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

Pull big execve/kernel_thread/fork unification series from Al Viro:
 "All architectures are converted to new model.  Quite a bit of that
  stuff is actually shared with architecture trees; in such cases it's
  literally shared branch pulled by both, not a cherry-pick.

  A lot of ugliness and black magic is gone (-3KLoC total in this one):

   - kernel_thread()/kernel_execve()/sys_execve() redesign.

     We don't do syscalls from kernel anymore for either kernel_thread()
     or kernel_execve():

     kernel_thread() is essentially clone(2) with callback run before we
     return to userland, the callbacks either never return or do
     successful do_execve() before returning.

     kernel_execve() is a wrapper for do_execve() - it doesn't need to
     do transition to user mode anymore.

     As a result kernel_thread() and kernel_execve() are
     arch-independent now - they live in kernel/fork.c and fs/exec.c
     resp.  sys_execve() is also in fs/exec.c and it's completely
     architecture-independent.

   - daemonize() is gone, along with its parts in fs/*.c

   - struct pt_regs * is no longer passed to do_fork/copy_process/
     copy_thread/do_execve/search_binary_handler/->load_binary/do_coredump.

   - sys_fork()/sys_vfork()/sys_clone() unified; some architectures
     still need wrappers (ones with callee-saved registers not saved in
     pt_regs on syscall entry), but the main part of those suckers is in
     kernel/fork.c now."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (113 commits)
  do_coredump(): get rid of pt_regs argument
  print_fatal_signal(): get rid of pt_regs argument
  ptrace_signal(): get rid of unused arguments
  get rid of ptrace_signal_deliver() arguments
  new helper: signal_pt_regs()
  unify default ptrace_signal_deliver
  flagday: kill pt_regs argument of do_fork()
  death to idle_regs()
  don't pass regs to copy_process()
  flagday: don't pass regs to copy_thread()
  bfin: switch to generic vfork, get rid of pointless wrappers
  xtensa: switch to generic clone()
  openrisc: switch to use of generic fork and clone
  unicore32: switch to generic clone(2)
  score: switch to generic fork/vfork/clone
  c6x: sanitize copy_thread(), get rid of clone(2) wrapper, switch to generic clone()
  take sys_fork/sys_vfork/sys_clone prototypes to linux/syscalls.h
  mn10300: switch to generic fork/vfork/clone
  h8300: switch to generic fork/vfork/clone
  tile: switch to generic clone()
  ...

Conflicts:
	arch/microblaze/include/asm/Kbuild

10 files changed, 39 insertions, 159 deletions

diff --git a/arch/avr32/Kconfig b/arch/avr32/Kconfig
index c2bbc9a72222..202d71a15be1 100644
--- a/arch/avr32/Kconfig
+++ b/arch/avr32/Kconfig
@@ -17,6 +17,8 @@ config AVR32
 	select GENERIC_CLOCKEVENTS
 	select HAVE_MOD_ARCH_SPECIFIC
 	select MODULES_USE_ELF_RELA
+	select GENERIC_KERNEL_THREAD
+	select GENERIC_KERNEL_EXECVE
 	help
 	  AVR32 is a high-performance 32-bit RISC microprocessor core,
 	  designed for cost-sensitive embedded applications, with particular
diff --git a/arch/avr32/include/asm/processor.h b/arch/avr32/include/asm/processor.h
index 87d8baccc60e..48d71c5c898a 100644
--- a/arch/avr32/include/asm/processor.h
+++ b/arch/avr32/include/asm/processor.h
@@ -142,9 +142,6 @@ struct task_struct;
 /* Free all resources held by a thread */
 extern void release_thread(struct task_struct *);
 
