From: Florian Weimer <fweimer@redhat.com>
To: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Cc: Paul Eggert <eggert@cs.ucla.edu>,
libc-alpha@sourceware.org, Bruno Haible <bruno@clisp.org>
Subject: Re: [PATCH 3/3] Misc: Add <sys/cstack.h> and the cstack_* family of functions
Date: Tue, 25 May 2021 14:23:02 +0200 [thread overview]
Message-ID: <8735ub0zq1.fsf@oldenburg.str.redhat.com> (raw)
In-Reply-To: <04c9457b-6d48-ca15-788c-da6de5d4abfc@linaro.org> (Adhemerval Zanella's message of "Tue, 25 May 2021 09:17:57 -0300")
* Adhemerval Zanella:
> On 25/05/2021 04:40, Florian Weimer wrote:
>> * Paul Eggert:
>>
>>> On 5/24/21 12:11 PM, Adhemerval Zanella via Libc-alpha wrote:
>>>
>>>> If this is really a requirement, I think the best options would be to add
>>>> an extra flag to opt-in.
>>>
>>> Opt-in works for me. Although the GNU apps I help maintain typically
>>> don't have nested functions, nested functions are a longstanding GNU C
>>> feature and are a good thing to have when you need them.
>>
>> Since the requirement for non-executable stacks does not encapsulate
>> well, I'd rather make this automatic if you think executable stack
>> support is required. (The code allocating the stack might not know
>> about the trampolines.)
>
> Although honoring PT_GNU_STACK seems the most straightforward I still
> think we should make it a opt-in, executable stacks has strong security
> implications and I think it is better the caller knows it is enabling.
The caller may not know whether signal handlers need executable stacks,
though. That's what I meant with the lack of encapsulation.
Thanks,
Florian
next prev parent reply other threads:[~2021-05-25 12:23 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-24 14:58 Bruno Haible
2021-05-24 15:28 ` Bruno Haible
2021-05-25 7:42 ` Florian Weimer
2021-05-24 19:11 ` Adhemerval Zanella
2021-05-24 23:41 ` Paul Eggert
2021-05-25 7:40 ` Florian Weimer
2021-05-25 12:17 ` Adhemerval Zanella
2021-05-25 12:23 ` Florian Weimer [this message]
2021-05-25 12:25 ` Adhemerval Zanella
2021-05-25 12:29 ` Adhemerval Zanella
2021-05-25 8:41 ` Florian Weimer
-- strict thread matches above, loose matches on Subject: below --
2021-05-20 12:11 [PATCH 0/3] Convenience function for allocating (alternate signal) stacks Florian Weimer
2021-05-20 12:13 ` [PATCH 3/3] Misc: Add <sys/cstack.h> and the cstack_* family of functions Florian Weimer
2021-05-20 12:21 ` Florian Weimer
2021-05-20 12:50 ` Andreas Schwab
2021-05-20 13:14 ` Florian Weimer
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