glibc/sysdeps/unix/sysv/linux/aarch64/clone3.S

86 lines
2.2 KiB
ArmAsm

/* The clone3 syscall wrapper. Linux/aarch64 version.
Copyright (C) 2023-2024 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/>. */
#include <sysdep.h>
#define _ERRNO_H 1
#include <bits/errno.h>
/* The userland implementation is:
int clone3 (struct clone_args *cl_args, size_t size,
int (*func)(void *arg), void *arg);
the kernel entry is:
int clone3 (struct clone_args *cl_args, size_t size);
The parameters are passed in registers from userland:
x0: cl_args
x1: size
x2: func
x3: arg */
.text
ENTRY(__clone3)
PTR_ARG (0)
PTR_ARG (1)
PTR_ARG (3)
PTR_ARG (4)
/* Save args for the child. */
mov x10, x0 /* cl_args */
mov x11, x2 /* func */
mov x12, x3 /* args */
/* Sanity check args. */
mov x0, #-EINVAL
cbz x10, .Lsyscall_error /* No NULL cl_args pointer. */
cbz x2, .Lsyscall_error /* No NULL function pointer. */
/* Do the system call, the kernel expects:
x8: system call number
x0: cl_args
x1: size */
mov x0, x10
mov x8, #SYS_ify(clone3)
svc 0x0
cmp x0, #0
beq thread_start
blt .Lsyscall_error
RET
PSEUDO_END (__clone3)
.align 4
.type thread_start, %function
thread_start:
cfi_startproc
cfi_undefined (x30)
mov x29, 0
/* Pick the function arg and execute. */
mov x0, x12
blr x11
/* We are done, pass the return value through x0. */
mov x8, #SYS_ify(exit)
svc 0x0
cfi_endproc
.size thread_start, .-thread_start
libc_hidden_def (__clone3)
weak_alias (__clone3, clone3)