From: Jim Mattson <jmattson@google.com>
Date: Sun, 13 May 2018 21:33:57 +0000 (-0400)
Subject: x86/cpu: Make alternative_msr_write work for 32-bit code
X-Git-Tag: v4.14.43~17
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=bd2059282934fc009d755d24527187df5fe448de;p=platform%2Fkernel%2Flinux-rpi.git

x86/cpu: Make alternative_msr_write work for 32-bit code

commit 5f2b745f5e1304f438f9b2cd03ebc8120b6e0d3b upstream

Cast val and (val >> 32) to (u32), so that they fit in a
general-purpose register in both 32-bit and 64-bit code.

[ tglx: Made it u32 instead of uintptr_t ]

Fixes: c65732e4f721 ("x86/cpu: Restore CPUID_8000_0008_EBX reload")
Signed-off-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/arch/x86/include/asm/nospec-branch.h b/arch/x86/include/asm/nospec-branch.h
index 328ea3c..bc258e6 100644
--- a/arch/x86/include/asm/nospec-branch.h
+++ b/arch/x86/include/asm/nospec-branch.h
@@ -265,8 +265,8 @@ void alternative_msr_write(unsigned int msr, u64 val, unsigned int feature)
 {
 	asm volatile(ALTERNATIVE("", "wrmsr", %c[feature])
 		: : "c" (msr),
-		    "a" (val),
-		    "d" (val >> 32),
+		    "a" ((u32)val),
+		    "d" ((u32)(val >> 32)),
 		    [feature] "i" (feature)
 		: "memory");
 }