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Subject[PATCH 4.9 70/87] x86/cpu: Make alternative_msr_write work for 32-bit code
Date
4.9-stable review patch.  If anyone has any objections, please let me know.

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

From: Jim Mattson <jmattson@google.com>

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: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/x86/include/asm/nospec-branch.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- 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
{
asm volatile(ALTERNATIVE("", "wrmsr", %c[feature])
: : "c" (msr),
- "a" (val),
- "d" (val >> 32),
+ "a" ((u32)val),
+ "d" ((u32)(val >> 32)),
[feature] "i" (feature)
: "memory");
}

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