[kprobe bug] pre-handler changes on globals lost

[Martin Hunt]

On Thu, 2005-06-16 at 11:51 -0400, Frank Ch. Eigler wrote:
> Hi -
> 
> Rusty, what happens if you insert some code into the pre_handler, to
> check that it actually executed?

I am playing with this on x86_64 FC3 with kprobes as distributed with it
and I see this bug.

The pre_handler is being executed each time and incrementing the value
of pcount.

There is nothing special about printk(). Instead I can put some code
that calls some function that does nothing and it will still work as
long as the compiler doesn't optimize it out.

Martin