Re: zd1211rw (2.6.22 sparc64): unaligned access (do_rx)

[Michael Buesch <mb@bu3sch.de>]

On Thursday 06 December 2007 22:25:25 Jean Tourrilhes wrote:
> On Wed, Dec 05, 2007 at 06:36:28PM -0800, David Miller wrote:
> > From: Jean Tourrilhes <jt@hpl.hp.com>
> > Date: Wed, 5 Dec 2007 13:56:00 -0800
> > 
> > > 	Personally, I was under the impression that in userspace libc
> > > trap unaligned access and make them work. I mean, this code was tested
> > > on other 64/32 bit platforms (PPC, AMD-64, PS3) and was working there,
> > > so this seems to be specific to your platform.
> > 
> > None of those listed platforms trap on unaligned accesses like sparc
> > does.
> 

> 	Now, I'm wondering how to deal with unaligned access in
> userspace. If you get data from hardware or the network, you can not
> guarantee that everything will always be aligned, so we need a way to
> deal with it.
> 	In the kernel, we have get_unaligned(). I wonder what's the
> equivalent in userspace.

Userspace handles this transparently through fault traps.

-- 
Greetings Michael.