIFT,
+		.min_field_value = ID_AA64PFR1_BT_BTI,
+		.sign = FTR_UNSIGNED,
+	},
+#endif
 	{},
 };
 
@@ -1655,6 +1685,9 @@ static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = {
 	HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_SM4_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_SM4, CAP_HWCAP, KERNEL_HWCAP_SVESM4),
 #endif
 	HWCAP_CAP(SYS_ID_AA64PFR1_EL1, ID_AA64PFR1_SSBS_SHIFT, FTR_UNSIGNED, ID_AA64PFR1_SSBS_PSTATE_INSNS, CAP_HWCAP, KERNEL_HWCAP_SSBS),
+#ifdef CONFIG_ARM64_BTI
+	HWCAP_CAP(SYS_ID_AA64PFR1_EL1, ID_AA64PFR1_BT_SHIFT, FTR_UNSIGNED, ID_AA64PFR1_BT_BTI, CAP_HWCAP, KERNEL_HWCAP_BTI),
+#endif
 #ifdef CONFIG_ARM64_PTR_AUTH
 	HWCAP_MULTI_CAP(ptr_auth_hwcap_addr_matches, CAP_HWCAP, KERNEL_HWCAP_PACA),
 	HWCAP_MULTI_CAP(ptr_auth_hwcap_gen_matches, CAP_HWCAP, KERNEL_HWCAP_PACG),
diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c
index 05933c0..e1fd053 100644
--- a/arch/arm64/kernel/cpuinfo.c
+++ b/arch/arm64/kernel/cpuinfo.c
@@ -84,6 +84,7 @@ static const char *const hwcap_str[] = {
 	"svesm4",
 	"flagm2",
 	"frint",
+	"bti",
 	NULL
 };
 
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index 84a8227..6c5adea 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -737,6 +737,8 @@ el0_sync:
 	b.eq	el0_pc
 	cmp	x24, #ESR_ELx_EC_UNKNOWN	// unknown exception in EL0
 	b.eq	el0_undef
+	cmp	x24, #ESR_ELx_EC_BTI		// branch target exception
+	b.eq	el0_bti
 	cmp	x24, #ESR_ELx_EC_BREAKPT_LOW	// debug exception in EL0
 	b.ge	el0_dbg
 	b	el0_inv
@@ -887,6 +889,15 @@ el0_undef:
 	mov	x0, sp
 	bl	do_undefinstr
 	b	ret_to_user
+el0_bti:
+	/*
+	 * Branch target exception
+	 */
+	ct_user_exit_irqoff
+	enable_daif
+	mov	x0, sp
+	bl	do_bti
+	b	ret_to_user
 el0_sys:
 	/*
 	 * System instructions, for trapped cache maintenance instructions
diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c
index 21176d0..ff5ea70 100644
--- a/arch/arm64/kernel/ptrace.c
+++ b/arch/arm64/kernel/ptrace.c
@@ -1853,7 +1853,7 @@ void syscall_trace_exit(struct pt_regs *regs)
  */
 #define SPSR_EL1_AARCH64_RES0_BITS \
 	(GENMASK_ULL(63, 32) | GENMASK_ULL(27, 25) | GENMASK_ULL(23, 22) | \
-	 GENMASK_ULL(20, 13) | GENMASK_ULL(11, 10) | GENMASK_ULL(5, 5))
+	 GENMASK_ULL(20, 13) | GENMASK_ULL(5, 5))
 #define SPSR_EL1_AARCH32_RES0_BITS \
 	(GENMASK_ULL(63, 32) | GENMASK_ULL(22, 22) | GENMASK_ULL(20, 20))
 
diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c
index dd2cdc0..b089eff 100644
--- a/arch/arm64/kernel/signal.c
+++ b/arch/arm64/kernel/signal.c
@@ -730,6 +730,22 @@ static void setup_return(struct pt_regs *regs, struct k_sigaction *ka,
 	regs->regs[29] = (unsigned long)&user->next_frame->fp;
 	regs->pc = (unsigned long)ka->sa.sa_handler;
 
