From 287ad220cd8b5a9d29f71c78f6e4051093f051fc Mon Sep 17 00:00:00 2001
From: Jonas Bonn <jonas@southpole.se>
Date: Sun, 14 Oct 2012 16:19:52 +0200
Subject: openrisc: pass correct arg to schedule_tail

schedule_tail() requires that the 'prev' task be passed as an argument
to it.  This arg is set in _switch, just before 'returning' to one of
the ret_* functions where schedule_tail is invoked.

Signed-off-by: Jonas Bonn <jonas@southpole.se>
---
 arch/openrisc/kernel/process.c | 1 -
 1 file changed, 1 deletion(-)

(limited to 'arch/openrisc/kernel/process.c')

diff --git a/arch/openrisc/kernel/process.c b/arch/openrisc/kernel/process.c
index c35f3ab1a8d3..ad26d5af2649 100644
--- a/arch/openrisc/kernel/process.c
+++ b/arch/openrisc/kernel/process.c
@@ -165,7 +165,6 @@ copy_thread(unsigned long clone_flags, unsigned long usp,
 	 * the kernel stack.
 	 */
 	kregs->sp = top_of_kernel_stack;
-	kregs->gpr[3] = (unsigned long)current;	/* arg to schedule_tail */
 	kregs->gpr[10] = (unsigned long)task_thread_info(p);
 	kregs->gpr[9] = (unsigned long)ret_from_fork;
 
-- 
cgit 


From cbf23cf1b96819599f6a1b9658d1bf3a97c6ff15 Mon Sep 17 00:00:00 2001
From: Jonas Bonn <jonas@southpole.se>
Date: Fri, 19 Oct 2012 18:07:44 +0200
Subject: openrisc: use generic kernel_thread/kernel_execve

Signed-off-by: Jonas Bonn <jonas@southpole.se>
---
 arch/openrisc/Kconfig          |   2 +
 arch/openrisc/kernel/entry.S   |  30 +++------
 arch/openrisc/kernel/process.c | 138 +++++++++++++++++------------------------
 3 files changed, 68 insertions(+), 102 deletions(-)

(limited to 'arch/openrisc/kernel/process.c')

diff --git a/arch/openrisc/Kconfig b/arch/openrisc/Kconfig
index 05f2ba41ff1a..e7f1a2993f78 100644
--- a/arch/openrisc/Kconfig
+++ b/arch/openrisc/Kconfig
@@ -22,6 +22,8 @@ config OPENRISC
 	select GENERIC_STRNCPY_FROM_USER
 	select GENERIC_STRNLEN_USER
 	select MODULES_USE_ELF_RELA
+	select GENERIC_KERNEL_THREAD
+	select GENERIC_KERNEL_EXECVE
 
 config MMU
 	def_bool y
diff --git a/arch/openrisc/kernel/entry.S b/arch/openrisc/kernel/entry.S
index 374e63e7c9f6..dce86aef8aba 100644
--- a/arch/openrisc/kernel/entry.S
+++ b/arch/openrisc/kernel/entry.S
@@ -894,6 +894,16 @@ ENTRY(ret_from_fork)
 	l.jal	schedule_tail
 	 l.nop
 
+	/* Check if we are a kernel thread */
+	l.sfeqi	r20,0
+	l.bf	1f
+	 l.nop
+
+	/* ...we are a kernel thread so invoke the requested callback */
+	l.jalr	r20
+	 l.or	r3,r22,r0
+
+1:
 	/* _syscall_returns expect r11 to contain return value */
 	l.lwz	r11,PT_GPR11(r1)
 
@@ -915,26 +925,6 @@ ENTRY(ret_from_fork)
 	l.j	_syscall_return
 	 l.nop
 
-/* Since syscalls don't save call-clobbered registers, the args to
- * kernel_thread_helper will need to be passed through callee-saved
- * registers and copied to the parameter registers when the thread
- * begins running.
- *
- * See arch/openrisc/kernel/process.c:
- * The args are passed as follows:
- *   arg1 (r3) : passed in r20
- *   arg2 (r4) : passed in r22
- */
-
-ENTRY(_kernel_thread_helper)
-	l.or	r3,r20,r0
-	l.or	r4,r22,r0
-	l.movhi	r31,hi(kernel_thread_helper)
-	l.ori	r31,r31,lo(kernel_thread_helper)
-	l.jr	r31
-	 l.nop
-
-
 /* ========================================================[ switch ] === */
 
 /*
diff --git a/arch/openrisc/kernel/process.c b/arch/openrisc/kernel/process.c
index ad26d5af2649..a0f467e438fc 100644
--- a/arch/openrisc/kernel/process.c
+++ b/arch/openrisc/kernel/process.c
@@ -109,65 +109,82 @@ void release_thread(struct task_struct *dead_task)
  */
 extern asmlinkage void ret_from_fork(void);
 
+/*
+ * copy_thread
+ * @clone_flags: flags
+ * @usp: user stack pointer or fn for kernel thread
+ * @arg: arg to fn for kernel thread; always NULL for userspace thread
+ * @p: the newly created task
+ * @regs: CPU context to copy for userspace thread; always NULL for kthread
+ *
+ * At the top of a newly initialized kernel stack are two stacked pt_reg
+ * structures.  The first (topmost) is the userspace context of the thread.
+ * The second is the kernelspace context of the thread.
+ *
+ * A kernel thread will not be returning to userspace, so the topmost pt_regs
+ * struct can be uninitialized; it _does_ need to exist, though, because
+ * a kernel thread can become a userspace thread by doing a kernel_execve, in
+ * which case the topmost context will be initialized and used for 'returning'
+ * to userspace.
+ *
+ * The second pt_reg struct needs to be initialized to 'return' to
+ * ret_from_fork.  A kernel thread will need to set r20 to the address of
+ * a function to call into (with arg in r22); userspace threads need to set
+ * r20 to NULL in which case ret_from_fork will just continue a return to
+ * userspace.
+ *
+ * A kernel thread 'fn' may return; this is effectively what happens when
+ * kernel_execve is called.  In that case, the userspace pt_regs must have
+ * been initialized (which kernel_execve takes care of, see start_thread
+ * below); ret_from_fork will then continue its execution causing the
+ * 'kernel thread' to return to userspace as a userspace thread.
+ */
+
 int
 copy_thread(unsigned long clone_flags, unsigned long usp,
-	    unsigned long unused, struct task_struct *p, struct pt_regs *regs)
+	    unsigned long arg, struct task_struct *p, struct pt_regs *regs)
 {
-	struct pt_regs *childregs;
+	struct pt_regs *userregs;
 	struct pt_regs *kregs;
 	unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
-	struct thread_info *ti;
 	unsigned long top_of_kernel_stack;
 
 	top_of_kernel_stack = sp;
 
 	p->set_child_tid = p->clear_child_tid = NULL;
 
