/* Ten plik zawiera kod asemblerowy funkcji clone(). */ /* Copyright (C) 1996, 1997 Free Software Foundation, Inc. Contributed by Richard Henderson (rth@tamu.edu)
/* Standardowa licencja GNU */ The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Library General Public License as published by the Free Software Foundation; either version 2 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 Library General Public License for more details. You should have received a copy of the GNU Library General Public License along with the GNU C Library; see the file COPYING.LIB. If not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, 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 <asm/errno.h> #include <asm/unistd.h> /* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg); */ .text .align 4 .globl __clone .type __clone,@function .weak clone clone = __clone __clone: /* Sanity check arguments. */ movl $-EINVAL,%eax movl 4(%esp),%ecx /* no NULL function pointers */ testl %ecx,%ecx jz syscall_error movl 8(%esp),%ecx /* no NULL stack pointers */ testl %ecx,%ecx jz syscall_error /* Insert the argument onto the new stack. */ subl $8,%ecx movl 16(%esp),%eax 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 4(%esp),%eax movl %eax,0(%ecx) /* Do the system call */ pushl %ebx movl 16(%esp),%ebx movl $__NR_clone,%eax int $0x80 popl %ebx test %eax,%eax jl syscall_error jz thread_start ret syscall_error: #ifdef __PIC__ pushl %ebx call syscall_error_1 syscall_error_1: popl %ebx addl $_GLOBAL_OFFSET_TABLE_+[.-syscall_error_1], %ebx #endif negl %eax pushl %eax #ifdef __PIC__ call __errno_location@PLT #else call __errno_location #endif popl 0(%eax) movl $-1, %eax #ifdef __PIC popl %ebx #endif ret thread_start: subl %ebp,%ebp /* terminate the stack frame */ call *%ebx pushl %eax #ifdef __PIC__ call thread_exit thread_exit: popl %ebx addl $_GLOBAL_OFFSET_TABLE_+[.-thread_exit], %ebx call _exit@PLT #else call _exit #endif