wayland crash debugging help required

[Vikas Patil]

Dear all,

I am observing "Segmentation fault" with below mentioned back-trace
while playing video (loop back mode )and continuously pressing home
button on target (which brings video screen to home screen of HMI).

Printing the locals shows null pointer deference (i.e. line 46, print
elm->next,  wl_list_insert, /wayland-1.8.1/src/wayland-util.c:46  )

Am I hitting some known issue with wayland/weston? How should I debug
this further and find the root cause if it is not known issue? Could
you guys please provide input/suggestion on finding the root cause?

I am on wayland/weston 1.8.0 and using i.MX6/Linux3.14.28. Test
application is based on gstreamer1.0 and uses wayland based
“imxeglvivsink“ as video sink plug-in. Home button is a gpio mapped to
KEY_HOME as standard keyboard and uses input stack as it is from
wayland/weston and libinput.


Backtrace:
warning: Unable to find libthread_db matching inferior's thread
library, thread debugging will not be available.
warning: Unable to find libthread_db matching inferior's thread
library, thread debugging will not be available.
Core was generated by `./testVideoPlayer'.
Program terminated with signal SIGSEGV, Segmentation fault.

#0  wl_list_insert (list=0x1, elm=0x1802660, elm at entry=0x16c) at
/usr/src/debug/wayland/1.8.1-r0/wayland-1.8.1/src/wayland-util.c:46

46              elm->next = list->next;

(gdb) bt

#0  wl_list_insert (list=0x1, elm=0x1802660, elm at entry=0x16c) at
/usr/src/debug/wayland/1.8.1-r0/wayland-1.8.1/src/wayland-util.c:46

#1  0x75c412c8 in queue_event (len=1975783972, display=0x180116c) at
/usr/src/debug/wayland/1.8.1-r0/wayland-1.8.1/src/wayland-client.c:1122

#2  read_events (display=<optimized out>) at
/usr/src/debug/wayland/1.8.1-r0/wayland-1.8.1/src/wayland-client.c:1207

#3  0x75c42030 in wl_display_dispatch_queue
(display=display at entry=0x76036800,  queue=queue at entry=0x760005a8) at
/usr/src/debug/wayland/1.8.1-r0/wayland-1.8.1/src/wayland-client.c:1579

#4  0x75c42290 in wl_display_roundtrip_queue (display=0x76036800,
queue=0x760005a8) at
/usr/src/debug/wayland/1.8.1-r0/wayland-1.8.1/src/wayland-client.c:982

#5  0x75d56cb4 in wl_egl_window_destroy (window=0x1801104) at
gc_egl_platform.c:779

#6  0x75d7ab44 in gst_imx_egl_viv_sink_egl_platform_shutdown_window (
platform=0x76016f00) at ../src/eglvivsink/egl_platform_wayland.c:990

#7  0x75d77e68 in gst_imx_egl_viv_sink_gles2_renderer_thread (
thread_data=<optimized out>) at ../src/eglvivsink/gles2_renderer.c:227

#8  0x76cf265c in ?? () from /usr/lib/libglib-2.0.so.0

Backtrace stopped: previous frame identical to this frame (corrupt stack?)

(gdb) print list
$1 = (struct wl_list *) 0x1

(gdb) print elm
$2 = (struct wl_list *) 0x1802660

(gdb) print elm->next
$3 = (struct wl_list *) 0x0

(gdb)



Thanks & Regards,
Vikas