SegFault

[keshto]

◗ wtype no && slurp
noSegmentation fault

Slurp segfaults when wtype is ran before?

[emersion]

Please provide a stack trace. You can do so by compiling from source, reproducing the crash and then running coredumpctl gdb and then bt full.

[keshto]

I don't touch systemd sorry.
Are you not able to reproduce by running wtype "" && slurp or even wlrctl keyboard type "" && slurp?
Note: running wtype "" && gdb -ex run slurp will not segfault interestingly.

[emersion]

Please provide a stack trace. Closing until then.

[keshto]

Reading symbols from slurp/build/slurp...
Starting program: /home/user/Downloads/slurp/build/slurp 
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".

Program received signal SIGSEGV, Segmentation fault.
0x00007ffff7e3d430 in xkb_state_update_mask ()
   from /usr/lib/x86_64-linux-gnu/libxkbcommon.so.0
A debugging session is active.

	Inferior 1 [process 3391] will be killed.

Quit anyway? (y or n) n
Not confirmed.
(gdb) backtrace
#0  0x00007ffff7e3d430 in xkb_state_update_mask ()
   from /usr/lib/x86_64-linux-gnu/libxkbcommon.so.0
#1  0x0000555555559be5 in keyboard_handle_modifiers (data=0x55555556e1c0, 
    wl_keyboard=0x555555587a50, serial=15271, mods_depressed=0, 
    mods_latched=0, mods_locked=0, group=0) at ../main.c:345
#2  0x00007ffff779bf7a in ?? () from /usr/lib/x86_64-linux-gnu/libffi.so.8
#3  0x00007ffff779b40e in ?? () from /usr/lib/x86_64-linux-gnu/libffi.so.8
#4  0x00007ffff779bb0d in ffi_call ()
   from /usr/lib/x86_64-linux-gnu/libffi.so.8
#5  0x00007ffff7e78761 in ?? ()
   from /usr/lib/x86_64-linux-gnu/libwayland-client.so.0
#6  0x00007ffff7e74aaa in ?? ()
   from /usr/lib/x86_64-linux-gnu/libwayland-client.so.0
#7  0x00007ffff7e7641c in wl_display_dispatch_queue_pending ()
   from /usr/lib/x86_64-linux-gnu/libwayland-client.so.0
#8  0x000055555555b950 in main (argc=1, argv=0x7fffffffe378) at ../main.c:1051

[tmccombs]

Are you not able to reproduce by running wtype "" && slurp

I am not able to reproduce with that, but I can with wtype "n" && slurp.

From the stack trace, it looks like the segfault is coming from within the call to wl_display_dispatch(state.display). This feels like a bug in libwayland-client to me. But I could be missing something. My guess is it has something to do with receiving a keyboard event before it is ready for it.

Interestingly,

$ (sleep .01; wtype n) & slurp

will segfualt, but

$ (sleep .02; wtype n) & slurp

won't.

[emersion]

Maybe we're trying to xkb_state_update_mask() when there is no keymap or something?

[tmccombs]

I don't touch systemd sorry.

well, it looks like you were able to figure out how to look at the coredump on whatever system you are using :)