return emulate_exception(ctxt, NM_VECTOR, 0, false);
}
-static inline void assign_eip_near(struct x86_emulate_ctxt *ctxt, ulong dst)
+static inline int assign_eip_far(struct x86_emulate_ctxt *ctxt, ulong dst,
+ int cs_l)
{
switch (ctxt->op_bytes) {
case 2:
case 4:
ctxt->_eip = (u32)dst;
break;
+#ifdef CONFIG_X86_64
case 8:
+ if ((cs_l && is_noncanonical_address(dst)) ||
+ (!cs_l && (dst >> 32) != 0))
+ return emulate_gp(ctxt, 0);
ctxt->_eip = dst;
break;
+#endif
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 void jmp_rel(struct x86_emulate_ctxt *ctxt, int rel)
+static inline int jmp_rel(struct x86_emulate_ctxt *ctxt, int rel)
{
- assign_eip_near(ctxt, ctxt->_eip + rel);
+ return assign_eip_near(ctxt, ctxt->_eip + rel);
}
static u16 get_segment_selector(struct x86_emulate_ctxt *ctxt, unsigned seg)
}
/* Does not support long mode */
-static int load_segment_descriptor(struct x86_emulate_ctxt *ctxt,
- u16 selector, int seg)
+static int __load_segment_descriptor(struct x86_emulate_ctxt *ctxt,
+ u16 selector, int seg, u8 cpl,
+ struct desc_struct *desc)
{
struct desc_struct seg_desc;
- u8 dpl, rpl, cpl;
+ u8 dpl, rpl;
unsigned err_vec = GP_VECTOR;
u32 err_code = 0;
bool null_selector = !(selector & ~0x3); /* 0000-0003 are null */
rpl = selector & 3;
dpl = seg_desc.dpl;
- cpl = ctxt->ops->cpl(ctxt);
switch (seg) {
case VCPU_SREG_SS:
}
load:
ctxt->ops->set_segment(ctxt, selector, &seg_desc, 0, seg);
+ if (desc)
+ *desc = seg_desc;
return X86EMUL_CONTINUE;
exception:
emulate_exception(ctxt, err_vec, err_code, true);
return X86EMUL_PROPAGATE_FAULT;
}
+static int load_segment_descriptor(struct x86_emulate_ctxt *ctxt,
+ u16 selector, int seg)
+{
+ u8 cpl = ctxt->ops->cpl(ctxt);
+ return __load_segment_descriptor(ctxt, selector, seg, cpl, NULL);
+}
+
static void write_register_operand(struct operand *op)
{
/* The 4-byte case *is* correct: in 64-bit mode we zero-extend. */
static int em_jmp_far(struct x86_emulate_ctxt *ctxt)
{
int rc;
- unsigned short sel;
+ unsigned short sel, old_sel;
+ struct desc_struct old_desc, new_desc;
+ const struct x86_emulate_ops *ops = ctxt->ops;
+ u8 cpl = ctxt->ops->cpl(ctxt);
+
+ /* Assignment of RIP may only fail in 64-bit mode */
+ if (ctxt->mode == X86EMUL_MODE_PROT64)
+ ops->get_segment(ctxt, &old_sel, &old_desc, NULL,
+ VCPU_SREG_CS);
memcpy(&sel, ctxt->src.valptr + ctxt->op_bytes, 2);
- rc = load_segment_descriptor(ctxt, sel, VCPU_SREG_CS);
+ rc = __load_segment_descriptor(ctxt, sel, VCPU_SREG_CS, cpl,
+ &new_desc);
if (rc != X86EMUL_CONTINUE)
return rc;
- ctxt->_eip = 0;
- memcpy(&ctxt->_eip, ctxt->src.valptr, ctxt->op_bytes);
- return X86EMUL_CONTINUE;
