Re: Probing symbols that are not EXPORT()ed

[William Cohen <wcohen at redhat dot com>]

Alan David Brunelle wrote:
> [Sorry for this newbie question...]
>
> How does one probe on a kernel function that does not have an
>
> EXPORT_SYMBOL()
>
> invocation?
>
> For example the following fails:
>
> global rqs
>
> probe kernel.function("scsi_dispatch_cmd")
> {
>        rqs <<< $cmd->request_bufflen
> }
>
> probe end
> {
>        print(@hist_linear(rqs, 0, 512000, 4000))
>        exit()
> }
>
> with:
>
> [root@bl25p1 06_08]# stap -v scwrite.stp
> Pass 1: parsed user script and 11 library script(s) in 40usr/0sys/51real 
> ms.
> semantic error: no match for probe point
>         while: resolving probe point kernel.function("scsi_dispatch_cmd")
> Pass 2: analyzed script: 1 probe(s), 4 function(s), 1 global(s) in 
> 150usr/20sys/163real ms.
> Pass 2: analysis failed.
>
> Thanks,
> Alan

Is this in the scsi module?

Shouldn't it be something like:

probe kernel.module("scsi_mod").function("scsi_dispatch_cmd")
{
       rqs <<< $cmd->request_bufflen
}