Re: [PATCH] i386 & x86_64: Live Patching Funcion on 2.6.11.7

[Andi Kleen <ak@muc.de>]

"David S. Miller" <davem@davemloft.net> writes:

> Takashi-san, have you ever investigated using kprobes to
> implement this feature?  It seems a perfect fit, and would
> allow support on several architectures other than just x86
> and x86_64.
>
> If kprobes does not meet your needs completely, it could
> be trivially extended to do so.

kprobes would require an exception for each patchpoint because
it uses an trap instruction. 

Probably a bit too costly for commonly used functions. Especially
on a P4 exceptions are quite costly. 

But you could add lightweight kprobes that just use jmp 
for it in the kprobes  framework, that might be useful for other stuff too

-Andi