linux-kernel - [tip:x86/pti] x86/mm/pti: Fix 32 bit PCID check

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Date:   Tue, 7 Aug 2018 09:55:05 -0700
From:   tip-bot for Joerg Roedel <tipbot@...or.com>
To:     linux-tip-commits@...r.kernel.org
Cc:     dhgutteridge@...patico.ca, bp@...en8.de, brgerst@...il.com,
        eduval@...zon.com, torvalds@...ux-foundation.org,
        boris.ostrovsky@...cle.com, mingo@...nel.org, aarcange@...hat.com,
        dave.hansen@...el.com, llong@...hat.com,
        gregkh@...uxfoundation.org, hpa@...or.com, jgross@...e.com,
        linux-kernel@...r.kernel.org, jpoimboe@...hat.com,
        tglx@...utronix.de, jroedel@...e.de, David.Laight@...lab.com,
        peterz@...radead.org, dvlasenk@...hat.com, luto@...nel.org,
        will.deacon@....com, jkosina@...e.cz, pavel@....cz
Subject: [tip:x86/pti] x86/mm/pti: Fix 32 bit PCID check

Commit-ID:  88c6f8a3977cc35997b47e2f99f080a15559c1eb
Gitweb:     https://git.kernel.org/tip/88c6f8a3977cc35997b47e2f99f080a15559c1eb
Author:     Joerg Roedel <jroedel@...e.de>
AuthorDate: Tue, 7 Aug 2018 12:24:29 +0200
Committer:  Thomas Gleixner <tglx@...utronix.de>
CommitDate: Tue, 7 Aug 2018 18:51:22 +0200

x86/mm/pti: Fix 32 bit PCID check

The check uses the wrong operator and causes false positive
warnings in the kernel log on some systems.

Fixes: 5e8105950a8b3 ('x86/mm/pti: Add Warning when booting on a PCID capable CPU')
Signed-off-by: Joerg Roedel <jroedel@...e.de>
Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
Cc: "H . Peter Anvin" <hpa@...or.com>
Cc: linux-mm@...ck.org
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Andy Lutomirski <luto@...nel.org>
Cc: Dave Hansen <dave.hansen@...el.com>
Cc: Josh Poimboeuf <jpoimboe@...hat.com>
Cc: Juergen Gross <jgross@...e.com>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Borislav Petkov <bp@...en8.de>
Cc: Jiri Kosina <jkosina@...e.cz>
Cc: Boris Ostrovsky <boris.ostrovsky@...cle.com>
Cc: Brian Gerst <brgerst@...il.com>
Cc: David Laight <David.Laight@...lab.com>
Cc: Denys Vlasenko <dvlasenk@...hat.com>
Cc: Eduardo Valentin <eduval@...zon.com>
Cc: Greg KH <gregkh@...uxfoundation.org>
Cc: Will Deacon <will.deacon@....com>
Cc: aliguori@...zon.com
Cc: daniel.gruss@...k.tugraz.at
Cc: hughd@...gle.com
Cc: keescook@...gle.com
Cc: Andrea Arcangeli <aarcange@...hat.com>
Cc: Waiman Long <llong@...hat.com>
Cc: Pavel Machek <pavel@....cz>
Cc: "David H . Gutteridge" <dhgutteridge@...patico.ca>
Cc: joro@...tes.org
Link: https://lkml.kernel.org/r/1533637471-30953-2-git-send-email-joro@8bytes.org

---
 arch/x86/mm/pti.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/mm/pti.c b/arch/x86/mm/pti.c
index ef8db6ffc836..113ba14a03d8 100644
--- a/arch/x86/mm/pti.c
+++ b/arch/x86/mm/pti.c
@@ -549,7 +549,7 @@ void __init pti_init(void)
 	 * supported on 32 bit anyway. To print the warning we need to
 	 * check with cpuid directly again.
 	 */
-	if (cpuid_ecx(0x1) && BIT(17)) {
+	if (cpuid_ecx(0x1) & BIT(17)) {
 		/* Use printk to work around pr_fmt() */
 		printk(KERN_WARNING "\n");
 		printk(KERN_WARNING "************************************************************\n");