From: Thomas Gleixner <tglx@linutronix.de>
To: Fenghua Yu <fenghua.yu@intel.com>
Cc: Ingo Molnar <mingo@elte.hu>, H Peter Anvin <hpa@zytor.com>,
Asit K Mallick <asit.k.mallick@intel.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Avi Kivity <avi@redhat.com>,
Arjan van de Ven <arjan@infradead.org>,
Andrew Morton <akpm@linux-foundation.org>,
Andi Kleen <andi@firstfloor.org>,
linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2 4/4] x86/kernel/common.c: Disable SMEP by kernel option nosmep
Date: Tue, 17 May 2011 00:01:55 +0200 (CEST) [thread overview]
Message-ID: <alpine.LFD.2.02.1105162359500.3078@ionos> (raw)
In-Reply-To: <1305581685-5144-5-git-send-email-fenghua.yu@intel.com>
On Mon, 16 May 2011, Fenghua Yu wrote:
> +/*
> + * If SMEP is supported by the processor, SMEP has been enabled in CR4 earlier.
> + * But if kernel option "nosmep" is given, we disable SMEP here.
> + */
> +static __init void config_smep(struct cpuinfo_x86 *c)
> +{
> + if (cpu_has(c, X86_FEATURE_SMEP) && unlikely(disable_smep)) {
That unlikely() is completely pointless. This is init code and inside
of a if() already. Where is the point ?
> + setup_clear_cpu_cap(X86_FEATURE_SMEP);
> + clear_in_cr4(X86_CR4_SMEP);
> + }
> +}
Thanks,
tglx
next prev parent reply other threads:[~2011-05-16 22:02 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-16 21:34 [PATCH v2 0/4] Enable SMEP CPU Feature Fenghua Yu
2011-05-16 21:34 ` [PATCH v2 1/4] x86, cpu: Add CPU flags for SMEP Fenghua Yu
2011-05-17 1:56 ` H. Peter Anvin
2011-05-16 21:34 ` [PATCH v2 2/4] x86, cpu: Add SMEP CPU feature in CR4 Fenghua Yu
2011-05-16 21:34 ` [PATCH v2 3/4] x86, head_32/64.S: Enable SMEP Fenghua Yu
2011-05-17 2:10 ` Matthew Garrett
2011-05-17 23:08 ` Yu, Fenghua
2011-05-17 23:12 ` H. Peter Anvin
2011-05-18 2:57 ` Yu, Fenghua
2011-05-16 21:34 ` [PATCH v2 4/4] x86/kernel/common.c: Disable SMEP by kernel option nosmep Fenghua Yu
2011-05-16 22:01 ` Thomas Gleixner [this message]
2011-05-16 21:52 ` [PATCH v2 0/4] Enable SMEP CPU Feature H. Peter Anvin
2011-05-17 7:05 ` Ingo Molnar
2011-05-17 9:15 ` Avi Kivity
2011-05-17 9:29 ` Ingo Molnar
2011-05-17 9:32 ` Avi Kivity
2011-05-17 10:46 ` Ingo Molnar
2011-05-17 11:34 ` Avi Kivity
2011-05-17 11:38 ` Ingo Molnar
2011-05-17 11:44 ` Avi Kivity
2011-05-17 11:47 ` Avi Kivity
2011-05-17 11:49 ` Pekka Enberg
2011-05-17 11:50 ` Ingo Molnar
2011-05-19 6:10 ` Tian, Kevin
2011-05-19 6:41 ` Shan, Haitao
2011-05-20 8:21 ` Ingo Molnar
2011-05-17 7:03 ` Ingo Molnar
2011-05-17 9:16 ` Avi Kivity
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=alpine.LFD.2.02.1105162359500.3078@ionos \
--to=tglx@linutronix.de \
--cc=akpm@linux-foundation.org \
--cc=andi@firstfloor.org \
--cc=arjan@infradead.org \
--cc=asit.k.mallick@intel.com \
--cc=avi@redhat.com \
--cc=fenghua.yu@intel.com \
--cc=hpa@zytor.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=torvalds@linux-foundation.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
Powered by JetHome