[RFC PATCH 04/13] x86/um: nommu: syscall handling

[Johannes Berg]

On Thu, 2024-10-24 at 21:09 +0900, Hajime Tazaki wrote:
> 
> +++ b/arch/x86/um/do_syscall_64.c
> @@ -0,0 +1,42 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +#include <linux/kernel.h>
> +#include <linux/ptrace.h>
> +#include <kern_util.h>
> +#include <sysdep/syscalls.h>
> +#include <os.h>
> +
> +#ifndef CONFIG_MMU

This seems unnecessary, you don't build the file with CONFIG_MMU in the
first place.

> +++ b/arch/x86/um/entry_64.S
> @@ -0,0 +1,88 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#include <asm/errno.h>
> +
> +#include <linux/linkage.h>
> +#include <asm/percpu.h>
> +#include <asm/desc.h>
> +
> +#include "../entry/calling.h"
> +
> +#ifdef CONFIG_SMP
> +#error need to stash these variables somewhere else
> +#endif
> +
> +#ifndef CONFIG_MMU

same here.

> +++ b/arch/x86/um/shared/sysdep/syscalls_64.h
> @@ -25,4 +25,8 @@ extern syscall_handler_t *sys_call_table[];
>  extern syscall_handler_t sys_modify_ldt;
>  extern syscall_handler_t sys_arch_prctl;
>  
> +__visible void do_syscall_64(struct pt_regs *regs);
> +extern long __kernel_vsyscall(int64_t a0, int64_t a1, int64_t a2, int64_t a3,
> +			      int64_t a4, int64_t a5, int64_t a6);
> +
> 

but maybe that should be ifdef'ed?

johannes