-/* Create a kernel thread without removing it from tasklists */
-extern int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
-
 /* Return saved PC of a blocked thread */
 #define thread_saved_pc(tsk)    ((tsk)->thread.cpu_context.pc)
 
diff --git a/arch/avr32/include/asm/signal.h b/arch/avr32/include/asm/signal.h
index 4d502fd6bad3..9326d182e9e5 100644
--- a/arch/avr32/include/asm/signal.h
+++ b/arch/avr32/include/asm/signal.h
@@ -37,6 +37,4 @@ struct k_sigaction {
 #include <asm/sigcontext.h>
 #undef __HAVE_ARCH_SIG_BITOPS
 
-#define ptrace_signal_deliver(regs, cookie) do { } while (0)
-
 #endif
diff --git a/arch/avr32/include/asm/unistd.h b/arch/avr32/include/asm/unistd.h
index 157b4bd3d5e5..f05a9804e8e2 100644
--- a/arch/avr32/include/asm/unistd.h
+++ b/arch/avr32/include/asm/unistd.h
@@ -39,6 +39,10 @@
 #define __ARCH_WANT_SYS_GETPGRP
 #define __ARCH_WANT_SYS_RT_SIGACTION
 #define __ARCH_WANT_SYS_RT_SIGSUSPEND
+#define __ARCH_WANT_SYS_EXECVE
+#define __ARCH_WANT_SYS_FORK
+#define __ARCH_WANT_SYS_VFORK
+#define __ARCH_WANT_SYS_CLONE
 
 /*
  * "Conditional" syscalls
diff --git a/arch/avr32/kernel/Makefile b/arch/avr32/kernel/Makefile
index 9e2c465ef3a6..119a2e41defe 100644
--- a/arch/avr32/kernel/Makefile
+++ b/arch/avr32/kernel/Makefile
@@ -7,7 +7,7 @@ extra-y				:= head.o vmlinux.lds
 obj-$(CONFIG_SUBARCH_AVR32B)	+= entry-avr32b.o
 obj-y				+= syscall_table.o syscall-stubs.o irq.o
 obj-y				+= setup.o traps.o ocd.o ptrace.o
-obj-y				+= signal.o sys_avr32.o process.o time.o
+obj-y				+= signal.o process.o time.o
 obj-y				+= switch_to.o cpu.o
 obj-$(CONFIG_MODULES)		+= module.o avr32_ksyms.o
 obj-$(CONFIG_KPROBES)		+= kprobes.o
diff --git a/arch/avr32/kernel/entry-avr32b.S b/arch/avr32/kernel/entry-avr32b.S
index df2884181313..9899d3cc6f03 100644
--- a/arch/avr32/kernel/entry-avr32b.S
+++ b/arch/avr32/kernel/entry-avr32b.S
@@ -251,13 +251,15 @@ syscall_badsys:
 	.global ret_from_fork
 ret_from_fork:
 	call   schedule_tail
+	mov	r12, 0
+	rjmp	syscall_return
 
-	/* check for syscall tracing */
-	get_thread_info r0
-	ld.w	r1, r0[TI_flags]
-	andl	r1, _TIF_ALLWORK_MASK, COH
-	brne	syscall_exit_work
-	rjmp    syscall_exit_cont
+	.global ret_from_kernel_thread
+ret_from_kernel_thread:
+	call   schedule_tail
+	mov	r12, r0
+	mov	lr, r2	/* syscall_return */
+	mov	pc, r1
 
 syscall_trace_enter:
 	pushm	r8-r12
diff --git a/arch/avr32/kernel/process.c b/arch/avr32/kernel/process.c
index 1bb0a8abd79b..fd78f58ea79a 100644
--- a/arch/avr32/kernel/process.c
+++ b/arch/avr32/kernel/process.c
@@ -69,44 +69,6 @@ void machine_restart(char *cmd)
 }
 
