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

7 files changed, 52 insertions, 86 deletions

diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
index e7c161433ea..953a7ba5d05 100644
--- a/arch/m68k/Kconfig
+++ b/arch/m68k/Kconfig
@@ -16,6 +16,7 @@ config M68K
 	select ARCH_WANT_IPC_PARSE_VERSION
 	select ARCH_USES_GETTIMEOFFSET if MMU && !COLDFIRE
 	select GENERIC_KERNEL_THREAD
+	select GENERIC_KERNEL_EXECVE
 	select HAVE_MOD_ARCH_SPECIFIC
 	select MODULES_USE_ELF_REL
 	select MODULES_USE_ELF_RELA
diff --git a/arch/m68k/include/asm/signal.h b/arch/m68k/include/asm/signal.h
index 2df26b57c26..9c8c46b06b0 100644
--- a/arch/m68k/include/asm/signal.h
+++ b/arch/m68k/include/asm/signal.h
@@ -86,11 +86,9 @@ static inline int sigfindinword(unsigned long word)
 
 #endif /* !CONFIG_CPU_HAS_NO_BITFIELDS */
 
-#ifdef __uClinux__
-#define ptrace_signal_deliver(regs, cookie) do { } while (0)
-#else
-struct pt_regs;
-extern void ptrace_signal_deliver(struct pt_regs *regs, void *cookie);
+#ifndef __uClinux__
+extern void ptrace_signal_deliver(void);
+#define ptrace_signal_deliver ptrace_signal_deliver
 #endif /* __uClinux__ */
 
 #endif /* _M68K_SIGNAL_H */
diff --git a/arch/m68k/include/asm/unistd.h b/arch/m68k/include/asm/unistd.h
index 5fc7f7bec1c..a021d67cdd7 100644
--- a/arch/m68k/include/asm/unistd.h
+++ b/arch/m68k/include/asm/unistd.h
@@ -32,7 +32,8 @@
 #define __ARCH_WANT_SYS_RT_SIGACTION
 #define __ARCH_WANT_SYS_RT_SIGSUSPEND
 #define __ARCH_WANT_SYS_EXECVE
-#define __ARCH_WANT_KERNEL_EXECVE
+#define __ARCH_WANT_SYS_FORK
+#define __ARCH_WANT_SYS_VFORK
 
 /*
  * "Conditional" syscalls
diff --git a/arch/m68k/kernel/entry.S b/arch/m68k/kernel/entry.S
index 946cb018775..a78f5649e8d 100644
--- a/arch/m68k/kernel/entry.S
+++ b/arch/m68k/kernel/entry.S
@@ -44,34 +44,29 @@
 
 .globl system_call, buserr, trap, resume
 .globl sys_call_table
-.globl sys_fork, sys_clone, sys_vfork
+.globl __sys_fork, __sys_clone, __sys_vfork
 .globl ret_from_interrupt, bad_interrupt
 .globl auto_irqhandler_fixup
 .globl user_irqvec_fixup
 
 .text
-ENTRY(sys_fork)
+ENTRY(__sys_fork)
 	SAVE_SWITCH_STACK
-	pea	%sp@(SWITCH_STACK_SIZE)
-	jbsr	m68k_fork
-	addql	#4,%sp
-	RESTORE_SWITCH_STACK
+	jbsr	sys_fork
+	lea     %sp@(24),%sp
 	rts
 
-ENTRY(sys_clone)
+ENTRY(__sys_clone)
 	SAVE_SWITCH_STACK
 	pea	%sp@(SWITCH_STACK_SIZE)
 	jbsr	m68k_clone
-	addql	#4,%sp
-	RESTORE_SWITCH_STACK
+	lea     %sp@(28),%sp
 	rts
 
