qemu/target/i386/tcg/seg_helper.c

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/*
* x86 segmentation related helpers:
* TSS, interrupts, system calls, jumps and call/task gates, descriptors
*
* Copyright (c) 2003 Fabrice Bellard
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include "qemu/osdep.h"
#include "cpu.h"
#include "qemu/log.h"
#include "exec/helper-proto.h"
#include "exec/exec-all.h"
#include "exec/cpu_ldst.h"
#include "exec/log.h"
#include "helper-tcg.h"
#include "seg_helper.h"
int get_pg_mode(CPUX86State *env)
{
int pg_mode = 0;
if (!(env->cr[0] & CR0_PG_MASK)) {
return 0;
}
if (env->cr[0] & CR0_WP_MASK) {
pg_mode |= PG_MODE_WP;
}
if (env->cr[4] & CR4_PAE_MASK) {
pg_mode |= PG_MODE_PAE;
if (env->efer & MSR_EFER_NXE) {
pg_mode |= PG_MODE_NXE;
}
}
if (env->cr[4] & CR4_PSE_MASK) {
pg_mode |= PG_MODE_PSE;
}
if (env->cr[4] & CR4_SMEP_MASK) {
pg_mode |= PG_MODE_SMEP;
}
if (env->hflags & HF_LMA_MASK) {
pg_mode |= PG_MODE_LMA;
if (env->cr[4] & CR4_PKE_MASK) {
pg_mode |= PG_MODE_PKE;
}
if (env->cr[4] & CR4_PKS_MASK) {
pg_mode |= PG_MODE_PKS;
}
if (env->cr[4] & CR4_LA57_MASK) {
pg_mode |= PG_MODE_LA57;
}
}
return pg_mode;
}
/* return non zero if error */
static inline int load_segment_ra(CPUX86State *env, uint32_t *e1_ptr,
uint32_t *e2_ptr, int selector,
uintptr_t retaddr)
{
SegmentCache *dt;
int index;
target_ulong ptr;
if (selector & 0x4) {
dt = &env->ldt;
} else {
dt = &env->gdt;
}
index = selector & ~7;
if ((index + 7) > dt->limit) {
return -1;
}
ptr = dt->base + index;
*e1_ptr = cpu_ldl_kernel_ra(env, ptr, retaddr);
*e2_ptr = cpu_ldl_kernel_ra(env, ptr + 4, retaddr);
return 0;
}
static inline int load_segment(CPUX86State *env, uint32_t *e1_ptr,
uint32_t *e2_ptr, int selector)
{
return load_segment_ra(env, e1_ptr, e2_ptr, selector, 0);
}
static inline unsigned int get_seg_limit(uint32_t e1, uint32_t e2)
{
unsigned int limit;
limit = (e1 & 0xffff) | (e2 & 0x000f0000);
if (e2 & DESC_G_MASK) {
limit = (limit << 12) | 0xfff;
}
return limit;
}
static inline uint32_t get_seg_base(uint32_t e1, uint32_t e2)
{
return (e1 >> 16) | ((e2 & 0xff) << 16) | (e2 & 0xff000000);
}
static inline void load_seg_cache_raw_dt(SegmentCache *sc, uint32_t e1,
uint32_t e2)
{
sc->base = get_seg_base(e1, e2);
sc->limit = get_seg_limit(e1, e2);
sc->flags = e2;
}
/* init the segment cache in vm86 mode. */
static inline void load_seg_vm(CPUX86State *env, int seg, int selector)
{
selector &= 0xffff;
cpu_x86_load_seg_cache(env, seg, selector, (selector << 4), 0xffff,
DESC_P_MASK | DESC_S_MASK | DESC_W_MASK |
DESC_A_MASK | (3 << DESC_DPL_SHIFT));
}
static inline void get_ss_esp_from_tss(CPUX86State *env, uint32_t *ss_ptr,
uint32_t *esp_ptr, int dpl,
uintptr_t retaddr)
{
X86CPU *cpu = env_archcpu(env);
int type, index, shift;
#if 0
{
int i;
printf("TR: base=%p limit=%x\n", env->tr.base, env->tr.limit);
for (i = 0; i < env->tr.limit; i++) {
printf("%02x ", env->tr.base[i]);
if ((i & 7) == 7) {
printf("\n");
}
}
printf("\n");
}
#endif
if (!(env->tr.flags & DESC_P_MASK)) {
cpu_abort(CPU(cpu), "invalid tss");
}
type = (env->tr.flags >> DESC_TYPE_SHIFT) & 0xf;
if ((type & 7) != 1) {
cpu_abort(CPU(cpu), "invalid tss type");
}
shift = type >> 3;
index = (dpl * 4 + 2) << shift;
if (index + (4 << shift) - 1 > env->tr.limit) {
raise_exception_err_ra(env, EXCP0A_TSS, env->tr.selector & 0xfffc, retaddr);
}
if (shift == 0) {
*esp_ptr = cpu_lduw_kernel_ra(env, env->tr.base + index, retaddr);
*ss_ptr = cpu_lduw_kernel_ra(env, env->tr.base + index + 2, retaddr);
} else {
*esp_ptr = cpu_ldl_kernel_ra(env, env->tr.base + index, retaddr);
*ss_ptr = cpu_lduw_kernel_ra(env, env->tr.base + index + 4, retaddr);
}
}
static void tss_load_seg(CPUX86State *env, X86Seg seg_reg, int selector,
int cpl, uintptr_t retaddr)
{
uint32_t e1, e2;
int rpl, dpl;
if ((selector & 0xfffc) != 0) {
if (load_segment_ra(env, &e1, &e2, selector, retaddr) != 0) {
raise_exception_err_ra(env, EXCP0A_TSS, selector & 0xfffc, retaddr);
}
if (!(e2 & DESC_S_MASK)) {
raise_exception_err_ra(env, EXCP0A_TSS, selector & 0xfffc, retaddr);
}
rpl = selector & 3;
dpl = (e2 >> DESC_DPL_SHIFT) & 3;
if (seg_reg == R_CS) {
if (!(e2 & DESC_CS_MASK)) {
raise_exception_err_ra(env, EXCP0A_TSS, selector & 0xfffc, retaddr);
}
if (dpl != rpl) {
raise_exception_err_ra(env, EXCP0A_TSS, selector & 0xfffc, retaddr);
}
} else if (seg_reg == R_SS) {
/* SS must be writable data */
if ((e2 & DESC_CS_MASK) || !(e2 & DESC_W_MASK)) {
raise_exception_err_ra(env, EXCP0A_TSS, selector & 0xfffc, retaddr);
}
if (dpl != cpl || dpl != rpl) {
raise_exception_err_ra(env, EXCP0A_TSS, selector & 0xfffc, retaddr);
}
} else {
/* not readable code */
if ((e2 & DESC_CS_MASK) && !(e2 & DESC_R_MASK)) {
raise_exception_err_ra(env, EXCP0A_TSS, selector & 0xfffc, retaddr);
}
/* if data or non conforming code, checks the rights */
if (((e2 >> DESC_TYPE_SHIFT) & 0xf) < 12) {
if (dpl < cpl || dpl < rpl) {
