Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal

Pull pile 2 of execve and kernel_thread unification work from Al Viro:
 "Stuff in there: kernel_thread/kernel_execve/sys_execve conversions for
  several more architectures plus assorted signal fixes and cleanups.

  There'll be more (in particular, real fixes for the alpha
  do_notify_resume() irq mess)..."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (43 commits)
  alpha: don't open-code trace_report_syscall_{enter,exit}
  Uninclude linux/freezer.h
  m32r: trim masks
  avr32: trim masks
  tile: don't bother with SIGTRAP in setup_frame
  microblaze: don't bother with SIGTRAP in setup_rt_frame()
  mn10300: don't bother with SIGTRAP in setup_frame()
  frv: no need to raise SIGTRAP in setup_frame()
  x86: get rid of duplicate code in case of CONFIG_VM86
  unicore32: remove pointless test
  h8300: trim _TIF_WORK_MASK
  parisc: decide whether to go to slow path (tracesys) based on thread flags
  parisc: don't bother looping in do_signal()
  parisc: fix double restarts
  bury the rest of TIF_IRET
  sanitize tsk_is_polling()
  bury _TIF_RESTORE_SIGMASK
  unicore32: unobfuscate _TIF_WORK_MASK
  mips: NOTIFY_RESUME is not needed in TIF masks
  mips: merge the identical "return from syscall" per-ABI code
  ...

Conflicts:
	arch/arm/include/asm/thread_info.h

arch/frv/kernel/Makefile

@@ -7,8 +7,8 @@ heads-$(CONFIG_MMU)		:= head-mmu-fr451.o
 
 extra-y:= head.o vmlinux.lds
 
-obj-y := $(heads-y) entry.o entry-table.o break.o switch_to.o kernel_thread.o \
-	 kernel_execve.o process.o traps.o ptrace.o signal.o dma.o \
+obj-y := $(heads-y) entry.o entry-table.o break.o switch_to.o \
+	 process.o traps.o ptrace.o signal.o dma.o \
 	 sys_frv.o time.o setup.o frv_ksyms.o \
 	 debug-stub.o irq.o sleep.o uaccess.o
 

arch/frv/kernel/entry.S

@@ -863,6 +863,19 @@ ret_from_fork:
 	setlos.p	#0,gr8
 	bra		__syscall_exit
 
+	.globl		ret_from_kernel_thread
+ret_from_kernel_thread:
+	lddi.p		@(gr28,#REG_GR(8)),gr20
+	call		schedule_tail
+	or.p		gr20,gr20,gr8
+	calll		@(gr21,gr0)
+	bra		sys_exit
+
+	.globl		ret_from_kernel_execve
+ret_from_kernel_execve:
+	ori		gr28,0,sp
+	bra		__syscall_exit
+
 ###################################################################################################
 #
 # Return to user mode is not as complex as all this looks,

arch/frv/kernel/frv_ksyms.c

@@ -30,7 +30,6 @@ EXPORT_SYMBOL(ip_fast_csum);
 EXPORT_SYMBOL(local_irq_count);
 EXPORT_SYMBOL(local_bh_count);
 #endif
-EXPORT_SYMBOL(kernel_thread);
 
 EXPORT_SYMBOL(__res_bus_clock_speed_HZ);
 EXPORT_SYMBOL(__page_offset);

arch/frv/kernel/kernel_execve.S

@@ -1,33 +0,0 @@
-/* in-kernel program execution
- *
- * Copyright (C) 2006 Red Hat, Inc. All Rights Reserved.
- * Written by David Howells (dhowells@redhat.com)
- *
- * 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.
- */
-
-#include <linux/linkage.h>
-#include <asm/unistd.h>
-
-###############################################################################
-#
-# Do a system call from kernel instead of calling sys_execve so we end up with
-# proper pt_regs.
-#
-# int kernel_execve(const char *filename, char *const argv[], char *const envp[])
-#
-# On entry: GR8/GR9/GR10: arguments to function
-# On return: GR8: syscall return.
-#
-###############################################################################
-	.globl		kernel_execve
-	.type		kernel_execve,@function
-kernel_execve:
-	setlos		__NR_execve,gr7
-	tira		gr0,#0
-	bralr
-
-	.size		kernel_execve,.-kernel_execve

