[PATCH 0/1] signal: use BUILD_BUG() instead of _NSIG_WORDS_is_unsupported_size()

[Oleg Nesterov <oleg@redhat.com>]

On 09/19, Josh Triplett wrote:
>
> On Fri, Sep 19, 2014 at 07:20:30PM +0200, Oleg Nesterov wrote:
>
> > But I have to admit it looks a bit ugly to me anyway.
> > Can't we simply kill _NSIG_WORDS_is_unsupported_size ?
>
> This looks quite preferable.  Can you post that with a commit message
> and signoff?

OK, please see 1/1.

> Also, the indentation on the second of the three BUILD_BUG
> calls has some spaces in it, which it shouldn't.

Yes, thanks, and it makes sense to also fix the indentation.

> With those fixed:
> Reviewed-by: Josh Triplett <josh@joshtriplett.org>

Thanks. Could you ack it again?

I didn't preserve your ack because it seems that BUILD_BUG() and/or
BUILD_BUG_ON_MSG() deserve some cleanups... For example,

	if (0)
		BUILD_BUG();

can't be compiled if __compiletime_error_fallback() falls back to a
negative-size array (see the changelog).

But I think that the code above must be correct by definition, see
the comment and the original changelog (1399ff86f2a2 "kernel.h: add
BUILD_BUG() macro"). So if this patch breaks the compilation with
some compiler/version we should update include/linux/compiler-xxx.h
or fix BUILD_BUG().

Oleg.

 include/linux/signal.h |   28 ++++++++++++----------------
 1 files changed, 12 insertions(+), 16 deletions(-)