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, 32 insertions, 116 deletions

diff --git a/arch/sparc/kernel/process_64.c b/arch/sparc/kernel/process_64.c
index c6e0c2910043..cdb80b2adbe0 100644
--- a/arch/sparc/kernel/process_64.c
+++ b/arch/sparc/kernel/process_64.c
@@ -601,8 +601,7 @@ asmlinkage long sparc_do_fork(unsigned long clone_flags,
 		child_tid_ptr = (int __user *) regs->u_regs[UREG_I4];
 	}
 
-	ret = do_fork(clone_flags, stack_start,
-		      regs, stack_size,
+	ret = do_fork(clone_flags, stack_start, stack_size,
 		      parent_tid_ptr, child_tid_ptr);
 
 	/* If we get an error and potentially restart the system
@@ -622,64 +621,55 @@ asmlinkage long sparc_do_fork(unsigned long clone_flags,
  * Child  -->  %o0 == parents pid, %o1 == 1
  */
 int copy_thread(unsigned long clone_flags, unsigned long sp,
-		unsigned long unused,
-		struct task_struct *p, struct pt_regs *regs)
+		unsigned long arg, struct task_struct *p)
 {
 	struct thread_info *t = task_thread_info(p);
+	struct pt_regs *regs = current_pt_regs();
 	struct sparc_stackf *parent_sf;
 	unsigned long child_stack_sz;
 	char *child_trap_frame;
-	int kernel_thread;
-
-	kernel_thread = (regs->tstate & TSTATE_PRIV) ? 1 : 0;
-	parent_sf = ((struct sparc_stackf *) regs) - 1;
 
 	/* Calculate offset to stack_frame & pt_regs */
-	child_stack_sz = ((STACKFRAME_SZ + TRACEREG_SZ) +
-			  (kernel_thread ? STACKFRAME_SZ : 0));
+	child_stack_sz = (STACKFRAME_SZ + TRACEREG_SZ);
 	child_trap_frame = (task_stack_page(p) +
 			    (THREAD_SIZE - child_stack_sz));
-	memcpy(child_trap_frame, parent_sf, child_stack_sz);
 
-	t->flags = (t->flags & ~((0xffUL << TI_FLAG_CWP_SHIFT) |
-				 (0xffUL << TI_FLAG_CURRENT_DS_SHIFT))) |
-		(((regs->tstate + 1) & TSTATE_CWP) << TI_FLAG_CWP_SHIFT);
 	t->new_child = 1;
 	t->ksp = ((unsigned long) child_trap_frame) - STACK_BIAS;
 	t->kregs = (struct pt_regs *) (child_trap_frame +
 				       sizeof(struct sparc_stackf));
 	t->fpsaved[0] = 0;
 
-	if (kernel_thread) {
-		struct sparc_stackf *child_sf = (struct sparc_stackf *)
-			(child_trap_frame + (STACKFRAME_SZ + TRACEREG_SZ));
-
-		/* Zero terminate the stack backtrace.  */
-		child_sf->fp = NULL;
-		t->kregs->u_regs[UREG_FP] =
-		  ((unsigned long) child_sf) - STACK_BIAS;
+	if (unlikely(p->flags & PF_KTHREAD)) {
+		memset(child_trap_frame, 0, child_stack_sz);
+		__thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP] = 
+			(current_pt_regs()->tstate + 1) & TSTATE_CWP;
+		t->current_ds = ASI_P;
+		t->kregs->u_regs[UREG_G1] = sp; /* function */
+		t->kregs->u_regs[UREG_G2] = arg;
+		return 0;
+	}
 
