xfdesktop terminated with signal 11, Segmentation fault

1. I used the xbrowser(xmanager) to login the server with the xdmcp protocol, sometimes, when i input the username/password for the first time login, I was forced to quit.
2. my xfdesktop version : xfdesktop-4.8.2-2.el6.x86_64 and OS is centos 6.10.
3. the xfdesktop core dump info :

Core was generated by `xfdesktop'. Program terminated with signal 11, Segmentation fault. (gdb) bt #0 _wordcopy_fwd_aligned (dstp=, srcp=, len=2305843009213686280) at wordcopy.c:115

#1 0x00000032ed483a42 in memmove (dest=0x11a9010, src=, len=18446744073709551608) at memmove.c:73

#2 (closed) 0x000000000042301a in workspace_destroyed_cb (wnck_screen=, workspace=, user_data=0x10c0de0) at /usr/include/bits/string3.h:59

#3 0x00000032ef80e3de in g_closure_invoke (closure=0x1099710, return_value=0x0, n_param_values=2, param_values=0x1171950, invocation_hint=0x7ffebf5829f0) at gclosure.c:767

#4 0x00000032ef8248c5 in signal_emit_unlocked_R (node=, detail=0, instance=0x114e830, emission_return=0x0, instance_and_params=0x1171950) at gsignal.c:3252

#5 (closed) 0x00000032ef825d76 in g_signal_emit_valist (instance=, signal_id=, detail=, var_args=0x7ffebf582be0) at gsignal.c:2983

#6 (closed) 0x00000032ef826333 in g_signal_emit (instance=, signal_id=, detail=) at gsignal.c:3040

#7 (closed) 0x00000032fd816ea6 in emit_workspace_destroyed (screen=0x114e830 [WnckScreen]) at screen.c:2417

#8 (closed) update_workspace_list (screen=0x114e830 [WnckScreen]) at screen.c:1888

#9 (closed) do_update_now (screen=0x114e830 [WnckScreen]) at screen.c:2313

#10 (closed) 0x00000032fd8174f4 in update_idle (data=) at screen.c:2337

#11 (closed) 0x00000032ee840555 in g_main_dispatch (context=0x10b2470) at gmain.c:2449\

#12 (closed) g_main_context_dispatch (context=0x10b2470) at gmain.c:3022

#13 0x00000032ee844d08 in g_main_context_iterate (context=0x10b2470, block=1, dispatch=1, self=)at gmain.c:3100

#14 (closed) 0x00000032ee845215 in g_main_loop_run (loop=0x11641d0) at gmain.c:3308

#15 0x00000032f7d4dd17 in IA__gtk_main () at gtkmain.c:1257

#16 (closed) 0x0000000000412897 in main (argc=1, argv=0x7ffebf583608) at main.c:396

(gdb) frame 0 #0 _wordcopy_fwd_aligned (dstp=, srcp=, len=2305843009213686280) at wordcopy.c:115

115 a0 = ((op_t *) srcp)[6];

(gdb) x/i Argument required (starting display address).

(gdb) info register rax 0x0 0

rbx 0x11a9018 18518040

rcx 0x0 0

rdx 0x1fffffffffffe208 2305843009213686280

rsi 0x11b7fd0 18579408

rdi 0x11b7fc0 18579392

rbp 0x11a9010 0x11a9010

rsp 0x7ffebf582858 0x7ffebf582858

r8 0xffffffff 4294967295

r9 0x0 0

r10 0x1 1

r11 0x1 1

r12 0x11a9010 18518032

r13 0xfffffffffffffff8 -8

r14 0x10 16

r15 0x0 0

rip 0x32ed489be0 0x32ed489be0 <_wordcopy_fwd_aligned+80> eflags 0x10202 [ IF RF ]

cs 0x33 51

ss 0x2b 43

ds 0x0 0

es 0x0 0

fs 0x0 0

gs 0x0 0

(gdb) x/i 0x32ed489be0 => 0x32ed489be0 <_wordcopy_fwd_aligned+80>: mov 0x30(%rsi),%rax

4. seems the %rax address is 0, is it the reason for segfault? if so , how to fix?

5. Also please check the attached file for xsession-errors log.

Any help is appreciated!

xsession-errors.problem

changed the description

Your version is almost a decade old, so there is no point in looking into this.

