Re: Fwd: What can a signal handler do with SIGSTKSZ?

[Florian Weimer <fweimer@redhat.com>]

* Christian Brauner:

> On January 11, 2019 9:00:29 PM GMT+01:00, Florian Weimer <fweimer@redhat.com> wrote:
>>* Zack Weinberg:
>>
>>> Now, if 8192 bytes is not enough to call some async-signal-safe
>>> functions, that's another problem and one I would like to see
>>> addressed by making the unwind library more space-efficient or
>>> something along those lines.
>>
>>Small nit: This is unrelated to async-signal-safe functions because
>>size
>>considerations also apply to synchronously delivered signals, where few
>>(if any) restrictions exist.
>>
>>Thanks,
>>Florian
>
> Does this need kernel-side input?

> Should we move parts of this to lkml or at least Cc a few people
> (Oleg, Andy, Eric)?  Just checking. :)

I think I tried to bring this up in the past.  The truth is that there
aren't any good options.  The proposal I made here (not preserve
AVX-512F state in the handler if in a squeeze) is likely quite bad, too:

  <https://bugzilla.kernel.org/show_bug.cgi?id=153531>

Signals are just very hard to get right.

Thanks,
Florian