diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h
index 711f64fa1aa04428a571f58773fe17603d400f6b..24dcda5c287455995fa7bfeab72aee8774c65db6 100644
--- a/arch/arm64/include/asm/cpufeature.h
+++ b/arch/arm64/include/asm/cpufeature.h
@@ -782,7 +782,8 @@ static inline bool system_supports_pbha(void)
 }
 #endif
 
-extern int do_emulate_mrs(struct pt_regs *regs, u32 sys_reg, u32 rt);
+int do_emulate_mrs(struct pt_regs *regs, u32 sys_reg, u32 rt);
+bool try_emulate_mrs(struct pt_regs *regs, u32 isn);
 
 static inline u32 id_aa64mmfr0_parange_to_phys_shift(int parange)
 {
diff --git a/arch/arm64/include/asm/exception.h b/arch/arm64/include/asm/exception.h
index 0756191f44f644b9a3153dd584cda74ecc75dd4e..861c03988b24933628388a00e3ea3f951d198ced 100644
--- a/arch/arm64/include/asm/exception.h
+++ b/arch/arm64/include/asm/exception.h
@@ -38,19 +38,22 @@ asmlinkage void exit_to_user_mode(void);
 void arm64_enter_nmi(struct pt_regs *regs);
 void arm64_exit_nmi(struct pt_regs *regs);
 void do_mem_abort(unsigned long addr, unsigned int esr, struct pt_regs *regs);
-void do_undefinstr(struct pt_regs *regs);
-void do_bti(struct pt_regs *regs);
+void do_el0_undef(struct pt_regs *regs, unsigned long esr);
+void do_el1_undef(struct pt_regs *regs, unsigned long esr);
+void do_el0_bti(struct pt_regs *regs);
+void do_el1_bti(struct pt_regs *regs, unsigned long esr);
 asmlinkage void bad_mode(struct pt_regs *regs, int reason, unsigned int esr);
 void do_debug_exception(unsigned long addr_if_watchpoint, unsigned int esr,
 			struct pt_regs *regs);
 void do_fpsimd_acc(unsigned int esr, struct pt_regs *regs);
 void do_sve_acc(unsigned int esr, struct pt_regs *regs);
 void do_fpsimd_exc(unsigned int esr, struct pt_regs *regs);
-void do_sysinstr(unsigned int esr, struct pt_regs *regs);
+void do_el0_sys(unsigned long esr, struct pt_regs *regs);
 void do_sp_pc_abort(unsigned long addr, unsigned int esr, struct pt_regs *regs);
 void bad_el0_sync(struct pt_regs *regs, int reason, unsigned int esr);
-void do_cp15instr(unsigned int esr, struct pt_regs *regs);
+void do_el0_cp15(unsigned long esr, struct pt_regs *regs);
 void do_el0_svc(struct pt_regs *regs);
 void do_el0_svc_compat(struct pt_regs *regs);
-void do_ptrauth_fault(struct pt_regs *regs, unsigned int esr);
+void do_el0_fpac(struct pt_regs *regs, unsigned long esr);
+void do_el1_fpac(struct pt_regs *regs, unsigned long esr);
 #endif	/* __ASM_EXCEPTION_H */
diff --git a/arch/arm64/include/asm/spectre.h b/arch/arm64/include/asm/spectre.h
index 4b3a5f050f71f946f8a8143733b99b1ee2ef75db..e48afcb69392b0b8484521a186fd58199ec6f71e 100644
--- a/arch/arm64/include/asm/spectre.h
+++ b/arch/arm64/include/asm/spectre.h
@@ -18,6 +18,7 @@ enum mitigation_state {
 	SPECTRE_VULNERABLE,
 };
 
+struct pt_regs;
 struct task_struct;
 
 enum mitigation_state arm64_get_spectre_v2_state(void);
@@ -33,4 +34,5 @@ enum mitigation_state arm64_get_spectre_bhb_state(void);
 bool is_spectre_bhb_affected(const struct arm64_cpu_capabilities *entry, int scope);
 u8 spectre_bhb_loop_affected(int scope);
 void spectre_bhb_enable_mitigation(const struct arm64_cpu_capabilities *__unused);
+bool try_emulate_el1_ssbs(struct pt_regs *regs, u32 instr);
 #endif	/* __ASM_SPECTRE_H */
diff --git a/arch/arm64/include/asm/system_misc.h b/arch/arm64/include/asm/system_misc.h
index 1ab63cfbbaf178df5b1e73dd832f81661d883f27..624a608933f139faa628d244d1643f47547ceb67 100644
--- a/arch/arm64/include/asm/system_misc.h
+++ b/arch/arm64/include/asm/system_misc.h
@@ -18,7 +18,7 @@
 
 struct pt_regs;
 
-void die(const char *msg, struct pt_regs *regs, int err);
+void die(const char *msg, struct pt_regs *regs, long err);
 
 struct siginfo;
 void arm64_notify_die(const char *str, struct pt_regs *regs,
diff --git a/arch/arm64/include/asm/traps.h b/arch/arm64/include/asm/traps.h
index d96dc2c7c09dab0320b12c0624f68fcd72dd4b8b..ca8f19956b92b15bc6d957eced4a5c3986487d59 100644
--- a/arch/arm64/include/asm/traps.h
+++ b/arch/arm64/include/asm/traps.h
@@ -13,17 +13,16 @@
 
 struct pt_regs;
 
-struct undef_hook {
-	struct list_head node;
-	u32 instr_mask;
-	u32 instr_val;
-	u64 pstate_mask;
-	u64 pstate_val;
-	int (*fn)(struct pt_regs *regs, u32 instr);
-};
+#ifdef CONFIG_ARMV8_DEPRECATED
+bool try_emulate_armv8_deprecated(struct pt_regs *regs, u32 insn);
+#else
+static inline bool
+try_emulate_armv8_deprecated(struct pt_regs *regs, u32 insn)
+{
+	return false;
+}
+#endif /* CONFIG_ARMV8_DEPRECATED */
 
