GNU bug report logs - #24884
Segfault on (mkstemp! "XX" 0)

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Message #5 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Jean Louis <bugs <at> gnu.support>
To: bug-guile <at> gnu.org
Subject: Segfault on (mkstemp! "XX" 0)
Date: Sat, 5 Nov 2016 21:16:58 +0300

I was just testing a function, and before I figured out what is
happening, it is segfaulting on:
(mkstemp! "XX" 0)

I don't say, I am using it right. It should not segfault.

Jean

guile (GNU Guile) 2.0.13
Copyright (C) 2016 Free Software Foundation, Inc.

Message #8 received at 24884 <at> debbugs.gnu.org (full text, mbox):

From: Matt Wette <mwette <at> alumni.caltech.edu>
To: 24884 <at> debbugs.gnu.org
Subject: Segfault on (mkstemp! "XX" 0)
Date: Fri, 11 Nov 2016 06:06:37 -0800

[Message part 1 (text/plain, inline)]

Please check 24862, which includes a patch: https://debbugs.gnu.org/cgi/bugreport.cgi?bug=24862 <https://debbugs.gnu.org/cgi/bugreport.cgi?bug=24862>

The issue is that (at least on Mac OS 10.12) mkstemp will only accept specific flags.

[Message part 2 (text/html, inline)]

Message #11 received at 24884 <at> debbugs.gnu.org (full text, mbox):

From: Andy Wingo <wingo <at> pobox.com>
To: Jean Louis <bugs <at> gnu.support>
Cc: 24884 <at> debbugs.gnu.org
Subject: Re: bug#24884: Segfault on (mkstemp! "XX" 0)
Date: Wed, 11 Jan 2017 22:33:30 +0100

On Sat 05 Nov 2016 19:16, Jean Louis <bugs <at> gnu.support> writes:

> I was just testing a function, and before I figured out what is
> happening, it is segfaulting on:
> (mkstemp! "XX" 0)
>
> I don't say, I am using it right. It should not segfault.

I agree.  This is a pending topic in Guile.  (The reason, of course:
mutating literal constants is not valid Scheme.  Guile allocates
some constant literals in read-only memory.  Mutating that memory, or
attempting to do so, segfaults, as you have seen.  We should raise an
error instead.)

Andy

Message #16 received at 24884-done <at> debbugs.gnu.org (full text, mbox):

From: Andy Wingo <wingo <at> pobox.com>
To: Jean Louis <bugs <at> gnu.support>
Cc: 24884-done <at> debbugs.gnu.org
Subject: Re: bug#24884: Segfault on (mkstemp! "XX" 0)
Date: Wed, 01 Mar 2017 14:52:37 +0100

On Wed 11 Jan 2017 22:33, Andy Wingo <wingo <at> pobox.com> writes:

> On Sat 05 Nov 2016 19:16, Jean Louis <bugs <at> gnu.support> writes:
>
>> I was just testing a function, and before I figured out what is
>> happening, it is segfaulting on:
>> (mkstemp! "XX" 0)
>>
>> I don't say, I am using it right. It should not segfault.
>
> I agree.  This is a pending topic in Guile.  (The reason, of course:
> mutating literal constants is not valid Scheme.  Guile allocates
> some constant literals in read-only memory.  Mutating that memory, or
> attempting to do so, segfaults, as you have seen.  We should raise an
> error instead.)

Sigh, spoke too soon.  This one turned out to be a rather more ordinary
bug.  Fixed in git on both branches.  Thanks for the report!

Andy

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