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Re: Probingof syscall.*.return fails
Hi Martin,
Martin SÃÃkraut wrote:
Do you have any suggestions how to probe syscall.*.return?
One possibility is to get away from kprobes and use the utrace-based
probes:
function iserr () { ... }
probe process.syscall { if (iserr ($return)) ... }
... but this syntax requires newer than released 0.7 code. Are you
willing to try building your own systemtap binary?
I'm doing this anyway. I switched to the latest snapshot
(cec7293bd301b4737da7abe8d1b70b9689fd3f00) from Sept. 6th.
I just push $return hack into git tree this evening,
could you try it?
The script is now:
probe process.syscall.return {
if (target() == pid())
printf ("%d: %d\n", $syscall, $return)
}
It will work. Note, AFAIK, rt_sigreturn() don't return
correct $syscall number in .return probe (because this
system call is very special, it breaks its context).
please take care of it.
Thank you,
--
Masami Hiramatsu
Software Engineer
Hitachi Computer Products (America) Inc.
Software Solutions Division
e-mail: mhiramat@redhat.com