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

12 files changed, 45 insertions, 174 deletions

diff --git a/arch/frv/Kconfig b/arch/frv/Kconfig
index 9d262645f667..b7412504f08a 100644
--- a/arch/frv/Kconfig
+++ b/arch/frv/Kconfig
@@ -12,6 +12,7 @@ config FRV
 	select ARCH_HAVE_NMI_SAFE_CMPXCHG
 	select GENERIC_CPU_DEVICES
 	select ARCH_WANT_IPC_PARSE_VERSION
+	select GENERIC_KERNEL_THREAD
 
 config ZONE_DMA
 	bool
diff --git a/arch/frv/include/asm/processor.h b/arch/frv/include/asm/processor.h
index dccb9d162318..a34f309e5801 100644
--- a/arch/frv/include/asm/processor.h
+++ b/arch/frv/include/asm/processor.h
@@ -92,14 +92,12 @@ extern struct task_struct *__kernel_current_task;
 
 /*
  * do necessary setup to start up a newly executed thread.
- * - need to discard the frame stacked by init() invoking the execve syscall
  */
 #define start_thread(_regs, _pc, _usp)			\
 do {							\
-	__frame = __kernel_frame0_ptr;			\
-	__frame->pc	= (_pc);			\
-	__frame->psr	&= ~PSR_S;			\
-	__frame->sp	= (_usp);			\
+	_regs->pc	= (_pc);			\
+	_regs->psr	&= ~PSR_S;			\
+	_regs->sp	= (_usp);			\
 } while(0)
 
 /* Free all resources held by a thread. */
@@ -107,7 +105,6 @@ static inline void release_thread(struct task_struct *dead_task)
 {
 }
 
-extern asmlinkage int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
 extern asmlinkage void save_user_regs(struct user_context *target);
 extern asmlinkage void *restore_user_regs(const struct user_context *target, ...);
 
diff --git a/arch/frv/include/asm/ptrace.h b/arch/frv/include/asm/ptrace.h
index ef6635ca4ecb..bd534b2d0258 100644
--- a/arch/frv/include/asm/ptrace.h
+++ b/arch/frv/include/asm/ptrace.h
@@ -76,6 +76,7 @@ register struct pt_regs *__frame asm("gr28");
 #define user_mode(regs)			(!((regs)->psr & PSR_S))
 #define instruction_pointer(regs)	((regs)->pc)
 #define user_stack_pointer(regs)	((regs)->sp)
+#define current_pt_regs()		(__frame)
 
 extern unsigned long user_stack(const struct pt_regs *);
 #define profile_pc(regs) ((regs)->pc)
diff --git a/arch/frv/include/asm/thread_info.h b/arch/frv/include/asm/thread_info.h
index 0ff03a33c81e..bebd7eadc772 100644
--- a/arch/frv/include/asm/thread_info.h
+++ b/arch/frv/include/asm/thread_info.h
@@ -94,7 +94,6 @@ register struct thread_info *__current_thread_info asm("gr15");
 #define TIF_NEED_RESCHED	3	/* rescheduling necessary */
 #define TIF_SINGLESTEP		4	/* restore singlestep on return to user mode */
 #define TIF_RESTORE_SIGMASK	5	/* restore signal mask in do_signal() */
-#define TIF_POLLING_NRFLAG	6	/* true if poll_idle() is polling TIF_NEED_RESCHED */
 #define TIF_MEMDIE		7	/* is terminating due to OOM killer */
 
 #define _TIF_SYSCALL_TRACE	(1 << TIF_SYSCALL_TRACE)
@@ -102,8 +101,6 @@ register struct thread_info *__current_thread_info asm("gr15");
 #define _TIF_SIGPENDING		(1 << TIF_SIGPENDING)
 #define _TIF_NEED_RESCHED	(1 << TIF_NEED_RESCHED)
 #define _TIF_SINGLESTEP		(1 << TIF_SINGLESTEP)
-#define _TIF_RESTORE_SIGMASK	(1 << TIF_RESTORE_SIGMASK)
-#define _TIF_POLLING_NRFLAG	(1 << TIF_POLLING_NRFLAG)
 
 /* work to do on interrupt/exception return */
 #define _TIF_WORK_MASK		\
diff --git a/arch/frv/include/asm/unistd.h b/arch/frv/include/asm/unistd.h
index 67f23a311db6..b6b07e55e473 100644
--- a/arch/frv/include/asm/unistd.h
+++ b/arch/frv/include/asm/unistd.h
@@ -372,6 +372,8 @@
 #define __ARCH_WANT_SYS_SIGPROCMASK
 #define __ARCH_WANT_SYS_RT_SIGACTION
 #define __ARCH_WANT_SYS_RT_SIGSUSPEND
+#define __ARCH_WANT_SYS_EXECVE
+#define __ARCH_WANT_KERNEL_EXECVE
 
 /*
  * "Conditional" syscalls
diff --git a/arch/frv/kernel/Makefile b/arch/frv/kernel/Makefile
index ad4087b69968..3cbb3294b9f9 100644
--- a/arch/frv/kernel/Makefile
+++ b/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
 
diff --git a/arch/frv/kernel/entry.S b/arch/frv/kernel/entry.S
index 7d5e000fd32e..002732960315 100644
--- a/arch/frv/kernel/entry.S
+++ b/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,
diff --git a/arch/frv/kernel/frv_ksyms.c b/arch/frv/kernel/frv_ksyms.c
index a89803b58b9a..86c516d96dcd 100644
--- a/arch/frv/kernel/frv_ksyms.c
+++ b/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);
diff --git a/arch/frv/kernel/kernel_execve.S b/arch/frv/kernel/kernel_execve.S
deleted file mode 100644
index 9b074a16a052..000000000000
--- a/arch/frv/kernel/kernel_execve.S
+++ /dev/null
@@ -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
diff --git a/arch/frv/kernel/kernel_thread.S b/arch/frv/kernel/kernel_thread.S
deleted file mode 100644
index f0e52943f923..000000000000
--- a/arch/frv/kernel/kernel_thread.S
+++ /dev/null
@@ -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
diff --git a/arch/frv/kernel/process.c b/arch/frv/kernel/process.c
index 2eb7fa5bf9d8..655d90d20bb0 100644
--- a/arch/frv/kernel/process.c
+++ b/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;
diff --git a/arch/frv/kernel/signal.c b/arch/frv/kernel/signal.c
index 864c2f0d497b..535810a3217a 100644
--- a/arch/frv/kernel/signal.c
+++ b/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,