-void register_undef_hook(struct undef_hook *hook);
-void unregister_undef_hook(struct undef_hook *hook);
 void force_signal_inject(int signal, int code, unsigned long address, unsigned int err);
 void arm64_notify_segfault(unsigned long addr);
 void arm64_force_sig_fault(int signo, int code, void __user *addr, const char *str);
diff --git a/arch/arm64/kernel/armv8_deprecated.c b/arch/arm64/kernel/armv8_deprecated.c
index ab955c249f370b490a93b03737d1b53e1034373f..637e57a4868ec9fd74e3bd021f70aeb9cf8dc527 100644
--- a/arch/arm64/kernel/armv8_deprecated.c
+++ b/arch/arm64/kernel/armv8_deprecated.c
@@ -17,7 +17,6 @@
 #include <asm/sysreg.h>
 #include <asm/system_misc.h>
 #include <asm/traps.h>
-#include <asm/kprobes.h>
 
 #define CREATE_TRACE_POINTS
 #include "trace-events-emulation.h"
@@ -39,228 +38,46 @@ enum insn_emulation_mode {
 enum legacy_insn_status {
 	INSN_DEPRECATED,
 	INSN_OBSOLETE,
-};
-
-struct insn_emulation_ops {
-	const char		*name;
-	enum legacy_insn_status	status;
-	struct undef_hook	*hooks;
-	int			(*set_hw_mode)(bool enable);
+	INSN_UNAVAILABLE,
 };
 
 struct insn_emulation {
-	struct list_head node;
-	struct insn_emulation_ops *ops;
+	const char			*name;
+	enum legacy_insn_status		status;
+	bool				(*try_emulate)(struct pt_regs *regs,
+						       u32 insn);
+	int				(*set_hw_mode)(bool enable);
+
 	int current_mode;
 	int min;
 	int max;
-};
-
-static LIST_HEAD(insn_emulation);
-static int nr_insn_emulated __initdata;
-static DEFINE_RAW_SPINLOCK(insn_emulation_lock);
-static DEFINE_MUTEX(insn_emulation_mutex);
-
-static void register_emulation_hooks(struct insn_emulation_ops *ops)
-{
-	struct undef_hook *hook;
-
-	BUG_ON(!ops->hooks);
-
-	for (hook = ops->hooks; hook->instr_mask; hook++)
-		register_undef_hook(hook);
-
-	pr_notice("Registered %s emulation handler\n", ops->name);
-}
-
-static void remove_emulation_hooks(struct insn_emulation_ops *ops)
-{
-	struct undef_hook *hook;
-
-	BUG_ON(!ops->hooks);
-
-	for (hook = ops->hooks; hook->instr_mask; hook++)
-		unregister_undef_hook(hook);
-
-	pr_notice("Removed %s emulation handler\n", ops->name);
-}
-
-static void enable_insn_hw_mode(void *data)
-{
-	struct insn_emulation *insn = (struct insn_emulation *)data;
-	if (insn->ops->set_hw_mode)
-		insn->ops->set_hw_mode(true);
-}
-
-static void disable_insn_hw_mode(void *data)
-{
-	struct insn_emulation *insn = (struct insn_emulation *)data;
-	if (insn->ops->set_hw_mode)
-		insn->ops->set_hw_mode(false);
-}
-
-/* Run set_hw_mode(mode) on all active CPUs */
-static int run_all_cpu_set_hw_mode(struct insn_emulation *insn, bool enable)
-{
-	if (!insn->ops->set_hw_mode)
-		return -EINVAL;
-	if (enable)
-		on_each_cpu(enable_insn_hw_mode, (void *)insn, true);
-	else
-		on_each_cpu(disable_insn_hw_mode, (void *)insn, true);
-	return 0;
-}
-
-/*
- * Run set_hw_mode for all insns on a starting CPU.
- * Returns:
- *  0 		- If all the hooks ran successfully.
- * -EINVAL	- At least one hook is not supported by the CPU.
- */
-static int run_all_insn_set_hw_mode(unsigned int cpu)
-{
-	int rc = 0;
-	unsigned long flags;
-	struct insn_emulation *insn;
-
-	raw_spin_lock_irqsave(&insn_emulation_lock, flags);
-	list_for_each_entry(insn, &insn_emulation, node) {
-		bool enable = (insn->current_mode == INSN_HW);
-		if (insn->ops->set_hw_mode && insn->ops->set_hw_mode(enable)) {
-			pr_warn("CPU[%u] cannot support the emulation of %s",
-				cpu, insn->ops->name);
-			rc = -EINVAL;
-		}
-	}
-	raw_spin_unlock_irqrestore(&insn_emulation_lock, flags);
-	return rc;
-}
-
-static int update_insn_emulation_mode(struct insn_emulation *insn,
-				       enum insn_emulation_mode prev)
-{
-	int ret = 0;
-
-	switch (prev) {
-	case INSN_UNDEF: /* Nothing to be done */
-		break;
-	case INSN_EMULATE:
-		remove_emulation_hooks(insn->ops);
-		break;
-	case INSN_HW:
-		if (!run_all_cpu_set_hw_mode(insn, false))
-			pr_notice("Disabled %s support\n", insn->ops->name);
-		break;
-	}
-
-	switch (insn->current_mode) {
-	case INSN_UNDEF:
-		break;
-	case INSN_EMULATE:
-		register_emulation_hooks(insn->ops);
-		break;
-	case INSN_HW:
-		ret = run_all_cpu_set_hw_mode(insn, true);
-		if (!ret)
-			pr_notice("Enabled %s support\n", insn->ops->name);
-		break;
-	}
-
-	return ret;
-}
 
