linux-kernel - RE: [Xen-devel] Regressions in v3.3-rc1 introduced by "xen/granttable: Grant tables V2 implementation"

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: <1327506463.24561.335.camel@zakaz.uk.xensource.com>
Date:	Wed, 25 Jan 2012 15:47:42 +0000
From:	Ian Campbell <Ian.Campbell@...rix.com>
To:	Paul Durrant <Paul.Durrant@...rix.com>
CC:	Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>,
	"annie.li@...cle.com" <annie.li@...cle.com>,
	"xen-devel@...ts.xensource.com" <xen-devel@...ts.xensource.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: RE: [Xen-devel] Regressions in v3.3-rc1 introduced by
 "xen/granttable: Grant tables V2 implementation"

On Wed, 2012-01-25 at 15:16 +0000, Paul Durrant wrote:
> > -----Original Message-----
> > 
> > On HVM for gnttab_shared we make an add_to_physmap call with
> > XENMAPSPACE_grant_table (in gnttab_map). I don't see any support call to
> > do something similar for the status array though and I don't see a
> > XENMAPSPACE_* specifically for that case either in the hypervisor either.
> > 
> 
> There is no map-space for the status pages. To map them you use the
> standard map space but OR a bit (top bit IIRC) into in the idx. It's a
> bit icky, but that's how it is.

I can't see that happening anywhere in the current Linux tree, there's
only one call to XENMAPSPACE_grant_table and it doesn't set the top bit,
so presumably this is at least part of the problem.

I hope that "top bit" is consistent for 32 and 64 bit domains....

Ian.

--
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/