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, 9 insertions, 48 deletions

diff --git a/arch/microblaze/kernel/entry.S b/arch/microblaze/kernel/entry.S
index 03f7b8ce6b6b..c217367dfc7b 100644
--- a/arch/microblaze/kernel/entry.S
+++ b/arch/microblaze/kernel/entry.S
@@ -293,24 +293,6 @@ C_ENTRY(_user_exception):
         swi     r1, r0, TOPHYS(PER_CPU(ENTRY_SP)) /* save stack */
         addi    r14, r14, 4     /* return address is 4 byte after call */
 
-        mfs     r1, rmsr
-        nop
-        andi    r1, r1, MSR_UMS
-        bnei    r1, 1f
-
-/* Kernel-mode state save - kernel execve */
-        lwi     r1, r0, TOPHYS(PER_CPU(ENTRY_SP)); /* Reload kernel stack-ptr*/
-        tophys(r1,r1);
-
-        addik   r1, r1, -PT_SIZE; /* Make room on the stack. */
-        SAVE_REGS
-
-        swi     r1, r1, PT_MODE; /* pt_regs -> kernel mode */
-        brid    2f;
-        nop;                            /* Fill delay slot */
-
-/* User-mode state save.  */
-1:
         lwi     r1, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); /* get saved current */
         tophys(r1,r1);
         lwi     r1, r1, TS_THREAD_INFO; /* get stack from task_struct */
@@ -460,18 +442,6 @@ TRAP_return:		/* Make global symbol for debugging */
         nop;
 
 
-/* These syscalls need access to the struct pt_regs on the stack, so we
-   implement them in assembly (they're basically all wrappers anyway).  */
-
-C_ENTRY(sys_fork_wrapper):
-        addi    r5, r0, SIGCHLD                 /* Arg 0: flags */
-        lwi     r6, r1, PT_R1   /* Arg 1: child SP (use parent's) */
-        addik   r7, r1, 0                       /* Arg 2: parent context */
-        add     r8, r0, r0                      /* Arg 3: (unused) */
-        add     r9, r0, r0;                     /* Arg 4: (unused) */
-        brid    do_fork         /* Do real work (tail-call) */
-        add     r10, r0, r0;                    /* Arg 5: (unused) */
-
 /* This the initial entry point for a new child thread, with an appropriate
    stack in place that makes it look the the child is in the middle of an
    syscall.  This function is actually `returned to' from switch_thread
@@ -479,28 +449,19 @@ C_ENTRY(sys_fork_wrapper):
    saved context).  */
 C_ENTRY(ret_from_fork):
         bralid  r15, schedule_tail; /* ...which is schedule_tail's arg */
-        add     r3, r5, r0;     /* switch_thread returns the prev task */
+        add     r5, r3, r0;     /* switch_thread returns the prev task */
                                 /* ( in the delay slot ) */
         brid    ret_from_trap;  /* Do normal trap return */
         add     r3, r0, r0;     /* Child's fork call should return 0. */
 
-C_ENTRY(sys_vfork):
-        brid    microblaze_vfork        /* Do real work (tail-call) */
-        addik   r5, r1, 0
-
-C_ENTRY(sys_clone):
-        bnei    r6, 1f;                 /* See if child SP arg (arg 1) is 0. */
-        lwi     r6, r1, PT_R1;  /* If so, use paret's stack ptr */
-1:      addik   r7, r1, 0;                      /* Arg 2: parent context */
-        lwi     r9, r1, PT_R8;          /* parent tid.  */
-        lwi     r10, r1, PT_R9;         /* child tid.  */
-        /* do_fork will pick up TLS from regs->r10.  */
-        brid    do_fork         /* Do real work (tail-call) */
-        add     r8, r0, r0;             /* Arg 3: (unused) */
-
-C_ENTRY(sys_execve):
-        brid    microblaze_execve;      /* Do real work (tail-call).*/
-        addik   r8, r1, 0;              /* add user context as 4th arg */
+C_ENTRY(ret_from_kernel_thread):
+        bralid  r15, schedule_tail; /* ...which is schedule_tail's arg */
+        add     r5, r3, r0;     /* switch_thread returns the prev task */
+                                /* ( in the delay slot ) */
+        brald   r15, r20        /* fn was left in r20 */
+        addk    r5, r0, r19     /* ... and argument - in r19 */
+        brid    ret_from_trap
+        add     r3, r0, r0
 
 C_ENTRY(sys_rt_sigreturn_wrapper):
         brid    sys_rt_sigreturn        /* Do real work */