From: Thomas Fitzsimmons <fitzsim@fitzsim.org>
To: Eli Zaretskii <eliz@gnu.org>
Cc: 63711@debbugs.gnu.org
Subject: bug#63711: 30.0.50; Crash in xdisp.c when it->string is 0x0
Date: Thu, 25 May 2023 09:02:26 -0400 [thread overview]
Message-ID: <m3lehc36ot.fsf@fitzsim.org> (raw)
In-Reply-To: <83ilcgn9ud.fsf@gnu.org> (Eli Zaretskii's message of "Thu, 25 May 2023 10:34:02 +0300")
Hi Eli,
Eli Zaretskii <eliz@gnu.org> writes:
>> From: Thomas Fitzsimmons <fitzsim@fitzsim.org>
>> Date: Thu, 25 May 2023 02:27:19 -0400
>>
>> I have been having long-running Emacs sessions crash, rarely, and I
>> finally caught one case in GDB. Full backtraces attached. I don't know
>> how it->string becomes 0x0, but it looks like SCHARS (it->string) then
>> attempts to dereference the null pointer. I'll keep the session running
>> in case there is anything else someone wants me to check.
>
> Thanks, but with an optimized build and without a recipe to reproduce
> this, it will be hard to debug this.
Thanks for taking a look at this. Agreed it will be difficult. After
this session I will rebuild Emacs with CFLAGS="-O0 -g" and run with GDB
attached to try to get a higher quality trace. (The recipe to reproduce
the crashes I've been seeing may be hard to obtain. I haven't
identified any particular activity that triggers these crashes, and
maybe there are different causes each time -- this is just the first one
I captured.)
> Still, I ask you below to produce some values from GDB in the hope
> that this would give some ideas.
OK:
> (gdb) p pos->overlay_string_index
$9 = 0
> (gdb) p it->current.overlay_string_index
$10 = 0
> (gdb) p it->sp
$11 = 0
> (gdb) p it->method
$12 = GET_FROM_BUFFER
> (gdb) p it->string
$13 = XIL(0)
> (gdb) xtype
Lisp_Symbol
The session is still open if you want me to check other values.
Thanks,
Thomas
next prev parent reply other threads:[~2023-05-25 13:02 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-25 6:27 bug#63711: 30.0.50; Crash in xdisp.c when it->string is 0x0 Thomas Fitzsimmons
2023-05-25 7:34 ` Eli Zaretskii
2023-05-25 13:02 ` Thomas Fitzsimmons [this message]
2023-05-25 13:35 ` Eli Zaretskii
2023-05-25 13:50 ` Thomas Fitzsimmons
2023-05-25 15:11 ` Eli Zaretskii
2023-05-25 15:25 ` Thomas Fitzsimmons
2023-05-25 15:54 ` Eli Zaretskii
2023-05-25 17:43 ` Thomas Fitzsimmons
2023-05-25 17:52 ` Eli Zaretskii
2023-05-25 18:12 ` Thomas Fitzsimmons
2023-06-01 3:19 ` Thomas Fitzsimmons
2023-06-01 6:29 ` Eli Zaretskii
2023-06-01 11:52 ` Thomas Fitzsimmons
2023-08-03 17:40 ` Thomas Fitzsimmons
2023-08-03 18:34 ` Eli Zaretskii
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