-	/* Copy registers */
-	/* redzone */
-	sp -= STACK_FRAME_OVERHEAD;
+	/* Locate userspace context on stack... */
+	sp -= STACK_FRAME_OVERHEAD;	/* redzone */
 	sp -= sizeof(struct pt_regs);
-	childregs = (struct pt_regs *)sp;
+	userregs = (struct pt_regs *) sp;
 
-	/* Copy parent registers */
-	*childregs = *regs;
+	/* ...and kernel context */
+	sp -= STACK_FRAME_OVERHEAD;	/* redzone */
+	sp -= sizeof(struct pt_regs);
+	kregs = (struct pt_regs *)sp;
 
-	if ((childregs->sr & SPR_SR_SM) == 1) {
-		/* for kernel thread, set `current_thread_info'
-		 * and stackptr in new task
-		 */
-		childregs->sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
-		childregs->gpr[10] = (unsigned long)task_thread_info(p);
+	if (unlikely(p->flags & PF_KTHREAD)) {
+		memset(kregs, 0, sizeof(struct pt_regs));
+		kregs->gpr[20] = usp; /* fn, kernel thread */
+		kregs->gpr[22] = arg;
 	} else {
-		childregs->sp = usp;
-	}
-
-	childregs->gpr[11] = 0;	/* Result from fork() */
+		*userregs = *regs;
 
-	/*
-	 * The way this works is that at some point in the future
-	 * some task will call _switch to switch to the new task.
-	 * That will pop off the stack frame created below and start
-	 * the new task running at ret_from_fork.  The new task will
-	 * do some house keeping and then return from the fork or clone
-	 * system call, using the stack frame created above.
-	 */
-	/* redzone */
-	sp -= STACK_FRAME_OVERHEAD;
-	sp -= sizeof(struct pt_regs);
-	kregs = (struct pt_regs *)sp;
+		userregs->sp = usp;
+		userregs->gpr[11] = 0;	/* Result from fork() */
 
-	ti = task_thread_info(p);
-	ti->ksp = sp;
+		kregs->gpr[20] = 0;	/* Userspace thread */
+	}
 
-	/* kregs->sp must store the location of the 'pre-switch' kernel stack
-	 * pointer... for a newly forked process, this is simply the top of
-	 * the kernel stack.
+	/*
+	 * _switch wants the kernel stack page in pt_regs->sp so that it
+	 * can restore it to thread_info->ksp... see _switch for details.
 	 */
 	kregs->sp = top_of_kernel_stack;
-	kregs->gpr[10] = (unsigned long)task_thread_info(p);
 	kregs->gpr[9] = (unsigned long)ret_from_fork;
 
+	task_thread_info(p)->ksp = (unsigned long)kregs;
+
 	return 0;
 }
 
@@ -176,16 +193,14 @@ copy_thread(unsigned long clone_flags, unsigned long usp,
  */
 void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long sp)
 {
-	unsigned long sr = regs->sr & ~SPR_SR_SM;
+	unsigned long sr = mfspr(SPR_SR) & ~SPR_SR_SM;
 
 	set_fs(USER_DS);
-	memset(regs->gpr, 0, sizeof(regs->gpr));
+	memset(regs, 0, sizeof(struct pt_regs));
 
 	regs->pc = pc;
 	regs->sr = sr;
 	regs->sp = sp;
-
-/*	printk("start thread, ksp = %lx\n", current_thread_info()->ksp);*/
 }
 
 /* Fill in the fpu structure for a core dump.  */
@@ -236,31 +251,6 @@ void dump_elf_thread(elf_greg_t *dest, struct pt_regs* regs)
 	dest[35] = 0;
 }
 
-extern void _kernel_thread_helper(void);
-
-void __noreturn kernel_thread_helper(int (*fn) (void *), void *arg)
-{
-	do_exit(fn(arg));
-}
-
-/*
- * Create a kernel thread.
- */
-int kernel_thread(int (*fn) (void *), void *arg, unsigned long flags)
-{
-	struct pt_regs regs;
-
-	memset(&regs, 0, sizeof(regs));
-
-	regs.gpr[20] = (unsigned long)fn;
-	regs.gpr[22] = (unsigned long)arg;
-	regs.sr = mfspr(SPR_SR);
-	regs.pc = (unsigned long)_kernel_thread_helper;
-
-	return do_fork(flags | CLONE_VM | CLONE_UNTRACED,
-		       0, &regs, 0, NULL, NULL);
-}
-
 /*
  * sys_execve() executes a new program.
  */
@@ -291,19 +281,3 @@ unsigned long get_wchan(struct task_struct *p)
 
 	return 0;
 }
-
-int kernel_execve(const char *filename, char *const argv[], char *const envp[])
-{
-	register long __res asm("r11") = __NR_execve;
-	register long __a asm("r3") = (long)(filename);
-	register long __b asm("r4") = (long)(argv);
-	register long __c asm("r5") = (long)(envp);
-	__asm__ volatile ("l.sys 1"
-			  : "=r" (__res), "=r"(__a), "=r"(__b), "=r"(__c)
-			  : "0"(__res), "1"(__a), "2"(__b), "3"(__c)
-			  : "r6", "r7", "r8", "r12", "r13", "r15",
-			    "r17", "r19", "r21", "r23", "r25", "r27",
-			    "r29", "r31");
-	__asm__ volatile ("l.nop");
-	return __res;
-}
-- 
cgit 


