Re: [scratch/igc] 985247b6bee crash on Linux, KDE, Wayland

[Pip Cet]

"Eval EXEC" <execvy@gmail.com> writes:

> Eval EXEC <execvy@gmail.com> writes:
>
>> I recompiled commit 95a30325a84 (HEAD -> scratch/igc, origin/scratch/igc)
>> * src/igc.c (fix_frame): Correct the previous change.
>>
>> After testing, I believe the issue has been resolved.
>
> scratch/igc 95a30325 crash again:
>
> I use latest scratch/igc commit: * 95a30325a84 - (HEAD -> scratch/igc, 
> origin/scratch/igc) * src/igc.c (fix_frame): Fix last change. (8 hours ago) 
> <Eli Zaretskii>
>
> build it by:
>
> #!/usr/bin/env bash
> set -ex
>
> make extraclean
>
> BRANCH_NAME=$(git branch --show-current | sed 's/\//_/g')
> COMMIT_ID=$(git rev-parse --short=8 HEAD)
> BUILD_DIR=${BRANCH_NAME}-commit-${COMMIT_ID}
> INSTALL_PREFIX=$(realpath ../emacs-build/${BUILD_DIR})
>
> ./autogen.sh
> ./configure CFLAGS='-g3 -ggdb -O2 -fno-omit-frame-pointer -mtune=native 
> -march=native' \
>   --prefix=${INSTALL_PREFIX} \
>   --with-mps=yes \
>   --with-imagemagick  \
>   --with-modules \
>   --without-compress-install \
>   --with-native-compilation  --with-mailutils\
>   --enable-link-time-optimization \
>   --with-tree-sitter --with-xinput2  \
>   --with-dbus  --with-native-compilation=aot \
>   --with-file-notification=inotify\
>   && make -j30 install
>
> rm ../emacs-build/emacs
> ln -s ${INSTALL_PREFIX} ../emacs-build/emacs

Thanks, and sorry you're seeing so many crashes.  It's stable here, so
we're going to need your help debugging this :-)

Did you use any special options or patches when building mps (link time
optimization or -O3, in particular)?  Could you please try (but please
keep the core file and binary for this crash) rebuilding mps with "-g3
-ggdb -O0" to see whether the problem is, maybe, mps rather than Emacs?
That should also improve the debugging output, so please provide further
crashes if they do happen with those options.

> #9  0x0000000000690c05 in fix_lisp_obj (ss=ss@entry=0x7ffc7653e6f8, 
> pobj=pobj@entry=0x7f08addd06b8) at 
> /home/exec/Projects/git.savannah.gnu.org/git/emacs/src/igc.c:975

This is the car of a cons cell, and it looks like it was freed by a
previous garbage collection so it's no longer valid.

>         off = <optimized out>
>         client = <optimized out>
>         base = 0x7f088a262a50

Could you open the coredump again and run

(gdb) x/32gx 0x7f088a262a00

so we can get an idea of what was allocated around that time?

>         res = <optimized out>
>         new_off = <optimized out>
>         p = 0x7f08addd06b8
>         word = <optimized out>
>         tag = <optimized out>
>         _ss = 0x7ffc7653e6f8
>         _mps_zs = <optimized out>
>         _mps_ufs = 36029896530599944
>         _mps_wt = <optimized out>
>         _mps_w = <optimized out>
> #10 0x00000000006919f8 in fix_cons (cons=0x7f08addd06b0, ss=0x7ffc7653e6f8) 
> at /home/exec/Projects/git.savannah.gnu.org/git/emacs/src/igc.c:1751

This is the cons cell itself (the IGC header is what "cons" points to).

Please also run

(gdb) x/64gx 0x7f08addd0600

Thanks!

Pip