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, 15 insertions, 79 deletions

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index a902a5c1c76..951a517a1a0 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -144,6 +144,8 @@ config PPC
 	select GENERIC_KERNEL_THREAD
 	select HAVE_MOD_ARCH_SPECIFIC
 	select MODULES_USE_ELF_RELA
+	select GENERIC_KERNEL_EXECVE
+	select CLONE_BACKWARDS
 
 config EARLY_PRINTK
 	bool
diff --git a/arch/powerpc/include/asm/signal.h b/arch/powerpc/include/asm/signal.h
index 189998bb61c..a101637725a 100644
--- a/arch/powerpc/include/asm/signal.h
+++ b/arch/powerpc/include/asm/signal.h
@@ -3,6 +3,4 @@
 
 #include <uapi/asm/signal.h>
 
-struct pt_regs;
-#define ptrace_signal_deliver(regs, cookie) do { } while (0)
 #endif /* _ASM_POWERPC_SIGNAL_H */
diff --git a/arch/powerpc/include/asm/syscalls.h b/arch/powerpc/include/asm/syscalls.h
index 329db4ec12c..b5308d3e6d3 100644
--- a/arch/powerpc/include/asm/syscalls.h
+++ b/arch/powerpc/include/asm/syscalls.h
@@ -17,15 +17,6 @@ asmlinkage unsigned long sys_mmap(unsigned long addr, size_t len,
 asmlinkage unsigned long sys_mmap2(unsigned long addr, size_t len,
 		unsigned long prot, unsigned long flags,
 		unsigned long fd, unsigned long pgoff);
-asmlinkage int sys_clone(unsigned long clone_flags, unsigned long usp,
-		int __user *parent_tidp, void __user *child_threadptr,
-		int __user *child_tidp, int p6, struct pt_regs *regs);
-asmlinkage int sys_fork(unsigned long p1, unsigned long p2,
-		unsigned long p3, unsigned long p4, unsigned long p5,
-		unsigned long p6, struct pt_regs *regs);
-asmlinkage int sys_vfork(unsigned long p1, unsigned long p2,
-		unsigned long p3, unsigned long p4, unsigned long p5,
-		unsigned long p6, struct pt_regs *regs);
 asmlinkage long sys_pipe(int __user *fildes);
 asmlinkage long sys_pipe2(int __user *fildes, int flags);
 asmlinkage long sys_rt_sigaction(int sig,
diff --git a/arch/powerpc/include/asm/unistd.h b/arch/powerpc/include/asm/unistd.h
index 921dce6d844..76fe846ec40 100644
--- a/arch/powerpc/include/asm/unistd.h
+++ b/arch/powerpc/include/asm/unistd.h
@@ -56,7 +56,9 @@
 #define __ARCH_WANT_COMPAT_SYS_SENDFILE
 #endif
 #define __ARCH_WANT_SYS_EXECVE
-#define __ARCH_WANT_KERNEL_EXECVE
+#define __ARCH_WANT_SYS_FORK
+#define __ARCH_WANT_SYS_VFORK
+#define __ARCH_WANT_SYS_CLONE
 
 /*
  * "Conditional" syscalls
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 9499385676e..d22e73e4618 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -444,11 +444,6 @@ ret_from_kernel_thread:
 	PPC440EP_ERR42
 	blrl
 	li	r3,0
-	b	do_exit		# no return
-
-	.globl	__ret_from_kernel_execve
-__ret_from_kernel_execve:
-	addi	r1,r3,-STACK_FRAME_OVERHEAD
 	b	ret_from_syscall
 
 /* Traced system call support */
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 56e0ff0878b..e9a906c2723 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -373,17 +373,11 @@ _GLOBAL(ret_from_fork)
 _GLOBAL(ret_from_kernel_thread)
 	bl	.schedule_tail
 	REST_NVGPRS(r1)
-	REST_GPR(2,r1)
+	ld	r14, 0(r14)
 	mtlr	r14
 	mr	r3,r15
 	blrl
 	li	r3,0
-	b	.do_exit	# no return
-
-_GLOBAL(__ret_from_kernel_execve)
-	addi	r1,r3,-STACK_FRAME_OVERHEAD
-	li	r10,1
-	std	r10,SOFTE(r1)
 	b	syscall_exit
 
