From: Andi Kleen <andi@firstfloor.org>
To: "Fenghua Yu" <fenghua.yu@intel.com>
Cc: "Ingo Molnar" <mingo@elte.hu>,
"Thomas Gleixner" <tglx@linutronix.de>,
"H Peter Anvin" <hpa@zytor.com>,
"Asit K Mallick" <asit.k.mallick@intel.com>,
"linux-kernel" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 3/3] x86, cpu: Enable/disable SMEP
Date: Wed, 11 May 2011 15:36:30 -0700 [thread overview]
Message-ID: <m2k4dwj24x.fsf@firstfloor.org> (raw)
In-Reply-To: <1305141480-843-4-git-send-email-fenghua.yu@intel.com> (Fenghua Yu's message of "Wed, 11 May 2011 12:18:00 -0700")
"Fenghua Yu" <fenghua.yu@intel.com> writes:
> +static int disable_smep;
If you add a __initdata here the whole thing will completely disappear
after boot.
> @@ -867,6 +886,8 @@ static void __cpuinit identify_cpu(struct cpuinfo_x86 *c)
> /* Init Machine Check Exception if available. */
> mcheck_cpu_init(c);
>
> + setup_smep(c);
My feeling is you're setting this too late. In theory there could be
early overflows. Better use a early_param and set it as early
as possible, directly after the cpuid flags are set up in early
initialization.
-Andi
--
ak@linux.intel.com -- Speaking for myself only
next prev parent reply other threads:[~2011-05-11 22:36 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-11 19:17 [PATCH 0/3] Enable SMEP CPU Feature Fenghua Yu
2011-05-11 19:17 ` [PATCH 1/3] x86, cpu: Add CPU flags for SMEP Fenghua Yu
2011-05-11 19:17 ` [PATCH 2/3] x86, cpu: Add SMEP CPU feature in CR4 Fenghua Yu
2011-05-11 19:18 ` [PATCH 3/3] x86, cpu: Enable/disable SMEP Fenghua Yu
2011-05-11 22:36 ` Andi Kleen [this message]
2011-05-12 6:06 ` H. Peter Anvin
2011-05-12 6:59 ` Ingo Molnar
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