linux-kernel - Re: [PATCH] Remove process freezer from suspend to RAM pathway

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:	Fri, 6 Jul 2007 19:16:16 +1000
From:	Nigel Cunningham <nigel@...el.suspend2.net>
To:	Miklos Szeredi <miklos@...redi.hu>
Cc:	oliver@...kum.org, rjw@...k.pl, nigel@...pend2.net, pavel@....cz,
	benh@...nel.crashing.org, mjg59@...f.ucam.org,
	linux-kernel@...r.kernel.org, linux-pm@...ts.linux-foundation.org
Subject: Re: [PATCH] Remove process freezer from suspend to RAM pathway

Hi.

On Friday 06 July 2007 19:09:43 Miklos Szeredi wrote:
> > > > Moreover, if FUSE implements syncing, then the sync from within the 
freezer
> > > > will almost certainly deadlock.
> > > 
> > > Rafael, think positively: by the time fuse implements sync(), the
> > > freezer will be long gone ;)
> > 
> > Now you are entering really dangerous territory.
> > If you can implement a meaningfull sync method, you must have dirty
> > pages in the page cache. That means you are in the page freeing path
> > of the vm. Then we are in real trouble. Don't even think about it.
> 
> VM induced deadlocks are real nasty.  I have thought about them a lot
> already.  Suspend shouldn't introduce any big surprises.

Suspend isn't introducing the surprises. Fuse is. It creates the potential 
deadlocks simply by existing (this isn't suspend or hibernate specific).

Nigel

Content of type "application/pgp-signature" skipped