| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.9 70/87] x86/cpu: Make alternative_msr_write work for 32-bit code | Date | Mon, 21 May 2018 23:11:46 +0200 |
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4.9-stable review patch. If anyone has any objections, please let me know.
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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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