linux-kernel - Re: [PATCH 0/8] livepatch: klp-convert tool

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <alpine.LSU.2.21.1710201537170.12558@san.suse.cz>
Date:   Fri, 20 Oct 2017 15:39:49 +0200 (CEST)
From:   Miroslav Benes <mbenes@...e.cz>
To:     Josh Poimboeuf <jpoimboe@...hat.com>
cc:     Torsten Duwe <duwe@....de>, Joao Moreira <jmoreira@...e.de>,
        live-patching@...r.kernel.org, linux-kernel@...r.kernel.org,
        mmarek@...e.cz, pmladek@...e.com, jikos@...e.cz, nstange@...e.de,
        jroedel@...e.de, matz@...e.de, khlebnikov@...dex-team.ru,
        jeyu@...nel.org
Subject: Re: [PATCH 0/8] livepatch: klp-convert tool


> > For -fpatchable-function-entries I switched
> > off IPA-RA, as especially on RISC there's _nothing_ you can do between
> > functions without at least one scratch reg. But for live patching, I'd like
> > the kernel to be compiled in the first place with 100% ABI adherence, IOW
> > all IPA optimisations turned off. Does anyone have numbers on the performance
> > impact?
> 
> I agree that would be the best option.
> 
> I don't think anyone has measured it because we don't know how to get
> the compiler to do that :-)  My guess is that it will be something close
> to negligible.

I asked Nicolai to do some performance testing with all the options that 
could be disabled disabled.

Miroslav