public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: "H. Peter Anvin" <hpa@zytor.com>
To: Mike Frysinger <vapier@gentoo.org>
Cc: Andi Kleen <andi@firstfloor.org>,
	tglx@linutronix.de, mingo@redhat.com,
	LKML <linux-kernel@vger.kernel.org>
Subject: Re: asm-x86/msr.h for sanitized headers: clean it or punt it
Date: Mon, 31 Dec 2007 10:15:36 -0800	[thread overview]
Message-ID: <477931C8.4060208@zytor.com> (raw)
In-Reply-To: <200712311310.32337.vapier@gentoo.org>

Mike Frysinger wrote:
>> ---
> Use __asm__ and __volatile__ in code that is exported to userspace.  Wrap
> kernel functions with __KERNEL__ so they get scrubbed.
> 
> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
> ---
> diff --git a/include/asm-x86/msr.h b/include/asm-x86/msr.h
> index ba4b314..ffb9319 100644
> --- a/include/asm-x86/msr.h
> +++ b/include/asm-x86/msr.h
> @@ -193,7 +193,7 @@ static inline int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
>  
>  /* wrmsr with exception handling */
>  #define wrmsr_safe(msr,a,b) ({ int ret__;			\
> -	asm volatile("2: wrmsr ; xorl %0,%0\n"			\
> +	__asm__ __volatile__("2: wrmsr ; xorl %0,%0\n"			\
>  		     "1:\n\t"					\
>  		     ".section .fixup,\"ax\"\n\t"		\
>  		     "3:  movl %4,%0 ; jmp 1b\n\t"		\

rdmsr_safe/wrmsr_safe are definitely kernel-only.

	-hpa

  reply	other threads:[~2007-12-31 18:16 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-12-31  5:45 asm-x86/msr.h for sanitized headers: clean it or punt it Mike Frysinger
2007-12-31  5:51 ` H. Peter Anvin
2007-12-31 12:26 ` Andi Kleen
2007-12-31 15:33   ` Mike Frysinger
2007-12-31 16:36     ` Andi Kleen
2007-12-31 18:10       ` Mike Frysinger
2007-12-31 18:15         ` H. Peter Anvin [this message]
2007-12-31 18:49           ` Mike Frysinger
2008-01-01 15:47             ` Ingo Molnar
2008-01-02  1:20             ` Adrian Bunk

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=477931C8.4060208@zytor.com \
    --to=hpa@zytor.com \
    --cc=andi@firstfloor.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@redhat.com \
    --cc=tglx@linutronix.de \
    --cc=vapier@gentoo.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox