linux-kernel - Re: [PATCH 1/3] x86: Separate out x86

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]

Date:   Tue, 15 Mar 2022 19:48:52 -0700
From:   Kees Cook <keescook@...omium.org>
To:     "Edgecombe, Rick P" <rick.p.edgecombe@...el.com>
Cc:     "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "viro@...iv.linux.org.uk" <viro@...iv.linux.org.uk>,
        "Williams, Dan J" <dan.j.williams@...el.com>,
        "Wysocki, Rafael J" <rafael.j.wysocki@...el.com>,
        "ebiederm@...ssion.com" <ebiederm@...ssion.com>,
        "Chatre, Reinette" <reinette.chatre@...el.com>,
        "linux-fsdevel@...r.kernel.org" <linux-fsdevel@...r.kernel.org>,
        "Luck, Tony" <tony.luck@...el.com>,
        "Hansen, Dave" <dave.hansen@...el.com>,
        "Brown, Len" <len.brown@...el.com>
Subject: Re: [PATCH 1/3] x86: Separate out x86_regset for 32 and 64 bit

On Tue, Mar 15, 2022 at 09:53:13PM +0000, Edgecombe, Rick P wrote:
> On Tue, 2022-03-15 at 13:41 -0700, Kees Cook wrote:
> > Have you verified there's no binary difference in machine code
> > output?
> 
> There actually was a different in the binaries. I investigated a bit,
> and it seemed at least part of it was due to the line numbers changing
> the WARN_ON()s. But otherwise, I assumed some compiler optimization
> must have been bumped.

Right, you can ignore all the debugging line number changes.
"diffoscope" should help see the difference by section. As long as the
actual object code isn't changing, you should be good.

-- 
Kees Cook