Subject: bug#52141: 29.0.50; Crash during redisplay

From: Andreas Schwab <[email-masked]>
Date: Sat, 27 Nov 2021 13:01:00 +0100

On Nov 27 2021, Eli Zaretskii wrote:

>> From: Po Lu <[email-masked]>
>> Cc: [email-masked]
>> Date: Sat, 27 Nov 2021 19:32:29 +0800
>> 
>> >> #9  set_next_vectorPython Exception <class 'gdb.MemoryError'>: Cannot access memory at address 0xfe94cc8
>> >>  (p=#10 setup_on_free_list (nbytes=<optimized out>, v=0x2ce6c10) at alloc.c:2977
>> >> #11 sweep_vectors () at alloc.c:3242
>> >> #12 0x0000000000561328 in gc_sweep () at alloc.c:7255
>> >> #13 garbage_collect () at alloc.c:6190
>> >> #14 0x0000000000561811 in maybe_garbage_collect () at alloc.c:6053
>> >> #15 0x00000000005804ad in maybe_gc () at /home/oldosfan/emacs-dev/emacs-gc/src/lisp.h:5161
>> >> #16 eval_sub (form=0x1e753d3) at eval.c:2449
>> >> #17 0x0000000000582149 in Feval (form=0x1e753d3, lexical=<optimized out>) at eval.c:2372
>> >                                    ^^^^
>> > What is this form we are evaluating here?  Can you show its contents?
>> > (Not that I think it is related to the crash.)
>> 
>> Its type is Lisp_Cons.  However, its address is invalid.  Running
>> `xcons' in gdb complains:
>> 
>> (gdb) xcons
>> $9 = (struct Lisp_Cons *) 0x1e753d0
>> Cannot access memory at address 0x1e753d0
>
> Hmm... and the address is very different from the one which caused the
> segfault.  Strange.

There could have been several corruptions that only surfaced just now.

Andreas.

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Andreas Schwab, [email-masked]
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