From a91a2bb1dbd87987645bdb56f49e6a50501b692a Mon Sep 17 00:00:00 2001
From: Jonas Bonn <jonas@southpole.se>
Date: Fri, 19 Oct 2012 18:25:36 +0200
Subject: openrisc: use generic sys_execve

Signed-off-by: Jonas Bonn <jonas@southpole.se>
---
 arch/openrisc/include/uapi/asm/unistd.h |  2 ++
 arch/openrisc/kernel/entry.S            |  4 ----
 arch/openrisc/kernel/process.c          | 24 ------------------------
 3 files changed, 2 insertions(+), 28 deletions(-)

(limited to 'arch/openrisc/kernel/process.c')

diff --git a/arch/openrisc/include/uapi/asm/unistd.h b/arch/openrisc/include/uapi/asm/unistd.h
index 437bdbb61b14..5db7bc0fa5a7 100644
--- a/arch/openrisc/include/uapi/asm/unistd.h
+++ b/arch/openrisc/include/uapi/asm/unistd.h
@@ -20,6 +20,8 @@
 
 #define sys_mmap2 sys_mmap_pgoff
 
+#define __ARCH_WANT_SYS_EXECVE
+
 #include <asm-generic/unistd.h>
 
 #define __NR_or1k_atomic __NR_arch_specific_syscall
diff --git a/arch/openrisc/kernel/entry.S b/arch/openrisc/kernel/entry.S
index dce86aef8aba..c60a09df323f 100644
--- a/arch/openrisc/kernel/entry.S
+++ b/arch/openrisc/kernel/entry.S
@@ -1083,10 +1083,6 @@ ENTRY(sys_fork)
 	l.j	_fork_save_extra_regs_and_call
 	 l.addi	r3,r1,0
 
-ENTRY(sys_execve)
-	l.j	_sys_execve
-	 l.addi	r6,r1,0
-
 ENTRY(sys_sigaltstack)
 	l.j	_sys_sigaltstack
 	 l.addi	r5,r1,0
diff --git a/arch/openrisc/kernel/process.c b/arch/openrisc/kernel/process.c
index a0f467e438fc..e0874b8e09e4 100644
--- a/arch/openrisc/kernel/process.c
+++ b/arch/openrisc/kernel/process.c
@@ -251,30 +251,6 @@ void dump_elf_thread(elf_greg_t *dest, struct pt_regs* regs)
 	dest[35] = 0;
 }
 
-/*
- * sys_execve() executes a new program.
- */
-asmlinkage long _sys_execve(const char __user *name,
-			    const char __user * const __user *argv,
-			    const char __user * const __user *envp,
-			    struct pt_regs *regs)
-{
-	int error;
-	struct filename *filename;
-
-	filename = getname(name);
-	error = PTR_ERR(filename);
-
-	if (IS_ERR(filename))
-		goto out;
-
-	error = do_execve(filename->name, argv, envp, regs);
-	putname(filename);
-
-out:
-	return error;
-}
-
 unsigned long get_wchan(struct task_struct *p)
 {
 	/* TODO */
-- 
cgit 


From 39d91a9eafec7524482e70af76ccbe803dce5b8e Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Fri, 26 Oct 2012 19:37:49 -0400
Subject: openrisc: switch to use of generic fork and clone

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 arch/openrisc/include/asm/syscalls.h    |  7 ++++
 arch/openrisc/include/uapi/asm/unistd.h |  2 ++
 arch/openrisc/kernel/Makefile           |  2 +-
 arch/openrisc/kernel/entry.S            | 12 +++----
 arch/openrisc/kernel/process.c          |  5 +--
 arch/openrisc/kernel/sys_or32.c         | 57 ---------------------------------
 6 files changed, 19 insertions(+), 66 deletions(-)
 delete mode 100644 arch/openrisc/kernel/sys_or32.c

(limited to 'arch/openrisc/kernel/process.c')

diff --git a/arch/openrisc/include/asm/syscalls.h b/arch/openrisc/include/asm/syscalls.h
index 84a978af44d7..8ee816812a9e 100644
--- a/arch/openrisc/include/asm/syscalls.h
+++ b/arch/openrisc/include/asm/syscalls.h
@@ -24,4 +24,11 @@ asmlinkage long sys_or1k_atomic(unsigned long type, unsigned long *v1,
 
 #include <asm-generic/syscalls.h>
 
+asmlinkage long __sys_clone(unsigned long clone_flags, unsigned long newsp,
+			void __user *parent_tid, void __user *child_tid, int tls);
+asmlinkage long __sys_fork(void);
+
+#define sys_clone __sys_clone
+#define sys_fork __sys_fork
+
 #endif /* __ASM_OPENRISC_SYSCALLS_H */
diff --git a/arch/openrisc/include/uapi/asm/unistd.h b/arch/openrisc/include/uapi/asm/unistd.h
index 5db7bc0fa5a7..5082b8066325 100644
--- a/arch/openrisc/include/uapi/asm/unistd.h
+++ b/arch/openrisc/include/uapi/asm/unistd.h
@@ -21,6 +21,8 @@
 #define sys_mmap2 sys_mmap_pgoff
 
 #define __ARCH_WANT_SYS_EXECVE
+#define __ARCH_WANT_SYS_FORK
+#define __ARCH_WANT_SYS_CLONE
 
