linux-kernel - [PATCH 4.4 2/3] x86/cpu: Probe CPUID leaf 6 even when cpuid

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Message-Id: <20180718145156.243426620@linuxfoundation.org>
Date:   Wed, 18 Jul 2018 17:01:59 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Andy Lutomirski <luto@...nel.org>,
        Borislav Petkov <bp@...en8.de>,
        Brian Gerst <brgerst@...il.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Brad Spengler <spender@...ecurity.net>
Subject: [PATCH 4.4 2/3] x86/cpu: Probe CPUID leaf 6 even when cpuid_level == 6

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Andy Lutomirski <luto@...nel.org>

commit 3df8d9208569ef0b2313e516566222d745f3b94b upstream.

A typo (or mis-merge?) resulted in leaf 6 only being probed if
cpuid_level >= 7.

Fixes: 2ccd71f1b278 ("x86/cpufeature: Move some of the scattered feature bits to x86_capability")
Signed-off-by: Andy Lutomirski <luto@...nel.org>
Acked-by: Borislav Petkov <bp@...en8.de>
Cc: Brian Gerst <brgerst@...il.com>
Link: http://lkml.kernel.org/r/6ea30c0e9daec21e488b54761881a6dfcf3e04d0.1481825597.git.luto@kernel.org
Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
Cc: Brad Spengler <spender@...ecurity.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 arch/x86/kernel/cpu/common.c |    7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -686,13 +686,14 @@ void get_cpu_cap(struct cpuinfo_x86 *c)
 		c->x86_capability[CPUID_1_EDX] = edx;
 	}
 
+	/* Thermal and Power Management Leaf: level 0x00000006 (eax) */
+	if (c->cpuid_level >= 0x00000006)
+		c->x86_capability[CPUID_6_EAX] = cpuid_eax(0x00000006);
+
 	/* Additional Intel-defined flags: level 0x00000007 */
 	if (c->cpuid_level >= 0x00000007) {
 		cpuid_count(0x00000007, 0, &eax, &ebx, &ecx, &edx);
-
 		c->x86_capability[CPUID_7_0_EBX] = ebx;
-
-		c->x86_capability[CPUID_6_EAX] = cpuid_eax(0x00000006);
 		c->x86_capability[CPUID_7_ECX] = ecx;
 	}