[tip: x86/urgent] x86/cpu/vmware: Use the full form of INL in VMWARE_PORT

[tip-bot2 for Sami Tolvanen]

The following commit has been merged into the x86/urgent branch of tip:

Commit-ID:     fbcfb8f0270bf24fe348393540b17a7f2ba577d7
Gitweb:        https://git.kernel.org/tip/fbcfb8f0270bf24fe348393540b17a7f2ba577d7
Author:        Sami Tolvanen <samitolvanen@xxxxxxxxxx>
AuthorDate:    Mon, 07 Oct 2019 12:21:29 -07:00
Committer:     Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Tue, 08 Oct 2019 13:26:42 +02:00

x86/cpu/vmware: Use the full form of INL in VMWARE_PORT

LLVM's assembler doesn't accept the short form INL instruction:

  inl (%%dx)

but instead insists on the output register to be explicitly specified:

  <inline asm>:1:7: error: invalid operand for instruction
          inl (%dx)
             ^
  LLVM ERROR: Error parsing inline asm

Use the full form of the instruction to fix the build.

Signed-off-by: Sami Tolvanen <samitolvanen@xxxxxxxxxx>
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Reviewed-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
Acked-by: Thomas Hellstrom <thellstrom@xxxxxxxxxx>
Cc: clang-built-linux@xxxxxxxxxxxxxxxx
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx
Cc: "VMware, Inc." <pv-drivers@xxxxxxxxxx>
Cc: x86-ml <x86@xxxxxxxxxx>
Link: https://github.com/ClangBuiltLinux/linux/issues/734
Link: https://lkml.kernel.org/r/20191007192129.104336-1-samitolvanen@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
 arch/x86/kernel/cpu/vmware.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/vmware.c b/arch/x86/kernel/cpu/vmware.c
index 9735139..46d7326 100644
--- a/arch/x86/kernel/cpu/vmware.c
+++ b/arch/x86/kernel/cpu/vmware.c
@@ -49,7 +49,7 @@
 #define VMWARE_CMD_VCPU_RESERVED 31
 
 #define VMWARE_PORT(cmd, eax, ebx, ecx, edx)				\
-	__asm__("inl (%%dx)" :						\
+	__asm__("inl (%%dx), %%eax" :					\
 		"=a"(eax), "=c"(ecx), "=d"(edx), "=b"(ebx) :		\
 		"a"(VMWARE_HYPERVISOR_MAGIC),				\
 		"c"(VMWARE_CMD_##cmd),					\