David Deyo ddeyo at
Fri Sep 17 13:35:29 UTC 2021

Hello All,

I have a pythno3 app that uses PyGobject to create a button.

I can reproduce a segfault by using a stylus to press and drag across that button.
When I use my finger, no segfault.

When programmed to do nothing, I can see that the button flickers; indicating intermittent  contact and multiple press/releases events.

The partial core dump I get is below:

Core was generated by `python3.8 ./'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0  wl_proxy_get_user_data (proxy=0x0) at ../wayland-1.18.0/src/wayland-client.c:2040
2040            return proxy->user_data;
[Current thread is 1 (Thread 0xffffa2609c60 (LWP 858))]
(gdb) bt
#0  wl_proxy_get_user_data (proxy=0x0) at ../wayland-1.18.0/src/wayland-client.c:2040
#1  0x0000ffff9f332a78 in  () at /usr/lib/
#2  0x0000ffffa1847008 in ffi_call_SYSV () at ../libffi-3.3/src/aarch64/sysv.S:114
#3  0x0000ffffa1846710 in ffi_call_int (cif=cif at entry=0xfffff21ab908, fn=0x0, orig_rvalue=0xfffff21ab9d8, orig_rvalue at entry=0x0, avalue=avalue at entry=0xfffff21ab9d8, closure=0xffff9f3396d0, closure at entry=0x0) at ../libffi-3.3/src/aarch64/ffi.c:747
#4  0x0000ffffa1846bb8 in ffi_call (cif=cif at entry=0xfffff21ab908, fn=<optimized out>, rvalue=rvalue at entry=0x0, avalue=avalue at entry=0xfffff21ab9d8) at ../libffi-3.3/src/aarch64/ffi.c:756

I believe this is indicating that proxy is null.
If so, I believe the problem could be exposed by over-sensitivity in the touch controller and have contacted the panel maker.
Where would I start to look to find out why proxy is null or prevent such a call if the proxy is null (if my assessment is correct)?

                                                                         David Deyo
[cid:image003.png at 01D7AB9E.F7F68630]

Firmware Engineer
TPI- Tire Profiles
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