Questions about tracing static function and statement probe

["sunzen w." <sunzen at gmail dot com>]

Hi,
I'm working on tracing JBD layer and upper filesystem layer, and would
like to get fine-grained setting of probes. Concretely speaking,  I
need to probe more static functions and some statements of in a large
function.

I encounter some problems when resorting to module(xxx).function(yyy)
and moule(xxx).statement(yyy).

Problem 1:  Probes on some static function fail to work while others do work.
For instance,  probes on entry/exit of
get_transaction(@fs/jbd/trasaction.c) fail because of  semantic errors
(failed to retrieve location attibution for target virable, or no
match for probe point).  But, probes on  some other static
functions(such as ext3_add_nondir@fs/ext3/namei.c,
add_dirent_to_buf@fs/ext3/namei.c) do work.

With nm I found there is difference in corresponding object files. In
one object file, there is symbol of static function. However, there
isn't in the other one. I wonder  the behind mechanism which cause the
difference,  and get concerned the effect on capability of systemtap.

Problem 2:  Statement probe fail to work because of semantic error (no
match for probe point)

I use systemtap-20070707 and kernel 2.6.22.1 on Fedora 7. A test
script is attached.
Thank you for your help.
--
sunzen
<<freedom & enjoyment>>

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