From: Dave Jones <davej@redhat.com>
To: Linux Kernel <linux-kernel@vger.kernel.org>
Cc: x86@kernel.org, "Bryan O'Donoghue" <pure.logic@nexus-software.ie>
Subject: [PATCH] Don't enable F00F workaround on Intel Quark processors.
Date: Tue, 28 Oct 2014 13:57:53 -0400 [thread overview]
Message-ID: <20141028175753.GA12743@redhat.com> (raw)
The Intel Quark processor is a part of family 5, but does not have the
F00F bug present in Pentiums of the same family.
Pentiums were models 0 through 8, Quark is model 9.
Cc: Bryan O'Donoghue <pure.logic@nexus-software.ie>
Signed-off-by: Dave Jones <davej@redhat.com>
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 1ef456273172..9cc6b6f25f42 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -213,12 +213,13 @@ static void intel_workarounds(struct cpuinfo_x86 *c)
{
#ifdef CONFIG_X86_F00F_BUG
/*
- * All current models of Pentium and Pentium with MMX technology CPUs
+ * All models of Pentium and Pentium with MMX technology CPUs
* have the F0 0F bug, which lets nonprivileged users lock up the
* system. Announce that the fault handler will be checking for it.
+ * The Quark is also family 5, but does not have the same bug.
*/
clear_cpu_bug(c, X86_BUG_F00F);
- if (!paravirt_enabled() && c->x86 == 5) {
+ if (!paravirt_enabled() && c->x86 == 5 && c->x86_model < 9) {
static int f00f_workaround_enabled;
set_cpu_bug(c, X86_BUG_F00F);
next reply other threads:[~2014-10-28 17:58 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-28 17:57 Dave Jones [this message]
2014-10-28 18:33 ` [tip:x86/urgent] x86: Don' t enable F00F workaround on Intel Quark processors tip-bot for Dave Jones
2014-10-29 0:02 ` [PATCH] Don't " Bryan O'Donoghue
2014-10-29 9:10 ` [tip:x86/urgent] x86: Don' t " tip-bot for Dave Jones
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