+ rc = assign_eip_far(ctxt, ctxt->src.val, new_desc.l);
+ if (rc != X86EMUL_CONTINUE) {
+ WARN_ON(ctxt->mode != X86EMUL_MODE_PROT64);
+ /* assigning eip failed; restore the old cs */
+ ops->set_segment(ctxt, old_sel, &old_desc, 0, VCPU_SREG_CS);
+ return rc;
+ }
+ return rc;
}
static int em_grp1a(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);
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;
+ unsigned long eip, cs;
+ u16 old_cs;
int cpl = ctxt->ops->cpl(ctxt);
+ struct desc_struct old_desc, new_desc;
+ const struct x86_emulate_ops *ops = ctxt->ops;
+
+ if (ctxt->mode == X86EMUL_MODE_PROT64)
+ ops->get_segment(ctxt, &old_cs, &old_desc, NULL,
+ VCPU_SREG_CS);
- rc = emulate_pop(ctxt, &ctxt->_eip, ctxt->op_bytes);
+ rc = emulate_pop(ctxt, &eip, ctxt->op_bytes);
if (rc != X86EMUL_CONTINUE)
return rc;
- if (ctxt->op_bytes == 4)
- ctxt->_eip = (u32)ctxt->_eip;
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);
+ rc = __load_segment_descriptor(ctxt, (u16)cs, VCPU_SREG_CS, 0,
+ &new_desc);
+ if (rc != X86EMUL_CONTINUE)
+ return rc;
+ rc = assign_eip_far(ctxt, eip, new_desc.l);
+ if (rc != X86EMUL_CONTINUE) {
+ WARN_ON(ctxt->mode != X86EMUL_MODE_PROT64);
+ ops->set_segment(ctxt, old_cs, &old_desc, 0, VCPU_SREG_CS);
+ }
return rc;
}
ss->p = 1;
}
+static bool vendor_intel(struct x86_emulate_ctxt *ctxt)
+{
+ u32 eax, ebx, ecx, edx;
+
+ eax = ecx = 0;
+ return ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx)
+ && ebx == X86EMUL_CPUID_VENDOR_GenuineIntel_ebx
+ && ecx == X86EMUL_CPUID_VENDOR_GenuineIntel_ecx
+ && edx == X86EMUL_CPUID_VENDOR_GenuineIntel_edx;
+}
+
static bool em_syscall_is_enabled(struct x86_emulate_ctxt *ctxt)
{
struct x86_emulate_ops *ops = ctxt->ops;
if (ctxt->mode == X86EMUL_MODE_REAL)
return emulate_gp(ctxt, 0);
+ /*
+ * Not recognized on AMD in compat mode (but is recognized in legacy
+ * mode).
+ */
+ if ((ctxt->mode != X86EMUL_MODE_PROT64) && (efer & EFER_LMA)
+ && !vendor_intel(ctxt))
+ return emulate_ud(ctxt);
+
/* XXX sysenter/sysexit have not been tested in 64bit mode.
* Therefore, we inject an #UD.
*/
setup_syscalls_segments(ctxt, &cs, &ss);
ops->get_msr(ctxt, MSR_IA32_SYSENTER_CS, &msr_data);
- switch (ctxt->mode) {
- case X86EMUL_MODE_PROT32:
- if ((msr_data & 0xfffc) == 0x0)
- return emulate_gp(ctxt, 0);
- break;
- case X86EMUL_MODE_PROT64:
- if (msr_data == 0x0)
- return emulate_gp(ctxt, 0);
- break;
- }
+ if ((msr_data & 0xfffc) == 0x0)
+ return emulate_gp(ctxt, 0);
ctxt->eflags &= ~(EFLG_VM | EFLG_IF | EFLG_RF);
- cs_sel = (u16)msr_data;
- cs_sel &= ~SELECTOR_RPL_MASK;
+ cs_sel = (u16)msr_data & ~SELECTOR_RPL_MASK;
ss_sel = cs_sel + 8;
