| From foo@baz Mon May 21 22:23:33 CEST 2018 |
| From: Jim Mattson <jmattson@google.com> |
| Date: Sun, 13 May 2018 17:33:57 -0400 |
| Subject: x86/cpu: Make alternative_msr_write work for 32-bit code |
| |
| 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"); |
| } |