-		t->flags |= ((long)ASI_P << TI_FLAG_CURRENT_DS_SHIFT);
-		t->kregs->u_regs[UREG_G6] = (unsigned long) t;
-		t->kregs->u_regs[UREG_G4] = (unsigned long) t->task;
-	} else {
-		if (t->flags & _TIF_32BIT) {
-			sp &= 0x00000000ffffffffUL;
-			regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
-		}
-		t->kregs->u_regs[UREG_FP] = sp;
-		t->flags |= ((long)ASI_AIUS << TI_FLAG_CURRENT_DS_SHIFT);
-		if (sp != regs->u_regs[UREG_FP]) {
-			unsigned long csp;
-
-			csp = clone_stackframe(sp, regs->u_regs[UREG_FP]);
-			if (!csp)
-				return -EFAULT;
-			t->kregs->u_regs[UREG_FP] = csp;
-		}
-		if (t->utraps)
-			t->utraps[0]++;
+	parent_sf = ((struct sparc_stackf *) regs) - 1;
+	memcpy(child_trap_frame, parent_sf, child_stack_sz);
+	if (t->flags & _TIF_32BIT) {
+		sp &= 0x00000000ffffffffUL;
+		regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
 	}
+	t->kregs->u_regs[UREG_FP] = sp;
+	__thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP] = 
+		(regs->tstate + 1) & TSTATE_CWP;
+	t->current_ds = ASI_AIUS;
+	if (sp != regs->u_regs[UREG_FP]) {
+		unsigned long csp;
+
+		csp = clone_stackframe(sp, regs->u_regs[UREG_FP]);
+		if (!csp)
+			return -EFAULT;
+		t->kregs->u_regs[UREG_FP] = csp;
+	}
+	if (t->utraps)
+		t->utraps[0]++;
 
 	/* Set the return value for the child. */
 	t->kregs->u_regs[UREG_I0] = current->pid;
@@ -694,45 +684,6 @@ int copy_thread(unsigned long clone_flags, unsigned long sp,
 	return 0;
 }
 
-/*
- * 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 freed until both the parent and the child have exited.
- */
-pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
-{
-	long retval;
-
-	/* If the parent runs before fn(arg) is called by the child,
-	 * the input registers of this function can be clobbered.
-	 * So we stash 'fn' and 'arg' into global registers which
-	 * will not be modified by the parent.
-	 */
-	__asm__ __volatile__("mov %4, %%g2\n\t"	   /* Save FN into global */
-			     "mov %5, %%g3\n\t"	   /* Save ARG into global */
-			     "mov %1, %%g1\n\t"	   /* Clone syscall nr. */
-			     "mov %2, %%o0\n\t"	   /* Clone flags. */
-			     "mov 0, %%o1\n\t"	   /* usp arg == 0 */
-			     "t 0x6d\n\t"	   /* Linux/Sparc clone(). */
-			     "brz,a,pn %%o1, 1f\n\t" /* Parent, just return. */
-			     " mov %%o0, %0\n\t"
-			     "jmpl %%g2, %%o7\n\t"   /* Call the function. */
-			     " mov %%g3, %%o0\n\t"   /* Set arg in delay. */
-			     "mov %3, %%g1\n\t"
-			     "t 0x6d\n\t"	   /* Linux/Sparc exit(). */
-			     /* Notreached by child. */
-			     "1:" :
-			     "=r" (retval) :
-			     "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED),
-			     "i" (__NR_exit),  "r" (fn), "r" (arg) :
-			     "g1", "g2", "g3", "o0", "o1", "memory", "cc");
-	return retval;
-}
-EXPORT_SYMBOL(kernel_thread);
-
 typedef struct {
 	union {
 		unsigned int	pr_regs[32];
@@ -799,41 +750,6 @@ int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
 }
 EXPORT_SYMBOL(dump_fpu);
 
-/*
- * sparc_execve() executes a new program after the asm stub has set
- * things up for us.  This should basically do what I want it to.
- */
-asmlinkage int sparc_execve(struct pt_regs *regs)
-{
-	int error, base = 0;
-	struct filename *filename;
-
-	/* User register window flush is done by entry.S */
-
-	/* Check for indirect call. */
-	if (regs->u_regs[UREG_G1] == 0)
-		base = 1;
-
-	filename = getname((char __user *)regs->u_regs[base + UREG_I0]);
-	error = PTR_ERR(filename);
-	if (IS_ERR(filename))
-		goto out;
-	error = do_execve(filename->name,
-			  (const char __user *const __user *)
-			  regs->u_regs[base + UREG_I1],
-			  (const char __user *const __user *)
-			  regs->u_regs[base + UREG_I2], regs);
-	putname(filename);
-	if (!error) {
-		fprs_write(0);
-		current_thread_info()->xfsr[0] = 0;
-		current_thread_info()->fpsaved[0] = 0;
-		regs->tstate &= ~TSTATE_PEF;
-	}
-out:
-	return error;
-}
-
 unsigned long get_wchan(struct task_struct *task)
 {
 	unsigned long pc, fp, bias = 0;