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- /* clone() implementation for Nios II.
- Copyright (C) 2008-2019 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)
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