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Diffstat (limited to 'arch/x86/kvm/emulate.c')
-rw-r--r--arch/x86/kvm/emulate.c108
1 files changed, 81 insertions, 27 deletions
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 5953dcea752d..4c01f022c6ac 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -663,11 +663,6 @@ static void rsp_increment(struct x86_emulate_ctxt *ctxt, int inc)
masked_increment(reg_rmw(ctxt, VCPU_REGS_RSP), stack_mask(ctxt), inc);
}
-static inline void jmp_rel(struct x86_emulate_ctxt *ctxt, int rel)
-{
- register_address_increment(ctxt, &ctxt->_eip, rel);
-}
-
static u32 desc_limit_scaled(struct desc_struct *desc)
{
u32 limit = get_desc_limit(desc);
@@ -741,6 +736,38 @@ static int emulate_nm(struct x86_emulate_ctxt *ctxt)
return emulate_exception(ctxt, NM_VECTOR, 0, false);
}
+static inline int assign_eip_far(struct x86_emulate_ctxt *ctxt, ulong dst,
+ int cs_l)
+{
+ switch (ctxt->op_bytes) {
+ case 2:
+ ctxt->_eip = (u16)dst;
+ break;
+ case 4:
+ ctxt->_eip = (u32)dst;
+ break;
+ case 8:
+ if ((cs_l && is_noncanonical_address(dst)) ||
+ (!cs_l && (dst & ~(u32)-1)))
+ return emulate_gp(ctxt, 0);
+ ctxt->_eip = dst;
+ break;
+ default:
+ WARN(1, "unsupported eip assignment size\n");
+ }
+ return X86EMUL_CONTINUE;
+}
+
+static inline int assign_eip_near(struct x86_emulate_ctxt *ctxt, ulong dst)
+{
+ return assign_eip_far(ctxt, dst, ctxt->mode == X86EMUL_MODE_PROT64);
+}
+
+static inline int jmp_rel(struct x86_emulate_ctxt *ctxt, int rel)
+{
+ return assign_eip_near(ctxt, ctxt->_eip + rel);
+}
+
static u16 get_segment_selector(struct x86_emulate_ctxt *ctxt, unsigned seg)
{
u16 selector;
@@ -2161,13 +2188,15 @@ static int em_grp45(struct x86_emulate_ctxt *ctxt)
case 2: /* call near abs */ {
long int old_eip;
old_eip = ctxt->_eip;
- ctxt->_eip = ctxt->src.val;
+ rc = assign_eip_near(ctxt, ctxt->src.val);
+ if (rc != X86EMUL_CONTINUE)
+ break;
ctxt->src.val = old_eip;
rc = em_push(ctxt);
break;
}
case 4: /* jmp abs */
- ctxt->_eip = ctxt->src.val;
+ rc = assign_eip_near(ctxt, ctxt->src.val);
break;
case 5: /* jmp far */
rc = em_jmp_far(ctxt);
@@ -2199,16 +2228,21 @@ static int em_cmpxchg8b(struct x86_emulate_ctxt *ctxt)
static int em_ret(struct x86_emulate_ctxt *ctxt)
{
- ctxt->dst.type = OP_REG;
- ctxt->dst.addr.reg = &ctxt->_eip;
- ctxt->dst.bytes = ctxt->op_bytes;
- return em_pop(ctxt);
+ int rc;
+ unsigned long eip;
+
+ rc = emulate_pop(ctxt, &eip, ctxt->op_bytes);
+ if (rc != X86EMUL_CONTINUE)
+ return rc;
+
+ return assign_eip_near(ctxt, eip);
}
static int em_ret_far(struct x86_emulate_ctxt *ctxt)
{
int rc;
unsigned long cs;
+ int cpl = ctxt->ops->cpl(ctxt);
rc = emulate_pop(ctxt, &ctxt->_eip, ctxt->op_bytes);
if (rc != X86EMUL_CONTINUE)
@@ -2218,6 +2252,9 @@ static int em_ret_far(struct x86_emulate_ctxt *ctxt)
rc = emulate_pop(ctxt, &cs, ctxt->op_bytes);
if (rc != X86EMUL_CONTINUE)
return rc;
+ /* Outer-privilege level return is not implemented */
+ if (ctxt->mode >= X86EMUL_MODE_PROT16 && (cs & 3) > cpl)
+ return X86EMUL_UNHANDLEABLE;
rc = load_segment_descriptor(ctxt, (u16)cs, VCPU_SREG_CS);
return rc;
}
@@ -2465,7 +2502,7 @@ static int em_sysexit(struct x86_emulate_ctxt *ctxt)
{
const struct x86_emulate_ops *ops = ctxt->ops;
struct desc_struct cs, ss;
- u64 msr_data;
+ u64 msr_data, rcx, rdx;
int usermode;
u16 cs_sel = 0, ss_sel = 0;
@@ -2481,6 +2518,9 @@ static int em_sysexit(struct x86_emulate_ctxt *ctxt)
else
usermode = X86EMUL_MODE_PROT32;
+ rcx = reg_read(ctxt, VCPU_REGS_RCX);
+ rdx = reg_read(ctxt, VCPU_REGS_RDX);
+
cs.dpl = 3;
ss.dpl = 3;
