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| -rw-r--r-- | libc/sysdeps/linux/arm/clone.S | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/libc/sysdeps/linux/arm/clone.S b/libc/sysdeps/linux/arm/clone.S new file mode 100644 index 000000000..c9a1ec23a --- /dev/null +++ b/libc/sysdeps/linux/arm/clone.S @@ -0,0 +1,62 @@ +/* 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. */ + +#include <sysdep.h> +#define _ERRNO_H 1 +#include <bits/errno.h> + +/* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg); */ + + .text +ENTRY(__clone) + @ sanity check args + cmp r0, #0 + cmpne r1, #0 + moveq r0, #-EINVAL + beq PLTJMP(syscall_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 + swi SYS_ify(clone) + movs a1, a1 + blt PLTJMP(C_SYMBOL_NAME(__syscall_error)) + RETINSTR(movne, pc, lr) + + @ 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 PLTJMP(_exit) + +PSEUDO_END (__clone) + +weak_alias (__clone, clone) |