Re: Backward compatibility for insn probe point

[David Smith <dsmith at redhat dot com>]

Maynard Johnson wrote:
> Frank has already made the changes in runtime/itrace.c to support
> backward compatibility with older utrace.
> I wanted to test the insn probe point on an older utrace, so I built
> and installed systemtap 0.9.5 on a ppc970 blade running RHEL 5.3.  I
> ran the following simple test:
> 
> # stap -c /bin/ls simple-test.stp /bin/ls -o simple-out -k -vvv 
>      where simple-test.stp is . . .
> =========simple-test.stp ========================
> global instrs = 0
> 
> probe begin {
> 	printf("systemtap starting probe\n")
> }
> 
> probe process(@1).insn {
> 	instrs += 1
> }
> 
> probe end { printf("systemtap ending probe\n")
> printf("itraced = %d\n", instrs)
> }
> ==================================
> 
> The result of the above test is that the stap command hangs at
> "stapio:start_cmd:195 execing target_cmd /bin/ls".  If I Ctl-C the
> job, it finished (i.e, I see "Pass 5: run completed ..."), but the
> output file contents indicate the insn probe was not hit (i.e.,
> "itraced = 0").
> 
> Any suggestions on where to look for the problem?

I took a look at this and fixed it.  For more details, see
<http://sources.redhat.com/bugzilla/show_bug.cgi?id=10091>.

-- 
David Smith
dsmith@redhat.com
Red Hat
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