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

From: tip-bot for Joerg Roedel
Date: Tue Aug 07 2018 - 12:57:06 EST


Commit-ID: 88c6f8a3977cc35997b47e2f99f080a15559c1eb
Gitweb: https://git.kernel.org/tip/88c6f8a3977cc35997b47e2f99f080a15559c1eb
Author: Joerg Roedel <jroedel@xxxxxxx>
AuthorDate: Tue, 7 Aug 2018 12:24:29 +0200
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
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@xxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: "H . Peter Anvin" <hpa@xxxxxxxxx>
Cc: linux-mm@xxxxxxxxx
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxx>
Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: Juergen Gross <jgross@xxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Jiri Kosina <jkosina@xxxxxxx>
Cc: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
Cc: Brian Gerst <brgerst@xxxxxxxxx>
Cc: David Laight <David.Laight@xxxxxxxxxx>
Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
Cc: Eduardo Valentin <eduval@xxxxxxxxxx>
Cc: Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Cc: aliguori@xxxxxxxxxx
Cc: daniel.gruss@xxxxxxxxxxxxxx
Cc: hughd@xxxxxxxxxx
Cc: keescook@xxxxxxxxxx
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: Waiman Long <llong@xxxxxxxxxx>
Cc: Pavel Machek <pavel@xxxxxx>
Cc: "David H . Gutteridge" <dhgutteridge@xxxxxxxxxxxx>
Cc: joro@xxxxxxxxxx
Link: https://lkml.kernel.org/r/1533637471-30953-2-git-send-email-joro@xxxxxxxxxx

---
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");