- ss_sel &= ~SELECTOR_RPL_MASK;
- if (ctxt->mode == X86EMUL_MODE_PROT64 || (efer & EFER_LMA)) {
+ if (efer & EFER_LMA) {
cs.d = 0;
cs.l = 1;
}
ops->set_segment(ctxt, ss_sel, &ss, 0, VCPU_SREG_SS);
ops->get_msr(ctxt, MSR_IA32_SYSENTER_EIP, &msr_data);
- ctxt->_eip = msr_data;
+ ctxt->_eip = (efer & EFER_LMA) ? msr_data : (u32)msr_data;
ops->get_msr(ctxt, MSR_IA32_SYSENTER_ESP, &msr_data);
- ctxt->regs[VCPU_REGS_RSP] = msr_data;
+ ctxt->regs[VCPU_REGS_RSP] = (efer & EFER_LMA) ? msr_data :
+ (u32)msr_data;
return X86EMUL_CONTINUE;
}
{
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;
else
usermode = X86EMUL_MODE_PROT32;
+ rcx = ctxt->regs[VCPU_REGS_RCX];
+ rdx = ctxt->regs[VCPU_REGS_RDX];
+
cs.dpl = 3;
ss.dpl = 3;
ops->get_msr(ctxt, MSR_IA32_SYSENTER_CS, &msr_data);
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;
ops->set_segment(ctxt, cs_sel, &cs, 0, VCPU_SREG_CS);
ops->set_segment(ctxt, ss_sel, &ss, 0, VCPU_SREG_SS);
- ctxt->_eip = ctxt->regs[VCPU_REGS_RDX];
- ctxt->regs[VCPU_REGS_RSP] = ctxt->regs[VCPU_REGS_RCX];
+ ctxt->_eip = rdx;
+ ctxt->regs[VCPU_REGS_RSP] = rcx;
return X86EMUL_CONTINUE;
}
struct tss_segment_16 *tss)
{
int ret;
+ u8 cpl;
ctxt->_eip = tss->ip;
ctxt->eflags = tss->flag | 2;
set_segment_selector(ctxt, tss->ss, VCPU_SREG_SS);
set_segment_selector(ctxt, tss->ds, VCPU_SREG_DS);
+ cpl = tss->cs & 3;
+
/*
* Now load segment descriptors. If fault happenes at this stage
* it is handled in a context of new task
*/
- ret = load_segment_descriptor(ctxt, tss->ldt, VCPU_SREG_LDTR);
+ ret = __load_segment_descriptor(ctxt, tss->ldt, VCPU_SREG_LDTR, cpl,
+ NULL);
if (ret != X86EMUL_CONTINUE)
return ret;
- ret = load_segment_descriptor(ctxt, tss->es, VCPU_SREG_ES);
+ ret = __load_segment_descriptor(ctxt, tss->es, VCPU_SREG_ES, cpl,
+ NULL);
if (ret != X86EMUL_CONTINUE)
return ret;
- ret = load_segment_descriptor(ctxt, tss->cs, VCPU_SREG_CS);
+ ret = __load_segment_descriptor(ctxt, tss->cs, VCPU_SREG_CS, cpl,
+ NULL);
if (ret != X86EMUL_CONTINUE)
return ret;
- ret = load_segment_descriptor(ctxt, tss->ss, VCPU_SREG_SS);
+ ret = __load_segment_descriptor(ctxt, tss->ss, VCPU_SREG_SS, cpl,
+ NULL);
if (ret != X86EMUL_CONTINUE)
return ret;
- ret = load_segment_descriptor(ctxt, tss->ds, VCPU_SREG_DS);
+ ret = __load_segment_descriptor(ctxt, tss->ds, VCPU_SREG_DS, cpl,
+ NULL);
if (ret != X86EMUL_CONTINUE)
return ret;
struct tss_segment_32 *tss)
{
int ret;
+ u8 cpl;
if (ctxt->ops->set_cr(ctxt, 3, tss->cr3))
return emulate_gp(ctxt, 0);
/*
* SDM says that segment selectors are loaded before segment
- * descriptors
+ * descriptors. This is important because CPL checks will
+ * use CS.RPL.
