Re: stap core dump

["Peter Teoh" <htmldeveloper at gmail dot com>]

Thank you for your accurate observation.

On Tue, Apr 15, 2008 at 9:21 PM, David Smith <dsmith@redhat.com> wrote:
> Peter Teoh wrote:
>  > After I install the latest systemtap via git from redhat, I got the
>  > following errors:
>  >
>  > export PATH=/usr/local/bin/:$PATH
>  >

As noted above, I have to explicitly redirect the PATH to first search
/usr/local/bin, where the latest "make install" will install stap to.
 The original FC7 stap is /usr/bin/stap (updated via yum install
systemtap).   But since the date is 2007, and earlier email mentioned
there is a bug fix, so I have to do a git install.

>  > stap -kvvve 'probe begin { log("hello world") exit () }'
>  >
>  > SystemTap translator/driver (version 0.7/0.133 non-git sources)
>  > Copyright (C) 2005-2008 Red Hat, Inc. and others
>  > This is free software; see the source for copying conditions.
>  > Created temporary directory "/tmp/stapBQKF7S"
>  > Searched '/usr/local/share/systemtap/tapset/i686/*.stp', found 1
>  > Searched '/usr/local/share/systemtap/tapset/*.stp', found 38
>  > Pass 1: parsed user script and 39 library script(s) in
>  > 260usr/0sys/303real ms.
>  > Eliding unused function warn
>  > Eliding unused function error
>  > Eliding unused function stp_print_binary
>  > Pass 2: analyzed script: 1 probe(s), 2 function(s), 0 embed(s), 0
>  > global(s) in 10usr/0sys/5real ms.
>  > Segmentation fault (core dumped)
>  >
>  >
>  > And probing into the core:
>
>  Here's the first thing that caught my eye:
>
>
>   > stap[5507]: segfault at 64 ip 00694776 sp bfdfb9a0 error 6 in
>  > libdw-0.131.so[680000+23000]
>  > stap[5508]: segfault at 64 ip 00694776 sp bff6f310 error 6 in
>  > libdw-0.131.so[680000+23000]
>  > stap[5509]: segfault at 64 ip 00694776 sp bfc96830 error 6 in
>  > libdw-0.131.so[680000+23000]
>  > stap[12186]: segfault at 64 ip b7edae68 sp bfc19f60 error 6 in
>  > libdw-0.133.so[b7ec6000+23000]
>  > stap[12193]: segfault at 64 ip b7fb5e68 sp bf8f7440 error 6 in
>  > libdw-0.133.so[b7fa1000+23000]
>  > stap[12194]: segfault at 64 ip b7f5ce68 sp bff9eae0 error 6 in
>  > libdw-0.133.so[b7f48000+23000]
>  > stap[12196]: segfault at 64 ip b7ef3e68 sp bfc35770 error 6 in
>  > libdw-0.133.so[b7edf000+23000]
>  > stap[12257]: segfault at 64 ip b7f54e68 sp bfd96900 error 6 in
>  > libdw-0.133.so[b7f40000+23000]
>  > stap[12258]: segfault at 64 ip b7ecee68 sp bff0ea70 error 6 in
>  > libdw-0.133.so[b7eba000+23000]
>
>  According to the above, you've got 2 different versions of libdw
>  installed on your system - 0.131.so and 0.133.so.  Is that just gdb
>  being confused or is that really the case?

The /usr/lib/libdw-0.131.so is linked with /usr/bin/stap, whereas that
of 133 is linked with /usr/local/bin/stap.   So that explained the
diff.

Let me work further on the coredump, as the coredump has now been
eliminated.....some other problem now....
-- 
Regards,
Peter Teoh