 #include <asm-generic/unistd.h>
 
diff --git a/arch/openrisc/kernel/Makefile b/arch/openrisc/kernel/Makefile
index e1ee0fa2bbda..35f92ce51c24 100644
--- a/arch/openrisc/kernel/Makefile
+++ b/arch/openrisc/kernel/Makefile
@@ -5,7 +5,7 @@
 extra-y	:= head.o vmlinux.lds
 
 obj-y	:= setup.o idle.o or32_ksyms.o process.o dma.o \
-	   traps.o time.o irq.o entry.o ptrace.o signal.o sys_or32.o \
+	   traps.o time.o irq.o entry.o ptrace.o signal.o \
 	   sys_call_table.o
 
 obj-$(CONFIG_MODULES)		+= module.o
diff --git a/arch/openrisc/kernel/entry.S b/arch/openrisc/kernel/entry.S
index c60a09df323f..5e5b30601bbf 100644
--- a/arch/openrisc/kernel/entry.S
+++ b/arch/openrisc/kernel/entry.S
@@ -1071,15 +1071,15 @@ _fork_save_extra_regs_and_call:
 	l.jr	r29
 	 l.sw    PT_GPR28(r1),r28
 
-ENTRY(sys_clone)
-	l.movhi	r29,hi(_sys_clone)
-	l.ori	r29,r29,lo(_sys_clone)
+ENTRY(__sys_clone)
+	l.movhi	r29,hi(sys_clone)
+	l.ori	r29,r29,lo(sys_clone)
 	l.j	_fork_save_extra_regs_and_call
 	 l.addi	r7,r1,0
 
-ENTRY(sys_fork)
-	l.movhi	r29,hi(_sys_fork)
-	l.ori	r29,r29,lo(_sys_fork)
+ENTRY(__sys_fork)
+	l.movhi	r29,hi(sys_fork)
+	l.ori	r29,r29,lo(sys_fork)
 	l.j	_fork_save_extra_regs_and_call
 	 l.addi	r3,r1,0
 
diff --git a/arch/openrisc/kernel/process.c b/arch/openrisc/kernel/process.c
index e0874b8e09e4..6b853668369b 100644
--- a/arch/openrisc/kernel/process.c
+++ b/arch/openrisc/kernel/process.c
@@ -168,9 +168,10 @@ copy_thread(unsigned long clone_flags, unsigned long usp,
 		kregs->gpr[20] = usp; /* fn, kernel thread */
 		kregs->gpr[22] = arg;
 	} else {
-		*userregs = *regs;
+		*userregs = *current_pt_regs();
 
-		userregs->sp = usp;
+		if (usp)
+			userregs->sp = usp;
 		userregs->gpr[11] = 0;	/* Result from fork() */
 
 		kregs->gpr[20] = 0;	/* Userspace thread */
diff --git a/arch/openrisc/kernel/sys_or32.c b/arch/openrisc/kernel/sys_or32.c
deleted file mode 100644
index 57060084c0cc..000000000000
--- a/arch/openrisc/kernel/sys_or32.c
+++ /dev/null
@@ -1,57 +0,0 @@
-/*
- * OpenRISC sys_or32.c
- *
- * Linux architectural port borrowing liberally from similar works of
- * others.  All original copyrights apply as per the original source
- * declaration.
- *
- * Modifications for the OpenRISC architecture:
- * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
- * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
- *
- *      This program is free software; you can redistribute it and/or
- *      modify it under the terms of the GNU General Public License
- *      as published by the Free Software Foundation; either version
- *      2 of the License, or (at your option) any later version.
- *
- * This file contains various random system calls that
- * have a non-standard calling sequence on some platforms.
- * Since we don't have to do any backwards compatibility, our
- * versions are done in the most "normal" way possible.
- */
-
-#include <linux/errno.h>
-#include <linux/syscalls.h>
-#include <linux/mm.h>
-
-#include <asm/syscalls.h>
-
-/* These are secondary entry points as the primary entry points are defined in
- * entry.S where we add the 'regs' parameter value
- */
-
-asmlinkage long _sys_clone(unsigned long clone_flags, unsigned long newsp,
-			   int __user *parent_tid, int __user *child_tid,
-			   struct pt_regs *regs)
-{
-	long ret;
-
-	/* FIXME: Is alignment necessary? */
-	/* newsp = ALIGN(newsp, 4); */
-
-	if (!newsp)
-		newsp = regs->sp;
-
-	ret = do_fork(clone_flags, newsp, regs, 0, parent_tid, child_tid);
-
-	return ret;
-}
-
-asmlinkage int _sys_fork(struct pt_regs *regs)
-{
-#ifdef CONFIG_MMU
-	return do_fork(SIGCHLD, regs->sp, regs, 0, NULL, NULL);
-#else
-	return -EINVAL;
-#endif
-}
-- 
cgit 


From afa86fc426ff7e7f5477f15da9c405d08d5cf790 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Mon, 22 Oct 2012 22:51:14 -0400
Subject: flagday: don't pass regs to copy_thread()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 arch/alpha/kernel/process.c         | 2 +-
 arch/arm/kernel/process.c           | 2 +-
 arch/arm64/kernel/process.c         | 3 +--
 arch/avr32/kernel/process.c         | 2 +-
 arch/blackfin/kernel/process.c      | 6 +++---
 arch/c6x/kernel/process.c           | 2 +-
 arch/cris/arch-v10/kernel/process.c | 3 +--
 arch/cris/arch-v32/kernel/process.c | 3 +--
 arch/frv/kernel/process.c           | 2 +-
 arch/h8300/kernel/process.c         | 2 +-
 arch/hexagon/kernel/process.c       | 3 +--
 arch/ia64/kernel/process.c          | 3 ++-
 arch/m32r/kernel/process.c          | 2 +-
 arch/m68k/kernel/process.c          | 3 +--
 arch/microblaze/kernel/process.c    | 3 +--
 arch/mips/kernel/process.c          | 4 ++--
 arch/mn10300/kernel/process.c       | 2 +-
 arch/openrisc/kernel/process.c      | 2 +-
 arch/parisc/kernel/process.c        | 5 ++---
 arch/powerpc/kernel/process.c       | 4 ++--
 arch/s390/kernel/process.c          | 3 +--
 arch/score/kernel/process.c         | 4 ++--
 arch/sh/kernel/process_32.c         | 3 +--
 arch/sh/kernel/process_64.c         | 5 ++---
 arch/sparc/kernel/process_32.c      | 5 ++---
 arch/sparc/kernel/process_64.c      | 4 ++--
 arch/tile/kernel/process.c          | 5 ++---
 arch/um/kernel/process.c            | 3 +--
 arch/unicore32/kernel/process.c     | 2 +-
 arch/x86/kernel/process_32.c        | 3 +--
 arch/x86/kernel/process_64.c        | 3 +--
 arch/xtensa/kernel/process.c        | 3 +--
 include/linux/sched.h               | 2 +-
 kernel/fork.c                       | 2 +-
 34 files changed, 45 insertions(+), 60 deletions(-)