raise_exception_err_ra(env, EXCP0A_TSS, selector & 0xfffc, retaddr);
}
}
}
if (!(e2 & DESC_P_MASK)) {
raise_exception_err_ra(env, EXCP0B_NOSEG, selector & 0xfffc, retaddr);
}
cpu_x86_load_seg_cache(env, seg_reg, selector,
get_seg_base(e1, e2),
get_seg_limit(e1, e2),
e2);
} else {
if (seg_reg == R_SS || seg_reg == R_CS) {
raise_exception_err_ra(env, EXCP0A_TSS, selector & 0xfffc, retaddr);
}
}
}
static void tss_set_busy(CPUX86State *env, int tss_selector, bool value,
uintptr_t retaddr)
{
target_ulong ptr = env->gdt.base + (tss_selector & ~7);
uint32_t e2 = cpu_ldl_kernel_ra(env, ptr + 4, retaddr);
if (value) {
e2 |= DESC_TSS_BUSY_MASK;
} else {
e2 &= ~DESC_TSS_BUSY_MASK;
}
cpu_stl_kernel_ra(env, ptr + 4, e2, retaddr);
}
#define SWITCH_TSS_JMP 0
#define SWITCH_TSS_IRET 1
#define SWITCH_TSS_CALL 2
/* return 0 if switching to a 16-bit selector */
static int switch_tss_ra(CPUX86State *env, int tss_selector,
uint32_t e1, uint32_t e2, int source,
uint32_t next_eip, uintptr_t retaddr)
{
int tss_limit, tss_limit_max, type, old_tss_limit_max, old_type, v1, v2, i;
target_ulong tss_base;
uint32_t new_regs[8], new_segs[6];
uint32_t new_eflags, new_eip, new_cr3, new_ldt, new_trap;
uint32_t old_eflags, eflags_mask;
SegmentCache *dt;
int index;
target_ulong ptr;
type = (e2 >> DESC_TYPE_SHIFT) & 0xf;
LOG_PCALL("switch_tss: sel=0x%04x type=%d src=%d\n", tss_selector, type,
source);
/* if task gate, we read the TSS segment and we load it */
if (type == 5) {
if (!(e2 & DESC_P_MASK)) {
raise_exception_err_ra(env, EXCP0B_NOSEG, tss_selector & 0xfffc, retaddr);
}
tss_selector = e1 >> 16;
if (tss_selector & 4) {
raise_exception_err_ra(env, EXCP0A_TSS, tss_selector & 0xfffc, retaddr);
}
if (load_segment_ra(env, &e1, &e2, tss_selector, retaddr) != 0) {
raise_exception_err_ra(env, EXCP0D_GPF, tss_selector & 0xfffc, retaddr);
}
if (e2 & DESC_S_MASK) {
raise_exception_err_ra(env, EXCP0D_GPF, tss_selector & 0xfffc, retaddr);
}
type = (e2 >> DESC_TYPE_SHIFT) & 0xf;
if ((type & 7) != 1) {
raise_exception_err_ra(env, EXCP0D_GPF, tss_selector & 0xfffc, retaddr);
}
}
if (!(e2 & DESC_P_MASK)) {
raise_exception_err_ra(env, EXCP0B_NOSEG, tss_selector & 0xfffc, retaddr);
}
if (type & 8) {
tss_limit_max = 103;
} else {
tss_limit_max = 43;
}
tss_limit = get_seg_limit(e1, e2);
tss_base = get_seg_base(e1, e2);
if ((tss_selector & 4) != 0 ||
tss_limit < tss_limit_max) {
raise_exception_err_ra(env, EXCP0A_TSS, tss_selector & 0xfffc, retaddr);
}
old_type = (env->tr.flags >> DESC_TYPE_SHIFT) & 0xf;
if (old_type & 8) {
old_tss_limit_max = 103;
} else {
old_tss_limit_max = 43;
}
/* read all the registers from the new TSS */
if (type & 8) {
/* 32 bit */
new_cr3 = cpu_ldl_kernel_ra(env, tss_base + 0x1c, retaddr);
new_eip = cpu_ldl_kernel_ra(env, tss_base + 0x20, retaddr);
new_eflags = cpu_ldl_kernel_ra(env, tss_base + 0x24, retaddr);
for (i = 0; i < 8; i++) {
new_regs[i] = cpu_ldl_kernel_ra(env, tss_base + (0x28 + i * 4),
retaddr);
}
for (i = 0; i < 6; i++) {
new_segs[i] = cpu_lduw_kernel_ra(env, tss_base + (0x48 + i * 4),
retaddr);
}
new_ldt = cpu_lduw_kernel_ra(env, tss_base + 0x60, retaddr);
new_trap = cpu_ldl_kernel_ra(env, tss_base + 0x64, retaddr);
} else {
/* 16 bit */
new_cr3 = 0;
new_eip = cpu_lduw_kernel_ra(env, tss_base + 0x0e, retaddr);
new_eflags = cpu_lduw_kernel_ra(env, tss_base + 0x10, retaddr);
for (i = 0; i < 8; i++) {
new_regs[i] = cpu_lduw_kernel_ra(env, tss_base + (0x12 + i * 2), retaddr);
}
for (i = 0; i < 4; i++) {
new_segs[i] = cpu_lduw_kernel_ra(env, tss_base + (0x22 + i * 2),
retaddr);
}
new_ldt = cpu_lduw_kernel_ra(env, tss_base + 0x2a, retaddr);
new_segs[R_FS] = 0;
new_segs[R_GS] = 0;
new_trap = 0;
}
/* XXX: avoid a compiler warning, see
http://support.amd.com/us/Processor_TechDocs/24593.pdf
chapters 12.2.5 and 13.2.4 on how to implement TSS Trap bit */
(void)new_trap;
/* NOTE: we must avoid memory exceptions during the task switch,
so we make dummy accesses before */
/* XXX: it can still fail in some cases, so a bigger hack is
necessary to valid the TLB after having done the accesses */
v1 = cpu_ldub_kernel_ra(env, env->tr.base, retaddr);
v2 = cpu_ldub_kernel_ra(env, env->tr.base + old_tss_limit_max, retaddr);
cpu_stb_kernel_ra(env, env->tr.base, v1, retaddr);
cpu_stb_kernel_ra(env, env->tr.base + old_tss_limit_max, v2, retaddr);
/* clear busy bit (it is restartable) */
if (source == SWITCH_TSS_JMP || source == SWITCH_TSS_IRET) {
tss_set_busy(env, env->tr.selector, 0, retaddr);
}
old_eflags = cpu_compute_eflags(env);
if (source == SWITCH_TSS_IRET) {
old_eflags &= ~NT_MASK;
}
/* save the current state in the old TSS */
if (old_type & 8) {
/* 32 bit */
cpu_stl_kernel_ra(env, env->tr.base + 0x20, next_eip, retaddr);
cpu_stl_kernel_ra(env, env->tr.base + 0x24, old_eflags, retaddr);
cpu_stl_kernel_ra(env, env->tr.base + (0x28 + 0 * 4), env->regs[R_EAX], retaddr);
cpu_stl_kernel_ra(env, env->tr.base + (0x28 + 1 * 4), env->regs[R_ECX], retaddr);
