[Bug tapsets/11433] New: __stp_stack_print() needs uprobes.ko

[Bug tapsets/11433] New: __stp_stack_print() needs uprobes.ko

[jistone at redhat dot com]

On i386 and x86_64, __stp_stack_print() calls uprobe_get_pc().  If uprobes.ko
doesn't happen to already be loaded, you'll get "Unknown symbol uprobe_get_pc"
in pass 5.

$ stap -e 'probe timer.profile { print_ubacktrace() }'
Error inserting module
'/tmp/stapUMosL6/stap_372d2e868930605380a28ec58c3bb989_1157.ko': Unknown symbol
in module
Retrying, after attempted removal of module
stap_372d2e868930605380a28ec58c3bb989_1157 (rc -1)
Error inserting module
'/tmp/stapUMosL6/stap_372d2e868930605380a28ec58c3bb989_1157.ko': Unknown symbol
in module
Pass 5: run failed.  Try again with another '--vp 00001' option.
$ dmesg | tail -n1
stap_372d2e868930605380a28ec58c3bb989_1157: Unknown symbol uprobe_get_pc

A possible answer is that print_ubacktrace() is useless outside of uprobes
probepoints anyway, but I hope we can do better than a pass-5 failure...

-- 
           Summary: __stp_stack_print() needs uprobes.ko
           Product: systemtap
           Version: unspecified
            Status: NEW
          Severity: normal
          Priority: P2
         Component: tapsets
        AssignedTo: systemtap at sources dot redhat dot com
        ReportedBy: jistone at redhat dot com


http://sourceware.org/bugzilla/show_bug.cgi?id=11433

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[Bug tapsets/11433] __stp_stack_print() needs uprobes.ko

[wenji dot huang at oracle dot com]

------- Additional Comments From wenji dot huang at oracle dot com  2010-04-21 09:16 -------
(In reply to comment #0)
> On i386 and x86_64, __stp_stack_print() calls uprobe_get_pc().  If uprobes.ko
> doesn't happen to already be loaded, you'll get "Unknown symbol uprobe_get_pc"
> in pass 5.
> 
> $ stap -e 'probe timer.profile { print_ubacktrace() }'
> Error inserting module
> '/tmp/stapUMosL6/stap_372d2e868930605380a28ec58c3bb989_1157.ko': Unknown symbol
> in module
> Retrying, after attempted removal of module
> stap_372d2e868930605380a28ec58c3bb989_1157 (rc -1)
> Error inserting module
> '/tmp/stapUMosL6/stap_372d2e868930605380a28ec58c3bb989_1157.ko': Unknown symbol
> in module
> Pass 5: run failed.  Try again with another '--vp 00001' option.
> $ dmesg | tail -n1
> stap_372d2e868930605380a28ec58c3bb989_1157: Unknown symbol uprobe_get_pc

This happens on utrace-kernel, but without loaded uprobe module. On non-utrace
kernel, it works well. 
See thread
http://sources.redhat.com/ml/systemtap/2010-q1/msg00370.html

> 
> A possible answer is that print_ubacktrace() is useless outside of uprobes
> probepoints anyway, but I hope we can do better than a pass-5 failure...

Or automatically check uprobe module before loading stap module once
print_ubacktrace() is called.


-- 


http://sourceware.org/bugzilla/show_bug.cgi?id=11433

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[Bug tapsets/11433] __stp_stack_print() needs uprobes.ko

[jistone at redhat dot com]

------- Additional Comments From jistone at redhat dot com  2010-05-06 00:23 -------
Duping to bug #11573, since a few solutions are discussed there.

*** This bug has been marked as a duplicate of 11573 ***

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


http://sourceware.org/bugzilla/show_bug.cgi?id=11433

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