(limited to 'arch/openrisc/kernel/process.c')

diff --git a/arch/alpha/kernel/process.c b/arch/alpha/kernel/process.c
index e9705bcc96f9..b5d0d0923699 100644
--- a/arch/alpha/kernel/process.c
+++ b/arch/alpha/kernel/process.c
@@ -241,7 +241,7 @@ release_thread(struct task_struct *dead_task)
 int
 copy_thread(unsigned long clone_flags, unsigned long usp,
 	    unsigned long arg,
-	    struct task_struct *p, struct pt_regs *wontuse)
+	    struct task_struct *p)
 {
 	extern void ret_from_fork(void);
 	extern void ret_from_kernel_thread(void);
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index 4ab80bbb6d95..9800338c5d1b 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -376,7 +376,7 @@ asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
 
 int
 copy_thread(unsigned long clone_flags, unsigned long stack_start,
-	    unsigned long stk_sz, struct task_struct *p, struct pt_regs *unused)
+	    unsigned long stk_sz, struct task_struct *p)
 {
 	struct thread_info *thread = task_thread_info(p);
 	struct pt_regs *childregs = task_pt_regs(p);
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index 5a1335caf6f1..cb0956bc96ed 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -234,8 +234,7 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
 asmlinkage void ret_from_fork(void) asm("ret_from_fork");
 
 int copy_thread(unsigned long clone_flags, unsigned long stack_start,
-		unsigned long stk_sz, struct task_struct *p,
-		struct pt_regs *unused)
+		unsigned long stk_sz, struct task_struct *p)
 {
 	struct pt_regs *childregs = task_pt_regs(p);
 	unsigned long tls = p->thread.tp_value;
diff --git a/arch/avr32/kernel/process.c b/arch/avr32/kernel/process.c
index 03d7aa4a4bc9..fd78f58ea79a 100644
--- a/arch/avr32/kernel/process.c
+++ b/arch/avr32/kernel/process.c
@@ -299,7 +299,7 @@ asmlinkage void syscall_return(void);
 
 int copy_thread(unsigned long clone_flags, unsigned long usp,
 		unsigned long arg,
-		struct task_struct *p, struct pt_regs *unused)
+		struct task_struct *p)
 {
 	struct pt_regs *childregs = task_pt_regs(p);
 
diff --git a/arch/blackfin/kernel/process.c b/arch/blackfin/kernel/process.c
index e5ae8fcab438..582276efaaa4 100644
--- a/arch/blackfin/kernel/process.c
+++ b/arch/blackfin/kernel/process.c
@@ -141,14 +141,14 @@ asmlinkage int bfin_clone(unsigned long clone_flags, unsigned long newsp)
 int
 copy_thread(unsigned long clone_flags,
 	    unsigned long usp, unsigned long topstk,
-	    struct task_struct *p, struct pt_regs *regs)
+	    struct task_struct *p)
 {
 	struct pt_regs *childregs;
 	unsigned long *v;
 
 	childregs = (struct pt_regs *) (task_stack_page(p) + THREAD_SIZE) - 1;
 	v = ((unsigned long *)childregs) - 2;
-	if (unlikely(!regs)) {
+	if (unlikely(p->flags & PF_KTHREAD)) {
 		memset(childregs, 0, sizeof(struct pt_regs));
 		v[0] = usp;
 		v[1] = topstk;
@@ -157,7 +157,7 @@ copy_thread(unsigned long clone_flags,
 		__asm__ __volatile__("%0 = syscfg;":"=da"(childregs->syscfg):);
 		p->thread.usp = 0;
 	} else {
-		*childregs = *regs;
+		*childregs = *current_pt_regs();
 		childregs->r0 = 0;
 		p->thread.usp = usp ? : rdusp();
 		v[0] = v[1] = 0;
diff --git a/arch/c6x/kernel/process.c b/arch/c6x/kernel/process.c
index a3f91895e8b4..6434df476f77 100644
--- a/arch/c6x/kernel/process.c
+++ b/arch/c6x/kernel/process.c
@@ -139,7 +139,7 @@ void start_thread(struct pt_regs *regs, unsigned int pc, unsigned long usp)
  */
 int copy_thread(unsigned long clone_flags, unsigned long usp,
 		unsigned long ustk_size,
-		struct task_struct *p, struct pt_regs *unused)
+		struct task_struct *p)
 {
 	struct pt_regs *childregs;
 
diff --git a/arch/cris/arch-v10/kernel/process.c b/arch/cris/arch-v10/kernel/process.c
index 520547c8b196..b1018750cffb 100644
--- a/arch/cris/arch-v10/kernel/process.c
+++ b/arch/cris/arch-v10/kernel/process.c
@@ -94,8 +94,7 @@ asmlinkage void ret_from_fork(void);
 asmlinkage void ret_from_kernel_thread(void);
 
 int copy_thread(unsigned long clone_flags, unsigned long usp,
-		unsigned long arg,
-		struct task_struct *p, struct pt_regs *unused)
+		unsigned long arg, struct task_struct *p)
 {
 	struct pt_regs *childregs = task_pt_regs(p);
 	struct switch_stack *swstack = ((struct switch_stack *)childregs) - 1;
diff --git a/arch/cris/arch-v32/kernel/process.c b/arch/cris/arch-v32/kernel/process.c
index 331e70252df0..2b23ef0e4452 100644
--- a/arch/cris/arch-v32/kernel/process.c
+++ b/arch/cris/arch-v32/kernel/process.c
@@ -109,8 +109,7 @@ extern asmlinkage void ret_from_kernel_thread(void);
 