+	/*
+	 * Signal delivery is a (wacky) indirect function call in
+	 * userspace, so simulate the same setting of BTYPE as a BLR
+	 * <register containing the signal handler entry point>.
+	 * Signal delivery to a location in a PROT_BTI guarded page
+	 * that is not a function entry point will now trigger a
+	 * SIGILL in userspace.
+	 *
+	 * If the signal handler entry point is not in a PROT_BTI
+	 * guarded page, this is harmless.
+	 */
+	if (system_supports_bti()) {
+		regs->pstate &= ~PSR_BTYPE_MASK;
+		regs->pstate |= PSR_BTYPE_C;
+	}
+
 	if (ka->sa.sa_flags & SA_RESTORER)
 		sigtramp = ka->sa.sa_restorer;
 	else
diff --git a/arch/arm64/kernel/syscall.c b/arch/arm64/kernel/syscall.c
index 871c739..b6b8e48 100644
--- a/arch/arm64/kernel/syscall.c
+++ b/arch/arm64/kernel/syscall.c
@@ -98,6 +98,24 @@ static void el0_svc_common(struct pt_regs *regs, int scno, int sc_nr,
 	regs->orig_x0 = regs->regs[0];
 	regs->syscallno = scno;
 
+	/*
+	 * BTI note:
+	 * The architecture does not guarantee that SPSR.BTYPE is zero
+	 * on taking an SVC, so we could return to userspace with a
+	 * non-zero BTYPE after the syscall.
+	 *
+	 * This shouldn't matter except when userspace is explicitly
+	 * doing something stupid, such as setting PROT_BTI on a page
+	 * that lacks conforming BTI/PACIxSP instructions, falling
+	 * through from one executable page to another with differing
+	 * PROT_BTI, or messing with BYTPE via ptrace: in such cases,
+	 * userspace should not be surprised if a SIGILL occurs on
+	 * syscall return.
+	 *
+	 * So, don't touch regs->pstate & PSR_BTYPE_MASK here.
+	 * (Similarly for HVC and SMC elsewhere.)
+	 */
+
 	cortex_a76_erratum_1463225_svc_handler();
 	local_daif_restore(DAIF_PROCCTX);
 	user_exit();
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index 34739e8..15e3c4f 100644
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -406,6 +406,12 @@ asmlinkage void __exception do_undefinstr(struct pt_regs *regs)
 	force_signal_inject(SIGILL, ILL_ILLOPC, regs->pc);
 }
 
+asmlinkage void __exception do_bti(struct pt_regs *regs)
+{
+	BUG_ON(!user_mode(regs));
+	force_signal_inject(SIGILL, ILL_ILLOPC, regs->pc);
+}
+
 #define __user_cache_maint(insn, address, res)			\
 	if (address >= user_addr_max()) {			\
 		res = -EFAULT;					\
@@ -737,6 +743,7 @@ static const char *esr_class_str[] = {
 	[ESR_ELx_EC_CP10_ID]		= "CP10 MRC/VMRS",
 	[ESR_ELx_EC_PAC]		= "PAC",
 	[ESR_ELx_EC_CP14_64]		= "CP14 MCRR/MRRC",
+	[ESR_ELx_EC_BTI]		= "BTI",
 	[ESR_ELx_EC_ILL]		= "PSTATE.IL",
 	[ESR_ELx_EC_SVC32]		= "SVC (AArch32)",
 	[ESR_ELx_EC_HVC32]		= "HVC (AArch32)",
diff --git a/include/linux/mm.h b/include/linux/mm.h
index cc29227..5ed5a99 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -329,6 +329,9 @@ extern unsigned int kobjsize(const void *objp);
 #elif defined(CONFIG_SPARC64)
 # define VM_SPARC_ADI	VM_ARCH_1	/* Uses ADI tag for access control */
 # define VM_ARCH_CLEAR	VM_SPARC_ADI
+#elif defined(CONFIG_ARM64)
+# define VM_ARM64_BTI	VM_ARCH_1	/* BTI guarded page, a.k.a. GP bit */
+# define VM_ARCH_CLEAR	VM_ARM64_BTI
 #elif !defined(CONFIG_MMU)
 # define VM_MAPPED_COPY	VM_ARCH_1	/* T if mapped copy of data (nommu mmap) */
 #endif
