linux-kernel - Re: Kevent POSIX timers support.

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: <20061128192236.GA2051@2ka.mipt.ru>
Date:	Tue, 28 Nov 2006 22:22:36 +0300
From:	Evgeniy Polyakov <johnpol@....mipt.ru>
To:	David Miller <davem@...emloft.net>
Cc:	drepper@...hat.com, akpm@...l.org, netdev@...r.kernel.org,
	zach.brown@...cle.com, hch@...radead.org,
	chase.venters@...entec.com, johann.borck@...sedata.com,
	linux-kernel@...r.kernel.org, jeff@...zik.org, aviro@...hat.com
Subject: Re: Kevent POSIX timers support.

On Tue, Nov 28, 2006 at 11:13:00AM -0800, David Miller (davem@...emloft.net) wrote:
> From: Evgeniy Polyakov <johnpol@....mipt.ru>
> Date: Tue, 28 Nov 2006 12:16:02 +0300
> 
> > Although ukevent has pointer embedded, it is unioned with u64, so there
> > should be no problems until 128 bit arch appeared, which likely will not
> > happen soon. There is also unused in kevent posix timers patch
> > 'u32 ret_val[2]' field, which can store segval's value too.
> > 
> > But the fact that ukevent does not and will not in any way have variable
> > size is absolutely.
> 
> I believe that in order to be %100 safe you will need to use the
> special aligned_u64 type, as that takes care of a crucial difference
> between x86 and x86_64 API, namely that u64 needs 8-byte alignment on
> x86_64 but not on x86.
> 
> You probably know this already :-)

Yep :)
So I put it at the end, where structure is already correctly aligned, so
there is no need for special alignment.
And, btw, last time I checked, aligned_u64 was not exported to
userspace.

-- 
	Evgeniy Polyakov
-
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/