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108 lines
2.9 KiB
ArmAsm
108 lines
2.9 KiB
ArmAsm
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/* clone() implementation for Nios II.
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Copyright (C) 2008-2015 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Andrew Jenner <andrew@codesourcery.com>, 2008.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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/* clone() is even more special than fork() as it mucks with stacks
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and invokes a function in the right context after its all over. */
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#include <sysdep.h>
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#define _ERRNO_H 1
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#include <bits/errno.h>
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#include <tcb-offsets.h>
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#define CLONE_VM 0x00000100
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#define CLONE_THREAD 0x00010000
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/* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg,
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void *parent_tidptr, void *tls, void *child_tidptr) */
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.text
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ENTRY(__clone)
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/* Sanity check arguments. */
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movi r2, EINVAL
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/* No NULL function pointers. */
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beq r4, zero, SYSCALL_ERROR_LABEL
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/* No NULL stack pointers. */
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beq r5, zero, SYSCALL_ERROR_LABEL
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subi r5, r5, 8 /* Reserve argument save space. */
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stw r4, 4(r5) /* Save function pointer. */
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stw r7, 0(r5) /* Save argument pointer. */
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/* Load arguments. */
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mov r4, r6
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ldw r6, 0(sp)
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ldw r7, 8(sp)
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ldw r8, 4(sp)
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/* Do the system call. */
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movi r2, SYS_ify (clone)
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/* End FDE now, because in the child the unwind info will be
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wrong. */
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cfi_endproc
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trap
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/* Check for errors. */
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bne r7, zero, SYSCALL_ERROR_LABEL
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/* See if we're on the newly created thread. */
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beq r2, zero, thread_start
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/* Successful return from the parent */
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ret
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thread_start:
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cfi_startproc
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cfi_undefined (ra)
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/* We expect the argument registers to be preserved across system
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calls and across task cloning, so flags should be in r4 here. */
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andhi r2, r4, %hi(CLONE_THREAD)
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bne r2, zero, 2f
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andi r3, r4, CLONE_VM
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movi r2, -1
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bne r3, zero, 3f
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DO_CALL (getpid, 0)
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3:
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stw r2, PID_OFFSET(r23)
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stw r2, TID_OFFSET(r23)
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2:
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ldw r5, 4(sp) /* Function pointer. */
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ldw r4, 0(sp) /* Argument pointer. */
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addi sp, sp, 8
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/* Call the user's function. */
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callr r5
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/* _exit with the result. */
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mov r4, r2
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#ifdef PIC
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nextpc r22
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1: movhi r8, %hiadj(_gp_got - 1b)
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addi r8, r8, %lo(_gp_got - 1b)
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add r22, r22, r8
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ldw r8, %call(HIDDEN_JUMPTARGET(_exit))(r22)
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jmp r8
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#else
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jmpi _exit
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#endif
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cfi_endproc
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cfi_startproc
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PSEUDO_END (__clone)
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weak_alias (__clone, clone)
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