diff options
Diffstat (limited to 'arch/x86/kvm/emulate.c')
| -rw-r--r-- | arch/x86/kvm/emulate.c | 25 |
1 files changed, 18 insertions, 7 deletions
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index c3b07574942f..81dcf7964701 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -741,19 +741,26 @@ static int assign_eip_far(struct x86_emulate_ctxt *ctxt, ulong dst, const struct desc_struct *cs_desc) { enum x86emul_mode mode = ctxt->mode; + int rc; #ifdef CONFIG_X86_64 - if (ctxt->mode >= X86EMUL_MODE_PROT32 && cs_desc->l) { - u64 efer = 0; + if (ctxt->mode >= X86EMUL_MODE_PROT16) { + if (cs_desc->l) { + u64 efer = 0; - ctxt->ops->get_msr(ctxt, MSR_EFER, &efer); - if (efer & EFER_LMA) - mode = X86EMUL_MODE_PROT64; + ctxt->ops->get_msr(ctxt, MSR_EFER, &efer); + if (efer & EFER_LMA) + mode = X86EMUL_MODE_PROT64; + } else + mode = X86EMUL_MODE_PROT32; /* temporary value */ } #endif if (mode == X86EMUL_MODE_PROT16 || mode == X86EMUL_MODE_PROT32) mode = cs_desc->d ? X86EMUL_MODE_PROT32 : X86EMUL_MODE_PROT16; - return assign_eip(ctxt, dst, mode); + rc = assign_eip(ctxt, dst, mode); + if (rc == X86EMUL_CONTINUE) + ctxt->mode = mode; + return rc; } static inline int jmp_rel(struct x86_emulate_ctxt *ctxt, int rel) @@ -3062,6 +3069,7 @@ static int em_call_far(struct x86_emulate_ctxt *ctxt) struct desc_struct old_desc, new_desc; const struct x86_emulate_ops *ops = ctxt->ops; int cpl = ctxt->ops->cpl(ctxt); + enum x86emul_mode prev_mode = ctxt->mode; old_eip = ctxt->_eip; ops->get_segment(ctxt, &old_cs, &old_desc, NULL, VCPU_SREG_CS); @@ -3085,11 +3093,14 @@ static int em_call_far(struct x86_emulate_ctxt *ctxt) rc = em_push(ctxt); /* If we failed, we tainted the memory, but the very least we should restore cs */ - if (rc != X86EMUL_CONTINUE) + if (rc != X86EMUL_CONTINUE) { + pr_warn_once("faulting far call emulation tainted memory\n"); goto fail; + } return rc; fail: ops->set_segment(ctxt, old_cs, &old_desc, 0, VCPU_SREG_CS); + ctxt->mode = prev_mode; return rc; } |