 int
 copy_thread(unsigned long clone_flags, unsigned long usp,
-	unsigned long arg,
-	struct task_struct *p, struct pt_regs *unused)
+	unsigned long arg, struct task_struct *p)
 {
 	struct pt_regs *childregs = task_pt_regs(p);
 	struct switch_stack *swstack = ((struct switch_stack *) childregs) - 1;
diff --git a/arch/frv/kernel/process.c b/arch/frv/kernel/process.c
index 0039bf77b192..23916b2a12a2 100644
--- a/arch/frv/kernel/process.c
+++ b/arch/frv/kernel/process.c
@@ -144,7 +144,7 @@ inline unsigned long user_stack(const struct pt_regs *regs)
  */
 int copy_thread(unsigned long clone_flags,
 		unsigned long usp, unsigned long arg,
-		struct task_struct *p, struct pt_regs *unused)
+		struct task_struct *p)
 {
 	struct pt_regs *childregs;
 
diff --git a/arch/h8300/kernel/process.c b/arch/h8300/kernel/process.c
index b0fb4054aee5..b609f63f1590 100644
--- a/arch/h8300/kernel/process.c
+++ b/arch/h8300/kernel/process.c
@@ -129,7 +129,7 @@ void flush_thread(void)
 
 int copy_thread(unsigned long clone_flags,
                 unsigned long usp, unsigned long topstk,
-		 struct task_struct * p, struct pt_regs *unused)
+		 struct task_struct * p)
 {
 	struct pt_regs * childregs;
 
diff --git a/arch/hexagon/kernel/process.c b/arch/hexagon/kernel/process.c
index 36dce17ed25c..06ae9ffcabd5 100644
--- a/arch/hexagon/kernel/process.c
+++ b/arch/hexagon/kernel/process.c
@@ -87,8 +87,7 @@ unsigned long thread_saved_pc(struct task_struct *tsk)
  * Copy architecture-specific thread state
  */
 int copy_thread(unsigned long clone_flags, unsigned long usp,
-		unsigned long arg, struct task_struct *p,
-		struct pt_regs *unused)
+		unsigned long arg, struct task_struct *p)
 {
 	struct thread_info *ti = task_thread_info(p);
 	struct hexagon_switch_stack *ss;
diff --git a/arch/ia64/kernel/process.c b/arch/ia64/kernel/process.c
index 25543a295ad9..31360cbbd5f8 100644
--- a/arch/ia64/kernel/process.c
+++ b/arch/ia64/kernel/process.c
@@ -393,12 +393,13 @@ ia64_load_extra (struct task_struct *task)
 int
 copy_thread(unsigned long clone_flags,
 	     unsigned long user_stack_base, unsigned long user_stack_size,
-	     struct task_struct *p, struct pt_regs *regs)
+	     struct task_struct *p)
 {
 	extern char ia64_ret_from_clone;
 	struct switch_stack *child_stack, *stack;
 	unsigned long rbs, child_rbs, rbs_size;
 	struct pt_regs *child_ptregs;
+	struct pt_regs *regs = current_pt_regs();
 	int retval = 0;
 
 	child_ptregs = (struct pt_regs *) ((unsigned long) p + IA64_STK_OFFSET) - 1;
diff --git a/arch/m32r/kernel/process.c b/arch/m32r/kernel/process.c
index c37e9a9a8f27..765d0f57c787 100644
--- a/arch/m32r/kernel/process.c
+++ b/arch/m32r/kernel/process.c
@@ -192,7 +192,7 @@ int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
 }
 
 int copy_thread(unsigned long clone_flags, unsigned long spu,
-	unsigned long arg, struct task_struct *tsk, struct pt_regs *unused)
+	unsigned long arg, struct task_struct *tsk)
 {
 	struct pt_regs *childregs = task_pt_regs(tsk);
 	extern void ret_from_fork(void);
diff --git a/arch/m68k/kernel/process.c b/arch/m68k/kernel/process.c
index aa9b11000273..9a3df4df73cc 100644
--- a/arch/m68k/kernel/process.c
+++ b/arch/m68k/kernel/process.c
@@ -154,8 +154,7 @@ asmlinkage int m68k_clone(struct pt_regs *regs)
 }
 
 int copy_thread(unsigned long clone_flags, unsigned long usp,
-		 unsigned long arg,
-		 struct task_struct * p, struct pt_regs * unused)
+		 unsigned long arg, struct task_struct *p)
 {
 	struct fork_frame {
 		struct switch_stack sw;
diff --git a/arch/microblaze/kernel/process.c b/arch/microblaze/kernel/process.c
index a5fed8db7263..40823fd1db0b 100644
--- a/arch/microblaze/kernel/process.c
+++ b/arch/microblaze/kernel/process.c
@@ -120,8 +120,7 @@ void flush_thread(void)
 }
 
 int copy_thread(unsigned long clone_flags, unsigned long usp,
-		unsigned long arg,
-		struct task_struct *p, struct pt_regs *unused)
+		unsigned long arg, struct task_struct *p)
 {
 	struct pt_regs *childregs = task_pt_regs(p);
 	struct thread_info *ti = task_thread_info(p);
diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c
index d13720ac656f..38097652d62d 100644
--- a/arch/mips/kernel/process.c
+++ b/arch/mips/kernel/process.c
@@ -114,10 +114,10 @@ void flush_thread(void)
 }
 
 int copy_thread(unsigned long clone_flags, unsigned long usp,
-	unsigned long arg, struct task_struct *p, struct pt_regs *regs)
+	unsigned long arg, struct task_struct *p)
 {
 	struct thread_info *ti = task_thread_info(p);
-	struct pt_regs *childregs;
+	struct pt_regs *childregs, *regs = current_pt_regs();
 	unsigned long childksp;
 	p->set_child_tid = p->clear_child_tid = NULL;
 
