Subversion Repositories openrisc_2011-10-31

/* Copyright (C) 1996, 1997, 1998, 1999, 2000 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   Contributed by Richard Henderson (rth@tamu.edu)

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, write to the Free

   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA

   02111-1307 USA.  */

/* clone() is even more special than fork() as it mucks with stacks

   and invokes a function in the right context after its all over.  */

#include 

#define _ERRNO_H        1

#include 

#include 

#include 

#include 

/* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg); */

#define PARMS   LINKAGE         /* no space for saved regs */

#define FUNC    PARMS

#define STACK   FUNC+4

#define FLAGS   STACK+PTR_SIZE

#define ARG     FLAGS+4

        .text

ENTRY (BP_SYM (__clone))

        /* Sanity check arguments.  */

        movl    $-EINVAL,%eax

        movl    FUNC(%esp),%ecx         /* no NULL function pointers */

#ifdef PIC

        jecxz   SYSCALL_ERROR_LABEL

#else

        testl   %ecx,%ecx

        jz      SYSCALL_ERROR_LABEL

#endif

        movl    STACK(%esp),%ecx        /* no NULL stack pointers */

#ifdef PIC

        jecxz   SYSCALL_ERROR_LABEL

#else

        testl   %ecx,%ecx

        jz      SYSCALL_ERROR_LABEL

#endif

        /* Insert the argument onto the new stack.  */

        subl    $8,%ecx

        movl    ARG(%esp),%eax          /* no negative argument counts */

        movl    %eax,4(%ecx)

        /* Save the function pointer as the zeroth argument.

           It will be popped off in the child in the ebx frobbing below.  */

        movl    FUNC(%esp),%eax

        movl    %eax,0(%ecx)

        /* Do the system call */

        pushl   %ebx

        movl    FLAGS+4(%esp),%ebx

        movl    $SYS_ify(clone),%eax

        int     $0x80

        popl    %ebx

        test    %eax,%eax

        jl      SYSCALL_ERROR_LABEL

        jz      thread_start

L(pseudo_end):

        ret

thread_start:

        subl    %ebp,%ebp       /* terminate the stack frame */

        call    *%ebx

#ifdef PIC

        call    L(here)

L(here):

        popl    %ebx

        addl    $_GLOBAL_OFFSET_TABLE_+[.-L(here)], %ebx

#endif

        pushl   %eax

        call    JUMPTARGET (_exit)

PSEUDO_END (BP_SYM (__clone))

weak_alias (BP_SYM (__clone), BP_SYM (clone))