linux-kernel - Re: 3.1-rc6 boot problem reason searching

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: <CAObL_7FpzpEcW=Q5Ch0YF3qQC4MTNJ-fOnZJVLRdTwGthJTcPg@mail.gmail.com>
Date:	Thu, 15 Sep 2011 11:56:35 -0700
From:	Andrew Lutomirski <luto@....edu>
To:	Linus Torvalds <torvalds@...ux-foundation.org>
Cc:	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	werner <w.landgraf@...ru>
Subject: Re: 3.1-rc6 boot problem reason searching

On Thu, Sep 15, 2011 at 11:23 AM, Linus Torvalds
<torvalds@...ux-foundation.org> wrote:
> On Thu, Sep 15, 2011 at 11:15 AM, Linus Torvalds
> <torvalds@...ux-foundation.org> wrote:
>>
>> It *used* to have an alignment of 8 back before your patch to make the
>> pointers be relative due to the 64-bit pointers. But now all fields
>> are 32-bit, and it could easily have a size of just 12 bytes, getting
>> rid of the 'pad2' field, and getting rid of the '.balign 8's.
>
> IOW, maybe the correct patch is just the attached one.
>
> Werner, does this fix the boot for you? It gets rid of all the bogus
> alignment stuff, it's all wrong anyway, the altinstructions section
> entries are all 12 bytes long so it starts out sufficiently aligned,
> and it *stays* aligned because if anybody ever adds a non-12-byte
> entry that would be a huge bug regardless. So any extra alignment is
> just likely to be buggy and hide much bigger issues.
>
> This is COMPLETELY UNTESTED, just looking at the source.

If you want to apply it this late, fine with me.  It looks generally
sane, but I haven't tested it.

OTOH, I have tested the attached minimal patch on 32-bit and 64-bit.

--Andy

View attachment "my_patch.diff" of type "text/x-patch" (757 bytes)