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

1 files changed, 14 insertions, 48 deletions

diff --git a/arch/alpha/kernel/process.c b/arch/alpha/kernel/process.c
index 51987dcf79b8..b5d0d0923699 100644
--- a/arch/alpha/kernel/process.c
+++ b/arch/alpha/kernel/process.c
@@ -235,51 +235,28 @@ release_thread(struct task_struct *dead_task)
 }
 
 /*
- * "alpha_clone()".. 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)
- *
- * Notice that "fork()" is implemented in terms of clone,
- * with parameters (SIGCHLD, 0).
- */
-int
-alpha_clone(unsigned long clone_flags, unsigned long usp,
-	    int __user *parent_tid, int __user *child_tid,
-	    unsigned long tls_value, struct pt_regs *regs)
-{
-	if (!usp)
-		usp = rdusp();
-
-	return do_fork(clone_flags, usp, regs, 0, parent_tid, child_tid);
-}
-
-int
-alpha_vfork(struct pt_regs *regs)
-{
-	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(),
-		       regs, 0, NULL, NULL);
-}
-
-/*
  * Copy an alpha thread..
  */
 
 int
 copy_thread(unsigned long clone_flags, unsigned long usp,
 	    unsigned long arg,
-	    struct task_struct * p, struct pt_regs * regs)
+	    struct task_struct *p)
 {
 	extern void ret_from_fork(void);
 	extern void ret_from_kernel_thread(void);
 
 	struct thread_info *childti = task_thread_info(p);
 	struct pt_regs *childregs = task_pt_regs(p);
+	struct pt_regs *regs = current_pt_regs();
 	struct switch_stack *childstack, *stack;
 	unsigned long settls;
 
 	childstack = ((struct switch_stack *) childregs) - 1;
-	if (unlikely(!regs)) {
+	childti->pcb.ksp = (unsigned long) childstack;
+	childti->pcb.flags = 1;	/* set FEN, clear everything else */
+
+	if (unlikely(p->flags & PF_KTHREAD)) {
 		/* kernel thread */
 		memset(childstack, 0,
 			sizeof(struct switch_stack) + sizeof(struct pt_regs));
@@ -288,12 +265,17 @@ copy_thread(unsigned long clone_flags, unsigned long usp,
 		childstack->r10 = arg;
 		childregs->hae = alpha_mv.hae_cache,
 		childti->pcb.usp = 0;
-		childti->pcb.ksp = (unsigned long) childstack;
-		childti->pcb.flags = 1;	/* set FEN, clear everything else */
 		return 0;
 	}
+	/* Note: if CLONE_SETTLS is not set, then we must inherit the
+	   value from the parent, which will have been set by the block
+	   copy in dup_task_struct.  This is non-intuitive, but is
+	   required for proper operation in the case of a threaded
+	   application calling fork.  */
+	if (clone_flags & CLONE_SETTLS)
+		childti->pcb.unique = regs->r20;
+	childti->pcb.usp = usp ?: rdusp();
 	*childregs = *regs;
-	settls = regs->r20;
 	childregs->r0 = 0;
 	childregs->r19 = 0;
 	childregs->r20 = 1;	/* OSF/1 has some strange fork() semantics.  */
@@ -301,22 +283,6 @@ copy_thread(unsigned long clone_flags, unsigned long usp,
 	stack = ((struct switch_stack *) regs) - 1;
 	*childstack = *stack;
 	childstack->r26 = (unsigned long) ret_from_fork;
-	childti->pcb.usp = usp;
-	childti->pcb.ksp = (unsigned long) childstack;
-	childti->pcb.flags = 1;	/* set FEN, clear everything else */
-
-	/* Set a new TLS for the child thread?  Peek back into the
-	   syscall arguments that we saved on syscall entry.  Oops,
-	   except we'd have clobbered it with the parent/child set
-	   of r20.  Read the saved copy.  */
-	/* Note: if CLONE_SETTLS is not set, then we must inherit the
-	   value from the parent, which will have been set by the block
-	   copy in dup_task_struct.  This is non-intuitive, but is
-	   required for proper operation in the case of a threaded
-	   application calling fork.  */
-	if (clone_flags & CLONE_SETTLS)
-		childti->pcb.unique = settls;
-
 	return 0;
 }