mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-02 17:50:20 +00:00
97 lines
2.7 KiB
ArmAsm
97 lines
2.7 KiB
ArmAsm
|
/* The clone syscall wrapper.
|
||
|
|
Copyright (C) 2022 Free Software Foundation, Inc.
|
||
|
|
|
||
|
|
This file is part of the GNU C Library.
|
||
|
|
|
||
|
|
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
|
||
|
|
<https://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 <sys/asm.h>
|
||
|
|
#include <sysdep.h>
|
||
|
|
#define _ERRNO_H 1
|
||
|
|
#include <bits/errno.h>
|
||
|
|
#include <tls.h>
|
||
|
|
#include "tcb-offsets.h"
|
||
|
|
|
||
|
|
/* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg,
|
||
|
|
void *parent_tidptr, void *tls, void *child_tidptr) */
|
||
|
|
|
||
|
|
ENTRY (__clone)
|
||
|
|
|
||
|
|
/* Align stack to 16. */
|
||
|
|
BSTRINS a1, zero, 3, 0
|
||
|
|
|
||
|
|
/* Sanity check arguments. */
|
||
|
|
beqz a0, L (invalid) /* No NULL function pointers. */
|
||
|
|
beqz a1, L (invalid) /* No NULL stack pointers. */
|
||
|
|
|
||
|
|
ADDI a1, a1, -16 /* Reserve argument save space. */
|
||
|
|
REG_S a0, a1, 0 /* Save function pointer. */
|
||
|
|
REG_S a3, a1, SZREG /* Save argument pointer. */
|
||
|
|
|
||
|
|
/* The syscall expects the args to be in different slots. */
|
||
|
|
or a0, a2, zero
|
||
|
|
or a2, a4, zero
|
||
|
|
or a3, a6, zero
|
||
|
|
or a4, a5, zero
|
||
|
|
|
||
|
|
/* Do the system call. */
|
||
|
|
LI a7,__NR_clone
|
||
|
|
syscall 0
|
||
|
|
|
||
|
|
blt a0, zero ,L (error)
|
||
|
|
beqz a0,L (thread_start)
|
||
|
|
|
||
|
|
/* Successful return from the parent. */
|
||
|
|
ret
|
||
|
|
|
||
|
|
L (invalid):
|
||
|
|
LI a0, -EINVAL
|
||
|
|
|
||
|
|
/* Something bad happened -- no child created. */
|
||
|
|
L (error):
|
||
|
|
b __syscall_error
|
||
|
|
|
||
|
|
END (__clone)
|
||
|
|
|
||
|
|
/* Load up the arguments to the function. Put this block of code in
|
||
|
|
its own function so that we can terminate the stack trace with our
|
||
|
|
debug info. */
|
||
|
|
ENTRY (__thread_start)
|
||
|
|
L (thread_start):
|
||
|
|
|
||
|
|
/* Terminate call stack by noting ra is undefined. Use a dummy
|
||
|
|
.cfi_label to force starting the FDE. */
|
||
|
|
.cfi_label .Ldummy
|
||
|
|
cfi_undefined (1)
|
||
|
|
|
||
|
|
/* Restore the arg for user's function. */
|
||
|
|
REG_L a1, sp, 0 /* Function pointer. */
|
||
|
|
REG_L a0, sp, SZREG /* Argument pointer. */
|
||
|
|
|
||
|
|
/* Call the user's function. */
|
||
|
|
jirl ra, a1, 0
|
||
|
|
|
||
|
|
/* Call exit with the function's return value. */
|
||
|
|
LI a7, __NR_exit
|
||
|
|
syscall 0
|
||
|
|
|
||
|
|
END (__thread_start)
|
||
|
|
|
||
|
|
libc_hidden_def (__clone)
|
||
|
|
weak_alias (__clone, clone)
|