Re: sigaltstack breaks swapcontext()

[Andy Lutomirski]

On Thu, Jan 7, 2016 at 7:33 AM, Stas Sergeev <stsp@xxxxxxx> wrote:
> 06.01.2016 22:53, Andy Lutomirski ÐÐÑÐÑ:
>>
>> On Wed, Jan 6, 2016 at 11:31 AM, Stas Sergeev <stsp@xxxxxxx> wrote:
>>>
>>> Exactly.
>>> Do you think this can be ignored?
>>> A man page should then be corrected with EPERM and the
>>> above note removed, right?
>>>
>> I think it can be ignored.  I'd go the SS_FORCE route, though, to
>> maintain POSIX compliance.
>
> I think such a flag would be a wrong thing to do.
> Allowing only SS_DISABLE (without any new flags) keeps
> you still "compatible with posix", and anything beyond
> SS_DISABLE in a sighandler is not needed.
>
> So I think we only have the following options:
> 1. Remove the check and forget (if anything, glibc can
> add the EPERM check to stay compatible with crap).
> 2. Allow only SS_DISABLE. This will mean a large patch,
> touching all arches, but the bonus is the compatibility
> with posix, that no one needs in this particular case.

Why does allowing SS_DISABLE require touching all arches?

--Andy

-- 
Andy Lutomirski
AMA Capital Management, LLC
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/