What is needed to run systemtap on a module built out of tree?

What is needed to run systemtap on a module built out of tree?

[Rick Beldin]

Hi... 

	We are trying to put probes on a module for RHEL4.5 that is
	built out of try (qlogic driver).  We get errors like: 

stap scsiinq.stp
WARNING: cannot find module qla2xxx debuginfo: invalid section index
WARNING: cannot find module qla2xxx debuginfo: invalid section index
semantic error: no match for probe point while resolving probe point
module("qla2xxx").function("qla2x00_issue_scsi_inquiry")
Pass 2: analysis failed. Try again with more '-v' (verbose) options

	The structure of the module is that it is a 3rd party 
	replacement module that is built out of tree from the
	rest of RHEL.  It doesn't use rpmbuild and doesn't get
	delivered in an rpm.   As a result, we don't have a 
	debuginfo, or rather we have the RH debuginfo for the
	module of the SAME name but a DIFFERENT module. 

	How do we deal with this situation?   We can control the
	build of the module, so we added CONFIG_DEBUG_INFO and
	CONFIG_KPROBES, but it still fails in the same way. 

	Thanks,

	Rick 
-- 
+----------------------------------------------------------------------+
| Rick Beldin                    |  Hewlett-Packard Company            |
| email: Rick.Beldin@hp.com      |  Global Solutions Engineering       |
| WTEC Linux, RHCE               |  5555 Windward Parkway West         |
|                                |  Alpharetta, GA 30004               |
+----------------------------------------------------------------------+

Re: What is needed to run systemtap on a module built out of tree?

[Frank Ch. Eigler]

Rick Beldin <rick.beldin@hp.com> writes:

> [...]
> 	The structure of the module is that it is a 3rd party 
> 	replacement module that is built out of tree from the
> 	rest of RHEL.  It doesn't use rpmbuild and doesn't get
> 	delivered in an rpm.   As a result, we don't have a 
> 	debuginfo, or rather we have the RH debuginfo for the
> 	module of the SAME name but a DIFFERENT module. 
> [...]

Can you zap somehow the RH qla2xxx .ko and .ko.debug files?  Can you
ensure that your build of the .ko includes all the .debug_* sections?

- FChE

Re: What is needed to run systemtap on a module built out of tree?

[Rick Beldin]

On Thu, 2008-06-05 at 20:01 +0000, Frank Ch. Eigler wrote:
> Can you zap somehow the RH qla2xxx .ko and .ko.debug files?  Can you
> ensure that your build of the .ko includes all the .debug_* sections?
> 
	Minutes after asking the question, we found that replacing
	the RH-supplied debuginfo was causing the problem.  After
	building the module with CONFIG_DEBUG_INFO and CONFIG_KPROBE
	and REPLACING the debuginfo from RH, it worked.  I'm not
	convinced that CONFIG_KPROBE was necessary. 

	Thanks for the quick response... 

	R
-- 
+----------------------------------------------------------------------+
| Rick Beldin                    |  Hewlett-Packard Company            |
| email: Rick.Beldin@hp.com      |  Global Solutions Engineering       |
| WTEC Linux, RHCE               |  5555 Windward Parkway West         |
|                                |  Alpharetta, GA 30004               |
+----------------------------------------------------------------------+