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, 17 insertions, 109 deletions

diff --git a/arch/m32r/kernel/process.c b/arch/m32r/kernel/process.c
index e7366276ef30..765d0f57c787 100644
--- a/arch/m32r/kernel/process.c
+++ b/arch/m32r/kernel/process.c
@@ -165,41 +165,6 @@ void show_regs(struct pt_regs * regs)
 }
 
 /*
- * Create a kernel thread
- */
-
-/*
- * This is the mechanism for creating a new kernel thread.
- *
- * NOTE! Only a kernel-only process(ie the swapper or direct descendants
- * who haven't done an "execve()") should use this: it will work within
- * a system call from a "real" process, but the process memory space will
- * not be free'd until both the parent and the child have exited.
- */
-static void kernel_thread_helper(void *nouse, int (*fn)(void *), void *arg)
-{
-	fn(arg);
-	do_exit(-1);
-}
-
-int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
-{
-	struct pt_regs regs;
-
-	memset(&regs, 0, sizeof (regs));
-	regs.r1 = (unsigned long)fn;
-	regs.r2 = (unsigned long)arg;
-
-	regs.bpc = (unsigned long)kernel_thread_helper;
-
-	regs.psw = M32R_PSW_BIE;
-
-	/* Ok, create the new process. */
-	return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs, 0, NULL,
-		NULL);
-}
-
-/*
  * Free current thread data structures etc..
  */
 void exit_thread(void)
@@ -227,88 +192,31 @@ int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
 }
 
 int copy_thread(unsigned long clone_flags, unsigned long spu,
-	unsigned long unused, struct task_struct *tsk, struct pt_regs *regs)
+	unsigned long arg, struct task_struct *tsk)
 {
 	struct pt_regs *childregs = task_pt_regs(tsk);
 	extern void ret_from_fork(void);
-
-	/* Copy registers */
-	*childregs = *regs;
-
-	childregs->spu = spu;
-	childregs->r0 = 0;	/* Child gets zero as return value */
-	regs->r0 = tsk->pid;
+	extern void ret_from_kernel_thread(void);
+
+	if (unlikely(tsk->flags & PF_KTHREAD)) {
+		memset(childregs, 0, sizeof(struct pt_regs));
+		childregs->psw = M32R_PSW_BIE;
+		childregs->r1 = spu;	/* fn */
+		childregs->r0 = arg;
+		tsk->thread.lr = (unsigned long)ret_from_kernel_thread;
+	} else {
+		/* Copy registers */
+		*childregs = *current_pt_regs();
+		if (spu)
+			childregs->spu = spu;
+		childregs->r0 = 0;	/* Child gets zero as return value */
+		tsk->thread.lr = (unsigned long)ret_from_fork;
+	}
 	tsk->thread.sp = (unsigned long)childregs;
-	tsk->thread.lr = (unsigned long)ret_from_fork;
 
 	return 0;
 }
 
-asmlinkage int sys_fork(unsigned long r0, unsigned long r1, unsigned long r2,
-	unsigned long r3, unsigned long r4, unsigned long r5, unsigned long r6,
-	struct pt_regs regs)
-{
-#ifdef CONFIG_MMU
-	return do_fork(SIGCHLD, regs.spu, &regs, 0, NULL, NULL);
-#else
-	return -EINVAL;
-#endif /* CONFIG_MMU */
-}
-
-asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
-			 unsigned long parent_tidptr,
-			 unsigned long child_tidptr,
-			 unsigned long r4, unsigned long r5, unsigned long r6,
-			 struct pt_regs regs)
-{
-	if (!newsp)
-		newsp = regs.spu;
-
-	return do_fork(clone_flags, newsp, &regs, 0,
-		       (int __user *)parent_tidptr, (int __user *)child_tidptr);
-}
-
-/*
- * This is trivial, and on the face of it looks like it
- * could equally well be done in user mode.
- *
- * Not so, for quite unobvious reasons - register pressure.
- * In user mode vfork() cannot have a stack frame, and if
- * done by calling the "clone()" system call directly, you
- * do not have enough call-clobbered registers to hold all
- * the information you need.
- */
-asmlinkage int sys_vfork(unsigned long r0, unsigned long r1, unsigned long r2,
-	unsigned long r3, unsigned long r4, unsigned long r5, unsigned long r6,
-	struct pt_regs regs)
-{
-	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs.spu, &regs, 0,
-			NULL, NULL);
-}
-
-/*
- * sys_execve() executes a new program.
- */
-asmlinkage int sys_execve(const char __user *ufilename,
-			  const char __user *const __user *uargv,
-			  const char __user *const __user *uenvp,
-			  unsigned long r3, unsigned long r4, unsigned long r5,
-			  unsigned long r6, 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;
-}
-
 /*
  * These bracket the sleeping functions..
  */