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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>
- /* 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
- 4:
- /* 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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