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/* The clone3 syscall wrapper. Linux/RISC-V 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 <asm/errno.h>
#include <sys/asm.h>
#include <sysdep.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:
a0: cl_args
a1: size
a2: func
a3: arg */
.text
ENTRY(__clone3)
/* Sanity check args. */
beqz a0, L(invalid) /* No NULL cl_args pointer. */
beqz a2, L(invalid) /* No NULL function pointer. */
/* Do the system call, the kernel expects:
a7: system call number
a0: cl_args
a1: size */
li a7, __NR_clone3
scall
bltz a0, L(error)
beqz a0, L(thread_start)
ret
L(invalid):
li a0, -EINVAL
L(error):
tail __syscall_error
END (__clone3)
ENTRY(__thread_start_clone3)
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 (ra)
/* Restore the arg for user's function and call the user's
function. */
mv a0, a3 /* Argument pointer. */
jalr a2
/* Call exit with the function's return value. */
li a7, __NR_exit
scall
END(__thread_start_clone3)
libc_hidden_def (__clone3)
weak_alias (__clone3, clone3)
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