12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667686970717273747576777879808182838485868788899091929394 |
- /* 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>
- #ifdef __UCLIBC_HAS_THREADS_NATIVE__
- #include <tcb-offsets.h>
- #endif
- #define CLONE_VM 0x00000100
- /* 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
- 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)
- trap
- /* See if we're on the newly created thread. */
- beq r2, zero, thread_start
- /* Successful return from the parent */
- ret
- thread_start:
- /* We expect the argument registers to be preserved across system
- calls and across task cloning, so flags should be in r4 here. */
- andi r2, r4, CLONE_VM
- bne r2, zero, 2f
- DO_CALL (getpid, 0)
- #ifdef RESET_PID
- stw r2, PID_OFFSET(r23)
- stw r2, TID_OFFSET(r23)
- #endif
- 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
- END(__clone)
- libc_hidden_def (__clone)
- weak_alias (__clone, clone)
|