cpu_stl_kernel_ra(env, env->tr.base + (0x28 + 2 * 4), env->regs[R_EDX], retaddr);
cpu_stl_kernel_ra(env, env->tr.base + (0x28 + 3 * 4), env->regs[R_EBX], retaddr);
cpu_stl_kernel_ra(env, env->tr.base + (0x28 + 4 * 4), env->regs[R_ESP], retaddr);
cpu_stl_kernel_ra(env, env->tr.base + (0x28 + 5 * 4), env->regs[R_EBP], retaddr);
cpu_stl_kernel_ra(env, env->tr.base + (0x28 + 6 * 4), env->regs[R_ESI], retaddr);
cpu_stl_kernel_ra(env, env->tr.base + (0x28 + 7 * 4), env->regs[R_EDI], retaddr);
for (i = 0; i < 6; i++) {
cpu_stw_kernel_ra(env, env->tr.base + (0x48 + i * 4),
env->segs[i].selector, retaddr);
}
} else {
/* 16 bit */
cpu_stw_kernel_ra(env, env->tr.base + 0x0e, next_eip, retaddr);
cpu_stw_kernel_ra(env, env->tr.base + 0x10, old_eflags, retaddr);
cpu_stw_kernel_ra(env, env->tr.base + (0x12 + 0 * 2), env->regs[R_EAX], retaddr);
cpu_stw_kernel_ra(env, env->tr.base + (0x12 + 1 * 2), env->regs[R_ECX], retaddr);
cpu_stw_kernel_ra(env, env->tr.base + (0x12 + 2 * 2), env->regs[R_EDX], retaddr);
cpu_stw_kernel_ra(env, env->tr.base + (0x12 + 3 * 2), env->regs[R_EBX], retaddr);
cpu_stw_kernel_ra(env, env->tr.base + (0x12 + 4 * 2), env->regs[R_ESP], retaddr);
cpu_stw_kernel_ra(env, env->tr.base + (0x12 + 5 * 2), env->regs[R_EBP], retaddr);
cpu_stw_kernel_ra(env, env->tr.base + (0x12 + 6 * 2), env->regs[R_ESI], retaddr);
cpu_stw_kernel_ra(env, env->tr.base + (0x12 + 7 * 2), env->regs[R_EDI], retaddr);
for (i = 0; i < 4; i++) {
cpu_stw_kernel_ra(env, env->tr.base + (0x22 + i * 2),
env->segs[i].selector, retaddr);
}
}
/* now if an exception occurs, it will occurs in the next task
context */
if (source == SWITCH_TSS_CALL) {
cpu_stw_kernel_ra(env, tss_base, env->tr.selector, retaddr);
new_eflags |= NT_MASK;
}
/* set busy bit */
if (source == SWITCH_TSS_JMP || source == SWITCH_TSS_CALL) {
tss_set_busy(env, tss_selector, 1, retaddr);
}
/* set the new CPU state */
/* from this point, any exception which occurs can give problems */
env->cr[0] |= CR0_TS_MASK;
env->hflags |= HF_TS_MASK;
env->tr.selector = tss_selector;
env->tr.base = tss_base;
env->tr.limit = tss_limit;
env->tr.flags = e2 & ~DESC_TSS_BUSY_MASK;
if ((type & 8) && (env->cr[0] & CR0_PG_MASK)) {
cpu_x86_update_cr3(env, new_cr3);
}
/* load all registers without an exception, then reload them with
possible exception */
env->eip = new_eip;
eflags_mask = TF_MASK | AC_MASK | ID_MASK |
IF_MASK | IOPL_MASK | VM_MASK | RF_MASK | NT_MASK;
if (type & 8) {
cpu_load_eflags(env, new_eflags, eflags_mask);
for (i = 0; i < 8; i++) {
env->regs[i] = new_regs[i];
}
} else {
cpu_load_eflags(env, new_eflags, eflags_mask & 0xffff);
for (i = 0; i < 8; i++) {
env->regs[i] = (env->regs[i] & 0xffff0000) | new_regs[i];
}
}
if (new_eflags & VM_MASK) {
for (i = 0; i < 6; i++) {
load_seg_vm(env, i, new_segs[i]);
}
} else {
/* first just selectors as the rest may trigger exceptions */
for (i = 0; i < 6; i++) {
cpu_x86_load_seg_cache(env, i, new_segs[i], 0, 0, 0);
}
}
env->ldt.selector = new_ldt & ~4;
env->ldt.base = 0;
env->ldt.limit = 0;
env->ldt.flags = 0;
/* load the LDT */
if (new_ldt & 4) {
raise_exception_err_ra(env, EXCP0A_TSS, new_ldt & 0xfffc, retaddr);
}
if ((new_ldt & 0xfffc) != 0) {
dt = &env->gdt;
index = new_ldt & ~7;
if ((index + 7) > dt->limit) {
raise_exception_err_ra(env, EXCP0A_TSS, new_ldt & 0xfffc, retaddr);
}
ptr = dt->base + index;
e1 = cpu_ldl_kernel_ra(env, ptr, retaddr);
e2 = cpu_ldl_kernel_ra(env, ptr + 4, retaddr);
if ((e2 & DESC_S_MASK) || ((e2 >> DESC_TYPE_SHIFT) & 0xf) != 2) {
raise_exception_err_ra(env, EXCP0A_TSS, new_ldt & 0xfffc, retaddr);
}
if (!(e2 & DESC_P_MASK)) {
raise_exception_err_ra(env, EXCP0A_TSS, new_ldt & 0xfffc, retaddr);
}
load_seg_cache_raw_dt(&env->ldt, e1, e2);
}
/* load the segments */
if (!(new_eflags & VM_MASK)) {
int cpl = new_segs[R_CS] & 3;
tss_load_seg(env, R_CS, new_segs[R_CS], cpl, retaddr);
tss_load_seg(env, R_SS, new_segs[R_SS], cpl, retaddr);
tss_load_seg(env, R_ES, new_segs[R_ES], cpl, retaddr);
tss_load_seg(env, R_DS, new_segs[R_DS], cpl, retaddr);
tss_load_seg(env, R_FS, new_segs[R_FS], cpl, retaddr);
tss_load_seg(env, R_GS, new_segs[R_GS], cpl, retaddr);
}
/* check that env->eip is in the CS segment limits */
if (new_eip > env->segs[R_CS].limit) {
/* XXX: different exception if CALL? */
raise_exception_err_ra(env, EXCP0D_GPF, 0, retaddr);
}
#ifndef CONFIG_USER_ONLY
/* reset local breakpoints */
if (env->dr[7] & DR7_LOCAL_BP_MASK) {
cpu_x86_update_dr7(env, env->dr[7] & ~DR7_LOCAL_BP_MASK);
}
#endif
return type >> 3;
}
static int switch_tss(CPUX86State *env, int tss_selector,
uint32_t e1, uint32_t e2, int source,
uint32_t next_eip)
{
return switch_tss_ra(env, tss_selector, e1, e2, source, next_eip, 0);
}
static inline unsigned int get_sp_mask(unsigned int e2)
{
#ifdef TARGET_X86_64
if (e2 & DESC_L_MASK) {
return 0;
} else
#endif
if (e2 & DESC_B_MASK) {
return 0xffffffff;
