Hi.

Prasanna S Panchamukhi wrote:
>> With kprobes enabled, vm86 doesn't feel
>> good. The problem is that kprobes steal
>> the interrupts (mainly int3 I think) from
>> it for no good reason.
> If the int3 is not registered through kprobes,
> kprobes handler does not handle it and it falls through the
> normal int3 handler AFAIK.
I was considering this, but I convinced
myself that checking the VM flag is good
in any case, because, as I presume, you
never need the interrupts from v86. Or do
you?
If there is a bug in kprobes, it would be
good to fix either, but I just think it
will not make my patch completely useless.

> Could you please provide a test case to show that kprobes 
> steals the interrupts.
Sure, attached. But it is not perfect: on
the patched kernel it passes the test, but
on the unpatched one (2.6.9), it just Oopses
the kernel without printing any reasonable
diagnostic. Because of the Oops, I can't
demonstrate the interrupt theft right away,
but I hope the test-case for the Oops in
kprobe_exceptions_notify() may also be
interesting for you.