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

5 files changed, 8 insertions, 48 deletions

diff --git a/arch/c6x/Kconfig b/arch/c6x/Kconfig
index aee1b569ee6e..66eab3703c75 100644
--- a/arch/c6x/Kconfig
+++ b/arch/c6x/Kconfig
@@ -18,6 +18,7 @@ config C6X
 	select OF_EARLY_FLATTREE
 	select GENERIC_CLOCKEVENTS
 	select GENERIC_KERNEL_THREAD
+	select GENERIC_KERNEL_EXECVE
 	select MODULES_USE_ELF_RELA
 
 config MMU
diff --git a/arch/c6x/include/asm/syscalls.h b/arch/c6x/include/asm/syscalls.h
index e7b8991dc07c..df3d05feb153 100644
--- a/arch/c6x/include/asm/syscalls.h
+++ b/arch/c6x/include/asm/syscalls.h
@@ -41,10 +41,6 @@ extern long sys_fallocate_c6x(int fd, int mode,
 			      u32 len_lo, u32 len_hi);
 extern int sys_cache_sync(unsigned long s, unsigned long e);
 
-struct pt_regs;
-
-extern asmlinkage long sys_c6x_clone(struct pt_regs *regs);
-
 #include <asm-generic/syscalls.h>
 
 #endif /* __ASM_C6X_SYSCALLS_H */
diff --git a/arch/c6x/include/uapi/asm/unistd.h b/arch/c6x/include/uapi/asm/unistd.h
index 4ff747d12dad..f3987a8703d9 100644
--- a/arch/c6x/include/uapi/asm/unistd.h
+++ b/arch/c6x/include/uapi/asm/unistd.h
@@ -14,8 +14,8 @@
  *   more details.
  */
 
-#define __ARCH_WANT_KERNEL_EXECVE
 #define __ARCH_WANT_SYS_EXECVE
+#define __ARCH_WANT_SYS_CLONE
 
 /* Use the standard ABI for syscalls. */
 #include <asm-generic/unistd.h>
diff --git a/arch/c6x/kernel/entry.S b/arch/c6x/kernel/entry.S
index 0ed6157dd256..5239057de4c4 100644
--- a/arch/c6x/kernel/entry.S
+++ b/arch/c6x/kernel/entry.S
@@ -415,19 +415,9 @@ ENTRY(ret_from_kernel_thread)
 0:
 	B	.S2	B10		   /* call fn */
 	LDW	.D2T1	*+SP(REGS_A1+8),A4 /* get arg */
-	MVKL	.S2	sys_exit,B11
-	MVKH	.S2	sys_exit,B11
-	ADDKPC	.S2	0f,B3,1
-0:
-	BNOP	.S2	B11,5	/* jump to sys_exit */
+	ADDKPC	.S2	ret_from_fork_2,B3,3
 ENDPROC(ret_from_kernel_thread)
 
-ENTRY(ret_from_kernel_execve)
-	GET_THREAD_INFO A12
-	BNOP	.S2	syscall_exit,4
-	ADD	.D2X	A4,-8,SP
-ENDPROC(ret_from_kernel_execve)
-
 	;;
 	;; These are the interrupt handlers, responsible for calling c6x_do_IRQ()
 	;;
@@ -624,18 +614,6 @@ ENDPROC(sys_sigaltstack)
 	;; Special system calls
 	;; return address is in B3
 	;;
-ENTRY(sys_clone)
-	ADD	.D1X	SP,8,A4
-#ifdef CONFIG_C6X_BIG_KERNEL
- ||	MVKL	.S1	sys_c6x_clone,A0
-	MVKH	.S1	sys_c6x_clone,A0
-	BNOP	.S2X	A0,5
-#else
- ||	B	.S2	sys_c6x_clone
-	NOP	5
-#endif
-ENDPROC(sys_clone)
-
 ENTRY(sys_rt_sigreturn)
 	ADD	.D1X	SP,8,A4
 #ifdef CONFIG_C6X_BIG_KERNEL
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;
 	}