} else {
return 0xffff;
}
}
int exception_has_error_code(int intno)
{
switch (intno) {
case 8:
case 10:
case 11:
case 12:
case 13:
case 14:
case 17:
return 1;
}
return 0;
}
#ifdef TARGET_X86_64
#define SET_ESP(val, sp_mask) \
do { \
if ((sp_mask) == 0xffff) { \
env->regs[R_ESP] = (env->regs[R_ESP] & ~0xffff) | \
((val) & 0xffff); \
} else if ((sp_mask) == 0xffffffffLL) { \
env->regs[R_ESP] = (uint32_t)(val); \
} else { \
env->regs[R_ESP] = (val); \
} \
} while (0)
#else
#define SET_ESP(val, sp_mask) \
do { \
env->regs[R_ESP] = (env->regs[R_ESP] & ~(sp_mask)) | \
((val) & (sp_mask)); \
} while (0)
#endif
/* in 64-bit machines, this can overflow. So this segment addition macro
* can be used to trim the value to 32-bit whenever needed */
#define SEG_ADDL(ssp, sp, sp_mask) ((uint32_t)((ssp) + (sp & (sp_mask))))
/* XXX: add a is_user flag to have proper security support */
#define PUSHW_RA(ssp, sp, sp_mask, val, ra) \
{ \
sp -= 2; \
cpu_stw_kernel_ra(env, (ssp) + (sp & (sp_mask)), (val), ra); \
}
#define PUSHL_RA(ssp, sp, sp_mask, val, ra) \
{ \
sp -= 4; \
cpu_stl_kernel_ra(env, SEG_ADDL(ssp, sp, sp_mask), (uint32_t)(val), ra); \
}
#define POPW_RA(ssp, sp, sp_mask, val, ra) \
{ \
val = cpu_lduw_kernel_ra(env, (ssp) + (sp & (sp_mask)), ra); \
sp += 2; \
}
#define POPL_RA(ssp, sp, sp_mask, val, ra) \
{ \
val = (uint32_t)cpu_ldl_kernel_ra(env, SEG_ADDL(ssp, sp, sp_mask), ra); \
sp += 4; \
}
#define PUSHW(ssp, sp, sp_mask, val) PUSHW_RA(ssp, sp, sp_mask, val, 0)
#define PUSHL(ssp, sp, sp_mask, val) PUSHL_RA(ssp, sp, sp_mask, val, 0)
#define POPW(ssp, sp, sp_mask, val) POPW_RA(ssp, sp, sp_mask, val, 0)
#define POPL(ssp, sp, sp_mask, val) POPL_RA(ssp, sp, sp_mask, val, 0)
/* protected mode interrupt */
static void do_interrupt_protected(CPUX86State *env, int intno, int is_int,
int error_code, unsigned int next_eip,
int is_hw)
{
SegmentCache *dt;
target_ulong ptr, ssp;
int type, dpl, selector, ss_dpl, cpl;
int has_error_code, new_stack, shift;
uint32_t e1, e2, offset, ss = 0, esp, ss_e1 = 0, ss_e2 = 0;
uint32_t old_eip, sp_mask;
int vm86 = env->eflags & VM_MASK;
has_error_code = 0;
if (!is_int && !is_hw) {
has_error_code = exception_has_error_code(intno);
}
if (is_int) {
old_eip = next_eip;
} else {
old_eip = env->eip;
}
dt = &env->idt;
if (intno * 8 + 7 > dt->limit) {
raise_exception_err(env, EXCP0D_GPF, intno * 8 + 2);
}
ptr = dt->base + intno * 8;
e1 = cpu_ldl_kernel(env, ptr);
e2 = cpu_ldl_kernel(env, ptr + 4);
/* check gate type */
type = (e2 >> DESC_TYPE_SHIFT) & 0x1f;
switch (type) {
case 5: /* task gate */
target/i386: Check privilege level for protected mode 'int N' task gate When the 'int N' instruction is executed in protected mode, the pseudocode in the architecture manual specifies that we need to check: * vector number within IDT limits * selected IDT descriptor is a valid type (interrupt, trap or task gate) * if this was a software interrupt then gate DPL < CPL The way we had structured the code meant that the privilege check for software interrupts ended up not in the code path taken for task gate handling, because all of the task gate handling code was in the 'case 5' of the switch which was checking "is this descriptor a valid type". Move the task gate handling code out of that switch (so that it is now purely doing the "valid type?" check) and below the software interrupt privilege check. The effect of this missing check was that in a guest userspace binary executing 'int 8' would cause a guest kernel panic rather than the userspace binary being handed a SEGV. This is essentially the same bug fixed in VirtualBox in 2012: https://www.halfdog.net/Security/2012/VirtualBoxSoftwareInterrupt0x8GuestCrash/ Note that for QEMU this is not a security issue because it is only present when using TCG. Fixes: https://bugs.launchpad.net/qemu/+bug/1813201 Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Message-Id: <20201121224445.16236-1-peter.maydell@linaro.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
2020-11-22 01:44:45 +03:00
case 6: /* 286 interrupt gate */
case 7: /* 286 trap gate */
case 14: /* 386 interrupt gate */
case 15: /* 386 trap gate */
break;
default:
raise_exception_err(env, EXCP0D_GPF, intno * 8 + 2);
break;
}
dpl = (e2 >> DESC_DPL_SHIFT) & 3;
cpl = env->hflags & HF_CPL_MASK;
/* check privilege if software int */
if (is_int && dpl < cpl) {
raise_exception_err(env, EXCP0D_GPF, intno * 8 + 2);
}
if (type == 5) {
/* task gate */
/* must do that check here to return the correct error code */
if (!(e2 & DESC_P_MASK)) {
raise_exception_err(env, EXCP0B_NOSEG, intno * 8 + 2);
}
shift = switch_tss(env, intno * 8, e1, e2, SWITCH_TSS_CALL, old_eip);
if (has_error_code) {
uint32_t mask;
/* push the error code */
if (env->segs[R_SS].flags & DESC_B_MASK) {
mask = 0xffffffff;
} else {
mask = 0xffff;
}
esp = (env->regs[R_ESP] - (2 << shift)) & mask;
ssp = env->segs[R_SS].base + esp;
