[Bug translator/3280] New: missing entrypc dwarf line record for function 'jprobe_return'

[Bug translator/3280] New: missing entrypc dwarf line record for function 'jprobe_return'

[dwilder at us dot ibm dot com]

When running the following tap script on s390:
probe kernel.function("*") {}
 
I receive the following error.
[...]
semantic error: missing entrypc dwarf line record for function
'jprobe_return'
semantic error: no match for probe point
while: resolving probe point kernel.function("jprobe_return")

jprobe_return() is tagged __kprobes so it should automatically blacklisted;
However, the error is thrown before the blacklist is consulted.  This results is
that the tap script not building.

Here is the
void __kprobes jprobe_return(void)
{
        asm volatile (".word 0x0002");
}

I discussed this on the systemtap ml.

>The problem here is that while some of these routines are blacklisted
>> in the kernel (kprobe_register will fail), they are not blacklisted in
>> the translator.  We need to teach the translator to look for the
>> kernel-side blacklist info too (the .kprobes section naming methinks),
>> and treat it similarly to the .init/.exit special cases already
>> present in tapsets.cxx.
>> 
>> This way, function("*") will quietly exclude the blacklisted
>> functions. 
>> 
>> - FChE


Indeed this would be nice -- see bug #2639.
http://sources.redhat.com/bugzilla/show_bug.cgi?id=2639

In the mean time, we can add additional functions to the static
blacklist in the translator.  See dwarf_query::build_blacklist().  It's
unfortunate that we have to try to maintain this, but I suppose it's
better than nothing.  And, as you mention, kprobe_register will block
these too, so this is really just a matter of *when* the error is
caught.

Josh

-- 
           Summary: missing entrypc dwarf line record for function
                    'jprobe_return'
           Product: systemtap
           Version: unspecified
            Status: NEW
          Severity: normal
          Priority: P2
         Component: translator
        AssignedTo: systemtap at sources dot redhat dot com
        ReportedBy: dwilder at us dot ibm dot com


http://sourceware.org/bugzilla/show_bug.cgi?id=3280

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[Bug translator/3280] missing entrypc dwarf line record for function 'jprobe_return'

[dsmith at redhat dot com]

------- Additional Comments From dsmith at redhat dot com  2006-10-12 16:05 -------
This issue needs to be retested since BZ2639 has been fixed.  All '__kprobes'
functions should be automatically blacklisted.

-- 


http://sourceware.org/bugzilla/show_bug.cgi?id=3280

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[Bug translator/3280] missing entrypc dwarf line record for function 'jprobe_return'

[fche at redhat dot com]

------- Additional Comments From fche at redhat dot com  2007-08-17 21:45 -------
translator blacklist automatically includes kernel __kprobes functions now.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED


http://sourceware.org/bugzilla/show_bug.cgi?id=3280

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