On 5/7/14, 5:43 PM, Bandan Das wrote:
Nadav Amit <namit@xxxxxxxxxxxxxxxxx> writes:Relative jumps and calls do the masking according to the operand size, and not according to the address size as the KVM emulator does today. In 64-bit mode, the resulting RIP is always 64-bit. Otherwise it is masked according to the instruction operand-size. Note that when 16-bit address size is used, bits 63:32 are unmodified. Signed-off-by: Nadav Amit <namit@xxxxxxxxxxxxxxxxx> --- arch/x86/kvm/emulate.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 6833b41..e406705 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -506,7 +506,9 @@ static void rsp_increment(struct x86_emulate_ctxt *ctxt, int inc) static inline void jmp_rel(struct x86_emulate_ctxt *ctxt, int rel) { - register_address_increment(ctxt, &ctxt->_eip, rel); + /* 64-bit mode relative jumps are always 64-bit; otherwise mask */ + int op_bytes = ctxt->mode == X86EMUL_MODE_PROT64 ? 8 : ctxt->op_bytes;Just a nit, probably break this up for readability ?
I will make it more readable on the next version. Thanks, Nadav -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