if (shift) {
cpu_stl_kernel(env, ssp, error_code);
} else {
cpu_stw_kernel(env, ssp, error_code);
}
SET_ESP(esp, mask);
}
return;
}
target/i386: Check privilege level for protected mode 'int N' task gate When the 'int N' instruction is executed in protected mode, the pseudocode in the architecture manual specifies that we need to check: * vector number within IDT limits * selected IDT descriptor is a valid type (interrupt, trap or task gate) * if this was a software interrupt then gate DPL < CPL The way we had structured the code meant that the privilege check for software interrupts ended up not in the code path taken for task gate handling, because all of the task gate handling code was in the 'case 5' of the switch which was checking "is this descriptor a valid type". Move the task gate handling code out of that switch (so that it is now purely doing the "valid type?" check) and below the software interrupt privilege check. The effect of this missing check was that in a guest userspace binary executing 'int 8' would cause a guest kernel panic rather than the userspace binary being handed a SEGV. This is essentially the same bug fixed in VirtualBox in 2012: https://www.halfdog.net/Security/2012/VirtualBoxSoftwareInterrupt0x8GuestCrash/ Note that for QEMU this is not a security issue because it is only present when using TCG. Fixes: https://bugs.launchpad.net/qemu/+bug/1813201 Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Message-Id: <20201121224445.16236-1-peter.maydell@linaro.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
2020-11-22 01:44:45 +03:00
/* Otherwise, trap or interrupt gate */
/* check valid bit */
if (!(e2 & DESC_P_MASK)) {
raise_exception_err(env, EXCP0B_NOSEG, intno * 8 + 2);
}
selector = e1 >> 16;
offset = (e2 & 0xffff0000) | (e1 & 0x0000ffff);
if ((selector & 0xfffc) == 0) {
raise_exception_err(env, EXCP0D_GPF, 0);
}
if (load_segment(env, &e1, &e2, selector) != 0) {
raise_exception_err(env, EXCP0D_GPF, selector & 0xfffc);
}
if (!(e2 & DESC_S_MASK) || !(e2 & (DESC_CS_MASK))) {
raise_exception_err(env, EXCP0D_GPF, selector & 0xfffc);
}
dpl = (e2 >> DESC_DPL_SHIFT) & 3;
if (dpl > cpl) {
raise_exception_err(env, EXCP0D_GPF, selector & 0xfffc);
}
if (!(e2 & DESC_P_MASK)) {
raise_exception_err(env, EXCP0B_NOSEG, selector & 0xfffc);
}
if (e2 & DESC_C_MASK) {
dpl = cpl;
}
if (dpl < cpl) {
/* to inner privilege */
get_ss_esp_from_tss(env, &ss, &esp, dpl, 0);
if ((ss & 0xfffc) == 0) {
raise_exception_err(env, EXCP0A_TSS, ss & 0xfffc);
}
if ((ss & 3) != dpl) {
raise_exception_err(env, EXCP0A_TSS, ss & 0xfffc);
}
if (load_segment(env, &ss_e1, &ss_e2, ss) != 0) {
raise_exception_err(env, EXCP0A_TSS, ss & 0xfffc);
}
ss_dpl = (ss_e2 >> DESC_DPL_SHIFT) & 3;
if (ss_dpl != dpl) {
raise_exception_err(env, EXCP0A_TSS, ss & 0xfffc);
}
if (!(ss_e2 & DESC_S_MASK) ||
(ss_e2 & DESC_CS_MASK) ||
!(ss_e2 & DESC_W_MASK)) {
raise_exception_err(env, EXCP0A_TSS, ss & 0xfffc);
}
if (!(ss_e2 & DESC_P_MASK)) {
raise_exception_err(env, EXCP0A_TSS, ss & 0xfffc);
}
new_stack = 1;
sp_mask = get_sp_mask(ss_e2);
ssp = get_seg_base(ss_e1, ss_e2);
} else {
/* to same privilege */
if (vm86) {
raise_exception_err(env, EXCP0D_GPF, selector & 0xfffc);
}
new_stack = 0;
sp_mask = get_sp_mask(env->segs[R_SS].flags);
ssp = env->segs[R_SS].base;
esp = env->regs[R_ESP];
}
shift = type >> 3;
#if 0
/* XXX: check that enough room is available */
push_size = 6 + (new_stack << 2) + (has_error_code << 1);
if (vm86) {
push_size += 8;
}
push_size <<= shift;
#endif
if (shift == 1) {
if (new_stack) {
if (vm86) {
PUSHL(ssp, esp, sp_mask, env->segs[R_GS].selector);
PUSHL(ssp, esp, sp_mask, env->segs[R_FS].selector);
PUSHL(ssp, esp, sp_mask, env->segs[R_DS].selector);
PUSHL(ssp, esp, sp_mask, env->segs[R_ES].selector);
}
PUSHL(ssp, esp, sp_mask, env->segs[R_SS].selector);
PUSHL(ssp, esp, sp_mask, env->regs[R_ESP]);
}
PUSHL(ssp, esp, sp_mask, cpu_compute_eflags(env));
PUSHL(ssp, esp, sp_mask, env->segs[R_CS].selector);
PUSHL(ssp, esp, sp_mask, old_eip);
if (has_error_code) {
PUSHL(ssp, esp, sp_mask, error_code);
}
} else {
if (new_stack) {
if (vm86) {
PUSHW(ssp, esp, sp_mask, env->segs[R_GS].selector);
PUSHW(ssp, esp, sp_mask, env->segs[R_FS].selector);
PUSHW(ssp, esp, sp_mask, env->segs[R_DS].selector);
PUSHW(ssp, esp, sp_mask, env->segs[R_ES].selector);
}
PUSHW(ssp, esp, sp_mask, env->segs[R_SS].selector);
PUSHW(ssp, esp, sp_mask, env->regs[R_ESP]);
}
PUSHW(ssp, esp, sp_mask, cpu_compute_eflags(env));
PUSHW(ssp, esp, sp_mask, env->segs[R_CS].selector);
PUSHW(ssp, esp, sp_mask, old_eip);
if (has_error_code) {
PUSHW(ssp, esp, sp_mask, error_code);
}
}
/* interrupt gate clear IF mask */
if ((type & 1) == 0) {
env->eflags &= ~IF_MASK;
}
env->eflags &= ~(TF_MASK | VM_MASK | RF_MASK | NT_MASK);
if (new_stack) {
if (vm86) {
cpu_x86_load_seg_cache(env, R_ES, 0, 0, 0, 0);
cpu_x86_load_seg_cache(env, R_DS, 0, 0, 0, 0);