-static void __init register_insn_emulation(struct insn_emulation_ops *ops)
-{
-	unsigned long flags;
-	struct insn_emulation *insn;
-
-	insn = kzalloc(sizeof(*insn), GFP_KERNEL);
-	if (!insn)
-		return;
-
-	insn->ops = ops;
-	insn->min = INSN_UNDEF;
-
-	switch (ops->status) {
-	case INSN_DEPRECATED:
-		insn->current_mode = INSN_EMULATE;
-		/* Disable the HW mode if it was turned on at early boot time */
-		run_all_cpu_set_hw_mode(insn, false);
-		insn->max = INSN_HW;
-		break;
-	case INSN_OBSOLETE:
-		insn->current_mode = INSN_UNDEF;
-		insn->max = INSN_EMULATE;
-		break;
-	}
-
-	raw_spin_lock_irqsave(&insn_emulation_lock, flags);
-	list_add(&insn->node, &insn_emulation);
-	nr_insn_emulated++;
-	raw_spin_unlock_irqrestore(&insn_emulation_lock, flags);
-
-	/* Register any handlers if required */
-	update_insn_emulation_mode(insn, INSN_UNDEF);
-}
-
-static int emulation_proc_handler(struct ctl_table *table, int write,
-				  void *buffer, size_t *lenp,
-				  loff_t *ppos)
-{
-	int ret = 0;
-	struct insn_emulation *insn;
-	enum insn_emulation_mode prev_mode;
-
-	mutex_lock(&insn_emulation_mutex);
-	insn = container_of(table->data, struct insn_emulation, current_mode);
-	prev_mode = insn->current_mode;
-	ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
+	/*
+	 * sysctl for this emulation + a sentinal entry.
+	 */
+	struct ctl_table sysctl[2];
+};
 
-	if (ret || !write || prev_mode == insn->current_mode)
-		goto ret;
+#define ARM_OPCODE_CONDTEST_FAIL   0
+#define ARM_OPCODE_CONDTEST_PASS   1
+#define ARM_OPCODE_CONDTEST_UNCOND 2
 
-	ret = update_insn_emulation_mode(insn, prev_mode);
-	if (ret) {
-		/* Mode change failed, revert to previous mode. */
-		insn->current_mode = prev_mode;
-		update_insn_emulation_mode(insn, INSN_UNDEF);
-	}
-ret:
-	mutex_unlock(&insn_emulation_mutex);
-	return ret;
-}
+#define	ARM_OPCODE_CONDITION_UNCOND	0xf
 
-static void __init register_insn_emulation_sysctl(void)
+static unsigned int __maybe_unused aarch32_check_condition(u32 opcode, u32 psr)
 {
-	unsigned long flags;
-	int i = 0;
-	struct insn_emulation *insn;
-	struct ctl_table *insns_sysctl, *sysctl;
-
-	insns_sysctl = kcalloc(nr_insn_emulated + 1, sizeof(*sysctl),
-			       GFP_KERNEL);
-	if (!insns_sysctl)
-		return;
-
-	raw_spin_lock_irqsave(&insn_emulation_lock, flags);
-	list_for_each_entry(insn, &insn_emulation, node) {
-		sysctl = &insns_sysctl[i];
-
-		sysctl->mode = 0644;
-		sysctl->maxlen = sizeof(int);
+	u32 cc_bits  = opcode >> 28;
 
-		sysctl->procname = insn->ops->name;
-		sysctl->data = &insn->current_mode;
-		sysctl->extra1 = &insn->min;
-		sysctl->extra2 = &insn->max;
-		sysctl->proc_handler = emulation_proc_handler;
-		i++;
+	if (cc_bits != ARM_OPCODE_CONDITION_UNCOND) {
+		if ((*aarch32_opcode_cond_checks[cc_bits])(psr))
+			return ARM_OPCODE_CONDTEST_PASS;
+		else
+			return ARM_OPCODE_CONDTEST_FAIL;
 	}
-	raw_spin_unlock_irqrestore(&insn_emulation_lock, flags);
-
-	register_sysctl("abi", insns_sysctl);
+	return ARM_OPCODE_CONDTEST_UNCOND;
 }
 
+#ifdef CONFIG_SWP_EMULATION
 /*
  *  Implement emulation of the SWP/SWPB instructions using load-exclusive and
  *  store-exclusive.
@@ -347,25 +164,6 @@ static int emulate_swpX(unsigned int address, unsigned int *data,
 	return res;
 }
 
-#define ARM_OPCODE_CONDTEST_FAIL   0
-#define ARM_OPCODE_CONDTEST_PASS   1
-#define ARM_OPCODE_CONDTEST_UNCOND 2
-
-#define	ARM_OPCODE_CONDITION_UNCOND	0xf
-
-static unsigned int __kprobes aarch32_check_condition(u32 opcode, u32 psr)
-{
-	u32 cc_bits  = opcode >> 28;
-
-	if (cc_bits != ARM_OPCODE_CONDITION_UNCOND) {
-		if ((*aarch32_opcode_cond_checks[cc_bits])(psr))
-			return ARM_OPCODE_CONDTEST_PASS;
-		else
-			return ARM_OPCODE_CONDTEST_FAIL;
-	}
-	return ARM_OPCODE_CONDTEST_UNCOND;
-}
-
 /*
  * swp_handler logs the id of calling process, dissects the instruction, sanity
  * checks the memory location, calls emulate_swpX for the actual operation and
@@ -438,28 +236,27 @@ static int swp_handler(struct pt_regs *regs, u32 instr)
 	return 0;
 }
 
-/*
- * Only emulate SWP/SWPB executed in ARM state/User mode.
- * The kernel must be SWP free and SWP{B} does not exist in Thumb.
- */
-static struct undef_hook swp_hooks[] = {
-	{
-		.instr_mask	= 0x0fb00ff0,
-		.instr_val	= 0x01000090,
-		.pstate_mask	= PSR_AA32_MODE_MASK,
-		.pstate_val	= PSR_AA32_MODE_USR,
-		.fn		= swp_handler
-	},
-	{ }
-};
+static bool try_emulate_swp(struct pt_regs *regs, u32 insn)
+{
+	/* SWP{B} only exists in ARM state and does not exist in Thumb */
+	if (!a32_user_mode(regs) || a32_thumb_mode(regs))
+		return false;
+
+	if ((insn & 0x0fb00ff0) != 0x01000090)
+		return false;
+
+	return swp_handler(regs, insn) == 0;
+}
 
-static struct insn_emulation_ops swp_ops = {
+static struct insn_emulation insn_swp = {
 	.name = "swp",
 	.status = INSN_OBSOLETE,
-	.hooks = swp_hooks,
+	.try_emulate = try_emulate_swp,
 	.set_hw_mode = NULL,
 };
+#endif /* CONFIG_SWP_EMULATION */
 
