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688903eb3e
* All files with FSF copyright notices: Update copyright dates using scripts/update-copyrights. * locale/programs/charmap-kw.h: Regenerated. * locale/programs/locfile-kw.h: Likewise.
177 lines
4.0 KiB
ArmAsm
177 lines
4.0 KiB
ArmAsm
/* Copyright (C) 2011-2018 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Chris Metcalf <cmetcalf@tilera.com>, 2011.
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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 it's 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 <asm/unistd.h>
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#include <arch/abi.h>
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#include <tls.h>
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#include <linux/sched.h>
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/* What we save where in the stack frame; must include all callee-saves. */
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#define FRAME_NEXT_LR (0 * REGSIZE) /* reserved by ABI; not used here */
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#define FRAME_SP (1 * REGSIZE)
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#define FRAME_R30 (2 * REGSIZE)
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#define FRAME_R31 (3 * REGSIZE)
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#define FRAME_R32 (4 * REGSIZE)
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#define FRAME_SIZE (5 * REGSIZE)
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/* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg,
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pid_t *ptid, struct user_desc *tls, pid_t *ctid); */
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.text
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ENTRY (__clone)
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/* Create a stack frame so we can pass callee-saves to new task. */
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{
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move r10, sp
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st sp, lr
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ADDI_PTR sp, sp, -FRAME_SIZE
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}
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cfi_offset (lr, 0)
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cfi_def_cfa_offset (FRAME_SIZE)
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ADDI_PTR r11, sp, FRAME_SP
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{
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st r11, r10
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ADDI_PTR r11, sp, FRAME_R30
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}
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{
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st r11, r30
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ADDI_PTR r11, sp, FRAME_R31
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}
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cfi_offset (r30, FRAME_R30 - FRAME_SIZE)
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{
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st r11, r31
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ADDI_PTR r11, sp, FRAME_R32
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}
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cfi_offset (r31, FRAME_R31 - FRAME_SIZE)
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st r11, r32
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cfi_offset (r32, FRAME_R32 - FRAME_SIZE)
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/* sanity check arguments */
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beqz r0, .Linvalid
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beqz r1, .Linvalid
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/* Make sure child stack is properly aligned, and set up the
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top frame so that we can call out of it immediately in the
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child. Setting it up here means we fault in the parent if
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it's bogus, which is probably cleaner than faulting first
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thing in the child. */
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ADDI_PTR r1, r1, -C_ABI_SAVE_AREA_SIZE
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andi r1, r1, -C_ABI_SAVE_AREA_SIZE
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ADDI_PTR r9, r1, REGSIZE /* sp of this frame on entry, i.e. zero */
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st r9, zero
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/* We need to switch the argument convention around from
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libc to kernel:
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libc:
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r0 fn
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r1 child_stack
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r2 flags
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r3 arg
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r4 ptid
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r5 tls
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r6 ctid
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kernel:
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r0 flags
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r1 child_stack [same as libc]
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r2 ptid
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r3 ctid
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r4 tls
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Plus the callee-saves as described at .Lthread_start, below. */
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{
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move r32, r0
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move r0, r2
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}
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{
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move r31, r3
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move r3, r6
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}
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{
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move r30, r2
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move r2, r4
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}
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{
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move r4, r5
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moveli TREG_SYSCALL_NR_NAME, __NR_clone
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}
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swint1
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beqz r0, .Lthread_start /* If in child task. */
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.Ldone:
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/* Restore the callee-saved registers and return. */
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ADDLI_PTR lr, sp, FRAME_SIZE
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{
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ld lr, lr
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ADDLI_PTR r30, sp, FRAME_R30
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}
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{
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ld r30, r30
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ADDLI_PTR r31, sp, FRAME_R31
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}
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{
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ld r31, r31
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ADDLI_PTR r32, sp, FRAME_R32
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}
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{
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ld r32, r32
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ADDI_PTR sp, sp, FRAME_SIZE
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}
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cfi_def_cfa_offset (0)
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bnez r1, .Lerror
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jrp lr
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.Lerror:
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j SYSCALL_ERROR_NAME
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.Linvalid:
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{
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movei r1, EINVAL
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j .Ldone
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}
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/* This function expects to receive:
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sp: the top of a valid stack area
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r30: clone() flags
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r31: the argument to pass to the user function
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r32: the user function pointer */
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.Lthread_start:
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cfi_def_cfa_offset (FRAME_SIZE)
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cfi_undefined (lr)
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{
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/* Invoke user function with specified argument. */
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move r0, r31
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jalr r32
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}
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moveli TREG_SYSCALL_NR_NAME, __NR_exit
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swint1
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PSEUDO_END (__clone)
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libc_hidden_def (__clone)
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weak_alias (__clone, clone)
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