Re: [PATCH v2 2/5] parisc: add __NR_Linux_syscalls macro with __NR_syscalls

From: Arnd Bergmann <arnd@arndb.de>
To: Firoz Khan <firoz.khan@linaro.org>
Cc: Parisc List <linux-parisc@vger.kernel.org>,
	"James E.J. Bottomley" <jejb@parisc-linux.org>,
	Helge Deller <deller@gmx.de>,
	Thomas Gleixner <tglx@linutronix.de>,
	gregkh <gregkh@linuxfoundation.org>,
	Philippe Ombredanne <pombredanne@nexb.com>,
	Kate Stewart <kstewart@linuxfoundation.org>,
	y2038 Mailman List <y2038@lists.linaro.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	linux-arch <linux-arch@vger.kernel.org>,
	Deepa Dinamani <deepa.kernel@gmail.com>,
	Marcin Juszkiewicz <marcin.juszkiewicz@linaro.org>
Subject: Re: [PATCH v2 2/5] parisc: add __NR_Linux_syscalls macro with __NR_syscalls
Date: Fri, 28 Sep 2018 14:14:26 +0200	[thread overview]
Message-ID: <CAK8P3a3ZOC-V0uOD6uD=Hg-AoN8mkJynD6ubpaTppevUvQ54qw@mail.gmail.com> (raw)
Message-ID: <20180928121426.Uk1_r0pRFagWtSidiZV7ElPceLEaHpLGZtuw9IsZqUc@z> (raw)
In-Reply-To: <1538058267-3765-3-git-send-email-firoz.khan@linaro.org>

On Thu, Sep 27, 2018 at 4:25 PM Firoz Khan <firoz.khan@linaro.org> wrote:
>
> 1. Update __NR_Linux_syscalls in uapi/asm/unistd.h manually
>    by counting the no.of system calls. No need to update
>    __NR_Linux_syscalls until we either add a new system call
>    or delete an 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 gener-
>    ated file. In this case we don't need to explicitly update
>    __NR_Linux_syscalls in asm/unistd.h file.
>
> The 2nd option will be the recommended one. For that, I moved
> the __NR_Linux_syscalls macro from uapi/asm/unistd.h 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@linaro.org>
> ---
>  arch/parisc/include/uapi/asm/unistd.h | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/arch/parisc/include/uapi/asm/unistd.h b/arch/parisc/include/uapi/asm/unistd.h
> index bb52e12..255c62a 100644
> --- a/arch/parisc/include/uapi/asm/unistd.h
> +++ b/arch/parisc/include/uapi/asm/unistd.h
> @@ -366,7 +366,11 @@
>  #define __NR_statx             (__NR_Linux + 349)
>  #define __NR_io_pgetevents     (__NR_Linux + 350)
>
> -#define __NR_Linux_syscalls    (__NR_io_pgetevents + 1)
> +#ifdef __KERNEL__
> +#define __NR_syscalls           351
> +#endif
> +
> +#define __NR_Linux_syscalls     __NR_syscalls
>

Hmm, now you have a __NR_Linux_syscalls macro that is defined in user
space to a another macro that is not visible there. How about moving
__NR_Linux_syscalls into arch/parisc/include/asm/unistd.h or
replacing its users with __NR_syscalls instead?

       Arnd