+#ifdef CONFIG_CP15_BARRIER_EMULATION
 static int cp15barrier_handler(struct pt_regs *regs, u32 instr)
 {
 	perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, regs->pc);
@@ -522,31 +319,29 @@ static int cp15_barrier_set_hw_mode(bool enable)
 	return 0;
 }
 
-static struct undef_hook cp15_barrier_hooks[] = {
-	{
-		.instr_mask	= 0x0fff0fdf,
-		.instr_val	= 0x0e070f9a,
-		.pstate_mask	= PSR_AA32_MODE_MASK,
-		.pstate_val	= PSR_AA32_MODE_USR,
-		.fn		= cp15barrier_handler,
-	},
-	{
-		.instr_mask	= 0x0fff0fff,
-		.instr_val	= 0x0e070f95,
-		.pstate_mask	= PSR_AA32_MODE_MASK,
-		.pstate_val	= PSR_AA32_MODE_USR,
-		.fn		= cp15barrier_handler,
-	},
-	{ }
-};
+static bool try_emulate_cp15_barrier(struct pt_regs *regs, u32 insn)
+{
+	if (!a32_user_mode(regs) || a32_thumb_mode(regs))
+		return false;
+
+	if ((insn & 0x0fff0fdf) == 0x0e070f9a)
+		return cp15barrier_handler(regs, insn) == 0;
+
+	if ((insn & 0x0fff0fff) == 0x0e070f95)
+		return cp15barrier_handler(regs, insn) == 0;
+
+	return false;
+}
 
-static struct insn_emulation_ops cp15_barrier_ops = {
+static struct insn_emulation insn_cp15_barrier = {
 	.name = "cp15_barrier",
 	.status = INSN_DEPRECATED,
-	.hooks = cp15_barrier_hooks,
+	.try_emulate = try_emulate_cp15_barrier,
 	.set_hw_mode = cp15_barrier_set_hw_mode,
 };
+#endif /* CONFIG_CP15_BARRIER_EMULATION */
 
+#ifdef CONFIG_SETEND_EMULATION
 static int setend_set_hw_mode(bool enable)
 {
 	if (!cpu_supports_mixed_endian_el0())
@@ -594,31 +389,221 @@ static int t16_setend_handler(struct pt_regs *regs, u32 instr)
 	return rc;
 }
 
-static struct undef_hook setend_hooks[] = {
-	{
-		.instr_mask	= 0xfffffdff,
-		.instr_val	= 0xf1010000,
-		.pstate_mask	= PSR_AA32_MODE_MASK,
-		.pstate_val	= PSR_AA32_MODE_USR,
-		.fn		= a32_setend_handler,
-	},
-	{
-		/* Thumb mode */
-		.instr_mask	= 0xfffffff7,
-		.instr_val	= 0x0000b650,
-		.pstate_mask	= (PSR_AA32_T_BIT | PSR_AA32_MODE_MASK),
-		.pstate_val	= (PSR_AA32_T_BIT | PSR_AA32_MODE_USR),
-		.fn		= t16_setend_handler,
-	},
-	{}
-};
+static bool try_emulate_setend(struct pt_regs *regs, u32 insn)
+{
+	if (a32_thumb_mode(regs) &&
+	    (insn & 0xfffffff7) == 0x0000b650)
+		return t16_setend_handler(regs, insn) == 0;
 
