GNU bug report logs - #29066
26.0.90; crash in gc involving buffer local symbols

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Message #52 received at 29066 <at> debbugs.gnu.org (full text, mbox):

From: Andreas Schwab <schwab <at> linux-m68k.org>
To: Eli Zaretskii <eliz <at> gnu.org>
Cc: 29066 <at> debbugs.gnu.org, mshinwell <at> janestreet.com,
 vgatien-baron <at> janestreet.com
Subject: Re: bug#29066: 26.0.90; crash in gc involving buffer local symbols
Date: Tue, 31 Oct 2017 23:00:10 +0100

On Okt 31 2017, Eli Zaretskii <eliz <at> gnu.org> wrote:

>> From: Andreas Schwab <schwab <at> linux-m68k.org>
>> Cc: vgatien-baron <at> janestreet.com,  29066 <at> debbugs.gnu.org,  mshinwell <at> janestreet.com
>> Date: Tue, 31 Oct 2017 22:03:26 +0100
>> 
>> >> A symbol on the symbol_free_list is a freed symbol, not available for
>> >> use.
>> >
>> > I guess you are saying that sweep_symbols has a bug?  Because it hits
>> > this "freed" symbol every GC, AFAICT.
>> 
>> Since GC is special, it needs to do special things.
>
> But the crash due to double-free did happen as part of GC doing those
> "special things".

That's why it helps to clear the pointer to the freed memory, instead of
leaving it dangling.

Andreas.

-- 
Andreas Schwab, schwab <at> linux-m68k.org
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