 	.section	".toc","aw"
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index ba48233500f..81430674e71 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -733,8 +733,7 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
 extern unsigned long dscr_default; /* defined in arch/powerpc/kernel/sysfs.c */
 
 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, *kregs;
 	extern void ret_from_fork(void);
@@ -745,25 +744,25 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
 	/* Copy registers */
 	sp -= sizeof(struct pt_regs);
 	childregs = (struct pt_regs *) sp;
-	if (!regs) {
-		/* for kernel thread, set `current' and stackptr in new task */
+	if (unlikely(p->flags & PF_KTHREAD)) {
+		struct thread_info *ti = (void *)task_stack_page(p);
 		memset(childregs, 0, sizeof(struct pt_regs));
 		childregs->gpr[1] = sp + sizeof(struct pt_regs);
+		childregs->gpr[14] = usp;	/* function */
 #ifdef CONFIG_PPC64
-		childregs->gpr[14] = *(unsigned long *)usp;
-		childregs->gpr[2] = ((unsigned long *)usp)[1],
 		clear_tsk_thread_flag(p, TIF_32BIT);
-#else
-		childregs->gpr[14] = usp;	/* function */
-		childregs->gpr[2] = (unsigned long) p;
+		childregs->softe = 1;
 #endif
 		childregs->gpr[15] = arg;
 		p->thread.regs = NULL;	/* no user register state */
+		ti->flags |= _TIF_RESTOREALL;
 		f = ret_from_kernel_thread;
 	} else {
+		struct pt_regs *regs = current_pt_regs();
 		CHECK_FULL_REGS(regs);
 		*childregs = *regs;
-		childregs->gpr[1] = usp;
+		if (usp)
+			childregs->gpr[1] = usp;
 		p->thread.regs = childregs;
 		childregs->gpr[3] = 0;  /* Result from fork() */
 		if (clone_flags & CLONE_SETTLS) {
@@ -1027,51 +1026,6 @@ int get_unalign_ctl(struct task_struct *tsk, unsigned long adr)
 	return put_user(tsk->thread.align_ctl, (unsigned int __user *)adr);
 }
 
-#define TRUNC_PTR(x)	((typeof(x))(((unsigned long)(x)) & 0xffffffff))
-
-int sys_clone(unsigned long clone_flags, unsigned long usp,
-	      int __user *parent_tidp, void __user *child_threadptr,
-	      int __user *child_tidp, int p6,
-	      struct pt_regs *regs)
-{
-	CHECK_FULL_REGS(regs);
-	if (usp == 0)
-		usp = regs->gpr[1];	/* stack pointer for child */
-#ifdef CONFIG_PPC64
-	if (is_32bit_task()) {
-		parent_tidp = TRUNC_PTR(parent_tidp);
-		child_tidp = TRUNC_PTR(child_tidp);
-	}
-#endif
- 	return do_fork(clone_flags, usp, regs, 0, parent_tidp, child_tidp);
-}
-
-int sys_fork(unsigned long p1, unsigned long p2, unsigned long p3,
-	     unsigned long p4, unsigned long p5, unsigned long p6,
-	     struct pt_regs *regs)
-{
-	CHECK_FULL_REGS(regs);
-	return do_fork(SIGCHLD, regs->gpr[1], regs, 0, NULL, NULL);
-}
-
-int sys_vfork(unsigned long p1, unsigned long p2, unsigned long p3,
-	      unsigned long p4, unsigned long p5, unsigned long p6,
-	      struct pt_regs *regs)
-{
-	CHECK_FULL_REGS(regs);
-	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->gpr[1],
-			regs, 0, NULL, NULL);
-}
-
-void __ret_from_kernel_execve(struct pt_regs *normal)
-__noreturn;
-
-void ret_from_kernel_execve(struct pt_regs *normal)
-{
-	set_thread_flag(TIF_RESTOREALL);
-	__ret_from_kernel_execve(normal);
-}
-
 static inline int valid_irq_stack(unsigned long sp, struct task_struct *p,
 				  unsigned long nbytes)
 {