[ltt-dev] [UST issue]: Waiting for ustd to shutdown...Segmentation fault

[Alexis Hallé]

Hi Srikanth,

2010/7/30 srikanth krishnakar <skrishnakar at gmail.com>:
> Hello Pierre/Mathieu,
>
> I have followed the instructions for UST(user space tracing)  from
> http://lttng.org/files/ust/manual/ust.html
>
> 1. Installed liburcu & ust
>
> liburcu-0.46
> ust-0.5
>
> 2. Compiled the usttest.c
>
> root at x86:~/ust-test# gcc -o usttest -lust usttest.c
>
> root at x86-generic:~/ust-test# ldd ./usttest
>         linux-gate.so.1 =>  (0xb789f000)
>         libust.so.0 => /usr/lib/libust.so.0 (0xb787a000)
>         libc.so.6 => /lib/libc.so.6 (0xb772d000)
>         /lib/ld-linux.so.2 (0xb78a0000)
>         liburcu-bp.so.0 => /usr/lib/liburcu-bp.so.0 (0xb772a000)
>         librt.so.1 => /lib/librt.so.1 (0xb7715000)
>         libpthread.so.0 => /lib/libpthread.so.0 (0xb76fb000)
> root at x86-generic:~/ust-test#
>
> Package Versions:
>
> ###################
> GLIBC: 2.11.1
> GCC: 4.4
> libglib-2.0-0
> ###################
>
> 3. Now start tracing :
>
> root at x86-generic:~/ust-test# usttrace ./usttest
> Waiting for ustd to shutdown...

The usttrace script starts a daemon on-the-fly for this tracing
session. When it is done tracing it sends this daemon a SIGTERM signal
and waits for it to shutdown. This message is perfectly normal.

> Trace was output in:
> /home/root/.usttraces/x86-generic-20100730144935535976601
> root at x86-generic:~/ust-test#
>
> Seems some issue in executing of ustctl..
>
> Now checking the presence of trace file:
>
> root at x86-generic:~/.usttraces/x86-generic-20100730144935535976601# du -sh *
> 20K     2851_5499711528108666788
> 0       app.log
> 0       ustd.log
> root at x86-generic:~/.usttraces/x86-generic-20100730144935535976601#
>
> 4. Dumping the result on console :
>
>
> root at x86-generic:~# lttv -m textDump -t
> /home/root/.usttraces/x86-generic-20100730144935535976601
>
> ** (process:2862): WARNING **: Unsupported trace version : 2.6
>
> ** (process:2862): WARNING **: parse_trace_header error
>
> ** (process:2862): WARNING **: Unsupported trace version : 2.6
>
> ** (process:2862): WARNING **: parse_trace_header error
>
> ** (process:2862): WARNING **: Unsupported trace version : 2.6
>
> ** (process:2862): WARNING **: parse_trace_header error
>
> ** (process:2862): WARNING **: Unsupported trace version : 2.6
>
> ** (process:2862): WARNING **: parse_trace_header error
>
> ** (process:2862): WARNING **: Trace
> /home/root/.usttraces/x86-20100730144935535976601 has no metadata tracefile
>
> ** (process:2862): CRITICAL **: cannot open trace
> /home/root/.usttraces/x86-20100730144935535976601
> Segmentation fault
> root at x86-generic:~#
>
> DMESG OUTPUT:
>
> root at x86-generic:~# dmesg | grep -ir ltt
> [ 5108.713591] lttv.real[2862]: segfault at 40 ip b7732222 sp bfd88e90 error
> 4 in libglib-2.0.so.0.2200.1[b7714000+b6000]
> root at x86-generic:~#
>
> What is mismatching section/package that is causing this segfault ?
>
> Your inputs are appreciated !! Thanks !!

When you look inside
/home/root/.usttraces/x86-generic-20100730144935535976601, you can see
a directory named 2851_5499711528108666788. This is the directory
containing the actual trace files, and it is this path that you must
pass to lttv with the -t switch.

>
>
> Regards,
> Srikanth Krishnakar
> **********************
>
> _______________________________________________
> ltt-dev mailing list
> ltt-dev at lists.casi.polymtl.ca
> http://lists.casi.polymtl.ca/cgi-bin/mailman/listinfo/ltt-dev
>
>

Regards,

-- 
Alexis Hallé
Software Engineering student
Intern, Tracing & Monitoring Project
École Polytechnique de Montréal