linux-kernel - Re: Bug#609371: linux-image-2.6.37-trunk-sparc64: module scsi

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:	Wed, 19 Jan 2011 11:18:57 -0500
From:	Mathieu Desnoyers <mathieu.desnoyers@...icios.com>
To:	Sam Ravnborg <sam@...nborg.org>
Cc:	David Miller <davem@...emloft.net>, rostedt@...dmis.org,
	richm@...elvet.org.uk, 609371@...s.debian.org, ben@...adent.org.uk,
	sparclinux@...r.kernel.org, linux-kernel@...r.kernel.org,
	fweisbec@...il.com, mingo@...hat.com
Subject: Re: Bug#609371: linux-image-2.6.37-trunk-sparc64: module scsi_mod:
	Unknown relocation: 36

* Sam Ravnborg (sam@...nborg.org) wrote:
> > 
> > If my memory serves me correctly, I think "long long" is aligned on 4 bytes on
> > ppc32, but on 8 bytes on x86_32 (yeah, that's weird). How about we create a
> > #define __long_long_aligned __attribute__((__aligned__(__alignof__(long long))))
> 
> #define __u64_aligned __attribute__((__aligned__(__alignof__(long long))))
> 
> A bit shorter but maybe less obvious.

Yep, that would make sense.

I'm tempted to try creating

#defined __u64_packed_aligned __attribute__((__packed__, __aligned__(__alignof__(long long))))

in the hope that gcc sees this as a strict alignment requirement (including a
max bound) rather than just a hint. From what I gather in my reading of 

http://gcc.gnu.org/onlinedocs/gcc/Type-Attributes.html

"The aligned attribute can only increase the alignment; but you can decrease it
by specifying packed as well. See below."

gcc seems to support having both specified. I think this would provide the kind
of alignment guarantees we really need here: both specifying the minimum _and_
maximum alignment.

Thoughts ?

Mathieu

> 
> 	Sam

-- 
Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.
http://www.efficios.com
--
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/