Skip to content
Permalink
9ff72da471
Switch branches/tags

Name already in use

A tag already exists with the provided branch name. Many Git commands accept both tag and branch names, so creating this branch may cause unexpected behavior. Are you sure you want to create this branch?
Go to file
 
 
Cannot retrieve contributors at this time
108 lines (90 sloc) 2.89 KB
/* clone() implementation for Nios II.
Copyright (C) 2008-2016 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>
#define CLONE_VM 0x00000100
#define CLONE_THREAD 0x00010000
/* 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)
/* We expect the argument registers to be preserved across system
calls and across task cloning, so flags should be in r4 here. */
andhi r2, r4, %hi(CLONE_THREAD)
bne r2, zero, 2f
andi r3, r4, CLONE_VM
movi r2, -1
bne r3, zero, 3f
DO_CALL (getpid, 0)
3:
stw r2, PID_OFFSET(r23)
stw r2, TID_OFFSET(r23)
2:
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. */
mov r4, r2
#ifdef PIC
nextpc r22
1: movhi r8, %hiadj(_gp_got - 1b)
addi r8, r8, %lo(_gp_got - 1b)
add r22, r22, r8
ldw r8, %call(HIDDEN_JUMPTARGET(_exit))(r22)
jmp r8
#else
jmpi _exit
#endif
cfi_endproc
cfi_startproc
PSEUDO_END (__clone)
libc_hidden_def (__clone)
weak_alias (__clone, clone)