== Comment: #0 - IRANNA D. ANKAD <iranna.ankad.com> - 2013-05-30 05:53:43 == I am trying vnc installation of fedora19 beta, once installer starts vnc server, I try connecting using vncviewer, after few seconds the vnc crashes with a message "Pane is dead". This issue consistently occurs with below different vnc (tried from my RHEL6.3 desktop): Tigervnc, vinagre & gvncviewer. I notice this vnc crash even with xtightvncviewer (from windows box), though it is intermittent there. This issue is sort of blocking my further vnc installation. FYI, I found below segfault & backtrace in /tmp/vncserver.log Thu May 30 08:07:57 2013 VNCSConnST: Client pixel format depth 24 (32bpp) little-endian rgb888 (EE) (EE) Backtrace: (EE) 0: Xvnc (xorg_backtrace+0xfff4adb8) [0x102267e8] (EE) 1: Xvnc (0x10000000+0x22b7dc) [0x1022b7dc] (EE) 2: (vdso) (__kernel_sigtramp_rt64+0x0) [0x3fff9fb80448] (EE) 3: Xvnc (GetEventMask+0xffef51d0) [0x101cd990] (EE) 4: Xvnc (0x10000000+0x1de91c) [0x101de91c] (EE) 5: Xvnc (GetPointerEvents+0xfff06f80) [0x101e0120] (EE) 6: Xvnc (QueuePointerEvents+0xfff0741c) [0x101e05cc] (EE) 7: Xvnc (_ZN11InputDevice11PointerMoveERKN3rfb5PointE+0xffe8d06c) [0x10160acc] (EE) 8: Xvnc (_ZN14XserverDesktop12pointerEventERKN3rfb5PointEi+0xffe86d74) [0x1015a394] (EE) 9: Xvnc (_ZN3rfb16VNCSConnectionST12pointerEventERKNS_5PointEi+0xffebc9b4) [0x10192b44] (EE) 10: Xvnc (_ZN3rfb10SMsgReader16readPointerEventEv+0xffecedd4) [0x101a5ad4] (EE) 11: Xvnc (_ZN3rfb12SMsgReaderV37readMsgEv+0xffeaad04) [0x10180264] (EE) 12: Xvnc (_ZN3rfb11SConnection10processMsgEv+0xffeaa154) [0x1017f5b4] (EE) 13: Xvnc (_ZN3rfb16VNCSConnectionST15processMessagesEv+0xffebf62c) [0x101959ec] (EE) 14: Xvnc (_ZN3rfb11VNCServerST18processSocketEventEPN7network6SocketE+0xffe99d14) [0x1016e5d4] (EE) 15: Xvnc (_ZN14XserverDesktop13wakeupHandlerEP6fd_seti+0xffe88aa8) [0x1015c2a8] (EE) 16: Xvnc (0x10000000+0x1522a8) [0x101522a8] (EE) 17: Xvnc (WakeupHandler+0xffef0f00) [0x101c9340] (EE) 18: Xvnc (WaitForSomething+0xfff4793c) [0x1022310c] (EE) 19: Xvnc (Dispatch+0xffeeb258) [0x101c32d8] (EE) 20: Xvnc (main+0xffd70af0) [0x10043a40] (EE) 21: /lib64/libc.so.6 (0x3fff9eff0000+0x4438c) [0x3fff9f03438c] (EE) 22: /lib64/libc.so.6 (__libc_start_main+0xffe62ff4) [0x3fff9f0345b4] (EE) (EE) Segmentation fault at address 0x3fff00000004 Fatal server error: Caught signal 11 (Segmentation fault). Server aborting
Created attachment 755252 [details] logs from /tmp
This backtrace is... sketchy. There's no call chain in xserver by which we can get from fill_pointer_events (in frame 4) to GetEventMask, at least not that I can find. Assuming I can trust this backtrace, I think it's the -> bit of: Mask GetEventMask(DeviceIntPtr dev, xEvent *event, InputClients * other) { int evtype; /* XI2 filters are only ever 8 bit, so let's return a 8 bit mask */ if ((evtype = xi2_get_type(event))) { return GetXI2MaskByte(other->xi2mask, dev, evtype); // ... Which suggests 'other' is busted somehow.
------- Comment From baude.com 2013-05-31 19:38 EDT------- Adam, at the risk of being redundant, i want to make sure everyone understands this is observed (right now) only with the install media. Is there something diff about the x stack on the media vs runtime?
The backtrace is probably wrong near the top, ie, I'd say (EE) 5: Xvnc (GetPointerEvents+0xfff06f80) [0x101e0120] Is more likely to be correct than GetEventMask. You should enable show_unhandled_signals in the ppc kernels. I've enabled it upstream in 3.10, I don't know why we didn't have it on by default but I think it can be done via a command line argument. At least the kernel would show you exactly the PC value of the segfault which would help sorting out what's right and what not in the backtrace.
------- Comment From kamaleshb.com 2013-06-03 09:10 EDT------- (In reply to comment #9) > The backtrace is probably wrong near the top, ie, I'd say > > (EE) 5: Xvnc (GetPointerEvents+0xfff06f80) [0x101e0120] > > Is more likely to be correct than GetEventMask. > > You should enable show_unhandled_signals in the ppc kernels. I've enabled > it upstream in 3.10, I don't know why we didn't have it on by default but > I think it can be done via a command line argument. echo 1 > /proc/sys/debug/exception-trace
------- Comment From iranna.ankad.com 2013-06-21 11:16 EDT------- It is quite some time, there are no updates on this bug. Any idea, if fix for this issue is already available or being worked on? Thanks!
This might have been fixed in 1.2.80-0.15.201314svn5065: * Sat Jun 08 2013 Dennis Gilmore <dennis> 1.2.80-0.15.20130314svn5065 - bump to rebuild and pick up bugfix causing X to crash on ppc and arm https://admin.fedoraproject.org/updates/FEDORA-2013-10453 This was pushed to stable a few days ago (16th). Unfortunately I don't think there are nightly composes for ppc/ppc64 to be able to test it at the moment.
------- Comment From iranna.ankad.com 2013-10-10 13:14 EDT------- Well..I verified this bug on the latest Fedora20 Alpha build (3.11.0-300.fc20) & I could not recreate the issue. I could successfully do VNC installation. Thanks!
Great. Thanks for re-testing.