"No match for probe point" for syscall.open with tutorial example strace-open.stp

[Fredy Neeser]

David Smith schrieb:
> Fredy Neeser wrote:
>> Hi,
>>
>> I am trying to use systemtap (20070818 snapshot) on an IA32 Core Duo 
>> system with
>> Fedora Core 5 and a kernel which I built from vanilla 2.6.18 sources.
>>
>
> (Note that I've never used systemtap with a self-built kernel, but 
> I'll take a stab at this anyway.)
>
> ... stuff deleted ...
>
>> the next tutorial example
>>
>>         [root@mythen stap_tests]# stap -vvv strace-open.stp
>>
>> gives "No match for probe point" for syscall.open:
>>
>> SystemTap translator/driver (version 0.6/0.128 built 2007-08-23)
>> Copyright (C) 2005-2007 Red Hat, Inc. and others
>> This is free software; see the source for copying conditions.
>> Created temporary directory "/tmp/stapyFwODp"
>> Searched '/usr/local/share/systemtap/tapset/i686/*.stp', found 1
>> Searched '/usr/local/share/systemtap/tapset/*.stp', found 36
>> Searched '/usr/local/share/systemtap/tapset/LKET/*.stp', found 19
>> Pass 1: parsed user script and 56 library script(s) in 
>> 320usr/10sys/356real ms.
>> control symbols: kts: 0x0 kte: 0x0 stext: 0x0
>
> This is very curious.  those 3 control symbols shouldn't be 0: kts is 
> '__kprobes_text_start', kte is '__kprobes_text_end', and stext is 
> '_stext'.  Can you grep for those symbols in /proc/kallsyms and see if 
> you find them?
>
> If you can't find /proc/kallsyms, you need to build your kernel with 
> CONFIG_KALLSYMS.  If you can find those symbols in /proc/kallsyms, I'd 
> bet systemtap can't find your kernel's debuginfo.
>
> Hope this helps.
>
Thanks for your thoughts.  The kernel is configured with
CONFIG_KALLSYMS=y
# CONFIG_KALLSYMS_ALL is not set
CONFIG_KALLSYMS_EXTRA_PASS=y

The symbols are there:
[fn@mythen ~]$ cat /proc/kallsyms | grep __kprobes_text_start
c02edf20 T __kprobes_text_start
[fn@mythen ~]$ cat /proc/kallsyms | grep __kprobes_text_end
c02efb87 T __kprobes_text_end
[fn@mythen ~]$ cat /proc/kallsyms | grep _stext
c0100294 T _stext

Hmm ... I will also try on another machine.

Cheers,
Fredy.