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, 5 insertions, 20 deletions

diff --git a/arch/c6x/kernel/process.c b/arch/c6x/kernel/process.c
index 2770d9a9a84e..6434df476f77 100644
--- a/arch/c6x/kernel/process.c
+++ b/arch/c6x/kernel/process.c
@@ -112,22 +112,6 @@ void exit_thread(void)
 {
 }
 
-SYSCALL_DEFINE1(c6x_clone, struct pt_regs *, regs)
-{
-	unsigned long clone_flags;
-	unsigned long newsp;
-
-	/* syscall puts clone_flags in A4 and usp in B4 */
-	clone_flags = regs->orig_a4;
-	if (regs->b4)
-		newsp = regs->b4;
-	else
-		newsp = regs->sp;
-
-	return do_fork(clone_flags, newsp, regs, 0, (int __user *)regs->a6,
-		       (int __user *)regs->b6);
-}
-
 /*
  * Do necessary setup to start up a newly executed thread.
  */
@@ -155,13 +139,13 @@ void start_thread(struct pt_regs *regs, unsigned int pc, unsigned long usp)
  */
 int copy_thread(unsigned long clone_flags, unsigned long usp,
 		unsigned long ustk_size,
-		struct task_struct *p, struct pt_regs *regs)
+		struct task_struct *p)
 {
 	struct pt_regs *childregs;
 
 	childregs = task_pt_regs(p);
 
-	if (!regs) {
+	if (unlikely(p->flags & PF_KTHREAD)) {
 		/* case of  __kernel_thread: we return to supervisor space */
 		memset(childregs, 0, sizeof(struct pt_regs));
 		childregs->sp = (unsigned long)(childregs + 1);
@@ -170,8 +154,9 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
 		childregs->a1 = ustk_size;	/* argument */
 	} else {
 		/* Otherwise use the given stack */
-		*childregs = *regs;
-		childregs->sp = usp;
+		*childregs = *current_pt_regs();
+		if (usp)
+			childregs->sp = usp;
 		p->thread.pc = (unsigned long) ret_from_fork;
 	}