 /*
- * PC is actually discarded when returning from a system call -- the
- * return address must be stored in LR. This function will make sure
- * LR points to do_exit before starting the thread.
- *
- * Also, when returning from fork(), r12 is 0, so we must copy the
- * argument as well.
- *
- *  r0 : The argument to the main thread function
- *  r1 : The address of do_exit
- *  r2 : The address of the main thread function
- */
-asmlinkage extern void kernel_thread_helper(void);
-__asm__("	.type	kernel_thread_helper, @function\n"
-	"kernel_thread_helper:\n"
-	"	mov	r12, r0\n"
-	"	mov	lr, r2\n"
-	"	mov	pc, r1\n"
-	"	.size	kernel_thread_helper, . - kernel_thread_helper");
-
-int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
-{
-	struct pt_regs regs;
-
-	memset(&regs, 0, sizeof(regs));
-
-	regs.r0 = (unsigned long)arg;
-	regs.r1 = (unsigned long)fn;
-	regs.r2 = (unsigned long)do_exit;
-	regs.lr = (unsigned long)kernel_thread_helper;
-	regs.pc = (unsigned long)kernel_thread_helper;
-	regs.sr = MODE_SUPERVISOR;
-
-	return do_fork(flags | CLONE_VM | CLONE_UNTRACED,
-		       0, &regs, 0, NULL, NULL);
-}
-EXPORT_SYMBOL(kernel_thread);
-
-/*
  * Free current thread data structures etc
  */
 void exit_thread(void)
@@ -332,26 +294,32 @@ int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
 }
 
 asmlinkage void ret_from_fork(void);
+asmlinkage void ret_from_kernel_thread(void);
+asmlinkage void syscall_return(void);
 
 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 *childregs;
-
-	childregs = ((struct pt_regs *)(THREAD_SIZE + (unsigned long)task_stack_page(p))) - 1;
-	*childregs = *regs;
-
-	if (user_mode(regs))
-		childregs->sp = usp;
-	else
-		childregs->sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
-
-	childregs->r12 = 0; /* Set return value for child */
+	struct pt_regs *childregs = task_pt_regs(p);
+
+	if (unlikely(p->flags & PF_KTHREAD)) {
+		memset(childregs, 0, sizeof(struct pt_regs));
+		p->thread.cpu_context.r0 = arg;
+		p->thread.cpu_context.r1 = usp; /* fn */
+		p->thread.cpu_context.r2 = syscall_return;
+		p->thread.cpu_context.pc = (unsigned long)ret_from_kernel_thread;
+		childregs->sr = MODE_SUPERVISOR;
+	} else {
+		*childregs = *current_pt_regs();
+		if (usp)
+			childregs->sp = usp;
+		childregs->r12 = 0; /* Set return value for child */
+		p->thread.cpu_context.pc = (unsigned long)ret_from_fork;
+	}
 
 	p->thread.cpu_context.sr = MODE_SUPERVISOR | SR_GM;
 	p->thread.cpu_context.ksp = (unsigned long)childregs;
-	p->thread.cpu_context.pc = (unsigned long)ret_from_fork;
 
 	clear_tsk_thread_flag(p, TIF_DEBUG);
 	if ((clone_flags & CLONE_PTRACE) && test_thread_flag(TIF_DEBUG))
@@ -360,49 +328,6 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
 	return 0;
 }
 
