1 files changed, 13 insertions, 12 deletions

diff --git a/arch/x86/include/asm/switch_to.h b/arch/x86/include/asm/switch_to.h
index b5f0d2ff47e4..499b1c15cc8b 100644
--- a/arch/x86/include/asm/switch_to.h
+++ b/arch/x86/include/asm/switch_to.h
@@ -12,7 +12,9 @@ struct task_struct *__switch_to_asm(struct task_struct *prev,
 __visible struct task_struct *__switch_to(struct task_struct *prev,
 					  struct task_struct *next);
 
-asmlinkage void ret_from_fork(void);
+asmlinkage void ret_from_fork_asm(void);
+__visible void ret_from_fork(struct task_struct *prev, struct pt_regs *regs,
+			     int (*fn)(void *), void *fn_arg);
 
 /*
  * This is the structure pointed to by thread.sp for an inactive task.  The
@@ -50,6 +52,8 @@ do {									\
 } while (0)
 
 #ifdef CONFIG_X86_32
+#include <asm/msr.h>
+
 static inline void refresh_sysenter_cs(struct thread_struct *thread)
 {
 	/* Only happens when SEP is enabled, no need to test "SEP"arately: */
@@ -57,7 +61,7 @@ static inline void refresh_sysenter_cs(struct thread_struct *thread)
 		return;
 
 	this_cpu_write(cpu_tss_rw.x86_tss.ss1, thread->sysenter_cs);
-	wrmsr(MSR_IA32_SYSENTER_CS, thread->sysenter_cs, 0);
+	wrmsrq(MSR_IA32_SYSENTER_CS, thread->sysenter_cs);
 }
 #endif
 
@@ -66,25 +70,22 @@ static inline void update_task_stack(struct task_struct *task)
 {
 	/* sp0 always points to the entry trampoline stack, which is constant: */
 #ifdef CONFIG_X86_32
-	if (static_cpu_has(X86_FEATURE_XENPV))
-		load_sp0(task->thread.sp0);
-	else
-		this_cpu_write(cpu_tss_rw.x86_tss.sp1, task->thread.sp0);
+	this_cpu_write(cpu_tss_rw.x86_tss.sp1, task->thread.sp0);
 #else
-	/* Xen PV enters the kernel on the thread stack. */
-	if (static_cpu_has(X86_FEATURE_XENPV))
+	if (!cpu_feature_enabled(X86_FEATURE_FRED) && cpu_feature_enabled(X86_FEATURE_XENPV))
+		/* Xen PV enters the kernel on the thread stack. */
 		load_sp0(task_top_of_stack(task));
 #endif
 }
 
 static inline void kthread_frame_init(struct inactive_task_frame *frame,
-				      unsigned long fun, unsigned long arg)
+				      int (*fun)(void *), void *arg)
 {
-	frame->bx = fun;
+	frame->bx = (unsigned long)fun;
 #ifdef CONFIG_X86_32
-	frame->di = arg;
+	frame->di = (unsigned long)arg;
 #else
-	frame->r12 = arg;
+	frame->r12 = (unsigned long)arg;
 #endif
 }