Commit 5f2b745f authored May 13, 2018 by Jim Mattson Committed by Thomas Gleixner May 14, 2018

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



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: c65732e4 ("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>

parent ffed645e

arch/x86/include/asm/nospec-branch.h

+2 −2

Original line number	Diff line number	Diff line
		@@ -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");
		}