-/* r12-r8 are dummy parameters to force the compiler to use the stack */
-asmlinkage int sys_fork(struct pt_regs *regs)
-{
-	return do_fork(SIGCHLD, regs->sp, regs, 0, NULL, NULL);
-}
-
-asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
-		void __user *parent_tidptr, void __user *child_tidptr,
-		struct pt_regs *regs)
-{
-	if (!newsp)
-		newsp = regs->sp;
-	return do_fork(clone_flags, newsp, regs, 0, parent_tidptr,
-			child_tidptr);
-}
-
-asmlinkage int sys_vfork(struct pt_regs *regs)
-{
-	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->sp, regs,
-		       0, NULL, NULL);
-}
-
-asmlinkage int sys_execve(const char __user *ufilename,
-			  const char __user *const __user *uargv,
-			  const char __user *const __user *uenvp,
-			  struct pt_regs *regs)
-{
-	int error;
-	struct filename *filename;
-
-	filename = getname(ufilename);
-	error = PTR_ERR(filename);
-	if (IS_ERR(filename))
-		goto out;
-
-	error = do_execve(filename->name, uargv, uenvp, regs);
-	putname(filename);
-
-out:
-	return error;
-}
-
-
 /*
  * This function is supposed to answer the question "who called
  * schedule()?"
diff --git a/arch/avr32/kernel/sys_avr32.c b/arch/avr32/kernel/sys_avr32.c
deleted file mode 100644
index 62635a09ae3e..000000000000
--- a/arch/avr32/kernel/sys_avr32.c
+++ /dev/null
@@ -1,24 +0,0 @@
-/*
- * Copyright (C) 2004-2006 Atmel Corporation
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- */
-#include <linux/unistd.h>
-
-int kernel_execve(const char *file,
-		  const char *const *argv,
-		  const char *const *envp)
-{
-	register long scno asm("r8") = __NR_execve;
-	register long sc1 asm("r12") = (long)file;
-	register long sc2 asm("r11") = (long)argv;
-	register long sc3 asm("r10") = (long)envp;
-
-	asm volatile("scall"
-		     : "=r"(sc1)
-		     : "r"(scno), "0"(sc1), "r"(sc2), "r"(sc3)
-		     : "cc", "memory");
-	return sc1;
-}
diff --git a/arch/avr32/kernel/syscall-stubs.S b/arch/avr32/kernel/syscall-stubs.S
index 0447a3e2ba64..275aab9731fd 100644
--- a/arch/avr32/kernel/syscall-stubs.S
+++ b/arch/avr32/kernel/syscall-stubs.S
@@ -32,30 +32,6 @@ __sys_rt_sigreturn:
 	mov	r12, sp
 	rjmp	sys_rt_sigreturn
 
-	.global	__sys_fork
-	.type	__sys_fork,@function
-__sys_fork:
-	mov	r12, sp
-	rjmp	sys_fork
-
-	.global	__sys_clone
-	.type	__sys_clone,@function
-__sys_clone:
-	mov	r8, sp
-	rjmp	sys_clone
-
-	.global	__sys_vfork
-	.type	__sys_vfork,@function
-__sys_vfork:
-	mov	r12, sp
-	rjmp	sys_vfork
-
-	.global	__sys_execve
-	.type	__sys_execve,@function
-__sys_execve:
-	mov	r9, sp
-	rjmp	sys_execve
-
 	.global	__sys_mmap2
 	.type	__sys_mmap2,@function
 __sys_mmap2:
diff --git a/arch/avr32/kernel/syscall_table.S b/arch/avr32/kernel/syscall_table.S
index 6eba53530d1c..f27bb878da6b 100644
--- a/arch/avr32/kernel/syscall_table.S
+++ b/arch/avr32/kernel/syscall_table.S
@@ -15,7 +15,7 @@
 sys_call_table:
 	.long	sys_restart_syscall
 	.long	sys_exit
-	.long	__sys_fork
+	.long	sys_fork
 	.long	sys_read
 	.long	sys_write
 	.long	sys_open		/* 5 */
@@ -24,7 +24,7 @@ sys_call_table:
 	.long	sys_creat
 	.long	sys_link
 	.long	sys_unlink		/* 10 */
-	.long	__sys_execve
+	.long	sys_execve
 	.long	sys_chdir
 	.long	sys_time
 	.long	sys_mknod
@@ -57,7 +57,7 @@ sys_call_table:
 	.long	sys_dup
 	.long	sys_pipe
 	.long	sys_times
-	.long	__sys_clone
+	.long	sys_clone
 	.long	sys_brk			/* 45 */
 	.long	sys_setgid
 	.long	sys_getgid
@@ -127,7 +127,7 @@ sys_call_table:
 	.long	sys_newuname
 	.long	sys_adjtimex
 	.long	sys_mprotect
-	.long	__sys_vfork
+	.long	sys_vfork
 	.long	sys_init_module		/* 115 */
 	.long	sys_delete_module
 	.long	sys_quotactl