Please update to 4.14 (or at least 4.12)!

closed

Yes, it is the old version , the 4.12 or 4.14 need high glibc version, which does not work with centos6.10. I still want to know the root cause. :) Can anyone explain the function of xfdesktop_rootwin_watch_workarea(). and what is meaning of "got _NET_WORKAREA change on rootwin!"

Thanks a lot!

See _NET_WORKAREA.

When the size of the work area changes, xfdesktop will react by resizing its icon grid so that all icons stay visible on the desktop.

got it,thanks. I compared the xsession-errors between the segfault occured and no-segfault log. The no-segfault(ie: the normal one) log is: DBG[xfdesktop-icon-view.c:2269] xfdesktop_setup_grids(): CELL_SIZE=102.000, TEXT_WIDTH=90.000, ICON_SIZE=36

DBG[xfdesktop-icon-view.c:2270] xfdesktop_setup_grids(): grid size is 6x13

DBG[xfdesktop-icon-view.c:2286] xfdesktop_setup_grids(): created grid_layout with 78 positions

DBG[xfdesktop-icon-view.c:2287] xfdesktop_setup_grids(): grid layout dump: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

TRACE[xfdesktop-icon-view.c:2199] xfdesktop_icon_view_setup_grids_xinerama(): entering TRACE[xfce-desktop.c:777] xfce_desktop_realize(): exiting

The segfault log is: DBG[xfdesktop-icon-view.c:1519] xfdesktop_icon_view_style_set(): cell spacing is 6 DBG[xfdesktop-icon-view.c:1520] xfdesktop_icon_view_style_set(): cell padding is 6 DBG[xfdesktop-icon-view.c:1521] xfdesktop_icon_view_style_set(): cell text width proportion is 2.500000 DBG[xfdesktop-icon-view.c:1522] xfdesktop_icon_view_style_set(): ellipsize icon label is true DBG[xfdesktop-icon-view.c:2269] xfdesktop_setup_grids(): CELL_SIZE=102.000, TEXT_WIDTH=90.000, ICON_SIZE=36 DBG[xfdesktop-icon-view.c:2270] xfdesktop_setup_grids(): grid size is 9x18 DBG[xfdesktop-icon-view.c:2286] xfdesktop_setup_grids(): created grid_layout with 162 positions DBG[xfdesktop-icon-view.c:2287] xfdesktop_setup_grids(): grid layout dump: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

TRACE[xfdesktop-icon-view.c:2199] xfdesktop_icon_view_setup_grids_xinerama(): entering TRACE[xfce-desktop.c:777] xfce_desktop_realize(): exiting Xlib: extension "DPMS" missing on display "10.236.95.40:1.0". DBG[xfdesktop-icon-view.c:2303] xfdesktop_rootwin_watch_workarea(): got _NET_WORKAREA change on rootwin! DBG[xfdesktop-icon-view.c:2796] xfdesktop_grid_do_resize(): grid layout dump: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

TRACE[xfdesktop-icon-view.c:2199] xfdesktop_icon_view_setup_grids_xinerama(): entering DBG[xfdesktop-icon-view.c:2804] xfdesktop_grid_do_resize(): grid layout dump: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

DBG[xfdesktop-icon-view.c:2303] xfdesktop_rootwin_watch_workarea(): got _NET_WORKAREA change on rootwin! DBG[xfdesktop-icon-view.c:2796] xfdesktop_grid_do_resize(): grid layout dump: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

DBG[xfdesktop-icon-view.c:2269] xfdesktop_setup_grids(): CELL_SIZE=102.000, TEXT_WIDTH=90.000, ICON_SIZE=36 DBG[xfdesktop-icon-view.c:2270] xfdesktop_setup_grids(): grid size is 9x18 DBG[xfdesktop-icon-view.c:2286] xfdesktop_setup_grids(): created grid_layout with 162 positions DBG[xfdesktop-icon-view.c:2287] xfdesktop_setup_grids(): grid layout dump: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

My question is why in the segfault case, we got so many infinite loop messages like " xfdesktop_rootwin_watch_workarea(): got _NET_WORKAREA change on rootwin! " ? What are the trigger conditions for this situation?

Thanks a lot!

Sadly, I have no idea. My motivation to debug this ancient crash is fairly low, especially since there a hundreds of other issues in the currently supported Xfce version.