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

[Masami Hiramatsu <mhiramat@redhat.com>]

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

Ingo, I also tested this on x86-64/x86/ia64.

Acked-by: Masami Hiramatsu <mhiramat@redhat.com>

Thanks,

-- 
Masami Hiramatsu

Software Engineer
Hitachi Computer Products (America) Inc.
Software Solutions Division

e-mail: mhiramat@redhat.com