cpu_x86_load_seg_cache(env, R_FS, 0, 0, 0, 0);
cpu_x86_load_seg_cache(env, R_GS, 0, 0, 0, 0);
}
ss = (ss & ~3) | dpl;
cpu_x86_load_seg_cache(env, R_SS, ss,
ssp, get_seg_limit(ss_e1, ss_e2), ss_e2);
}
SET_ESP(esp, sp_mask);
selector = (selector & ~3) | dpl;
cpu_x86_load_seg_cache(env, R_CS, selector,
get_seg_base(e1, e2),
get_seg_limit(e1, e2),
e2);
env->eip = offset;
}
#ifdef TARGET_X86_64
#define PUSHQ_RA(sp, val, ra) \
{ \
sp -= 8; \
cpu_stq_kernel_ra(env, sp, (val), ra); \
}
#define POPQ_RA(sp, val, ra) \
{ \
val = cpu_ldq_kernel_ra(env, sp, ra); \
sp += 8; \
}
#define PUSHQ(sp, val) PUSHQ_RA(sp, val, 0)
#define POPQ(sp, val) POPQ_RA(sp, val, 0)
static inline target_ulong get_rsp_from_tss(CPUX86State *env, int level)
{
X86CPU *cpu = env_archcpu(env);
int index, pg_mode;
target_ulong rsp;
int32_t sext;
#if 0
printf("TR: base=" TARGET_FMT_lx " limit=%x\n",
env->tr.base, env->tr.limit);
#endif
if (!(env->tr.flags & DESC_P_MASK)) {
cpu_abort(CPU(cpu), "invalid tss");
}
index = 8 * level + 4;
if ((index + 7) > env->tr.limit) {
raise_exception_err(env, EXCP0A_TSS, env->tr.selector & 0xfffc);
}
rsp = cpu_ldq_kernel(env, env->tr.base + index);
/* test virtual address sign extension */
pg_mode = get_pg_mode(env);
sext = (int64_t)rsp >> (pg_mode & PG_MODE_LA57 ? 56 : 47);
if (sext != 0 && sext != -1) {
raise_exception_err(env, EXCP0C_STACK, 0);
}
return rsp;
}
/* 64 bit interrupt */
static void do_interrupt64(CPUX86State *env, int intno, int is_int,
int error_code, target_ulong next_eip, int is_hw)
{
SegmentCache *dt;
target_ulong ptr;
int type, dpl, selector, cpl, ist;
int has_error_code, new_stack;
uint32_t e1, e2, e3, ss;
target_ulong old_eip, esp, offset;
has_error_code = 0;
if (!is_int && !is_hw) {
has_error_code = exception_has_error_code(intno);
}
if (is_int) {
old_eip = next_eip;
} else {
old_eip = env->eip;
}
dt = &env->idt;
if (intno * 16 + 15 > dt->limit) {
raise_exception_err(env, EXCP0D_GPF, intno * 8 + 2);
}
ptr = dt->base + intno * 16;
e1 = cpu_ldl_kernel(env, ptr);
e2 = cpu_ldl_kernel(env, ptr + 4);
e3 = cpu_ldl_kernel(env, ptr + 8);
/* check gate type */
type = (e2 >> DESC_TYPE_SHIFT) & 0x1f;
switch (type) {
case 14: /* 386 interrupt gate */
case 15: /* 386 trap gate */
break;
default:
raise_exception_err(env, EXCP0D_GPF, intno * 8 + 2);
break;
}
dpl = (e2 >> DESC_DPL_SHIFT) & 3;
cpl = env->hflags & HF_CPL_MASK;
/* check privilege if software int */
if (is_int && dpl < cpl) {
raise_exception_err(env, EXCP0D_GPF, intno * 8 + 2);
}
/* check valid bit */
if (!(e2 & DESC_P_MASK)) {
raise_exception_err(env, EXCP0B_NOSEG, intno * 8 + 2);
}
selector = e1 >> 16;
offset = ((target_ulong)e3 << 32) | (e2 & 0xffff0000) | (e1 & 0x0000ffff);
ist = e2 & 7;
if ((selector & 0xfffc) == 0) {
raise_exception_err(env, EXCP0D_GPF, 0);
}
if (load_segment(env, &e1, &e2, selector) != 0) {
raise_exception_err(env, EXCP0D_GPF, selector & 0xfffc);
}
if (!(e2 & DESC_S_MASK) || !(e2 & (DESC_CS_MASK))) {
raise_exception_err(env, EXCP0D_GPF, selector & 0xfffc);
}
dpl = (e2 >> DESC_DPL_SHIFT) & 3;
if (dpl > cpl) {
raise_exception_err(env, EXCP0D_GPF, selector & 0xfffc);
}
if (!(e2 & DESC_P_MASK)) {
raise_exception_err(env, EXCP0B_NOSEG, selector & 0xfffc);
}
if (!(e2 & DESC_L_MASK) || (e2 & DESC_B_MASK)) {
raise_exception_err(env, EXCP0D_GPF, selector & 0xfffc);
}
if (e2 & DESC_C_MASK) {
dpl = cpl;
}
if (dpl < cpl || ist != 0) {
/* to inner privilege */
new_stack = 1;
esp = get_rsp_from_tss(env, ist != 0 ? ist + 3 : dpl);
ss = 0;
} else {
/* to same privilege */
if (env->eflags & VM_MASK) {
raise_exception_err(env, EXCP0D_GPF, selector & 0xfffc);
}
new_stack = 0;
esp = env->regs[R_ESP];
}
esp &= ~0xfLL; /* align stack */
PUSHQ(esp, env->segs[R_SS].selector);
PUSHQ(esp, env->regs[R_ESP]);
PUSHQ(esp, cpu_compute_eflags(env));
PUSHQ(esp, env->segs[R_CS].selector);
PUSHQ(esp, old_eip);
if (has_error_code) {
PUSHQ(esp, error_code);
}
/* interrupt gate clear IF mask */
if ((type & 1) == 0) {
env->eflags &= ~IF_MASK;
}
env->eflags &= ~(TF_MASK | VM_MASK | RF_MASK | NT_MASK);
if (new_stack) {
ss = 0 | dpl;
cpu_x86_load_seg_cache(env, R_SS, ss, 0, 0, dpl << DESC_DPL_SHIFT);
}
env->regs[R_ESP] = esp;
selector = (selector & ~3) | dpl;
cpu_x86_load_seg_cache(env, R_CS, selector,
get_seg_base(e1, e2),
get_seg_limit(e1, e2),
e2);
env->eip = offset;
}
#endif /* TARGET_X86_64 */
void helper_sysret(CPUX86State *env, int dflag)
{
int cpl, selector;
if (!(env->efer & MSR_EFER_SCE)) {
raise_exception_err_ra(env, EXCP06_ILLOP, 0, GETPC());
}
cpl = env->hflags & HF_CPL_MASK;
if (!(env->cr[0] & CR0_PE_MASK) || cpl != 0) {
raise_exception_err_ra(env, EXCP0D_GPF, 0, GETPC());
}
selector = (env->star >> 48) & 0xffff;
#ifdef TARGET_X86_64
if (env->hflags & HF_LMA_MASK) {
cpu_load_eflags(env, (uint32_t)(env->regs[11]), TF_MASK | AC_MASK
| ID_MASK | IF_MASK | IOPL_MASK | VM_MASK | RF_MASK |
NT_MASK);
if (dflag == 2) {