-static struct insn_emulation_ops setend_ops = {
+	if (a32_user_mode(regs) &&
+	    (insn & 0xfffffdff) == 0xf1010000)
+		return a32_setend_handler(regs, insn) == 0;
+
+	return false;
+}
+
+static struct insn_emulation insn_setend = {
 	.name = "setend",
 	.status = INSN_DEPRECATED,
-	.hooks = setend_hooks,
+	.try_emulate = try_emulate_setend,
 	.set_hw_mode = setend_set_hw_mode,
 };
+#endif /* CONFIG_SETEND_EMULATION */
+
+static struct insn_emulation *insn_emulations[] = {
+#ifdef CONFIG_SWP_EMULATION
+	&insn_swp,
+#endif
+#ifdef CONFIG_CP15_BARRIER_EMULATION
+	&insn_cp15_barrier,
+#endif
+#ifdef CONFIG_SETEND_EMULATION
+	&insn_setend,
+#endif
+};
+
+static DEFINE_MUTEX(insn_emulation_mutex);
+
+static void enable_insn_hw_mode(void *data)
+{
+	struct insn_emulation *insn = (struct insn_emulation *)data;
+	if (insn->set_hw_mode)
+		insn->set_hw_mode(true);
+}
+
+static void disable_insn_hw_mode(void *data)
+{
+	struct insn_emulation *insn = (struct insn_emulation *)data;
+	if (insn->set_hw_mode)
+		insn->set_hw_mode(false);
+}
+
+/* Run set_hw_mode(mode) on all active CPUs */
+static int run_all_cpu_set_hw_mode(struct insn_emulation *insn, bool enable)
+{
+	if (!insn->set_hw_mode)
+		return -EINVAL;
+	if (enable)
+		on_each_cpu(enable_insn_hw_mode, (void *)insn, true);
+	else
+		on_each_cpu(disable_insn_hw_mode, (void *)insn, true);
+	return 0;
+}
+
+/*
+ * Run set_hw_mode for all insns on a starting CPU.
+ * Returns:
+ *  0 		- If all the hooks ran successfully.
+ * -EINVAL	- At least one hook is not supported by the CPU.
+ */
+static int run_all_insn_set_hw_mode(unsigned int cpu)
+{
+	int i;
+	int rc = 0;
+	unsigned long flags;
+
+	/*
+	 * Disable IRQs to serialize against an IPI from
+	 * run_all_cpu_set_hw_mode(), ensuring the HW is programmed to the most
+	 * recent enablement state if the two race with one another.
+	 */
+	local_irq_save(flags);
+	for (i = 0; i < ARRAY_SIZE(insn_emulations); i++) {
+		struct insn_emulation *insn = insn_emulations[i];
+		bool enable = READ_ONCE(insn->current_mode) == INSN_HW;
+		if (insn->set_hw_mode && insn->set_hw_mode(enable)) {
+			pr_warn("CPU[%u] cannot support the emulation of %s",
+				cpu, insn->name);
+			rc = -EINVAL;
+		}
+	}
+	local_irq_restore(flags);
+
+	return rc;
+}
+
+static int update_insn_emulation_mode(struct insn_emulation *insn,
+				       enum insn_emulation_mode prev)
+{
+	int ret = 0;
+
+	switch (prev) {
+	case INSN_UNDEF: /* Nothing to be done */
+		break;
+	case INSN_EMULATE:
+		break;
+	case INSN_HW:
+		if (!run_all_cpu_set_hw_mode(insn, false))
+			pr_notice("Disabled %s support\n", insn->name);
+		break;
+	}
+
+	switch (insn->current_mode) {
+	case INSN_UNDEF:
+		break;
+	case INSN_EMULATE:
+		break;
+	case INSN_HW:
+		ret = run_all_cpu_set_hw_mode(insn, true);
+		if (!ret)
+			pr_notice("Enabled %s support\n", insn->name);
+		break;
+	}
+
+	return ret;
+}
+
+static int emulation_proc_handler(struct ctl_table *table, int write,
+				  void *buffer, size_t *lenp,
+				  loff_t *ppos)
+{
+	int ret = 0;
+	struct insn_emulation *insn = container_of(table->data, struct insn_emulation, current_mode);
+	enum insn_emulation_mode prev_mode = insn->current_mode;
+
+	mutex_lock(&insn_emulation_mutex);
+	ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
+
+	if (ret || !write || prev_mode == insn->current_mode)
+		goto ret;
+
+	ret = update_insn_emulation_mode(insn, prev_mode);
+	if (ret) {
+		/* Mode change failed, revert to previous mode. */
+		WRITE_ONCE(insn->current_mode, prev_mode);
+		update_insn_emulation_mode(insn, INSN_UNDEF);
+	}
+ret:
+	mutex_unlock(&insn_emulation_mutex);
+	return ret;
+}
+
+static void __init register_insn_emulation(struct insn_emulation *insn)
+{
+	struct ctl_table *sysctl;
+
+	insn->min = INSN_UNDEF;
+
+	switch (insn->status) {
+	case INSN_DEPRECATED:
+		insn->current_mode = INSN_EMULATE;
+		/* Disable the HW mode if it was turned on at early boot time */
+		run_all_cpu_set_hw_mode(insn, false);
+		insn->max = INSN_HW;
+		break;
+	case INSN_OBSOLETE:
+		insn->current_mode = INSN_UNDEF;
+		insn->max = INSN_EMULATE;
+		break;
+	case INSN_UNAVAILABLE:
+		insn->current_mode = INSN_UNDEF;
+		insn->max = INSN_UNDEF;
+		break;
+	}
+
+	/* Program the HW if required */
+	update_insn_emulation_mode(insn, INSN_UNDEF);
+
+	if (insn->status != INSN_UNAVAILABLE) {
+		sysctl = &insn->sysctl[0];
+
+		sysctl->mode = 0644;
+		sysctl->maxlen = sizeof(int);
+
+		sysctl->procname = insn->name;
+		sysctl->data = &insn->current_mode;
+		sysctl->extra1 = &insn->min;
+		sysctl->extra2 = &insn->max;
+		sysctl->proc_handler = emulation_proc_handler;
+
+		register_sysctl("abi", sysctl);
+	}
+}
+
+bool try_emulate_armv8_deprecated(struct pt_regs *regs, u32 insn)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(insn_emulations); i++) {
+		struct insn_emulation *ie = insn_emulations[i];
+
+		if (ie->status == INSN_UNAVAILABLE)
+			continue;
+
+		/*
+		 * A trap may race with the mode being changed
+		 * INSN_EMULATE<->INSN_HW. Try to emulate the instruction to
+		 * avoid a spurious UNDEF.
+		 */
+		if (READ_ONCE(ie->current_mode) == INSN_UNDEF)
+			continue;
+
+		if (ie->try_emulate(regs, insn))
+			return true;
+	}
+
+	return false;
+}
 
 /*
  * Invoked as core_initcall, which guarantees that the instruction
@@ -626,24 +611,27 @@ static struct insn_emulation_ops setend_ops = {
  */
 static int __init armv8_deprecated_init(void)
 {
-	if (IS_ENABLED(CONFIG_SWP_EMULATION))
-		register_insn_emulation(&swp_ops);
+	int i;
 
-	if (IS_ENABLED(CONFIG_CP15_BARRIER_EMULATION))
-		register_insn_emulation(&cp15_barrier_ops);
+#ifdef CONFIG_SETEND_EMULATION
+	if (!system_supports_mixed_endian_el0()) {
+		insn_setend.status = INSN_UNAVAILABLE;
+		pr_info("setend instruction emulation is not supported on this system\n");
+	}
 
-	if (IS_ENABLED(CONFIG_SETEND_EMULATION)) {
-		if (system_supports_mixed_endian_el0())
-			register_insn_emulation(&setend_ops);
-		else
-			pr_info("setend instruction emulation is not supported on this system\n");
+#endif
+	for (i = 0; i < ARRAY_SIZE(insn_emulations); i++) {
+		struct insn_emulation *ie = insn_emulations[i];
+
+		if (ie->status == INSN_UNAVAILABLE)
+			continue;
+
+		register_insn_emulation(ie);
 	}
 
 	cpuhp_setup_state_nocalls(CPUHP_AP_ARM64_ISNDEP_STARTING,
 				  "arm64/isndep:starting",
 				  run_all_insn_set_hw_mode, NULL);
-	register_insn_emulation_sysctl();
-
 	return 0;
 }
 
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 97744503704d077a8f965f6d300340cb1fd312b7..22eb4b53f5dd6db28d872d2775cc5b3d6ef1f6b5 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -3232,35 +3232,22 @@ int do_emulate_mrs(struct pt_regs *regs, u32 sys_reg, u32 rt)
 	return rc;
 }
 
-static int emulate_mrs(struct pt_regs *regs, u32 insn)
+bool try_emulate_mrs(struct pt_regs *regs, u32 insn)
 {
 	u32 sys_reg, rt;
 
