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Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/include/asm/kvm_emulate.h2
-rw-r--r--arch/x86/kvm/emulate.c5
2 files changed, 5 insertions, 2 deletions
diff --git a/arch/x86/include/asm/kvm_emulate.h b/arch/x86/include/asm/kvm_emulate.h
index b7ed2c42311..7c18e1230f5 100644
--- a/arch/x86/include/asm/kvm_emulate.h
+++ b/arch/x86/include/asm/kvm_emulate.h
@@ -129,7 +129,7 @@ struct decode_cache {
u8 seg_override;
unsigned int d;
unsigned long regs[NR_VCPU_REGS];
- unsigned long eip;
+ unsigned long eip, eip_orig;
/* modrm */
u8 modrm;
u8 modrm_mod;
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index d226dff47d7..7e8faea4651 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -622,6 +622,9 @@ static int do_insn_fetch(struct x86_emulate_ctxt *ctxt,
{
int rc = 0;
+ /* x86 instructions are limited to 15 bytes. */
+ if (eip + size - ctxt->decode.eip_orig > 15)
+ return X86EMUL_UNHANDLEABLE;
eip += ctxt->cs_base;
while (size--) {
rc = do_fetch_insn_byte(ctxt, ops, eip++, dest++);
@@ -880,7 +883,7 @@ x86_decode_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops)
/* Shadow copy of register state. Committed on successful emulation. */
memset(c, 0, sizeof(struct decode_cache));
- c->eip = kvm_rip_read(ctxt->vcpu);
+ c->eip = c->eip_orig = kvm_rip_read(ctxt->vcpu);
ctxt->cs_base = seg_base(ctxt, VCPU_SREG_CS);
memcpy(c->regs, ctxt->vcpu->arch.regs, sizeof c->regs);