-ENTRY(sys_vfork)
+ENTRY(__sys_vfork)
 	SAVE_SWITCH_STACK
-	pea	%sp@(SWITCH_STACK_SIZE)
-	jbsr	m68k_vfork
-	addql	#4,%sp
-	RESTORE_SWITCH_STACK
+	jbsr	sys_vfork
+	lea     %sp@(24),%sp
 	rts
 
 ENTRY(sys_sigreturn)
@@ -115,16 +110,9 @@ ENTRY(ret_from_kernel_thread)
 	| a3 contains the kernel thread payload, d7 - its argument
 	movel	%d1,%sp@-
 	jsr	schedule_tail
-	GET_CURRENT(%d0)
 	movel	%d7,(%sp)
 	jsr	%a3@
 	addql	#4,%sp
-	movel	%d0,(%sp)
-	jra	sys_exit
-
-ENTRY(ret_from_kernel_execve)
-	movel	4(%sp), %sp
-	GET_CURRENT(%d0)
 	jra	ret_from_exception
 
 #if defined(CONFIG_COLDFIRE) || !defined(CONFIG_MMU)
diff --git a/arch/m68k/kernel/process.c b/arch/m68k/kernel/process.c
index c51bb172e14..d538694ad20 100644
--- a/arch/m68k/kernel/process.c
+++ b/arch/m68k/kernel/process.c
@@ -136,57 +136,35 @@ void flush_thread(void)
 }
 
 /*
- * "m68k_fork()".. By the time we get here, the
- * non-volatile registers have also been saved on the
- * stack. We do some ugly pointer stuff here.. (see
- * also copy_thread)
+ * Why not generic sys_clone, you ask?  m68k passes all arguments on stack.
+ * And we need all registers saved, which means a bunch of stuff pushed
+ * on top of pt_regs, which means that sys_clone() arguments would be
+ * buried.  We could, of course, copy them, but it's too costly for no
+ * good reason - generic clone() would have to copy them *again* for
+ * do_fork() anyway.  So in this case it's actually better to pass pt_regs *
+ * and extract arguments for do_fork() from there.  Eventually we might
+ * go for calling do_fork() directly from the wrapper, but only after we
+ * are finished with do_fork() prototype conversion.
  */
-
-asmlinkage int m68k_fork(struct pt_regs *regs)
-{
-#ifdef CONFIG_MMU
-	return do_fork(SIGCHLD, rdusp(), regs, 0, NULL, NULL);
-#else
-	return -EINVAL;
-#endif
-}
-
-asmlinkage int m68k_vfork(struct pt_regs *regs)
-{
-	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0,
-		       NULL, NULL);
-}
-
 asmlinkage int m68k_clone(struct pt_regs *regs)
 {
-	unsigned long clone_flags;
-	unsigned long newsp;
-	int __user *parent_tidptr, *child_tidptr;
-
-	/* syscall2 puts clone_flags in d1 and usp in d2 */
-	clone_flags = regs->d1;
-	newsp = regs->d2;
-	parent_tidptr = (int __user *)regs->d3;
-	child_tidptr = (int __user *)regs->d4;
-	if (!newsp)
-		newsp = rdusp();
-	return do_fork(clone_flags, newsp, regs, 0,
-		       parent_tidptr, child_tidptr);
+	/* regs will be equal to current_pt_regs() */
+	return do_fork(regs->d1, regs->d2, 0,
+		       (int __user *)regs->d3, (int __user *)regs->d4);
 }
 
 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 switch_stack *childstack;
+	struct fork_frame {
+		struct switch_stack sw;
+		struct pt_regs regs;
+	} *frame;
 
-	childregs = (struct pt_regs *) (task_stack_page(p) + THREAD_SIZE) - 1;
-	childstack = ((struct switch_stack *) childregs) - 1;
+	frame = (struct fork_frame *) (task_stack_page(p) + THREAD_SIZE) - 1;
 
-	p->thread.usp = usp;
-	p->thread.ksp = (unsigned long)childstack;
-	p->thread.esp0 = (unsigned long)childregs;
+	p->thread.ksp = (unsigned long)frame;
+	p->thread.esp0 = (unsigned long)&frame->regs;
 
