Re: [PATCH v3 1/3] sh: add __NR_syscalls along with NR_syscalls

From: Arnd Bergmann
Date: Mon Nov 19 2018 - 12:37:29 EST


On Wed, Nov 14, 2018 at 5:32 AM Firoz Khan <firoz.khan@xxxxxxxxxx> wrote:
>
> NR_syscalls macro holds the number of system call exist
> in sh architecture. We have to change the value of NR-
> _syscalls, if we add or delete a system call.
>
> One of the patch in this patch series has a script which
> will generate a uapi header based on syscall.tbl file.
> The syscall.tbl file contains the total number of system
> calls information. So we have two option to update NR_sy-
> scalls value.
>
> 1. Update NR_syscalls in asm/unistd.h manually by count-
> ing the no.of system calls. No need to update NR_sys-
> calls until we either add a new system call or delete
> existing system call.
>
> 2. We can keep this feature it above mentioned script,
> that will count the number of syscalls and keep it in
> a generated file. In this case we don't need to expli-
> citly update NR_syscalls in asm/unistd.h file.
>
> The 2nd option will be the recommended one. For that, I
> added the __NR_syscalls macro in uapi/asm/unistd_32/64.h
> along with NR_syscalls which is moved to asm/unistd.h.
> The macro __NR_syscalls also added for making the name
> convention same across all architecture. While __NR_sys-
> calls isn't strictly part of the uapi, having it as part
> of the generated header to simplifies the implementation.
> We also need to enclose this macro with #ifdef __KERNEL__
> to avoid side effects.
>
> Signed-off-by: Firoz Khan <firoz.khan@xxxxxxxxxx>

Looks correct to me, but since there are only three references to
'NR_syscalls' in arch/sh, I wonder if we should just replace it with
__NR_syscalls in the same patch.

Arnd