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/*
* Copyright (C) 2016-2017 Andes Technology, Inc.
* Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
*/
/* Copyright (C) 2010-2014 Free Software Foundation, Inc.
Contributed by Pat Beirne <patb@corelcomputer.com>
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, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
/* 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 RESET_PID
#include <tcb-offsets.h>
#endif
#define CLONE_VM 0x00000100
#define CLONE_THREAD 0x00010000
/* int clone(int (*fn)(void *), void *child_stack, int flags, void *arg);
_syscall2(int, clone, int, flags, void *, child_stack) */
ENTRY(__clone)
#ifdef __NDS32_ABI_2FP_PLUS__
lwi $r4, [$sp]
lwi $r5, [$sp+4]
#endif
#ifdef PIC
/* set GP register to parent only, cause child's $SP will be $r1. */
pushm $fp, $gp
cfi_adjust_cfa_offset(8)
cfi_rel_offset(fp, 0)
cfi_rel_offset(gp, 4)
mfusr $r15, $pc
sethi $gp, hi20(_GLOBAL_OFFSET_TABLE_+4)
ori $gp, $gp, lo12(_GLOBAL_OFFSET_TABLE_+8)
add $gp, $gp, $r15
#endif /* PIC */
/* sanity check arguments. */
beqz $r0, 1f
bnez $r1, 2f
1:
movi $r0, -EINVAL
5:
#ifdef PIC
/* restore GP register, only in parent's stack */
la $r15, C_SYMBOL_NAME(__syscall_error@PLT)
push $lp
cfi_adjust_cfa_offset(4)
cfi_rel_offset(lp, 0)
addi $sp, $sp, -4
cfi_adjust_cfa_offset(4)
jral $r15
addi $sp, $sp, 4
cfi_adjust_cfa_offset(-4)
pop $lp
cfi_adjust_cfa_offset(-4)
cfi_restore(lp)
popm $fp, $gp
cfi_adjust_cfa_offset(-8)
cfi_restore(fp)
cfi_restore(gp)
ret
#else /* ! PIC */
la $r15, C_SYMBOL_NAME(__syscall_error)
jr $r15
#endif /* ! PIC */
2:
/* Child's $sp will be $r1, make $sp 8-byte alignment */
bitci $r1, $r1, 7
/* push to child's stack only. */
addi $r1, $r1, -4
swi.p $r3, [$r1], -4 ! arg
swi $r0, [$r1] ! fn
/* do the system call */
or $r0, $r2, $r2 ! move $r0, $r2
move $r3, $r5
move $r5, $r2 ! Use $r5 to backup $r2
! The pt_regs is placed in $r5 in kerenl (sys_clone_wrapper)
move $r2, $r4
#ifdef __NDS32_ABI_2FP_PLUS__
# ifdef PIC
lwi $r4, [$sp+#0x10]
# else
lwi $r4, [$sp+#0x8]
# endif
#else
# ifdef PIC
lwi $r4, [$sp+#0x8]
# else
lwi $r4, [$sp]
# endif
#endif
__do_syscall(clone)
beqz $r0, 4f
bltz $r0, 5b
10:
#ifdef PIC
/* restore GP register, only in parent's stack */
popm $fp, $gp
cfi_adjust_cfa_offset(-8)
cfi_restore(gp)
cfi_restore(fp)
#endif /* PIC */
ret
#ifdef RESET_PID
4:
cfi_undefined(lp)
movi $r0, CLONE_THREAD ! Skip when CLONE_THREAD is set.
and $r0, $r5, $r0
bnez $r0, 8f
movi $r0, CLONE_VM ! Value = -1 when CLONE_VM is set.
and $r0, $r5, $r0
beqz $r0, 6f
movi $r0, -1
j 7f
6:
__do_syscall(getpid) ! __do_syscall(gettid) ! __do_syscall(getpid)
7:
swi $r0, [$r25 + PID_OFFSET]
swi $r0, [$r25 + TID_OFFSET]
8:
#else
4:
#endif
/* Only in child's stack. */
pop $r1 ! fn
pop $r0 ! arg
#if !defined(__NDS32_ABI_2__) && !defined(__NDS32_ABI_2FP_PLUS__)
addi $sp, $sp, -24
#endif /* !defined(__NDS32_ABI_2__) && !defined(__NDS32_ABI_2FP_PLUS__) */
! use $r15 in case _exit is PIC
bral $r1
#if !defined(__NDS32_ABI_2__) && !defined(__NDS32_ABI_2FP_PLUS__)
addi $sp, $sp, 24
#endif /* !defined(__NDS32_ABI_2__) && !defined(__NDS32_ABI_2FP_PLUS__) */
! use $r15 in case _exit is PIC
#ifdef PIC
la $r15, C_SYMBOL_NAME(_exit@PLT)
#else /* ! PIC */
la $r15, C_SYMBOL_NAME(_exit)
#endif /* ! PIC */
jr $r15
PSEUDO_END (__clone)
weak_alias (__clone, clone)
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