linux-kernel - Re: [patch 16/21] Xen-paravirt: Add code into head.S to handle being booted by Xen

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] [day] [month] [year] [list]

Message-ID: <m1sld8m9b2.fsf@ebiederm.dsl.xmission.com>
Date:	Wed, 14 Feb 2007 19:41:37 -0700
From:	ebiederm@...ssion.com (Eric W. Biederman)
To:	Jeremy Fitzhardinge <jeremy@...p.org>
Cc:	Andi Kleen <ak@....de>, Andrew Morton <akpm@...l.org>,
	linux-kernel@...r.kernel.org, virtualization@...ts.osdl.org,
	xen-devel@...ts.xensource.com, Chris Wright <chrisw@...s-sol.org>,
	Zachary Amsden <zach@...are.com>,
	Ian Campbell <Ian.Campbell@...Source.com>
Subject: Re: [patch 16/21] Xen-paravirt: Add code into head.S to handle being booted by Xen

Jeremy Fitzhardinge <jeremy@...p.org> writes:

> Eric W. Biederman wrote:
>> I'm pretty certain we explicitly drop the weird GNU note that
>> is automatically generated by gcc and specifies something informational.
>>   
> But that's something else again, since it appears as a PT_GNU_STACK phdr.

Not that.  It's more like abi version or gcc version or something
like.  At least there used to be one of those notes in every .o file
and compiled program.

>> I don't think anything we are doing is wrong but ld gets confused easily
>> in the corner cases.  I'm modestly surprised we didn't have to mark our
>> .note.xxx scions as ".section .note.xxx @note"  or whatever the proper
>> gas syntax is.
>
> I did try that, and it didn't make a difference.  The manual says that
> the output section type follows the input section type, so I agree its a
> bit surprising we ever get a SHT_NOTE out of it without the @note stuff.

Right.  So the surprise is that SHT_NOTE got set.  There are some
defaults based on the section name somewhere that appear to have done
the right thing.

My best hunch really is that ld treated the .note sections normally
and just mist the handling of the magic SHT_NOTE type.  Which is why
I'm not to worried.

Eric
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/