From 5e1f777d673a7d618087f093d1ca551da118d34b Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Thu, 12 Sep 2013 09:53:11 -0700 Subject: Revert "KVM: X86 emulator: fix source operand decoding for 8bit mov[zs]x instructions" MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This reverts commit 5b5b30580218eae22609989546bac6e44d0eda6e, which was commit 660696d1d16a71e15549ce1bf74953be1592bcd3 upstream. Paul Gortmaker writes: [this patch] introduces the following: arch/x86/kvm/emulate.c: In function ‘decode_operand’: arch/x86/kvm/emulate.c:3974:4: warning: passing argument 1 of ‘decode_register’ makes integer from pointer +without a cast [enabled by default] arch/x86/kvm/emulate.c:789:14: note: expected ‘u8’ but argument is of type ‘struct x86_emulate_ctxt *’ arch/x86/kvm/emulate.c:3974:4: warning: passing argument 2 of ‘decode_register’ makes pointer from integer +without a cast [enabled by default] arch/x86/kvm/emulate.c:789:14: note: expected ‘long unsigned int *’ but argument is of type ‘u8’ Based on the severity of the warnings above, I'm reasonably sure there will be some kind of runtime regressions due to this, but I stopped to investigate the warnings as soon as I saw them, before any run time testing. It happens because mainline v3.7-rc1~113^2~40 (dd856efafe60) does this: -static void *decode_register(u8 modrm_reg, unsigned long *regs, +static void *decode_register(struct x86_emulate_ctxt *ctxt, u8 modrm_reg, Since 660696d1d16a71e1 was only applied to stable 3.4, 3.8, and 3.9 -- and the prerequisite above is in 3.7+, the issue should be limited to 3.4.44+ Reported-by: Paul Gortmaker Acked-by: Paolo Bonzini Cc: Gleb Natapov Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/emulate.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 8c45818c732f..83756223f8aa 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -3737,10 +3737,6 @@ static int decode_operand(struct x86_emulate_ctxt *ctxt, struct operand *op, break; case OpMem8: ctxt->memop.bytes = 1; - if (ctxt->memop.type == OP_REG) { - ctxt->memop.addr.reg = decode_register(ctxt, ctxt->modrm_rm, 1); - fetch_register_operand(&ctxt->memop); - } goto mem_common; case OpMem16: ctxt->memop.bytes = 2; -- cgit v1.2.3