+	if (compat_user_mode(regs) || !aarch64_insn_is_mrs(insn))
+		return false;
+
 	/*
 	 * sys_reg values are defined as used in mrs/msr instruction.
 	 * shift the imm value to get the encoding.
 	 */
 	sys_reg = (u32)aarch64_insn_decode_immediate(AARCH64_INSN_IMM_16, insn) << 5;
 	rt = aarch64_insn_decode_register(AARCH64_INSN_REGTYPE_RT, insn);
-	return do_emulate_mrs(regs, sys_reg, rt);
+	return do_emulate_mrs(regs, sys_reg, rt) == 0;
 }
 
-static struct undef_hook mrs_hook = {
-	.instr_mask = 0xfff00000,
-	.instr_val  = 0xd5300000,
-	.pstate_mask = PSR_AA32_MODE_MASK,
-	.pstate_val = PSR_MODE_EL0t,
-	.fn = emulate_mrs,
-};
-
-static int __init enable_mrs_emulation(void)
-{
-	register_undef_hook(&mrs_hook);
-	return 0;
-}
-
-core_initcall(enable_mrs_emulation);
-
 ssize_t cpu_show_meltdown(struct device *dev, struct device_attribute *attr,
 			  char *buf)
 {
diff --git a/arch/arm64/kernel/entry-common.c b/arch/arm64/kernel/entry-common.c
index b8a527ac67814b9c705836852073466d921d8050..3fcc72a6ba95a3de8380d1194346582caf410eee 100644
--- a/arch/arm64/kernel/entry-common.c
+++ b/arch/arm64/kernel/entry-common.c
@@ -133,11 +133,20 @@ static void noinstr el1_pc(struct pt_regs *regs, unsigned long esr)
 	exit_to_kernel_mode(regs);
 }
 
-static void noinstr el1_undef(struct pt_regs *regs)
+static void noinstr el1_undef(struct pt_regs *regs, unsigned long esr)
 {
 	enter_from_kernel_mode(regs);
 	local_daif_inherit(regs);
-	do_undefinstr(regs);
+	do_el1_undef(regs, esr);
+	local_daif_mask();
+	exit_to_kernel_mode(regs);
+}
+
+static void noinstr el1_bti(struct pt_regs *regs, unsigned long esr)
+{
+	enter_from_kernel_mode(regs);
+	local_daif_inherit(regs);
+	do_el1_bti(regs, esr);
 	local_daif_mask();
 	exit_to_kernel_mode(regs);
 }
@@ -195,7 +204,7 @@ static void noinstr el1_fpac(struct pt_regs *regs, unsigned long esr)
 {
 	enter_from_kernel_mode(regs);
 	local_daif_inherit(regs);
-	do_ptrauth_fault(regs, esr);
+	do_el1_fpac(regs, esr);
 	local_daif_mask();
 	exit_to_kernel_mode(regs);
 }
@@ -218,7 +227,10 @@ asmlinkage void noinstr el1_sync_handler(struct pt_regs *regs)
 		break;
 	case ESR_ELx_EC_SYS64:
 	case ESR_ELx_EC_UNKNOWN:
-		el1_undef(regs);
+		el1_undef(regs, esr);
+		break;
+	case ESR_ELx_EC_BTI:
+		el1_bti(regs, esr);
 		break;
 	case ESR_ELx_EC_BREAKPT_CUR:
 	case ESR_ELx_EC_SOFTSTP_CUR:
@@ -302,7 +314,7 @@ static void noinstr el0_sys(struct pt_regs *regs, unsigned long esr)
 {
 	enter_from_user_mode();
 	local_daif_restore(DAIF_PROCCTX);
-	do_sysinstr(esr, regs);
+	do_el0_sys(esr, regs);
 }
 
 static void noinstr el0_pc(struct pt_regs *regs, unsigned long esr)
@@ -324,18 +336,18 @@ static void noinstr el0_sp(struct pt_regs *regs, unsigned long esr)
 	do_sp_pc_abort(regs->sp, esr, regs);
 }
 
-static void noinstr el0_undef(struct pt_regs *regs)
+static void noinstr el0_undef(struct pt_regs *regs, unsigned long esr)
 {
 	enter_from_user_mode();
 	local_daif_restore(DAIF_PROCCTX);
-	do_undefinstr(regs);
+	do_el0_undef(regs, esr);
 }
 
 static void noinstr el0_bti(struct pt_regs *regs)
 {
 	enter_from_user_mode();
 	local_daif_restore(DAIF_PROCCTX);
-	do_bti(regs);
+	do_el0_bti(regs);
 }
 
 static void noinstr el0_inv(struct pt_regs *regs, unsigned long esr)
@@ -365,7 +377,7 @@ static void noinstr el0_fpac(struct pt_regs *regs, unsigned long esr)
 {
 	enter_from_user_mode();
 	local_daif_restore(DAIF_PROCCTX);
-	do_ptrauth_fault(regs, esr);
+	do_el0_fpac(regs, esr);
 }
 
 asmlinkage void noinstr el0_sync_handler(struct pt_regs *regs)
@@ -402,7 +414,7 @@ asmlinkage void noinstr el0_sync_handler(struct pt_regs *regs)
 		el0_pc(regs, esr);
 		break;
 	case ESR_ELx_EC_UNKNOWN:
-		el0_undef(regs);
+		el0_undef(regs, esr);
 		break;
 	case ESR_ELx_EC_BTI:
 		el0_bti(regs);
@@ -426,7 +438,7 @@ static void noinstr el0_cp15(struct pt_regs *regs, unsigned long esr)
 {
 	enter_from_user_mode();
 	local_daif_restore(DAIF_PROCCTX);
-	do_cp15instr(esr, regs);
+	do_el0_cp15(esr, regs);
 }
 
 static void noinstr el0_svc_compat(struct pt_regs *regs)
@@ -462,7 +474,7 @@ asmlinkage void noinstr el0_sync_compat_handler(struct pt_regs *regs)
 	case ESR_ELx_EC_CP14_MR:
 	case ESR_ELx_EC_CP14_LS:
 	case ESR_ELx_EC_CP14_64:
-		el0_undef(regs);
+		el0_undef(regs, esr);
 		break;
 	case ESR_ELx_EC_CP15_32:
 	case ESR_ELx_EC_CP15_64:
diff --git a/arch/arm64/kernel/proton-pack.c b/arch/arm64/kernel/proton-pack.c
index 372aeda02bff09f0aa36f77b62d84a24e549c10a..c569889b0322c93aefdafa924e8adda3fb8992cf 100644
--- a/arch/arm64/kernel/proton-pack.c
+++ b/arch/arm64/kernel/proton-pack.c
@@ -546,10 +546,13 @@ bool has_spectre_v4(const struct arm64_cpu_capabilities *cap, int scope)
 	return state != SPECTRE_UNAFFECTED;
 }
 
