sys_kcmp (was: Re: [PATCH 1/2] ARM: add finit_module syscall to ARM)

Geert Uytterhoeven
2012-09-22T10:56:45Z

On Fri, Sep 21, 2012 at 6:51 PM, Russell King <rmk@arm.linux.org.uk> wrote:
> That brings up another question though - when was kcmp added to x86, and
> why aren't we getting notifications from checksyscalls.sh that ARM hasn't
> been updated?
>
> It seems to be that the script was broken, and no one has noticed.

It seems Heiko did notice: http://www.serverphorums.com/read.php?12,559093

Now, I'm a bit puzzled by what follows: Heiko proposes a patch to
ignore sys_kcmp,
as it's x86-specific, which is acked by Cyrill. Then it suddenly
switches to Heiko
enabling it on s390 anyway?

> commit 29dc54c673ea2531d589400badb4ada5f5f60dae
> Author: H. Peter Anvin <hpa@linux.intel.com>
> Date: Fri Nov 11 15:57:53 2011 -0800
>
> checksyscalls: Use arch/x86/syscalls/syscall_32.tbl as source
>
> Use the new arch/x86/syscalls/syscall_32.tbl file as source instead of
> arch/x86/include/asm/unistd_32.h.
>
> Cc: Michal Marek <mmarek@suse.cz>
> Cc: Geert Uytterhoeven <geert@linux-m68k.org>
> Cc: Sam Ravnborg <sam@ravnborg.org>
> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
>
> is the culpret, more specifically this fragment:
>
> + echo <<EOF
> +#if !defined(__NR_${name}) && !defined(__IGNORE_${name})
> +#warning syscall ${name} not implemented
> +#endif
> +EOF
>
> "echo <<EOF" doesn't read from its stdin and output to stdout, so the
> above just generates a blank line for each entry in x86's syscalls_32.tbl,
> resulting in the compiler doing no checking for us.
>
> That "echo <<EOF" should be "cat <<EOF"... and with that fixed we get:
>
> <stdin>:1220:2: warning: #warning syscall kcmp not implemented
>
> So, actually, I want to add this kcmp syscall _now_ into -rc which I'm
> afraid will break your patch, and bump your syscall number on ARM to 379.

With a CC to stable for v3.5? ;-)

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds