/* Copyright (C) 1996, 1997, 1998, 1999 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Pat Beirne <patb@corelcomputer.com> 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. */ #define _ERRNO_H #include <features.h> #include <bits/errno.h> #include <sys/syscall.h> #include <bits/arm_asm.h> #if defined(__NR_clone) /* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg); */ .text .global __clone .type __clone,%function .align 2 #if defined(THUMB1_ONLY) .thumb_func __clone: @ sanity check args cmp r0, #0 beq __einval cmp r1, #0 beq __einval @ insert the args onto the new stack sub r1, r1, #8 str r3, [r1, #4] @ save the function pointer as the 0th element str r0, [r1] @ do the system call @ get flags mov r0, r2 @ new sp is already in r1 @ load remaining arguments off the stack stmfd sp!, {r4} ldr r2, [sp, #4] ldr r3, [sp, #8] ldr r4, [sp, #12] DO_CALL (clone) movs a1, a1 blt __error ldmnefd sp!, {r4} beq 1f bx lr 1: @ pick the function arg and call address off the stack and execute ldr r0, [sp, #4] ldr r1, [sp] bl 2f @ blx r1 @ and we are done, passing the return value through r0 bl HIDDEN_JUMPTARGET(_exit) @ Should never return b . 2: bx r1 __einval: ldr r0, =-EINVAL __error: push {r3, lr} bl __syscall_error POP_RET .pool #else __clone: @ sanity check args cmp r0, #0 IT(te, ne) cmpne r1, #0 moveq r0, #-EINVAL beq __error @ insert the args onto the new stack sub r1, r1, #8 str r3, [r1, #4] @ save the function pointer as the 0th element str r0, [r1] @ do the system call @ get flags mov r0, r2 @ new sp is already in r1 @ load remaining arguments off the stack stmfd sp!, {r4} ldr r2, [sp, #4] ldr r3, [sp, #8] ldr r4, [sp, #12] DO_CALL (clone) movs a1, a1 blt __error ldmnefd sp!, {r4} IT(t, ne) #if defined(__USE_BX__) bxne lr #else movne pc, lr #endif @ pick the function arg and call address off the stack and execute ldr r0, [sp, #4] mov lr, pc ldr pc, [sp] @ and we are done, passing the return value through r0 b HIDDEN_JUMPTARGET(_exit) __error: b __syscall_error #endif .size __clone,.-__clone weak_alias(__clone, clone) #endif