cpu_x86_load_seg_cache(env, R_CS, (selector + 16) | 3,
0, 0xffffffff,
DESC_G_MASK | DESC_P_MASK |
DESC_S_MASK | (3 << DESC_DPL_SHIFT) |
DESC_CS_MASK | DESC_R_MASK | DESC_A_MASK |
DESC_L_MASK);
env->eip = env->regs[R_ECX];
} else {
cpu_x86_load_seg_cache(env, R_CS, selector | 3,
0, 0xffffffff,
DESC_G_MASK | DESC_B_MASK | DESC_P_MASK |
DESC_S_MASK | (3 << DESC_DPL_SHIFT) |
DESC_CS_MASK | DESC_R_MASK | DESC_A_MASK);
env->eip = (uint32_t)env->regs[R_ECX];
}
cpu_x86_load_seg_cache(env, R_SS, (selector + 8) | 3,
0, 0xffffffff,
DESC_G_MASK | DESC_B_MASK | DESC_P_MASK |
DESC_S_MASK | (3 << DESC_DPL_SHIFT) |
DESC_W_MASK | DESC_A_MASK);
} else
#endif
{
env->eflags |= IF_MASK;
cpu_x86_load_seg_cache(env, R_CS, selector | 3,
0, 0xffffffff,
DESC_G_MASK | DESC_B_MASK | DESC_P_MASK |
DESC_S_MASK | (3 << DESC_DPL_SHIFT) |
DESC_CS_MASK | DESC_R_MASK | DESC_A_MASK);
env->eip = (uint32_t)env->regs[R_ECX];
cpu_x86_load_seg_cache(env, R_SS, (selector + 8) | 3,
0, 0xffffffff,
DESC_G_MASK | DESC_B_MASK | DESC_P_MASK |
DESC_S_MASK | (3 << DESC_DPL_SHIFT) |
DESC_W_MASK | DESC_A_MASK);
}
}
/* real mode interrupt */
static void do_interrupt_real(CPUX86State *env, int intno, int is_int,
int error_code, unsigned int next_eip)
{
SegmentCache *dt;
target_ulong ptr, ssp;
int selector;
uint32_t offset, esp;
uint32_t old_cs, old_eip;
/* real mode (simpler!) */
dt = &env->idt;
if (intno * 4 + 3 > dt->limit) {
raise_exception_err(env, EXCP0D_GPF, intno * 8 + 2);
}
ptr = dt->base + intno * 4;
offset = cpu_lduw_kernel(env, ptr);
selector = cpu_lduw_kernel(env, ptr + 2);
esp = env->regs[R_ESP];
ssp = env->segs[R_SS].base;
if (is_int) {
old_eip = next_eip;
} else {
old_eip = env->eip;
}
old_cs = env->segs[R_CS].selector;
/* XXX: use SS segment size? */
PUSHW(ssp, esp, 0xffff, cpu_compute_eflags(env));
PUSHW(ssp, esp, 0xffff, old_cs);
PUSHW(ssp, esp, 0xffff, old_eip);
/* update processor state */
env->regs[R_ESP] = (env->regs[R_ESP] & ~0xffff) | (esp & 0xffff);
env->eip = offset;
env->segs[R_CS].selector = selector;
env->segs[R_CS].base = (selector << 4);
env->eflags &= ~(IF_MASK | TF_MASK | AC_MASK | RF_MASK);
}
/*
* Begin execution of an interruption. is_int is TRUE if coming from
* the int instruction. next_eip is the env->eip value AFTER the interrupt
* instruction. It is only relevant if is_int is TRUE.
*/
void do_interrupt_all(X86CPU *cpu, int intno, int is_int,
int error_code, target_ulong next_eip, int is_hw)
{
CPUX86State *env = &cpu->env;
if (qemu_loglevel_mask(CPU_LOG_INT)) {
if ((env->cr[0] & CR0_PE_MASK)) {
static int count;
qemu_log("%6d: v=%02x e=%04x i=%d cpl=%d IP=%04x:" TARGET_FMT_lx
" pc=" TARGET_FMT_lx " SP=%04x:" TARGET_FMT_lx,
count, intno, error_code, is_int,
env->hflags & HF_CPL_MASK,
env->segs[R_CS].selector, env->eip,
(int)env->segs[R_CS].base + env->eip,
env->segs[R_SS].selector, env->regs[R_ESP]);
if (intno == 0x0e) {
qemu_log(" CR2=" TARGET_FMT_lx, env->cr[2]);
} else {
qemu_log(" env->regs[R_EAX]=" TARGET_FMT_lx, env->regs[R_EAX]);
}
qemu_log("\n");
log_cpu_state(CPU(cpu), CPU_DUMP_CCOP);
#if 0
{
int i;
target_ulong ptr;
qemu_log(" code=");
ptr = env->segs[R_CS].base + env->eip;
for (i = 0; i < 16; i++) {
qemu_log(" %02x", ldub(ptr + i));
}
qemu_log("\n");
}
#endif
count++;
}
}
if (env->cr[0] & CR0_PE_MASK) {
#if !defined(CONFIG_USER_ONLY)
if (env->hflags & HF_GUEST_MASK) {
handle_even_inj(env, intno, is_int, error_code, is_hw, 0);
}
#endif
#ifdef TARGET_X86_64
if (env->hflags & HF_LMA_MASK) {
do_interrupt64(env, intno, is_int, error_code, next_eip, is_hw);
} else
#endif
{
do_interrupt_protected(env, intno, is_int, error_code, next_eip,
is_hw);
}
} else {
#if !defined(CONFIG_USER_ONLY)
if (env->hflags & HF_GUEST_MASK) {
handle_even_inj(env, intno, is_int, error_code, is_hw, 1);
}
#endif
do_interrupt_real(env, intno, is_int, error_code, next_eip);
}
#if !defined(CONFIG_USER_ONLY)
if (env->hflags & HF_GUEST_MASK) {
CPUState *cs = CPU(cpu);
uint32_t event_inj = x86_ldl_phys(cs, env->vm_vmcb +
offsetof(struct vmcb,
control.event_inj));
x86_stl_phys(cs,
env->vm_vmcb + offsetof(struct vmcb, control.event_inj),
event_inj & ~SVM_EVTINJ_VALID);
}
#endif
}
void do_interrupt_x86_hardirq(CPUX86State *env, int intno, int is_hw)
{
do_interrupt_all(env_archcpu(env), intno, 0, 0, 0, is_hw);
}
void helper_lldt(CPUX86State *env, int selector)
{
SegmentCache *dt;
uint32_t e1, e2;
int index, entry_limit;
target_ulong ptr;
selector &= 0xffff;
if ((selector & 0xfffc) == 0) {
/* XXX: NULL selector case: invalid LDT */
env->ldt.base = 0;
env->ldt.limit = 0;
} else {
if (selector & 0x4) {
raise_exception_err_ra(env, EXCP0D_GPF, selector & 0xfffc, GETPC());
}
dt = &env->gdt;
index = selector & ~7;
#ifdef TARGET_X86_64
if (env->hflags & HF_LMA_MASK) {
entry_limit = 15;
} else
#endif
{
entry_limit = 7;
}
if ((index + entry_limit) > dt->limit) {
raise_exception_err_ra(env, EXCP0D_GPF, selector & 0xfffc, GETPC());
}
ptr = dt->base + index;