-static int ssbs_emulation_handler(struct pt_regs *regs, u32 instr)
+bool try_emulate_el1_ssbs(struct pt_regs *regs, u32 instr)
 {
-	if (user_mode(regs))
-		return 1;
+	const u32 instr_mask = ~(1U << PSTATE_Imm_shift);
+	const u32 instr_val = 0xd500401f | PSTATE_SSBS;
+
+	if ((instr & instr_mask) != instr_val)
+		return false;
 
 	if (instr & BIT(PSTATE_Imm_shift))
 		regs->pstate |= PSR_SSBS_BIT;
@@ -557,19 +560,11 @@ static int ssbs_emulation_handler(struct pt_regs *regs, u32 instr)
 		regs->pstate &= ~PSR_SSBS_BIT;
 
 	arm64_skip_faulting_instruction(regs, 4);
-	return 0;
+	return true;
 }
 
-static struct undef_hook ssbs_emulation_hook = {
-	.instr_mask	= ~(1U << PSTATE_Imm_shift),
-	.instr_val	= 0xd500401f | PSTATE_SSBS,
-	.fn		= ssbs_emulation_handler,
-};
-
 static enum mitigation_state spectre_v4_enable_hw_mitigation(void)
 {
-	static bool undef_hook_registered = false;
-	static DEFINE_RAW_SPINLOCK(hook_lock);
 	enum mitigation_state state;
 
 	/*
@@ -580,13 +575,6 @@ static enum mitigation_state spectre_v4_enable_hw_mitigation(void)
 	if (state != SPECTRE_MITIGATED || !this_cpu_has_cap(ARM64_SSBS))
 		return state;
 
-	raw_spin_lock(&hook_lock);
-	if (!undef_hook_registered) {
-		register_undef_hook(&ssbs_emulation_hook);
-		undef_hook_registered = true;
-	}
-	raw_spin_unlock(&hook_lock);
-
 	if (spectre_v4_mitigations_off()) {
 		sysreg_clear_set(sctlr_el1, 0, SCTLR_ELx_DSSBS);
 		set_pstate_ssbs(1);
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index f8ec533eb5906db9a13e436d2a8f46e8fe28d5dd..cec7064afb01e0bb8ebcbc155fc4b632487f4eb5 100644
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -91,12 +91,12 @@ static void dump_kernel_instr(const char *lvl, struct pt_regs *regs)
 
 #define S_SMP " SMP"
 
-static int __die(const char *str, int err, struct pt_regs *regs)
+static int __die(const char *str, long err, struct pt_regs *regs)
 {
 	static int die_counter;
 	int ret;
 
-	pr_emerg("Internal error: %s: %x [#%d]" S_PREEMPT S_SMP "\n",
+	pr_emerg("Internal error: %s: %016lx [#%d]" S_PREEMPT S_SMP "\n",
 		 str, err, ++die_counter);
 
 	/* trap and error numbers are mostly meaningless on ARM */
@@ -117,7 +117,7 @@ static DEFINE_RAW_SPINLOCK(die_lock);
 /*
  * This function is protected against re-entrancy.
  */
-void die(const char *str, struct pt_regs *regs, int err)
+void die(const char *str, struct pt_regs *regs, long err)
 {
 	int ret;
 	unsigned long flags;
@@ -283,51 +283,22 @@ void arm64_skip_faulting_instruction(struct pt_regs *regs, unsigned long size)
 		regs->pstate &= ~PSR_BTYPE_MASK;
 }
 
-static LIST_HEAD(undef_hook);
-static DEFINE_RAW_SPINLOCK(undef_lock);
-
-void register_undef_hook(struct undef_hook *hook)
+static int user_insn_read(struct pt_regs *regs, u32 *insnp)
 {
-	unsigned long flags;
-
-	raw_spin_lock_irqsave(&undef_lock, flags);
-	list_add(&hook->node, &undef_hook);
-	raw_spin_unlock_irqrestore(&undef_lock, flags);
-}
-
-void unregister_undef_hook(struct undef_hook *hook)
-{
-	unsigned long flags;
-
-	raw_spin_lock_irqsave(&undef_lock, flags);
-	list_del(&hook->node);
-	raw_spin_unlock_irqrestore(&undef_lock, flags);
-}
-
-static int call_undef_hook(struct pt_regs *regs)
-{
-	struct undef_hook *hook;
-	unsigned long flags;
 	u32 instr;
-	int (*fn)(struct pt_regs *regs, u32 instr) = NULL;
 	void __user *pc = (void __user *)instruction_pointer(regs);
 
-	if (!user_mode(regs)) {
-		__le32 instr_le;
-		if (get_kernel_nofault(instr_le, (__force __le32 *)pc))
-			goto exit;
-		instr = le32_to_cpu(instr_le);
-	} else if (a32_thumb_mode(regs)) {
+	if (a32_thumb_mode(regs)) {
 		/* 16-bit Thumb instruction */
 		__le16 instr_le;
 		if (get_user(instr_le, (__le16 __user *)pc))
-			goto exit;
+			return -EFAULT;
 		instr = le16_to_cpu(instr_le);
 		if (aarch32_insn_is_wide(instr)) {
 			u32 instr2;
 
 			if (get_user(instr_le, (__le16 __user *)(pc + 2)))
-				goto exit;
+				return -EFAULT;
 			instr2 = le16_to_cpu(instr_le);
 			instr = (instr << 16) | instr2;
 		}
@@ -335,19 +306,12 @@ static int call_undef_hook(struct pt_regs *regs)
 		/* 32-bit ARM instruction */
 		__le32 instr_le;
 		if (get_user(instr_le, (__le32 __user *)pc))
-			goto exit;
+			return -EFAULT;
 		instr = le32_to_cpu(instr_le);
 	}
 
