diff options
Diffstat (limited to 'libc/sysdeps/linux/nios2/clone.S')
| -rw-r--r-- | libc/sysdeps/linux/nios2/clone.S | 152 |
1 files changed, 88 insertions, 64 deletions
diff --git a/libc/sysdeps/linux/nios2/clone.S b/libc/sysdeps/linux/nios2/clone.S index 4afcb7d75..0626d8aa2 100644 --- a/libc/sysdeps/linux/nios2/clone.S +++ b/libc/sysdeps/linux/nios2/clone.S @@ -1,70 +1,94 @@ -/* - * libc/sysdeps/linux/nios2/clone.S -- `clone' syscall for linux/nios2 - * - * Copyright (C) 2004 Microtronix Datacom Ltd - * - * This file is subject to the terms and conditions of the GNU Lesser - * General Public License. See the file COPYING.LIB in the main - * directory of this archive for more details. - * - * Written by Wentao Xu <wentao@microtronix.com> - */ - -#define _ERRNO_H +/* 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 <sys/syscall.h> - -#ifdef __NR_clone -/* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg); */ - -.text -.global clone -.type clone,%function -.align 4 -clone: - addi sp,sp,-8 - mov r8,r4 - stw ra,4(sp) - stw r16,0(sp) - - mov r4,r6 - movi r2,-EINVAL - - /* sanity check */ - beq r8,zero,CLONE_ERROR_LABEL - beq r5,zero,CLONE_ERROR_LABEL - - /* system call */ - movi r2,TRAP_ID_SYSCALL - movi r3,__NR_clone - trap - - /* child call the function */ - mov r4,r7 - bne r2,zero,CLONE_ERROR_LABEL - callr r8 - - /* exit if it returns */ - mov r4,r2 - movi r3,__NR_exit + +#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 - -CLONE_ERROR_LABEL: - movi r3,-4096 - sub r16,zero,r2 - bgeu r3,r2,CLONE_OK - - /* store errno */ - call __errno_location - stw r16,0(r2) - movi r2,-1 - -CLONE_OK: - ldw ra,4(sp) - ldw r16,0(sp) - addi sp,sp,8 + + /* See if we're on the newly created thread. */ + beq r2, zero, thread_start + /* Successful return from the parent */ ret -.size clone,.-clone +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) |