linux-kernel - Re: [RFC PATCH] x86/cpu: Fix MSR value truncation issue

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: <20151030193253.GK20952@pd.tnic>
Date:	Fri, 30 Oct 2015 20:32:53 +0100
From:	Borislav Petkov <bp@...en8.de>
To:	Andy Lutomirski <luto@...capital.net>
Cc:	LKML <linux-kernel@...r.kernel.org>,
	Andy Lutomirski <luto@...nel.org>,
	"H. Peter Anvin" <hpa@...or.com>, Ingo Molnar <mingo@...nel.org>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Peter Zijlstra <peterz@...radead.org>,
	Thomas Gleixner <tglx@...utronix.de>
Subject: Re: [RFC PATCH] x86/cpu: Fix MSR value truncation issue

On Fri, Oct 30, 2015 at 12:26:42PM -0700, Andy Lutomirski wrote:
> Want to add that to the patch or make it another patch?

Yeah, I'll make another one as it is going to document why we're
explicitly ANDing with 0xffffffffull.

> Fair enough.  I suppose that this thing is a handful of separate
> fields as opposed to being just a number.

You mean MSR_STAR?

Just the two upper 16-bit values. The lower 32-bit are reserved on Intel
while on AMD they're "32-bit SYSCALL Target EIP", meaning that you can
use SYSCALL on 32-bit too.

-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.
--
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/