| /* clone() implementation for Nios II. |
| Copyright (C) 2008-2018 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| Contributed by Andrew Jenner <andrew@codesourcery.com>, 2008. |
| |
| 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> |
| #define _ERRNO_H 1 |
| #include <bits/errno.h> |
| #include <tcb-offsets.h> |
| |
| /* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg, |
| void *parent_tidptr, void *tls, void *child_tidptr) */ |
| |
| .text |
| ENTRY(__clone) |
| /* Sanity check arguments. */ |
| movi r2, EINVAL |
| /* No NULL function pointers. */ |
| beq r4, zero, SYSCALL_ERROR_LABEL |
| /* No NULL stack pointers. */ |
| beq r5, zero, SYSCALL_ERROR_LABEL |
| |
| subi r5, r5, 8 /* Reserve argument save space. */ |
| stw r4, 4(r5) /* Save function pointer. */ |
| stw r7, 0(r5) /* Save argument pointer. */ |
| |
| /* Load arguments. */ |
| mov r4, r6 |
| ldw r6, 0(sp) |
| ldw r7, 8(sp) |
| ldw r8, 4(sp) |
| |
| /* Do the system call. */ |
| movi r2, SYS_ify (clone) |
| |
| /* End FDE now, because in the child the unwind info will be |
| wrong. */ |
| cfi_endproc |
| trap |
| |
| /* Check for errors. */ |
| bne r7, zero, SYSCALL_ERROR_LABEL |
| /* See if we're on the newly created thread. */ |
| beq r2, zero, thread_start |
| /* Successful return from the parent */ |
| ret |
| |
| thread_start: |
| cfi_startproc |
| cfi_undefined (ra) |
| |
| ldw r5, 4(sp) /* Function pointer. */ |
| ldw r4, 0(sp) /* Argument pointer. */ |
| addi sp, sp, 8 |
| |
| /* Call the user's function. */ |
| callr r5 |
| |
| /* exit with the result. */ |
| movi r2, SYS_ify (exit) |
| trap |
| cfi_endproc |
| |
| cfi_startproc |
| PSEUDO_END (__clone) |
| libc_hidden_def (__clone) |
| weak_alias (__clone, clone) |
