diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index bc3f00f..9f57318 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -11,6 +11,7 @@ config ARM64
 	select ARCH_HAS_GCOV_PROFILE_ALL
 	select ARCH_HAS_KCOV
 	select ARCH_HAS_SG_CHAIN
+	select ARCH_HAS_OWN_THREAD_INFO
 	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
 	select ARCH_USE_CMPXCHG_LOCKREF
 	select ARCH_SUPPORTS_ATOMIC_RMW
@@ -110,6 +111,7 @@ config ARM64
 	select POWER_SUPPLY
 	select SPARSE_IRQ
 	select SYSCTL_EXCEPTION_TRACE
+	select THREAD_INFO_IN_TASK
 	help
 	  ARM 64-bit (AArch64) Linux support.
 
diff --git a/arch/arm64/include/asm/Kbuild b/arch/arm64/include/asm/Kbuild
index f43d2c4..a716c6f 100644
--- a/arch/arm64/include/asm/Kbuild
+++ b/arch/arm64/include/asm/Kbuild
@@ -2,7 +2,6 @@ generic-y += bug.h
 generic-y += bugs.h
 generic-y += clkdev.h
 generic-y += cputime.h
-generic-y += current.h
 generic-y += delay.h
 generic-y += div64.h
 generic-y += dma.h
diff --git a/arch/arm64/include/asm/current.h b/arch/arm64/include/asm/current.h
new file mode 100644
index 0000000..f2bcbe2
--- /dev/null
+++ b/arch/arm64/include/asm/current.h
@@ -0,0 +1,22 @@
+#ifndef __ASM_CURRENT_H
+#define __ASM_CURRENT_H
+
+#include <linux/compiler.h>
+
+#include <asm/sysreg.h>
+
+#ifndef __ASSEMBLY__
+
+struct task_struct;
+
+static __always_inline struct task_struct *get_current(void)
+{
+	return (struct task_struct *)read_sysreg(sp_el0);
+}
+
+#define current get_current()
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* __ASM_CURRENT_H */
+
diff --git a/arch/arm64/include/asm/smp.h b/arch/arm64/include/asm/smp.h
index 0226447..fef90c0 100644
--- a/arch/arm64/include/asm/smp.h
+++ b/arch/arm64/include/asm/smp.h
@@ -73,6 +73,7 @@ asmlinkage void secondary_start_kernel(void);
  */
 struct secondary_data {
 	void *stack;
+	struct task_struct *task;
 	long status;
 };
 
diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h
index 796af24..5b16b34 100644
--- a/arch/arm64/include/asm/thread_info.h
+++ b/arch/arm64/include/asm/thread_info.h
@@ -46,14 +46,12 @@ typedef unsigned long mm_segment_t;
 struct thread_info {
 	unsigned long		flags;		/* low level flags */
 	mm_segment_t		addr_limit;	/* address limit */
-	struct task_struct	*task;		/* main task structure */
 	int			preempt_count;	/* 0 => preemptable, <0 => bug */
 	int			cpu;		/* cpu */
 };
 
 #define INIT_THREAD_INFO(tsk)						\
 {									\
-	.task		= &tsk,						\
 	.flags		= 0,						\
 	.preempt_count	= INIT_PREEMPT_COUNT,				\
 	.addr_limit	= KERNEL_DS,					\
@@ -66,23 +64,6 @@ struct thread_info {
  */
 register unsigned long current_stack_pointer asm ("sp");
 
-/*
- * how to get the thread information struct from C
- */
-static inline struct thread_info *current_thread_info(void) __attribute_const__;
-
-/*
- * struct thread_info can be accessed directly via sp_el0.
- */
-static inline struct thread_info *current_thread_info(void)
-{
-	unsigned long sp_el0;
-
-	asm ("mrs %0, sp_el0" : "=r" (sp_el0));
-
-	return (struct thread_info *)sp_el0;
-}
-
 #define thread_saved_pc(tsk)	\
 	((unsigned long)(tsk->thread.cpu_context.pc))
 #define thread_saved_sp(tsk)	\
diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c
index ee764eb..242fe909 100644
--- a/arch/arm64/kernel/asm-offsets.c
+++ b/arch/arm64/kernel/asm-offsets.c
@@ -120,6 +120,7 @@ int main(void)
   DEFINE(TZ_DSTTIME,		offsetof(struct timezone, tz_dsttime));
   BLANK();
   DEFINE(CPU_BOOT_STACK,	offsetof(struct secondary_data, stack));
+  DEFINE(CPU_BOOT_TASK,		offsetof(struct secondary_data, task));
   BLANK();
 #ifdef CONFIG_KVM_ARM_HOST
   DEFINE(VCPU_CONTEXT,		offsetof(struct kvm_vcpu, arch.ctxt));
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index 52b4241..f844e7f 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -123,6 +123,7 @@
 	 * Set sp_el0 to current thread_info.
 	 */
 	.if	\el == 0
+	ldr_this_cpu	tsk, __entry_task, x21
 	msr	sp_el0, tsk
 	.endif
 
@@ -680,8 +681,7 @@ ENTRY(cpu_switch_to)
 	ldp	x29, x9, [x8], #16
 	ldr	lr, [x8]
 	mov	sp, x9
-	and	x9, x9, #~(THREAD_SIZE - 1)
-	msr	sp_el0, x9
+	msr	sp_el0, x1
 	ret
 ENDPROC(cpu_switch_to)
 
