Re: [PATCH] Subject: kprobes-x86: correct post-eip value in post_hander()

[Ananth N Mavinakayanahalli <ananth@in.ibm.com>]

On Fri, Mar 21, 2008 at 12:08:04PM +0100, Ingo Molnar wrote:
> 
> * Yakov Lerner <iler.ml@gmail.com> wrote:
> 
> > I was trying to get the address of instruction to be executed next 
> > after the kprobed instruction.  But regs->eip in post_handler() 
> > contains value which is useless to the user. It's pre-corrected value. 
> > This value is difficult to use without access to resume_execution(), 
> > which is not exported anyway. I moved the invocation of post_handler() 
> > to *after* resume_execution(). Now regs->eip contains meaningful value 
> > in post_handler().
> > 
> > I do not think this change breaks any backward-compatibility. To make 
> > meaning of the old value, post_handler() would need access to 
> > resume_execution() which is not exported.  I have difficulty to 
> > believe that previous, uncorrected, regs->eip can be meaningfully used 
> > in post_handler().
> 
> thanks, i've added your patch to the .26 bucket of x86.git, but it would 
> be nice to get an Ack/Nack from a kprobes person as well.
 
Ingo,

I've tested Yakov's more comprehensive patch on powerpc too. This has my
ack.

Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>