Re: [PATCH 4/5] arm: Add the clone3 wrapper

[Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>]

Ping.

On 03/02/23 14:12, Adhemerval Zanella wrote:
> It follows the internal signature:
> 
>   extern int clone3 (struct clone_args *__cl_args, size_t __size,
> 		    int (*__func) (void *__arg), void *__arg);
> 
> Checked on arm-linux-gnueabihf.
> ---
>  sysdeps/unix/sysv/linux/arm/clone3.S | 80 ++++++++++++++++++++++++++++
>  sysdeps/unix/sysv/linux/arm/sysdep.h |  1 +
>  2 files changed, 81 insertions(+)
>  create mode 100644 sysdeps/unix/sysv/linux/arm/clone3.S
> 
> diff --git a/sysdeps/unix/sysv/linux/arm/clone3.S b/sysdeps/unix/sysv/linux/arm/clone3.S
> new file mode 100644
> index 0000000000..f236d18390
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/arm/clone3.S
> @@ -0,0 +1,80 @@
> +/* The clone3 syscall wrapper.  Linux/arm version.
> +   Copyright (C) 2023 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:
> +   r0: cl_args
> +   r1: size
> +   r2: func
> +   r3: arg  */
> +
> +        .text
> +ENTRY(__clone3)
> +	/* Sanity check args.  */
> +	cmp	r0, #0
> +	ite	ne
> +	cmpne	r1, #0
> +	moveq	r0, #-EINVAL
> +	beq	PLTJMP(syscall_error)
> +
> +	/* Do the syscall, the kernel expects:
> +	   r7: system call number:
> +	   r0: cl_args
> +	   r1: size  */
> +	push    { r7 }
> +	cfi_adjust_cfa_offset (4)
> +	cfi_rel_offset (r7, 0)
> +	ldr     r7, =SYS_ify(clone3)
> +	swi	0x0
> +	cfi_endproc
> +
> +	cmp	r0, #0
> +	beq	1f
> +	pop     {r7}
> +	blt	PLTJMP(C_SYMBOL_NAME(__syscall_error))
> +	RETINSTR(, lr)
> +
> +	cfi_startproc
> +PSEUDO_END (__clone3)
> +
> +1:
> +	.fnstart
> +	.cantunwind
> +	mov	r0, r3
> +	mov	ip, r2
> +	BLX (ip)
> +
> +	/* And we are done, passing the return value through r0.  */
> +	ldr	r7, =SYS_ify(exit)
> +	swi	0x0
> +
> +	.fnend
> +
> +libc_hidden_def (__clone3)
> +weak_alias (__clone3, clone3)
> diff --git a/sysdeps/unix/sysv/linux/arm/sysdep.h b/sysdeps/unix/sysv/linux/arm/sysdep.h
> index 2f321881c8..57fc5f16bd 100644
> --- a/sysdeps/unix/sysv/linux/arm/sysdep.h
> +++ b/sysdeps/unix/sysv/linux/arm/sysdep.h
> @@ -362,6 +362,7 @@ __local_syscall_error:						\
>  #define HAVE_CLOCK_GETTIME_VSYSCALL	"__vdso_clock_gettime"
>  #define HAVE_CLOCK_GETTIME64_VSYSCALL	"__vdso_clock_gettime64"
>  #define HAVE_GETTIMEOFDAY_VSYSCALL	"__vdso_gettimeofday"
> +#define HAVE_CLONE3_WRAPPER		1
>  
>  #define LOAD_ARGS_0()
>  #define ASM_ARGS_0