*/
set_segment_selector(ctxt, tss->ldt_selector, VCPU_SREG_LDTR);
set_segment_selector(ctxt, tss->es, VCPU_SREG_ES);
set_segment_selector(ctxt, tss->fs, VCPU_SREG_FS);
set_segment_selector(ctxt, tss->gs, VCPU_SREG_GS);
+ cpl = tss->cs & 3;
+
/*
* Now load segment descriptors. If fault happenes at this stage
* it is handled in a context of new task
*/
- ret = load_segment_descriptor(ctxt, tss->ldt_selector, VCPU_SREG_LDTR);
+ ret = __load_segment_descriptor(ctxt, tss->ldt_selector, VCPU_SREG_LDTR,
+ cpl, NULL);
if (ret != X86EMUL_CONTINUE)
return ret;
- ret = load_segment_descriptor(ctxt, tss->es, VCPU_SREG_ES);
+ ret = __load_segment_descriptor(ctxt, tss->es, VCPU_SREG_ES, cpl,
+ NULL);
if (ret != X86EMUL_CONTINUE)
return ret;
- ret = load_segment_descriptor(ctxt, tss->cs, VCPU_SREG_CS);
+ ret = __load_segment_descriptor(ctxt, tss->cs, VCPU_SREG_CS, cpl,
+ NULL);
if (ret != X86EMUL_CONTINUE)
return ret;
- ret = load_segment_descriptor(ctxt, tss->ss, VCPU_SREG_SS);
+ ret = __load_segment_descriptor(ctxt, tss->ss, VCPU_SREG_SS, cpl,
+ NULL);
if (ret != X86EMUL_CONTINUE)
return ret;
- ret = load_segment_descriptor(ctxt, tss->ds, VCPU_SREG_DS);
+ ret = __load_segment_descriptor(ctxt, tss->ds, VCPU_SREG_DS, cpl,
+ NULL);
if (ret != X86EMUL_CONTINUE)
return ret;
- ret = load_segment_descriptor(ctxt, tss->fs, VCPU_SREG_FS);
+ ret = __load_segment_descriptor(ctxt, tss->fs, VCPU_SREG_FS, cpl,
+ NULL);
if (ret != X86EMUL_CONTINUE)
return ret;
- ret = load_segment_descriptor(ctxt, tss->gs, VCPU_SREG_GS);
+ ret = __load_segment_descriptor(ctxt, tss->gs, VCPU_SREG_GS, cpl,
+ NULL);
if (ret != X86EMUL_CONTINUE)
return ret;
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);
}
u16 sel, old_cs;
ulong old_eip;
int rc;
+ struct desc_struct old_desc, new_desc;
+ const struct x86_emulate_ops *ops = ctxt->ops;
+ int cpl = ctxt->ops->cpl(ctxt);
- old_cs = get_segment_selector(ctxt, VCPU_SREG_CS);
old_eip = ctxt->_eip;
+ ops->get_segment(ctxt, &old_cs, &old_desc, NULL, VCPU_SREG_CS);
memcpy(&sel, ctxt->src.valptr + ctxt->op_bytes, 2);
- if (load_segment_descriptor(ctxt, sel, VCPU_SREG_CS))
+ rc = __load_segment_descriptor(ctxt, sel, VCPU_SREG_CS, cpl,
+ &new_desc);
+ if (rc != X86EMUL_CONTINUE)
return X86EMUL_CONTINUE;
- ctxt->_eip = 0;
- memcpy(&ctxt->_eip, ctxt->src.valptr, ctxt->op_bytes);
+ rc = assign_eip_far(ctxt, ctxt->src.val, new_desc.l);
+ if (rc != X86EMUL_CONTINUE)
+ goto fail;
ctxt->src.val = old_cs;
rc = em_push(ctxt);
if (rc != X86EMUL_CONTINUE)
- return rc;
+ goto fail;
ctxt->src.val = old_eip;
- return em_push(ctxt);
+ rc = em_push(ctxt);
+ /* If we failed, we tainted the memory, but the very least we should
+ restore cs */
+ if (rc != X86EMUL_CONTINUE)
+ goto fail;
+ return rc;
+fail:
+ ops->set_segment(ctxt, old_cs, &old_desc, 0, VCPU_SREG_CS);
+ return rc;
+
}
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;
register_address_increment(ctxt, &ctxt->regs[VCPU_REGS_RSP], ctxt->src.val);
static int em_loop(struct x86_emulate_ctxt *ctxt)
{
+ int rc = X86EMUL_CONTINUE;
+
register_address_increment(ctxt, &ctxt->regs[VCPU_REGS_RCX], -1);
if ((address_mask(ctxt, ctxt->regs[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, ctxt->regs[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_cli(struct x86_emulate_ctxt *ctxt)
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;
goto do_io_out;
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 0xec: /* in al,dx */
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);
git.openpandora.org / pandora-kernel.git / blobdiff