-	raw_spin_lock_irqsave(&undef_lock, flags);
-	list_for_each_entry(hook, &undef_hook, node)
-		if ((instr & hook->instr_mask) == hook->instr_val &&
-			(regs->pstate & hook->pstate_mask) == hook->pstate_val)
-			fn = hook->fn;
-
-	raw_spin_unlock_irqrestore(&undef_lock, flags);
-exit:
-	return fn ? fn(regs, instr) : 1;
+	*insnp = instr;
+	return 0;
 }
 
 void force_signal_inject(int signal, int code, unsigned long address, unsigned int err)
@@ -396,39 +360,64 @@ void arm64_notify_segfault(unsigned long addr)
 	force_signal_inject(SIGSEGV, code, addr, 0);
 }
 
-void do_undefinstr(struct pt_regs *regs)
+void do_el0_undef(struct pt_regs *regs, unsigned long esr)
 {
+	u32 insn;
+
 	/* check for AArch32 breakpoint instructions */
 	if (!aarch32_break_handler(regs))
 		return;
 
-	if (call_undef_hook(regs) == 0)
+	if (user_insn_read(regs, &insn))
+		goto out_err;
+
+	if (try_emulate_mrs(regs, insn))
 		return;
 
-	if (!user_mode(regs))
-		die("Oops - undefined instruction", regs, 0);
+	if (try_emulate_armv8_deprecated(regs, insn))
+		return;
 
+out_err:
 	force_signal_inject(SIGILL, ILL_ILLOPC, regs->pc, 0);
 }
-NOKPROBE_SYMBOL(do_undefinstr);
 
-void do_bti(struct pt_regs *regs)
+void do_el1_undef(struct pt_regs *regs, unsigned long esr)
+{
+	u32 insn;
+
+	if (aarch64_insn_read((void *)regs->pc, &insn))
+		goto out_err;
+
+	if (try_emulate_el1_ssbs(regs, insn))
+		return;
+
+out_err:
+	die("Oops - Undefined instruction", regs, esr);
+}
+
+void do_el0_bti(struct pt_regs *regs)
 {
-	BUG_ON(!user_mode(regs));
 	force_signal_inject(SIGILL, ILL_ILLOPC, regs->pc, 0);
 }
-NOKPROBE_SYMBOL(do_bti);
 
-void do_ptrauth_fault(struct pt_regs *regs, unsigned int esr)
+void do_el1_bti(struct pt_regs *regs, unsigned long esr)
+{
+	die("Oops - BTI", regs, esr);
+}
+
+void do_el0_fpac(struct pt_regs *regs, unsigned long esr)
+{
+	force_signal_inject(SIGILL, ILL_ILLOPN, regs->pc, esr);
+}
+
+void do_el1_fpac(struct pt_regs *regs, unsigned long esr)
 {
 	/*
-	 * Unexpected FPAC exception or pointer authentication failure in
-	 * the kernel: kill the task before it does any more harm.
+	 * Unexpected FPAC exception in the kernel: kill the task before it
+	 * does any more harm.
 	 */
-	BUG_ON(!user_mode(regs));
-	force_signal_inject(SIGILL, ILL_ILLOPN, regs->pc, esr);
+	die("Oops - FPAC", regs, esr);
 }
-NOKPROBE_SYMBOL(do_ptrauth_fault);
 
 #define __user_cache_maint(insn, address, res)			\
 	if (address >= user_addr_max()) {			\
@@ -654,7 +643,7 @@ static const struct sys64_hook cp15_64_hooks[] = {
 	{},
 };
 
-void do_cp15instr(unsigned int esr, struct pt_regs *regs)
+void do_el0_cp15(unsigned long esr, struct pt_regs *regs)
 {
 	const struct sys64_hook *hook, *hook_base;
 
@@ -675,7 +664,7 @@ void do_cp15instr(unsigned int esr, struct pt_regs *regs)
 		hook_base = cp15_64_hooks;
 		break;
 	default:
-		do_undefinstr(regs);
+		do_el0_undef(regs, esr);
 		return;
 	}
 
@@ -690,12 +679,11 @@ void do_cp15instr(unsigned int esr, struct pt_regs *regs)
 	 * EL0. Fall back to our usual undefined instruction handler
 	 * so that we handle these consistently.
 	 */
-	do_undefinstr(regs);
+	do_el0_undef(regs, esr);
 }
-NOKPROBE_SYMBOL(do_cp15instr);
 #endif
 
-void do_sysinstr(unsigned int esr, struct pt_regs *regs)
+void do_el0_sys(unsigned long esr, struct pt_regs *regs)
 {
 	const struct sys64_hook *hook;
 
@@ -710,9 +698,8 @@ void do_sysinstr(unsigned int esr, struct pt_regs *regs)
 	 * back to our usual undefined instruction handler so that we handle
 	 * these consistently.
 	 */
-	do_undefinstr(regs);
+	do_el0_undef(regs, esr);
 }
-NOKPROBE_SYMBOL(do_sysinstr);
 
 static const char *esr_class_str[] = {
 	[0 ... ESR_ELx_EC_MAX]		= "UNRECOGNIZED EC",
@@ -913,7 +900,7 @@ static int bug_handler(struct pt_regs *regs, unsigned int esr)
 {
 	switch (report_bug(regs->pc, regs)) {
 	case BUG_TRAP_TYPE_BUG:
-		die("Oops - BUG", regs, 0);
+		die("Oops - BUG", regs, esr);
 		break;
 
 	case BUG_TRAP_TYPE_WARN:
@@ -981,7 +968,7 @@ static int kasan_handler(struct pt_regs *regs, unsigned int esr)
 	 * This is something that might be fixed at some point in the future.
 	 */
 	if (!recover)
-		die("Oops - KASAN", regs, 0);
+		die("Oops - KASAN", regs, esr);
 
 	/* If thread survives, skip over the brk instruction and continue: */
 	arm64_skip_faulting_instruction(regs, AARCH64_INSN_SIZE);