diff --git a/arch/mn10300/kernel/process.c b/arch/mn10300/kernel/process.c
index 5e0ef396458d..eb09f5a552ff 100644
--- a/arch/mn10300/kernel/process.c
+++ b/arch/mn10300/kernel/process.c
@@ -206,7 +206,7 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
  */
 int copy_thread(unsigned long clone_flags,
 		unsigned long c_usp, unsigned long ustk_size,
-		struct task_struct *p, struct pt_regs *unused)
+		struct task_struct *p)
 {
 	struct thread_info *ti = task_thread_info(p);
 	struct pt_regs *c_regs;
diff --git a/arch/openrisc/kernel/process.c b/arch/openrisc/kernel/process.c
index 6b853668369b..00c233bf0d06 100644
--- a/arch/openrisc/kernel/process.c
+++ b/arch/openrisc/kernel/process.c
@@ -142,7 +142,7 @@ extern asmlinkage void ret_from_fork(void);
 
 int
 copy_thread(unsigned long clone_flags, unsigned long usp,
-	    unsigned long arg, struct task_struct *p, struct pt_regs *regs)
+	    unsigned long arg, struct task_struct *p)
 {
 	struct pt_regs *userregs;
 	struct pt_regs *kregs;
diff --git a/arch/parisc/kernel/process.c b/arch/parisc/kernel/process.c
index 9753ecf49a06..d13507246c5d 100644
--- a/arch/parisc/kernel/process.c
+++ b/arch/parisc/kernel/process.c
@@ -204,10 +204,9 @@ int dump_task_fpu (struct task_struct *tsk, elf_fpregset_t *r)
 
 int
 copy_thread(unsigned long clone_flags, unsigned long usp,
-	    unsigned long arg,
-	    struct task_struct *p, struct pt_regs *unused)
+	    unsigned long arg, struct task_struct *p)
 {
-	struct pt_regs * cregs = &(p->thread.regs);
+	struct pt_regs *cregs = &(p->thread.regs);
 	void *stack = task_stack_page(p);
 	
 	/* We have to use void * instead of a function pointer, because
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index a31437567631..81430674e71c 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -733,8 +733,7 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
 extern unsigned long dscr_default; /* defined in arch/powerpc/kernel/sysfs.c */
 
 int copy_thread(unsigned long clone_flags, unsigned long usp,
-		unsigned long arg, struct task_struct *p,
-		struct pt_regs *regs)
+		unsigned long arg, struct task_struct *p)
 {
 	struct pt_regs *childregs, *kregs;
 	extern void ret_from_fork(void);
@@ -759,6 +758,7 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
 		ti->flags |= _TIF_RESTOREALL;
 		f = ret_from_kernel_thread;
 	} else {
+		struct pt_regs *regs = current_pt_regs();
 		CHECK_FULL_REGS(regs);
 		*childregs = *regs;
 		if (usp)
diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c
index e37677796a09..536d64579d9a 100644
--- a/arch/s390/kernel/process.c
+++ b/arch/s390/kernel/process.c
@@ -117,8 +117,7 @@ void release_thread(struct task_struct *dead_task)
 }
 
 int copy_thread(unsigned long clone_flags, unsigned long new_stackp,
-		unsigned long arg,
-		struct task_struct *p, struct pt_regs *unused)
+		unsigned long arg, struct task_struct *p)
 {
 	struct thread_info *ti;
 	struct fake_frame
diff --git a/arch/score/kernel/process.c b/arch/score/kernel/process.c
index f96379a5aee0..79568466b578 100644
--- a/arch/score/kernel/process.c
+++ b/arch/score/kernel/process.c
@@ -87,11 +87,11 @@ void flush_thread(void) {}
  * set up the kernel stack and exception frames for a new process
  */
 int copy_thread(unsigned long clone_flags, unsigned long usp,
-		unsigned long arg,
-		struct task_struct *p, struct pt_regs *regs)
+		unsigned long arg, struct task_struct *p)
 {
 	struct thread_info *ti = task_thread_info(p);
 	struct pt_regs *childregs = task_pt_regs(p);
+	struct pt_regs *regs = current_pt_regs();
 
 	p->thread.reg0 = (unsigned long) childregs;
 	if (unlikely(p->flags & PF_KTHREAD)) {
diff --git a/arch/sh/kernel/process_32.c b/arch/sh/kernel/process_32.c
index 1786d16b6c64..73eb66fc6253 100644
--- a/arch/sh/kernel/process_32.c
+++ b/arch/sh/kernel/process_32.c
@@ -128,8 +128,7 @@ asmlinkage void ret_from_fork(void);
 asmlinkage void ret_from_kernel_thread(void);
 
 int copy_thread(unsigned long clone_flags, unsigned long usp,
-		unsigned long arg,
-		struct task_struct *p, struct pt_regs *unused)
+		unsigned long arg, struct task_struct *p)
 {
 	struct thread_info *ti = task_thread_info(p);
 	struct pt_regs *childregs;
diff --git a/arch/sh/kernel/process_64.c b/arch/sh/kernel/process_64.c
index d5c86a8a3849..e611c85144b1 100644
--- a/arch/sh/kernel/process_64.c
+++ b/arch/sh/kernel/process_64.c
@@ -371,10 +371,9 @@ asmlinkage void ret_from_fork(void);
 asmlinkage void ret_from_kernel_thread(void);
 
 int copy_thread(unsigned long clone_flags, unsigned long usp,
-		unsigned long arg,
-		struct task_struct *p, struct pt_regs *regs)
+		unsigned long arg, struct task_struct *p)
 {
-	struct pt_regs *childregs;
+	struct pt_regs *childregs, *regs = current_pt_regs();
 
