Re: [BK PATCH 2.5] fs/binfmt_aout.c: Use PAGE_ALIGN_LL() on

Anton Altaparmakov (aia21@cantab.net)
Sun, 28 Jul 2002 19:55:51 +0100

At 18:59 28/07/02, Eric W. Biederman wrote:
>Anton Altaparmakov <aia21@cantab.net> writes:
> > Following from previous patch which introduced PAGE_ALIGN_LL, this
> > one fixes a bug in fs/binfmt_aout.c which was using PAGE_ALIGN
> > on 64-bit values... It now uses PAGE_ALIGN_LL.
> >
> > Patch together with the other two patches available from:
> >
> > bk pull http://linux-ntfs.bkbits.net/linux-2.5-pm
>
>Huh?
>
>All virtual addresses on 32bit platforms are 32bit, as are all lengths
>of address space.

I thought (intel) CPUs did 48-bit addressing? How do we support 32GiB of
RAM? With pure 32-bit addressing it would be limited to 4GiB only... No?
(Of course I am probably confusing varius types of addresses...)

>Unless you are running a 32bit kernel with a 64bit user space,
>which is simply crazy, unless you are stuck doing it that way.

The code is still broken. The values ARE 64-bit (check the struct
definitions if you don't believe me). This is just a matter of correctness.
It is incorrect as it is right now and it will do Bad Things(tm) if the
supplied values are > 32-bit. (Whether it is possible for a malicious user
to supply them is beyond my knowledge.)

Best regards,

Anton

-- 
   "I've not lost my mind. It's backed up on tape somewhere." - Unknown

-- 
Anton Altaparmakov <aia21 at cantab.net> (replace at with @)
Linux NTFS Maintainer / IRC: #ntfs on irc.openprojects.net
WWW: http://linux-ntfs.sf.net/ & http://www-stu.christs.cam.ac.uk/~aia21/


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