From: Jeremy Fitzhardinge <jeremy@goop.org>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Ingo Molnar <mingo@elte.hu>, Thomas Gleixner <tglx@linutronix.de>,
Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>,
Avi Kivity <avi@qumranet.com>
Subject: Re: The msr_safe functions and returning -EFAULT
Date: Mon, 31 Aug 2009 17:24:43 -0700 [thread overview]
Message-ID: <4A9C69CB.1050603@goop.org> (raw)
In-Reply-To: <4A9AE998.4040201@zytor.com>
On 08/30/09 14:05, H. Peter Anvin wrote:
> Right now, the *msr_safe() functions are returning -EFAULT. As far as I
> can tell, this makes absolutely no sense -- EFAULT is a nonsensical
> error (it means a pointer into user memory given to a system call is
> invalid), and the only user that seems to use this as anything other
> than a boolean is the MSR driver, which wants EIO.
>
> Sending out an email in case I have missed any instances, but I'm
> inclined to just change this to EIO globally.
>
> Anyone has objections?
>
I think the only rationale for EFAULT is that the *msr will fail with
GP, and a GPing instruction will send a SIGSEGV to usermode, and EFAULT
is the synchronous error-code equiv of SIGSEGV. Sorta.
EIO makes more sense overall. Or ENXIO.
J
next prev parent reply other threads:[~2009-09-01 0:24 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-08-30 21:05 The msr_safe functions and returning -EFAULT H. Peter Anvin
2009-09-01 0:24 ` Jeremy Fitzhardinge [this message]
2009-09-01 0:27 ` H. Peter Anvin
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