VDR Webvideo Plugin

Got same vdr-crash with latest vdr 1.7.41

Mar 18 22:30:39 htpc kernel: [198851.546785] vdr[13961]: segfault at ac1cdd88 ip 00007f23abfb907b sp 00007f236e7fa930 error 6 in libvdr-webvideo.so.1.7.41[7f23abfa5000+27000]


Hi,

Unfortunately it crashes already by startup with the following error:

Mar 20 21:54:04 htpc vdr: [18762] loading plugin: /data/home/vdr_ubuntu/vdr-1.7.41/PLUGINS/lib/libvdr-webvideo.so.1.7.41
Mar 20 21:54:04 htpc vdr: [18762] ERROR: /data/home/vdr_ubuntu/vdr-1.7.41/PLUGINS/lib/libvdr-webvideo.so.1.7.41: undefined symbol: xmlFree

The undefined symbol error means that linking with libxml2.so failed for some reason.

Do you have libxml2-dev installed? What does xml2-config --libs output? The output should be something similar to

$ xml2-config --libs
-L/usr/lib -lxml2

I get this:

root@htpc:~# xml2-config --libs
-L/usr/lib/x86_64-linux-gnu -lxml2

I btw updated to vdr 1.7.42, and when doing a "make all" inside the source-dir i don't get the plugin copied to PLUGINS/lib. To get this done i need to do a make plugins in the source-dir of vdr. Not sure if it's because of the new Makefile-change in VDR..

xml2-config output looks sensible, but is doesn't explain why libxml is not found when the plugin is loaded.

Antoher thing you can try is running ldd on the plugin .so file:

$ ldd /usr/lib/vdr/plugins/libvdr-webvideo.so.1.7.41
        linux-gate.so.1 =>  (0xb77ac000)
        libxml2.so.2 => /usr/lib/i386-linux-gnu/libxml2.so.2 (0xb7626000)
        libwebvi.so.1 => /usr/lib/libwebvi.so.1 (0xb7620000)
        libstdc++.so.6 => /usr/lib/i386-linux-gnu/libstdc++.so.6 (0xb7533000)
        libm.so.6 => /lib/i386-linux-gnu/i686/cmov/libm.so.6 (0xb750d000)
        libgcc_s.so.1 => /lib/i386-linux-gnu/libgcc_s.so.1 (0xb74f0000)
        libc.so.6 => /lib/i386-linux-gnu/i686/cmov/libc.so.6 (0xb738d000)
        libdl.so.2 => /lib/i386-linux-gnu/i686/cmov/libdl.so.2 (0xb7389000)
        libz.so.1 => /lib/i386-linux-gnu/libz.so.1 (0xb736f000)
        liblzma.so.5 => /lib/i386-linux-gnu/liblzma.so.5 (0xb7348000)
        libpython2.7.so.1.0 => /usr/lib/libpython2.7.so.1.0 (0xb707a000)
        /lib/ld-linux.so.2 (0xb77ad000)
        libpthread.so.0 => /lib/i386-linux-gnu/i686/cmov/libpthread.so.0 (0xb7061000)
        libutil.so.1 => /lib/i386-linux-gnu/i686/cmov/libutil.so.1 (0xb705d000)

Check that it founds all the libraries (otherwise the output says "not found").

At least on 1.7.41, make all should do make plugins automatically. Maybe this has changed in 1.7.42?

Hmm.. Looks like it does not find the libxml2.so.2.. I wonder what i have messed up...

root@htpc:~# ldd lib/libvdr-webvideo.so.1.7.41 
        linux-vdso.so.1 =>  (0x00007fffc5992000)
        libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007f94e1923000)
        libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007f94e170d000)
        libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f94e134d000)
        libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f94e1051000)
        /lib64/ld-linux-x86-64.so.2 (0x00007f94e1e69000)

Can you try again with the latest git version? I modified the library link order. The old link command might in some cases cause the symptoms you are seeing.

Hi,

Now i get to the main-menu, but when i pick for example Youtube it crashes again vdr with the following line in syslog:

Mar 25 00:37:41 htpc kernel: [102303.677201] vdr[31756]: segfault at c9baad88 ip 00007f1bc999607b sp 00007f1b9effb910 error 6 in libvdr-webvideo.so.1.7.41[7f1bc9982000+27000]

I have no idea what is the problem this time... Can you generate a backtrace and attach it here or send it to me by email? Approximate instructions (more in German at http://www.vdr-wiki.de/wiki/index.php/Gdb):

1. Make sure that the plugin is compiled with debug information. This should be the default (unless you use the Debian packaging scripts). If the output of the command file libvdr-webvideo.so includes text "not stripped", everything is fine.

2. Start vdr

3. In a new terminal window, attach debugger to the running vdr process by typing gdb /usr/bin/vdr `pidof vdr`

4. In the gdb prompt, type continue.

5. In VDR, browse in the webvideo menu and wait for a crash.

6. After a crash, you get back to the gdb prompt. Type threads apply all bt and send to output to me.

Another thing that might be useful is the full output of the make command.

I don't understand why it would segfault where the log shows. This probably means that it is some kind of nasty memory corruption bug, and that the actual error is somewhere else.

One thing that might still help, is valgrind log. Run valgrind --leak-check=yes vdr --lirc -Pwebvideo (you probably need to give more arguments to vdr) and post the log.

According to valgrind log, there are dubious out-of-bounds reads in cNavigationMenu::NewLinkItem, but I can't see anything wrong in the code. I'll have to go through the code more thoroughly.

Does it work, if you remove all other plugins and run without valgrind? This could also be due to some kind interaction with other plugins.

Hi,

10 months later i upgraded vdr to the latest devel-version 2.1.3, and webvideo still segfaults vdr..

Jan 25 17:10:53 htpc kernel: [13235.641553] show_signal_msg: 52 callbacks suppressed
Jan 25 17:10:53 htpc kernel: [13235.641558] vdr[21804]: segfault at aefa3d88 ip 00007f1daed8f09b sp 00007f1d8951d910 error 6 in libvdr-webvideo.so.2.1.3[7f1daed7b000+27000]

Any chance that webvideo would get fixed for VDR 2.x?