linux-kernel - Re: fuse, get_user_pages, flush_anon_page, aliasing caches and all that again

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 for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 01 Jan 2007 09:35:17 -0500
From:	James Bottomley <James.Bottomley@...elEye.com>
To:	Linus Torvalds <torvalds@...l.org>
Cc:	Russell King <rmk+lkml@....linux.org.uk>,
	Miklos Szeredi <miklos@...redi.hu>,
	linux-kernel@...r.kernel.org, linux-arch@...r.kernel.org,
	Andrew Morton <akpm@...l.org>
Subject: Re: fuse, get_user_pages, flush_anon_page, aliasing caches and all
	that again

On Sat, 2006-12-30 at 10:26 -0800, Linus Torvalds wrote:
> 
> On Sat, 30 Dec 2006, Russell King wrote:
> > 
> > And here's the flush_anon_page() part.

This looks fine to me (if you need my ack).

> > Add flush_anon_page() for ARM, to avoid data corruption issues when using
> > fuse or other subsystems using get_user_pages().
> 
> Btw, since this doesn't actually change any code for anybody but ARM, just 
> adds a parameter that is obviously unused by everybody else, and if it 
> actually fixes a real bug for ARM, I'll obviously happily take it even 
> before 2.6.20. So go ahead put it in your ARM tree, and we'll get some 
> testing through that. And just ask me to pull at some point.
> 
> I wonder why nobody else seems to have a "flush_anon_page()"? This would 
> seem to be a potential issue for architectures like sparc too.. Although 
> maybe sparc can do a flush by physical index with "flush_dcache_page()".

The sparc handling of anonymous pages is different ... they accitentally
sweep them up in flush_dcache_page().  When I audited the architectures
to try to make fuse work on parisc, parisc and arm were the only ones
that actually needed flush_anon_page().

James


-
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/