Bug#498397: vlc segfaults during test run in build process on mips resulting in build failure

[Reinhard Tartler]

tags 498397 help
stop

peter green <plugwash at p10link.net> writes:

>> Could you add -vvv and retry ?
>> Could you also try with ffmpeg-dbg installed ?
>>   
> Ok i've reverted to the libavcodec package from the repositry and 
> installed ffmpeg-dbg and libc6-dbg. Results of run with -vvv under those 
> conditions
>
>
> debian-mips:~/vlc-0.8.6.h# ./vlc -vvv --reset-plugins-cache -l -I rc 
> vlc:quit
> GNU gdb 6.8-debian
> Copyright (C) 2008 Free Software Foundation, Inc.
> License GPLv3+: GNU GPL version 3 or later 
> <http://gnu.org/licenses/gpl.html>
> This is free software: you are free to change and redistribute it.
> There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
> and "show warranty" for details.
> This GDB was configured as "mips-linux-gnu"...
> (gdb) run
> Starting program: /root/vlc-0.8.6.h/.libs/lt-vlc -vvv 
> --reset-plugins-cache -l -I rc vlc:quit
> [Thread debugging using libthread_db enabled]
> VLC media player 0.8.6h Janus
> starting VLC root wrapper...[New Thread 0x2b77c820 (LWP 3600)]
>  using UID 0 (root)
> ***************************************
> * Running VLC as root is discouraged. *
> ***************************************
>
>  It is potentially dangerous, and might not even work properly.
> [00000001] main private debug: checking builtin modules
> [00000001] main private debug: checking plugin modules
> [00000001] main private debug: removing plugins cache file 
> /root/.vlc/cache/plugins-0404be.dat
> [00000001] main private debug: recursively browsing `/usr/lib/vlc'
> [00000001] main private debug: module bank initialized, found 3 modules
>   main                  main program
>   help                  Help options
>   mux_ts                TS muxer (libdvbpsi)
>   theora                Theora video decoder
>   theora                Theora video packetizer
>   theora                Theora video encoder
> [00000001] main private debug: saving plugins cache file 
> /root/.vlc/cache/plugins-0404be.dat
>
> Program received signal SIGSEGV, Segmentation fault.
> [Switching to Thread 0x2b77c820 (LWP 3600)]
> 0x2b00026c in do_free ()
>     at /build/buildd/ffmpeg-debian-0.svn20080206/libavcodec/utils.c:108
> 108     /build/buildd/ffmpeg-debian-0.svn20080206/libavcodec/utils.c: No 
> such file or directory.
>         in /build/buildd/ffmpeg-debian-0.svn20080206/libavcodec/utils.c
> (gdb) bt
> #0  0x2b00026c in do_free ()
>     at /build/buildd/ffmpeg-debian-0.svn20080206/libavcodec/utils.c:108
> #1  0x2af50104 in _ftext () from /usr/lib/libavcodec.so.51
> #2  0x2b281f80 in _fini () from /usr/lib/libavcodec.so.51
> #3  0x2aab8c40 in _dl_fini () from /lib/ld.so.1
> #4  0x2ad712e0 in exit () from /lib/libc.so.6
> #5  0x2ad53894 in __libc_start_main () from /lib/libc.so.6
> #6  0x004009c8 in _ftext ()
> (gdb)
>
> to me it looks like it is failing somewhere in the unloading of libavcodec

Looking at the source:

73: static unsigned int last_static = 0;

...

106: void av_free_static(void)
107: {
108:    while(last_static){
109:	    av_freep(&array_static[--last_static]);
110:    }
111:    av_freep(&array_static);
112: }

A segfault in line 108 is, uhm, strange.

>> Could you try to build vlc-0.8.6.h-1 (the one in lenny)?
>>   
> I have started it building, a full build attempt takes me quite some 
> time though (I'm using qemu-system-mips on my laptop which gets 
> hibernated at night for noise reasons, I only care about this bug 
> because I care about vlc and it's blocking other rc bugfixes from 
> getting into lenny, not because I care about mips). Note also that I had 
> to force the build to start without libdc1394-13 due to conflicts.

Thanks for investigating the issue!


>> Do you get the same if you don't run it as root ?
>>   
> I haven't personally tried running it as anything other than root but it 
> is also segfaulting on the mips and mipsel buildds so I would assume 
> that userid and presense or absense of a homedir are irrelevent to this bug.

I tend to agree...

-- 
Gruesse/greetings,
Reinhard Tartler, KeyID 945348A4