linux-kernel - Re: [Xen-devel] [PATCH] xen/x86: Adjust stack pointer in xen

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] [day] [month] [year] [list]

Message-ID: <564B8234.4000004@oracle.com>
Date:	Tue, 17 Nov 2015 14:38:28 -0500
From:	Boris Ostrovsky <boris.ostrovsky@...cle.com>
To:	Andy Lutomirski <luto@...capital.net>,
	Andrew Cooper <andrew.cooper3@...rix.com>
Cc:	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	xen-devel <xen-devel@...ts.xen.org>,
	Borislav Petkov <bp@...en8.de>,
	David Vrabel <david.vrabel@...rix.com>,
	"H. Peter Anvin" <hpa@...or.com>
Subject: Re: [Xen-devel] [PATCH] xen/x86: Adjust stack pointer in xen_sysexit

On 11/17/2015 02:37 PM, Boris Ostrovsky wrote:
> On 11/17/2015 02:16 PM, Andy Lutomirski wrote:
>>>> Looks good to me.  Does Xen have any sysexit/sysret32 equivalent to
>>>> return to 32-bit user mode?  If so, it could be worth trying to wire
>>>> it up by patching the jz instead of the test instruction.
>
> We can actually make patching a little bit more efficient by replacing 
> the test instruction with 'xor %eax,%eax'. That way we won't need any 
> 'nop's.

Nevermind that, we are looking at flags, not register.

-boris
--
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/