arch/frv/kernel/kernel_thread.S

@@ -1,77 +0,0 @@
-/* kernel_thread.S: kernel thread creation
- *
- * Copyright (C) 2003 Red Hat, Inc. All Rights Reserved.
- * Written by David Howells (dhowells@redhat.com)
- *
- * 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.
- */
-
-#include <linux/linkage.h>
-#include <linux/kern_levels.h>
-#include <asm/unistd.h>
-
-#define CLONE_VM	0x00000100	/* set if VM shared between processes */
-
-	.section .rodata
-kernel_thread_emsg:
-	.asciz	KERN_ERR "failed to create kernel thread: error=%d\n"
-
-	.text
-	.balign		4
-
-###############################################################################
-#
-# Create a kernel thread
-#
-# int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
-#
-###############################################################################
-	.globl		kernel_thread
-	.type		kernel_thread,@function
-kernel_thread:
-	or.p		gr8,gr0,gr4
-	or		gr9,gr0,gr5
-
-	# start by forking the current process, but with shared VM
-	setlos.p	#__NR_clone,gr7		; syscall number
-	ori		gr10,#CLONE_VM,gr8	; first syscall arg	[clone_flags]
-	sethi.p		#0xe4e4,gr9		; second syscall arg	[newsp]
-	setlo		#0xe4e4,gr9
-	setlos.p	#0,gr10			; third syscall arg	[parent_tidptr]
-	setlos		#0,gr11			; fourth syscall arg	[child_tidptr]
-	tira		gr0,#0
-	setlos.p	#4095,gr7
-	andcc		gr8,gr8,gr0,icc0
-	addcc.p		gr8,gr7,gr0,icc1
-	bnelr		icc0,#2
-	bc		icc1,#0,kernel_thread_error
-
-	# now invoke the work function
-	or		gr5,gr0,gr8
-	calll		@(gr4,gr0)
-
-	# and finally exit the thread
-	setlos		#__NR_exit,gr7		; syscall number
-	tira		gr0,#0
-
-kernel_thread_error:
-	subi		sp,#8,sp
-	movsg		lr,gr4
-	sti		gr8,@(sp,#0)
-	sti.p		gr4,@(sp,#4)
-
-	or		gr8,gr0,gr9
-	sethi.p		%hi(kernel_thread_emsg),gr8
-	setlo		%lo(kernel_thread_emsg),gr8
-
-	call		printk
-
-	ldi		@(sp,#4),gr4
-	ldi		@(sp,#0),gr8
-	subi		sp,#8,sp
-	jmpl		@(gr4,gr0)
-
-	.size		kernel_thread,.-kernel_thread

arch/frv/kernel/process.c

@@ -38,6 +38,7 @@
 #include "local.h"
 
 asmlinkage void ret_from_fork(void);
+asmlinkage void ret_from_kernel_thread(void);
 
 #include <asm/pgalloc.h>
 
@@ -172,32 +173,13 @@ asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
  * set up the kernel stack and exception frames for a new process
  */
 int copy_thread(unsigned long clone_flags,
-		unsigned long usp, unsigned long topstk,
+		unsigned long usp, unsigned long arg,
 		struct task_struct *p, struct pt_regs *regs)
 {
-	struct pt_regs *childregs0, *childregs, *regs0;
+	struct pt_regs *childregs;
 