 	/*
 	 * Must save the current SFC/DFC value, NOT the value when
@@ -194,25 +172,24 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
 	 */
 	p->thread.fs = get_fs().seg;
 
-	if (unlikely(!regs)) {
+	if (unlikely(p->flags & PF_KTHREAD)) {
 		/* kernel thread */
-		memset(childstack, 0,
-			sizeof(struct switch_stack) + sizeof(struct pt_regs));
-		childregs->sr = PS_S;
-		childstack->a3 = usp; /* function */
-		childstack->d7 = arg;
-		childstack->retpc = (unsigned long)ret_from_kernel_thread;
+		memset(frame, 0, sizeof(struct fork_frame));
+		frame->regs.sr = PS_S;
+		frame->sw.a3 = usp; /* function */
+		frame->sw.d7 = arg;
+		frame->sw.retpc = (unsigned long)ret_from_kernel_thread;
 		p->thread.usp = 0;
 		return 0;
 	}
-	*childregs = *regs;
-	childregs->d0 = 0;
-
-	*childstack = ((struct switch_stack *) regs)[-1];
-	childstack->retpc = (unsigned long)ret_from_fork;
+	memcpy(frame, container_of(current_pt_regs(), struct fork_frame, regs),
+		sizeof(struct fork_frame));
+	frame->regs.d0 = 0;
+	frame->sw.retpc = (unsigned long)ret_from_fork;
+	p->thread.usp = usp ?: rdusp();
 
 	if (clone_flags & CLONE_SETTLS)
-		task_thread_info(p)->tp_value = regs->d5;
+		task_thread_info(p)->tp_value = frame->regs.d5;
 
 #ifdef CONFIG_FPU
 	if (!FPU_IS_EMU) {
diff --git a/arch/m68k/kernel/signal.c b/arch/m68k/kernel/signal.c
index 710a528b928..9a396cda314 100644
--- a/arch/m68k/kernel/signal.c
+++ b/arch/m68k/kernel/signal.c
@@ -108,8 +108,9 @@ int handle_kernel_fault(struct pt_regs *regs)
 	return 1;
 }
 
-void ptrace_signal_deliver(struct pt_regs *regs, void *cookie)
+void ptrace_signal_deliver(void)
 {
+	struct pt_regs *regs = signal_pt_regs();
 	if (regs->orig_d0 < 0)
 		return;
 	switch (regs->d0) {
diff --git a/arch/m68k/kernel/syscalltable.S b/arch/m68k/kernel/syscalltable.S
index 4fc2e29b771..c30da5b3f2d 100644
--- a/arch/m68k/kernel/syscalltable.S
+++ b/arch/m68k/kernel/syscalltable.S
@@ -22,7 +22,7 @@ ALIGN
 ENTRY(sys_call_table)
 	.long sys_restart_syscall	/* 0 - old "setup()" system call, used for restarting */
 	.long sys_exit
-	.long sys_fork
+	.long __sys_fork
 	.long sys_read
 	.long sys_write
 	.long sys_open			/* 5 */
@@ -140,7 +140,7 @@ ENTRY(sys_call_table)
 	.long sys_ipc
 	.long sys_fsync
 	.long sys_sigreturn
-	.long sys_clone			/* 120 */
+	.long __sys_clone		/* 120 */
 	.long sys_setdomainname
 	.long sys_newuname
 	.long sys_cacheflush		/* modify_ldt for i386 */
@@ -210,7 +210,7 @@ ENTRY(sys_call_table)
 	.long sys_sendfile
 	.long sys_ni_syscall		/* streams1 */
 	.long sys_ni_syscall		/* streams2 */
-	.long sys_vfork			/* 190 */
+	.long __sys_vfork		/* 190 */
 	.long sys_getrlimit
 	.long sys_mmap2
 	.long sys_truncate64