Re: jprobe bug?

[William Cohen <wcohen at redhat dot com>]

Martin Hunt wrote:
> I just noticed this afternoon that my poll probe example wasn't working
> correctly.  I can simplify it to a single empty probe and still see the
> problem.  The probe is
>
> void fastcall inst_add_wait_queue (wait_queue_head_t *q, wait_queue_t
> *wait)
> {
>   jprobe_return();
> }
>
> I'll attach full source.
>
> I compile that code into a module and load it.  Then launch Firefox.
> Firefox almost never launches.  It usually hangs immediately.  In the
> rare case it launches, if I close it and try to launch it again, it
> hangs. Eventually the system locks up.
>
> This happens on an x86_64 running 2.6.10-1.753_FC3.smp and an x86
> running 2.6.10-1.741_FC3.smp
>
> Martin

To avoid having to mess with the various address I converted the example 
back to a dtr script. I have attached the script to this email. The 
script seemed to install okay. Does the address used in the module look 
okay? I don't have a version of that kernel built.

Does the problem exist on the UP kernel?

I tried this dtr script with a slightly older kernel on a AMD64 machine:

2.6.10-1.7241_FC3	(appeared to work/not crash system)
2.6.10-1.741_FC3smp	(appeared to work/not crash system)

-Will
# trying to replicate martin hunts problem

probe add_wait_queue:entry {
}

proto {
void fastcall add_wait_queue (wait_queue_head_t *q, wait_queue_t *wait);
}