 #ifdef CONFIG_SH_FPU
 	/* can't happen for a kernel thread */
diff --git a/arch/sparc/kernel/process_32.c b/arch/sparc/kernel/process_32.c
index bf4c6addce7b..ecde946ef834 100644
--- a/arch/sparc/kernel/process_32.c
+++ b/arch/sparc/kernel/process_32.c
@@ -319,11 +319,10 @@ extern void ret_from_fork(void);
 extern void ret_from_kernel_thread(void);
 
 int copy_thread(unsigned long clone_flags, unsigned long sp,
-		unsigned long arg,
-		struct task_struct *p, struct pt_regs *regs)
+		unsigned long arg, struct task_struct *p)
 {
 	struct thread_info *ti = task_thread_info(p);
-	struct pt_regs *childregs;
+	struct pt_regs *childregs, *regs = current_pt_regs();
 	char *new_stack;
 
 #ifndef CONFIG_SMP
diff --git a/arch/sparc/kernel/process_64.c b/arch/sparc/kernel/process_64.c
index dff54f46728d..58ef19e7e82f 100644
--- a/arch/sparc/kernel/process_64.c
+++ b/arch/sparc/kernel/process_64.c
@@ -622,10 +622,10 @@ asmlinkage long sparc_do_fork(unsigned long clone_flags,
  * Child  -->  %o0 == parents pid, %o1 == 1
  */
 int copy_thread(unsigned long clone_flags, unsigned long sp,
-		unsigned long arg,
-		struct task_struct *p, struct pt_regs *regs)
+		unsigned long arg, struct task_struct *p)
 {
 	struct thread_info *t = task_thread_info(p);
+	struct pt_regs *regs = current_pt_regs();
 	struct sparc_stackf *parent_sf;
 	unsigned long child_stack_sz;
 	char *child_trap_frame;
diff --git a/arch/tile/kernel/process.c b/arch/tile/kernel/process.c
index 267936b51b59..0e5661e7d00d 100644
--- a/arch/tile/kernel/process.c
+++ b/arch/tile/kernel/process.c
@@ -157,10 +157,9 @@ void arch_release_thread_info(struct thread_info *info)
 static void save_arch_state(struct thread_struct *t);
 
 int copy_thread(unsigned long clone_flags, unsigned long sp,
-		unsigned long arg,
-		struct task_struct *p, struct pt_regs *unused)
+		unsigned long arg, struct task_struct *p)
 {
-	struct pt_regs *childregs = task_pt_regs(p);
+	struct pt_regs *childregs = task_pt_regs(p), *regs = current_pt_regs();
 	unsigned long ksp;
 	unsigned long *callee_regs;
 
diff --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c
index c502c804e8bb..b462b13c5bae 100644
--- a/arch/um/kernel/process.c
+++ b/arch/um/kernel/process.c
@@ -161,8 +161,7 @@ void fork_handler(void)
 }
 
 int copy_thread(unsigned long clone_flags, unsigned long sp,
-		unsigned long arg, struct task_struct * p,
-		struct pt_regs *regs)
+		unsigned long arg, struct task_struct * p)
 {
 	void (*handler)(void);
 	int kthread = current->flags & PF_KTHREAD;
diff --git a/arch/unicore32/kernel/process.c b/arch/unicore32/kernel/process.c
index 79e44e8ae31c..62bad9fed03e 100644
--- a/arch/unicore32/kernel/process.c
+++ b/arch/unicore32/kernel/process.c
@@ -262,7 +262,7 @@ asmlinkage void ret_from_kernel_thread(void) __asm__("ret_from_kernel_thread");
 
 int
 copy_thread(unsigned long clone_flags, unsigned long stack_start,
-	    unsigned long stk_sz, struct task_struct *p, struct pt_regs *unused)
+	    unsigned long stk_sz, struct task_struct *p)
 {
 	struct thread_info *thread = task_thread_info(p);
 	struct pt_regs *childregs = task_pt_regs(p);
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index 16efa974532b..b5a8905785e6 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -128,8 +128,7 @@ void release_thread(struct task_struct *dead_task)
 }
 
 int copy_thread(unsigned long clone_flags, unsigned long sp,
-	unsigned long arg,
-	struct task_struct *p, struct pt_regs *unused)
+	unsigned long arg, struct task_struct *p)
 {
 	struct pt_regs *childregs = task_pt_regs(p);
 	struct task_struct *tsk;
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 74aac76c6e34..6e68a6194965 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -146,8 +146,7 @@ static inline u32 read_32bit_tls(struct task_struct *t, int tls)
 }
 
 int copy_thread(unsigned long clone_flags, unsigned long sp,
-		unsigned long arg,
-	struct task_struct *p, struct pt_regs *regs)
+		unsigned long arg, struct task_struct *p)
 {
 	int err;
 	struct pt_regs *childregs;
diff --git a/arch/xtensa/kernel/process.c b/arch/xtensa/kernel/process.c
index 0036c14739f8..1accf28da5f5 100644
--- a/arch/xtensa/kernel/process.c
+++ b/arch/xtensa/kernel/process.c
@@ -199,8 +199,7 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
  */
 
 int copy_thread(unsigned long clone_flags, unsigned long usp_thread_fn,
-		unsigned long thread_fn_arg,
-		struct task_struct *p, struct pt_regs *unused)
+		unsigned long thread_fn_arg, struct task_struct *p)
 {
 	struct pt_regs *childregs = task_pt_regs(p);
 
diff --git a/include/linux/sched.h b/include/linux/sched.h
index c57249782e48..78a2ae3470df 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -2271,7 +2271,7 @@ extern void mm_release(struct task_struct *, struct mm_struct *);
 extern struct mm_struct *dup_mm(struct task_struct *tsk);
 
 extern int copy_thread(unsigned long, unsigned long, unsigned long,
-			struct task_struct *, struct pt_regs *);
+			struct task_struct *);
 extern void flush_thread(void);
 extern void exit_thread(void);
 
diff --git a/kernel/fork.c b/kernel/fork.c
index 27a337549dab..d96a562b1311 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1320,7 +1320,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 	retval = copy_io(clone_flags, p);
 	if (retval)
 		goto bad_fork_cleanup_namespaces;
-	retval = copy_thread(clone_flags, stack_start, stack_size, p, regs);
+	retval = copy_thread(clone_flags, stack_start, stack_size, p);
 	if (retval)
 		goto bad_fork_cleanup_io;
 
-- 
cgit