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index b77f583..abc7330 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -433,8 +433,7 @@ __primary_switched:
 	dsb	ishst				// Make zero page visible to PTW
 
 	adr_l	sp, initial_sp, x4
-	mov	x4, sp
-	and	x4, x4, #~(THREAD_SIZE - 1)
+	adr_l	x4, init_task
 	msr	sp_el0, x4			// Save thread_info
 	str_l	x21, __fdt_pointer, x5		// Save FDT pointer
 
@@ -680,10 +679,10 @@ __secondary_switched:
 	isb
 
 	adr_l	x0, secondary_data
-	ldr	x0, [x0, #CPU_BOOT_STACK]	// get secondary_data.stack
-	mov	sp, x0
-	and	x0, x0, #~(THREAD_SIZE - 1)
-	msr	sp_el0, x0			// save thread_info
+	ldr	x1, [x0, #CPU_BOOT_STACK]	// get secondary_data.stack
+	mov	sp, x1
+	ldr	x2, [x0, #CPU_BOOT_TASK]
+	msr	sp_el0, x2
 	mov	x29, #0
 	b	secondary_start_kernel
 ENDPROC(__secondary_switched)
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index 6cd2612..e35043d 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -45,6 +45,7 @@
 #include <linux/personality.h>
 #include <linux/notifier.h>
 #include <trace/events/power.h>
+#include <linux/percpu.h>
 
 #include <asm/alternative.h>
 #include <asm/compat.h>
@@ -314,6 +315,17 @@ static void uao_thread_switch(struct task_struct *next)
 }
 
 /*
+ * We store our current task in sp_el0, which is clobbered by userspace. Keep a
+ * shadow copy so that we can restore this upon entry from userspace.
+ */
+DEFINE_PER_CPU(struct task_struct *, __entry_task) = &init_task;
+
+static void entry_task_switch(struct task_struct *next)
+{
+	__this_cpu_write(__entry_task, next);
+}
+
+/*
  * Thread switching.
  */
 struct task_struct *__switch_to(struct task_struct *prev,
@@ -325,6 +337,7 @@ struct task_struct *__switch_to(struct task_struct *prev,
 	tls_thread_switch(next);
 	hw_breakpoint_thread_switch(next);
 	contextidr_thread_switch(next);
+	entry_task_switch(next);
 	uao_thread_switch(next);
 
 	/*
@@ -342,11 +355,14 @@ struct task_struct *__switch_to(struct task_struct *prev,
 unsigned long get_wchan(struct task_struct *p)
 {
 	struct stackframe frame;
-	unsigned long stack_page;
+	unsigned long stack_page, ret = 0;
 	int count = 0;
 	if (!p || p == current || p->state == TASK_RUNNING)
 		return 0;
 
+	if (!try_get_task_stack(p))
+		return 0;
+
 	frame.fp = thread_saved_fp(p);
 	frame.sp = thread_saved_sp(p);
 	frame.pc = thread_saved_pc(p);
@@ -358,11 +374,16 @@ unsigned long get_wchan(struct task_struct *p)
 		if (frame.sp < stack_page ||
 		    frame.sp >= stack_page + THREAD_SIZE ||
 		    unwind_frame(p, &frame))
-			return 0;
-		if (!in_sched_functions(frame.pc))
-			return frame.pc;
+			goto out;
+		if (!in_sched_functions(frame.pc)) {
+			ret = frame.pc;
+			goto out;
+		}
 	} while (count ++ < 16);
-	return 0;
+
+out:
+	put_task_stack(p);
+	return ret;
 }
 
 unsigned long arch_align_stack(unsigned long sp)
diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index d93d433..d84be9db 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -146,6 +146,7 @@ int __cpu_up(unsigned int cpu, struct task_struct *idle)
 	 * We need to tell the secondary core where to find its stack and the
 	 * page tables.
 	 */
+	secondary_data.task = idle;
 	secondary_data.stack = task_stack_page(idle) + THREAD_START_SP;
 	update_cpu_boot_status(CPU_MMU_OFF);
 	__flush_dcache_area(&secondary_data, sizeof(secondary_data));
@@ -170,6 +171,7 @@ int __cpu_up(unsigned int cpu, struct task_struct *idle)
 		pr_err("CPU%u: failed to boot: %d\n", cpu, ret);
 	}
 
+	secondary_data.task = NULL;
 	secondary_data.stack = NULL;
 	status = READ_ONCE(secondary_data.status);
 	if (ret && status) {
diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c
index d9751a4..4e0efe8 100644
--- a/arch/arm64/kernel/stacktrace.c
+++ b/arch/arm64/kernel/stacktrace.c
@@ -157,6 +157,9 @@ void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
 	struct stack_trace_data data;
 	struct stackframe frame;
 
+	if (!try_get_task_stack(tsk))
+		return;
+
 	data.trace = trace;
 	data.skip = trace->skip;
 
@@ -178,6 +181,8 @@ void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
 	walk_stackframe(tsk, &frame, save_trace, &data);
 	if (trace->nr_entries < trace->max_entries)
 		trace->entries[trace->nr_entries++] = ULONG_MAX;
+
+	put_task_stack(tsk);
 }
 
 void save_stack_trace(struct stack_trace *trace)