ops->get_msr(ctxt, MSR_IA32_SYSENTER_CS, &msr_data);
@@ -2498,6 +2538,9 @@ static int em_sysexit(struct x86_emulate_ctxt *ctxt)
ss_sel = cs_sel + 8;
cs.d = 0;
cs.l = 1;
+ if (is_noncanonical_address(rcx) ||
+ is_noncanonical_address(rdx))
+ return emulate_gp(ctxt, 0);
break;
}
cs_sel |= SELECTOR_RPL_MASK;
@@ -2506,8 +2549,8 @@ static int em_sysexit(struct x86_emulate_ctxt *ctxt)
ops->set_segment(ctxt, cs_sel, &cs, 0, VCPU_SREG_CS);
ops->set_segment(ctxt, ss_sel, &ss, 0, VCPU_SREG_SS);
- ctxt->_eip = reg_read(ctxt, VCPU_REGS_RDX);
- *reg_write(ctxt, VCPU_REGS_RSP) = reg_read(ctxt, VCPU_REGS_RCX);
+ ctxt->_eip = rdx;
+ *reg_write(ctxt, VCPU_REGS_RSP) = rcx;
return X86EMUL_CONTINUE;
}
@@ -3046,10 +3089,13 @@ static int em_aad(struct x86_emulate_ctxt *ctxt)
static int em_call(struct x86_emulate_ctxt *ctxt)
{
+ int rc;
long rel = ctxt->src.val;
ctxt->src.val = (unsigned long)ctxt->_eip;
- jmp_rel(ctxt, rel);
+ rc = jmp_rel(ctxt, rel);
+ if (rc != X86EMUL_CONTINUE)
+ return rc;
return em_push(ctxt);
}
@@ -3081,11 +3127,12 @@ static int em_call_far(struct x86_emulate_ctxt *ctxt)
static int em_ret_near_imm(struct x86_emulate_ctxt *ctxt)
{
int rc;
+ unsigned long eip;
- ctxt->dst.type = OP_REG;
- ctxt->dst.addr.reg = &ctxt->_eip;
- ctxt->dst.bytes = ctxt->op_bytes;
- rc = emulate_pop(ctxt, &ctxt->dst.val, ctxt->op_bytes);
+ rc = emulate_pop(ctxt, &eip, ctxt->op_bytes);
+ if (rc != X86EMUL_CONTINUE)
+ return rc;
+ rc = assign_eip_near(ctxt, eip);
if (rc != X86EMUL_CONTINUE)
return rc;
rsp_increment(ctxt, ctxt->src.val);
@@ -3375,20 +3422,24 @@ static int em_lmsw(struct x86_emulate_ctxt *ctxt)
static int em_loop(struct x86_emulate_ctxt *ctxt)
{
+ int rc = X86EMUL_CONTINUE;
+
register_address_increment(ctxt, reg_rmw(ctxt, VCPU_REGS_RCX), -1);
if ((address_mask(ctxt, reg_read(ctxt, VCPU_REGS_RCX)) != 0) &&
(ctxt->b == 0xe2 || test_cc(ctxt->b ^ 0x5, ctxt->eflags)))
- jmp_rel(ctxt, ctxt->src.val);
+ rc = jmp_rel(ctxt, ctxt->src.val);
- return X86EMUL_CONTINUE;
+ return rc;
}
static int em_jcxz(struct x86_emulate_ctxt *ctxt)
{
+ int rc = X86EMUL_CONTINUE;
+
if (address_mask(ctxt, reg_read(ctxt, VCPU_REGS_RCX)) == 0)
- jmp_rel(ctxt, ctxt->src.val);
+ rc = jmp_rel(ctxt, ctxt->src.val);
- return X86EMUL_CONTINUE;
+ return rc;
}
static int em_in(struct x86_emulate_ctxt *ctxt)
@@ -4207,7 +4258,10 @@ static int decode_operand(struct x86_emulate_ctxt *ctxt, struct operand *op,
case OpMem8:
ctxt->memop.bytes = 1;
if (ctxt->memop.type == OP_REG) {
- ctxt->memop.addr.reg = decode_register(ctxt, ctxt->modrm_rm, 1);
+ int highbyte_regs = ctxt->rex_prefix == 0;
+
+ ctxt->memop.addr.reg = decode_register(ctxt, ctxt->modrm_rm,
+ highbyte_regs);
fetch_register_operand(&ctxt->memop);
}
goto mem_common;
@@ -4714,7 +4768,7 @@ special_insn:
break;
case 0x70 ... 0x7f: /* jcc (short) */
if (test_cc(ctxt->b, ctxt->eflags))
- jmp_rel(ctxt, ctxt->src.val);
+ rc = jmp_rel(ctxt, ctxt->src.val);
break;
case 0x8d: /* lea r16/r32, m */
ctxt->dst.val = ctxt->src.addr.mem.ea;
@@ -4743,7 +4797,7 @@ special_insn:
break;
case 0xe9: /* jmp rel */
case 0xeb: /* jmp rel short */
- jmp_rel(ctxt, ctxt->src.val);
+ rc = jmp_rel(ctxt, ctxt->src.val);
ctxt->dst.type = OP_NONE; /* Disable writeback. */
break;
case 0xf4: /* hlt */
@@ -4855,7 +4909,7 @@ twobyte_insn:
break;
case 0x80 ... 0x8f: /* jnz rel, etc*/
if (test_cc(ctxt->b, ctxt->eflags))
- jmp_rel(ctxt, ctxt->src.val);
+ rc = jmp_rel(ctxt, ctxt->src.val);
break;
case 0x90 ... 0x9f: /* setcc r/m8 */
ctxt->dst.val = test_cc(ctxt->b, ctxt->eflags);
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-24 09:31:40 +0000