From: "H. Peter Anvin" <hpa@zytor.com>
To: Yuhong Bao <yuhongbao_386@hotmail.com>
Cc: "mingo@kernel.org" <mingo@kernel.org>,
"linux-tip-commits@vger.kernel.org"
<linux-tip-commits@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"tglx@linutronix.de" <tglx@linutronix.de>
Subject: Re: [tip:x86/smap] x86-32: Start out eflags and cr4 clean
Date: Fri, 23 Nov 2012 21:06:16 -0800 [thread overview]
Message-ID: <50B055C8.2030209@zytor.com> (raw)
In-Reply-To: <SNT002-W1128F6F94A63B050C01347BC3590@phx.gbl>
On 11/23/2012 07:49 PM, Yuhong Bao wrote:
>> + * Specifically, cr4 exists if and only if CPUID exists,
>> + * which in turn exists if and only if EFLAGS.ID exists.
> This may be true for *Intel* 486 CPUs as VME was implemented at the same time as CPUID, but I am not sure that it is true for AMD 486 CPUs.
>
> Yuhong Bao
That is the architecture; if you know of a counterexample speak up. "I
am not sure" doesn't count.
-hpa
--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel. I don't speak on their behalf.
next prev parent reply other threads:[~2012-11-24 5:06 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-21 19:43 [PATCH 00/11] x86: Supervisor Mode Access Prevention H. Peter Anvin
2012-09-21 19:43 ` [PATCH 01/11] x86, cpufeature: Add feature bit for SMAP H. Peter Anvin
2012-09-21 19:43 ` [PATCH 02/11] x86-32, mm: The WP test should be done on a kernel page H. Peter Anvin
2012-09-21 19:58 ` [tip:x86/smap] " tip-bot for H. Peter Anvin
2012-09-21 19:43 ` [PATCH 03/11] x86, smap: Add CR4 bit for SMAP H. Peter Anvin
2012-09-21 19:59 ` [tip:x86/smap] " tip-bot for H. Peter Anvin
2012-09-21 19:43 ` [PATCH 04/11] x86, alternative: Use .pushsection/.popsection H. Peter Anvin
2012-09-21 20:00 ` [tip:x86/smap] " tip-bot for H. Peter Anvin
2012-09-21 19:43 ` [PATCH 05/11] x86, alternative: Add header guards to <asm/alternative-asm.h> H. Peter Anvin
2012-09-21 20:01 ` [tip:x86/smap] x86, alternative: Add header guards to <asm/ alternative-asm.h> tip-bot for H. Peter Anvin
2012-09-21 19:43 ` [PATCH 06/11] x86, smap: Add a header file with macros for STAC/CLAC H. Peter Anvin
2012-09-21 20:02 ` [tip:x86/smap] x86, smap: Add a header file with macros for STAC/ CLAC tip-bot for H. Peter Anvin
2012-09-21 19:43 ` [PATCH 07/11] x86, uaccess: Merge prototypes for clear_user/__clear_user H. Peter Anvin
2012-09-21 20:03 ` [tip:x86/smap] x86, uaccess: Merge prototypes for clear_user/ __clear_user tip-bot for H. Peter Anvin
2012-09-21 19:43 ` [PATCH 08/11] x86, smap: Add STAC and CLAC instructions to control user space access H. Peter Anvin
2012-09-21 20:04 ` [tip:x86/smap] " tip-bot for H. Peter Anvin
2012-09-22 0:16 ` [tip:x86/smap] x86-32, smap: Add STAC/ CLAC instructions to 32-bit kernel entry tip-bot for H. Peter Anvin
2012-09-21 19:43 ` [PATCH 09/11] x86, smap: Turn on Supervisor Mode Access Prevention H. Peter Anvin
2012-09-21 20:05 ` [tip:x86/smap] " tip-bot for H. Peter Anvin
2012-09-21 19:43 ` [PATCH 10/11] x86, smap: A page fault due to SMAP is an oops H. Peter Anvin
2012-09-21 20:06 ` [tip:x86/smap] " tip-bot for H. Peter Anvin
2012-09-21 19:43 ` [PATCH 11/11] x86, smap: Reduce the SMAP overhead for signal handling H. Peter Anvin
2012-09-21 20:07 ` [tip:x86/smap] " tip-bot for H. Peter Anvin
2012-09-21 19:54 ` [PATCH 00/11] x86: Supervisor Mode Access Prevention Linus Torvalds
2012-09-21 19:57 ` H. Peter Anvin
2012-09-21 20:08 ` Ingo Molnar
2012-09-21 21:03 ` H. Peter Anvin
2012-09-21 21:09 ` Linus Torvalds
2012-09-21 21:12 ` H. Peter Anvin
2012-09-21 22:07 ` Eric W. Biederman
2012-09-21 22:12 ` H. Peter Anvin
2012-09-22 0:41 ` Eric W. Biederman
2012-09-24 23:27 ` [RFC PATCH] x86-32: Start out eflags and cr4 clean H. Peter Anvin
2012-09-25 13:27 ` Konrad Rzeszutek Wilk
2012-09-25 13:48 ` Ian Campbell
2012-09-26 11:29 ` Konrad Rzeszutek Wilk
2012-09-27 6:11 ` [tip:x86/smap] " tip-bot for H. Peter Anvin
2012-11-24 3:49 ` Yuhong Bao
2012-11-24 5:06 ` H. Peter Anvin [this message]
2012-09-27 6:11 ` [tip:x86/smap] x86, suspend: On wakeup always initialize cr4 and EFER tip-bot for H. Peter Anvin
2012-10-01 22:04 ` [tip:x86/urgent] x86, suspend: Correct the restore of CR4, EFER; skip computing EFLAGS.ID tip-bot for H. Peter Anvin
2012-10-02 6:52 ` tip-bot for H. Peter Anvin
2012-10-10 19:59 ` [RFC PATCH] x86-32: Start out eflags and cr4 clean Andres Salomon
2013-01-19 0:40 ` Andres Salomon
2013-01-19 0:42 ` H. Peter Anvin
2013-01-19 1:05 ` [Techteam] " Mitch Bradley
2013-01-19 2:35 ` H. Peter Anvin
2013-01-19 7:44 ` Mitch Bradley
2013-01-19 12:34 ` Daniel Drake
2013-01-19 19:15 ` [tip:x86/urgent] x86-32: Start out cr0 clean, disable paging before modifying cr3/4 tip-bot for H. Peter Anvin
2012-09-21 22:08 ` [PATCH 00/11] x86: Supervisor Mode Access Prevention Dave Jones
2012-09-21 22:10 ` H. Peter Anvin
2012-09-22 11:32 ` Ingo Molnar
2012-09-24 20:31 ` H. Peter Anvin
2012-09-24 20:43 ` Kees Cook
2012-09-24 20:51 ` H. Peter Anvin
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