| /* Copyright (C) 1996-2018 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, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| /* 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> |
| #include <tcb-offsets.h> |
| #define _ERRNO_H 1 |
| #include <bits/errno.h> |
| |
| /* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg, |
| pid_t *ptid, struct user_desc *tls, pid_t *ctid); */ |
| |
| .text |
| ENTRY(__clone) |
| @ sanity check args |
| cmp r0, #0 |
| ite ne |
| cmpne r1, #0 |
| moveq r0, #-EINVAL |
| beq PLTJMP(syscall_error) |
| |
| @ insert the args onto the new stack |
| str r3, [r1, #-4]! |
| str r0, [r1, #-4]! |
| |
| @ do the system call |
| @ get flags |
| mov r0, r2 |
| mov ip, r2 |
| @ new sp is already in r1 |
| push {r4, r7} |
| cfi_adjust_cfa_offset (8) |
| cfi_rel_offset (r4, 0) |
| cfi_rel_offset (r7, 4) |
| ldr r2, [sp, #8] |
| ldr r3, [sp, #12] |
| ldr r4, [sp, #16] |
| ldr r7, =SYS_ify(clone) |
| swi 0x0 |
| cfi_endproc |
| cmp r0, #0 |
| beq 1f |
| pop {r4, r7} |
| blt PLTJMP(C_SYMBOL_NAME(__syscall_error)) |
| RETINSTR(, lr) |
| |
| cfi_startproc |
| PSEUDO_END (__clone) |
| |
| 1: |
| .fnstart |
| .cantunwind |
| @ pick the function arg and call address off the stack and execute |
| ldr r0, [sp, #4] |
| ldr ip, [sp], #8 |
| BLX (ip) |
| |
| @ and we are done, passing the return value through r0 |
| ldr r7, =SYS_ify(exit) |
| swi 0x0 |
| |
| .fnend |
| |
| libc_hidden_def (__clone) |
| weak_alias (__clone, clone) |
