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

From: Ingo Molnar
Date: Fri Mar 21 2008 - 07:08:29 EST



* Yakov Lerner <iler.ml@xxxxxxxxx> 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
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