-	regs0 = __kernel_frame0_ptr;
-	childregs0 = (struct pt_regs *)
+	childregs = (struct pt_regs *)
 		(task_stack_page(p) + THREAD_SIZE - FRV_FRAME0_SIZE);
-	childregs = childregs0;
-
-	/* set up the userspace frame (the only place that the USP is stored) */
-	*childregs0 = *regs0;
-
-	childregs0->gr8		= 0;
-	childregs0->sp		= usp;
-	childregs0->next_frame	= NULL;
-
-	/* set up the return kernel frame if called from kernel_thread() */
-	if (regs != regs0) {
-		childregs--;
-		*childregs = *regs;
-		childregs->sp = (unsigned long) childregs0;
-		childregs->next_frame = childregs0;
-		childregs->gr15 = (unsigned long) task_thread_info(p);
-		childregs->gr29 = (unsigned long) p;
-	}
 
 	p->set_child_tid = p->clear_child_tid = NULL;
 
@@ -206,8 +188,25 @@ int copy_thread(unsigned long clone_flags,
 	p->thread.sp	 = (unsigned long) childregs;
 	p->thread.fp	 = 0;
 	p->thread.lr	 = 0;
-	p->thread.pc	 = (unsigned long) ret_from_fork;
-	p->thread.frame0 = childregs0;
+	p->thread.frame0 = childregs;
+
+	if (unlikely(!regs)) {
+		memset(childregs, 0, sizeof(struct pt_regs));
+		childregs->gr9 = usp; /* function */
+		childregs->gr8 = arg;
+		chilregs->psr = PSR_S;
+		p->thread.pc = (unsigned long) ret_from_kernel_thread;
+		save_user_regs(p->thread.user);
+		return 0;
+	}
+
+	/* set up the userspace frame (the only place that the USP is stored) */
+	*childregs = *regs;
+
+	childregs->sp		= usp;
+	childregs->next_frame	= NULL;
+
+	p->thread.pc = (unsigned long) ret_from_fork;
 
 	/* the new TLS pointer is passed in as arg #5 to sys_clone() */
 	if (clone_flags & CLONE_SETTLS)
@@ -218,25 +217,6 @@ int copy_thread(unsigned long clone_flags,
 	return 0;
 } /* end copy_thread() */
 
-/*
- * sys_execve() executes a new program.
- */
-asmlinkage int sys_execve(const char __user *name,
-			  const char __user *const __user *argv,
-			  const char __user *const __user *envp)
-{
-	int error;
-	char * filename;
-
-	filename = getname(name);
-	error = PTR_ERR(filename);
-	if (IS_ERR(filename))
-		return error;
-	error = do_execve(filename, argv, envp, __frame);
-	putname(filename);
-	return error;
-}
-
 unsigned long get_wchan(struct task_struct *p)
 {
 	struct pt_regs *regs0;

arch/frv/kernel/signal.c

@@ -20,7 +20,6 @@
 #include <linux/ptrace.h>
 #include <linux/unistd.h>
 #include <linux/personality.h>
-#include <linux/freezer.h>
 #include <linux/tracehook.h>
 #include <asm/ucontext.h>
 #include <asm/uaccess.h>
@@ -298,10 +297,6 @@ static int setup_frame(int sig, struct k_sigaction *ka, sigset_t *set)
 	__frame->lr   = (unsigned long) &frame->retcode;
 	__frame->gr8  = sig;
 
-	/* the tracer may want to single-step inside the handler */
-	if (test_thread_flag(TIF_SINGLESTEP))
-		ptrace_notify(SIGTRAP);
-
 #if DEBUG_SIG
 	printk("SIG deliver %d (%s:%d): sp=%p pc=%lx ra=%p\n",
 	       sig, current->comm, current->pid, frame, __frame->pc,
@@ -400,10 +395,6 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
 	__frame->gr8 = sig;
 	__frame->gr9 = (unsigned long) &frame->info;
 
-	/* the tracer may want to single-step inside the handler */
-	if (test_thread_flag(TIF_SINGLESTEP))
-		ptrace_notify(SIGTRAP);
-
 #if DEBUG_SIG
 	printk("SIG deliver %d (%s:%d): sp=%p pc=%lx ra=%p\n",
 	       sig, current->comm, current->pid, frame, __frame->pc,