3 files changed, 10 insertions, 44 deletions

diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 9499385676e7..d22e73e4618b 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -444,11 +444,6 @@ ret_from_kernel_thread:
 	PPC440EP_ERR42
 	blrl
 	li	r3,0
-	b	do_exit		# no return
-
-	.globl	__ret_from_kernel_execve
-__ret_from_kernel_execve:
-	addi	r1,r3,-STACK_FRAME_OVERHEAD
 	b	ret_from_syscall
 
 /* Traced system call support */
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 56e0ff0878b5..e9a906c27234 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -373,17 +373,11 @@ _GLOBAL(ret_from_fork)
 _GLOBAL(ret_from_kernel_thread)
 	bl	.schedule_tail
 	REST_NVGPRS(r1)
-	REST_GPR(2,r1)
+	ld	r14, 0(r14)
 	mtlr	r14
 	mr	r3,r15
 	blrl
 	li	r3,0
-	b	.do_exit	# no return
-
-_GLOBAL(__ret_from_kernel_execve)
-	addi	r1,r3,-STACK_FRAME_OVERHEAD
-	li	r10,1
-	std	r10,SOFTE(r1)
 	b	syscall_exit
 
 	.section	".toc","aw"
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index ba48233500f6..f6d244db9203 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -745,25 +745,24 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
 	/* Copy registers */
 	sp -= sizeof(struct pt_regs);
 	childregs = (struct pt_regs *) sp;
-	if (!regs) {
-		/* for kernel thread, set `current' and stackptr in new task */
+	if (unlikely(p->flags & PF_KTHREAD)) {
+		struct thread_info *ti = (void *)task_stack_page(p);
 		memset(childregs, 0, sizeof(struct pt_regs));
 		childregs->gpr[1] = sp + sizeof(struct pt_regs);
+		childregs->gpr[14] = usp;	/* function */
 #ifdef CONFIG_PPC64
-		childregs->gpr[14] = *(unsigned long *)usp;
-		childregs->gpr[2] = ((unsigned long *)usp)[1],
 		clear_tsk_thread_flag(p, TIF_32BIT);
-#else
-		childregs->gpr[14] = usp;	/* function */
-		childregs->gpr[2] = (unsigned long) p;
+		childregs->softe = 1;
 #endif
 		childregs->gpr[15] = arg;
 		p->thread.regs = NULL;	/* no user register state */
+		ti->flags |= _TIF_RESTOREALL;
 		f = ret_from_kernel_thread;
 	} else {
 		CHECK_FULL_REGS(regs);
 		*childregs = *regs;
-		childregs->gpr[1] = usp;
+		if (usp)
+			childregs->gpr[1] = usp;
 		p->thread.regs = childregs;
 		childregs->gpr[3] = 0;  /* Result from fork() */
 		if (clone_flags & CLONE_SETTLS) {
@@ -1027,22 +1026,11 @@ int get_unalign_ctl(struct task_struct *tsk, unsigned long adr)
 	return put_user(tsk->thread.align_ctl, (unsigned int __user *)adr);
 }
 
-#define TRUNC_PTR(x)	((typeof(x))(((unsigned long)(x)) & 0xffffffff))
-
 int sys_clone(unsigned long clone_flags, unsigned long usp,
 	      int __user *parent_tidp, void __user *child_threadptr,
 	      int __user *child_tidp, int p6,
 	      struct pt_regs *regs)
 {
-	CHECK_FULL_REGS(regs);
-	if (usp == 0)
-		usp = regs->gpr[1];	/* stack pointer for child */
-#ifdef CONFIG_PPC64
-	if (is_32bit_task()) {
-		parent_tidp = TRUNC_PTR(parent_tidp);
-		child_tidp = TRUNC_PTR(child_tidp);
-	}
-#endif
  	return do_fork(clone_flags, usp, regs, 0, parent_tidp, child_tidp);
 }
 
@@ -1050,28 +1038,17 @@ int sys_fork(unsigned long p1, unsigned long p2, unsigned long p3,
 	     unsigned long p4, unsigned long p5, unsigned long p6,
 	     struct pt_regs *regs)
 {
-	CHECK_FULL_REGS(regs);
-	return do_fork(SIGCHLD, regs->gpr[1], regs, 0, NULL, NULL);
+	return do_fork(SIGCHLD, 0, regs, 0, NULL, NULL);
 }
 
 int sys_vfork(unsigned long p1, unsigned long p2, unsigned long p3,
 	      unsigned long p4, unsigned long p5, unsigned long p6,
 	      struct pt_regs *regs)
 {
-	CHECK_FULL_REGS(regs);
-	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->gpr[1],
+	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, 0,
 			regs, 0, NULL, NULL);
 }
 
-void __ret_from_kernel_execve(struct pt_regs *normal)
-__noreturn;
-
-void ret_from_kernel_execve(struct pt_regs *normal)
-{
-	set_thread_flag(TIF_RESTOREALL);
-	__ret_from_kernel_execve(normal);
-}
-
 static inline int valid_irq_stack(unsigned long sp, struct task_struct *p,
 				  unsigned long nbytes)
 {