| /* 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 <sysdep.h> |
| #define _ERRNO_H 1 |
| #include <bits/errno.h> |
| #include <asm/unistd.h> |
| #include <bp-sym.h> |
| #include <bp-asm.h> |
| |
| /* 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)) |
