From: Florian Weimer <fweimer@redhat.com>
To: Carlos O'Donell <carlos@redhat.com>
Cc: Szabolcs Nagy <Szabolcs.Nagy@arm.com>,
Zack Weinberg <zackw@panix.com>,
Christian Brauner <christian@brauner.io>, nd <nd@arm.com>,
GNU C Library <libc-alpha@sourceware.org>
Subject: Re: Fwd: What can a signal handler do with SIGSTKSZ?
Date: Mon, 14 Jan 2019 17:31:35 +0100 [thread overview]
Message-ID: <87va2r9p5k.fsf@oldenburg2.str.redhat.com> (raw)
In-Reply-To: <0a995c61-62d6-7b09-8b5d-1d77b33a242d@redhat.com> (Carlos O'Donell's message of "Mon, 14 Jan 2019 11:22:53 -0500")
* Carlos O'Donell:
> On 1/14/19 11:18 AM, Florian Weimer wrote:
>> * Szabolcs Nagy:
>>
>>> i think proposing sysconf(_SC_{MIN}SIGSTKSZ) for posix is the
>>> right solution with the kernel providing an upper bound of the
>>> stack frame in AT_MINSIGSTKSZ (as it already does on aarch64).
>>
>> It's still a bit nasty for process migration, but at least it should for
>> VM migration. I think that would be a reasonable compromise.
>>
>> Of course, we'd still need a way to determine how much we should add on
>> top of AT_MINSIGSTKSZ for the application developer's benefit. 8-)
>
> The value of SIGSTKSZ seems to be a "culturally relevant detail" that will
> probably be impossible to pin down to a real value.
The embedded folks have tooling for this: avoid recursive calls,
documenting stack size requirements, all that. There are few things in
GCC we could use (but I don't think upstream focus is on C/C++ in this
area). Then we could have some hard numbers and also statically verify
them.
With callbacks, things get more complicated obviously, but I think it
would still be manageable.
Thanks,
Florian
next prev parent reply other threads:[~2019-01-14 16:31 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-11 17:44 What can a signal handler do with SIGSTKSZ? Carlos O'Donell
2019-01-11 19:02 ` Szabolcs Nagy
2019-01-11 19:11 ` Carlos O'Donell
2019-01-11 20:23 ` Szabolcs Nagy
[not found] ` <CAKCAbMiCaBst_ofjKkH3Ck1CoOV86wPKv3QSkC89XW_zu=1BLA@mail.gmail.com>
2019-01-11 19:34 ` Fwd: " Zack Weinberg
2019-01-11 20:00 ` Florian Weimer
2019-01-11 20:06 ` Christian Brauner
2019-01-11 20:14 ` Florian Weimer
2019-01-11 20:26 ` Christian Brauner
2019-01-14 16:15 ` Florian Weimer
2019-01-11 20:09 ` Zack Weinberg
2019-01-11 20:29 ` Florian Weimer
2019-01-11 23:59 ` Zack Weinberg
2019-01-14 11:18 ` Szabolcs Nagy
2019-01-14 11:29 ` Adhemerval Zanella
2019-01-14 16:34 ` Zack Weinberg
2019-01-14 20:29 ` Carlos O'Donell
2019-01-14 16:18 ` Florian Weimer
2019-01-14 16:22 ` Carlos O'Donell
2019-01-14 16:31 ` Florian Weimer [this message]
2019-01-14 16:34 ` Szabolcs Nagy
2019-01-14 18:19 ` Joseph Myers
2019-01-14 20:30 ` Carlos O'Donell
2019-01-16 22:51 ` Christian Brauner
2019-01-11 19:40 ` Florian Weimer
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