e1 = cpu_ldl_kernel_ra(env, ptr, GETPC());
e2 = cpu_ldl_kernel_ra(env, ptr + 4, GETPC());
if ((e2 & DESC_S_MASK) || ((e2 >> DESC_TYPE_SHIFT) & 0xf) != 2) {
raise_exception_err_ra(env, EXCP0D_GPF, selector & 0xfffc, GETPC());
}
if (!(e2 & DESC_P_MASK)) {
raise_exception_err_ra(env, EXCP0B_NOSEG, selector & 0xfffc, GETPC());
}
#ifdef TARGET_X86_64
if (env->hflags & HF_LMA_MASK) {
uint32_t e3;
e3 = cpu_ldl_kernel_ra(env, ptr + 8, GETPC());
load_seg_cache_raw_dt(&env->ldt, e1, e2);
env->ldt.base |= (target_ulong)e3 << 32;
} else
#endif
{
load_seg_cache_raw_dt(&env->ldt, e1, e2);
}
}
env->ldt.selector = selector;
}
void helper_ltr(CPUX86State *env, int selector)
{
SegmentCache *dt;
uint32_t e1, e2;
int index, type, entry_limit;
target_ulong ptr;
selector &= 0xffff;
if ((selector & 0xfffc) == 0) {
/* NULL selector case: invalid TR */
env->tr.base = 0;
env->tr.limit = 0;
env->tr.flags = 0;
} else {
if (selector & 0x4) {
raise_exception_err_ra(env, EXCP0D_GPF, selector & 0xfffc, GETPC());
}
dt = &env->gdt;
index = selector & ~7;
#ifdef TARGET_X86_64
if (env->hflags & HF_LMA_MASK) {
entry_limit = 15;
} else
#endif
{
entry_limit = 7;
}
if ((index + entry_limit) > dt->limit) {
raise_exception_err_ra(env, EXCP0D_GPF, selector & 0xfffc, GETPC());
}
ptr = dt->base + index;
e1 = cpu_ldl_kernel_ra(env, ptr, GETPC());
e2 = cpu_ldl_kernel_ra(env, ptr + 4, GETPC());
type = (e2 >> DESC_TYPE_SHIFT) & 0xf;
if ((e2 & DESC_S_MASK) ||
(type != 1 && type != 9)) {
raise_exception_err_ra(env, EXCP0D_GPF, selector & 0xfffc, GETPC());
}
if (!(e2 & DESC_P_MASK)) {
raise_exception_err_ra(env, EXCP0B_NOSEG, selector & 0xfffc, GETPC());
}
#ifdef TARGET_X86_64
if (env->hflags & HF_LMA_MASK) {
uint32_t e3, e4;
e3 = cpu_ldl_kernel_ra(env, ptr + 8, GETPC());
e4 = cpu_ldl_kernel_ra(env, ptr + 12, GETPC());
if ((e4 >> DESC_TYPE_SHIFT) & 0xf) {
raise_exception_err_ra(env, EXCP0D_GPF, selector & 0xfffc, GETPC());
}
load_seg_cache_raw_dt(&env->tr, e1, e2);
env->tr.base |= (target_ulong)e3 << 32;
} else
#endif
{
load_seg_cache_raw_dt(&env->tr, e1, e2);
}
e2 |= DESC_TSS_BUSY_MASK;
cpu_stl_kernel_ra(env, ptr + 4, e2, GETPC());
}
env->tr.selector = selector;
}
/* only works if protected mode and not VM86. seg_reg must be != R_CS */
void helper_load_seg(CPUX86State *env, int seg_reg, int selector)
{
uint32_t e1, e2;
int cpl, dpl, rpl;
SegmentCache *dt;
int index;
target_ulong ptr;
selector &= 0xffff;
cpl = env->hflags & HF_CPL_MASK;
if ((selector & 0xfffc) == 0) {
/* null selector case */
if (seg_reg == R_SS
#ifdef TARGET_X86_64
&& (!(env->hflags & HF_CS64_MASK) || cpl == 3)
#endif
) {
raise_exception_err_ra(env, EXCP0D_GPF, 0, GETPC());
}
cpu_x86_load_seg_cache(env, seg_reg, selector, 0, 0, 0);
} else {
if (selector & 0x4) {
dt = &env->ldt;
} else {
dt = &env->gdt;
}
index = selector & ~7;
if ((index + 7) > dt->limit) {
raise_exception_err_ra(env, EXCP0D_GPF, selector & 0xfffc, GETPC());
}
ptr = dt->base + index;
e1 = cpu_ldl_kernel_ra(env, ptr, GETPC());
e2 = cpu_ldl_kernel_ra(env, ptr + 4, GETPC());
if (!(e2 & DESC_S_MASK)) {
raise_exception_err_ra(env, EXCP0D_GPF, selector & 0xfffc, GETPC());
}
rpl = selector & 3;
dpl = (e2 >> DESC_DPL_SHIFT) & 3;
if (seg_reg == R_SS) {
/* must be writable segment */
if ((e2 & DESC_CS_MASK) || !(e2 & DESC_W_MASK)) {
raise_exception_err_ra(env, EXCP0D_GPF, selector & 0xfffc, GETPC());
}
if (rpl != cpl || dpl != cpl) {
raise_exception_err_ra(env, EXCP0D_GPF, selector & 0xfffc, GETPC());
}
} else {
/* must be readable segment */
if ((e2 & (DESC_CS_MASK | DESC_R_MASK)) == DESC_CS_MASK) {
raise_exception_err_ra(env, EXCP0D_GPF, selector & 0xfffc, GETPC());
}
if (!(e2 & DESC_CS_MASK) || !(e2 & DESC_C_MASK)) {
/* if not conforming code, test rights */
if (dpl < cpl || dpl < rpl) {
raise_exception_err_ra(env, EXCP0D_GPF, selector & 0xfffc, GETPC());
}
}
}
if (!(e2 & DESC_P_MASK)) {
if (seg_reg == R_SS) {
raise_exception_err_ra(env, EXCP0C_STACK, selector & 0xfffc, GETPC());
} else {
raise_exception_err_ra(env, EXCP0B_NOSEG, selector & 0xfffc, GETPC());
}
}
/* set the access bit if not already set */
if (!(e2 & DESC_A_MASK)) {
e2 |= DESC_A_MASK;
cpu_stl_kernel_ra(env, ptr + 4, e2, GETPC());
}
cpu_x86_load_seg_cache(env, seg_reg, selector,
get_seg_base(e1, e2),
get_seg_limit(e1, e2),
e2);
#if 0
qemu_log("load_seg: sel=0x%04x base=0x%08lx limit=0x%08lx flags=%08x\n",
selector, (unsigned long)sc->base, sc->limit, sc->flags);
#endif
}
}
/* protected mode jump */
void helper_ljmp_protected(CPUX86State *env, int new_cs, target_ulong new_eip,
target_ulong next_eip)
{
int gate_cs, type;
uint32_t e1, e2, cpl, dpl, rpl, limit;
if ((new_cs & 0xfffc) == 0) {
raise_exception_err_ra(env, EXCP0D_GPF, 0, GETPC());
}
if (load_segment_ra(env, &e1, &e2, new_cs, GETPC()) != 0) {
raise_exception_err_ra(env, EXCP0D_GPF, new_cs & 0xfffc, GETPC());
}
cpl = env->hflags & HF_CPL_MASK;
if (e2 & DESC_S_MASK) {
if (!(e2 & DESC_CS_MASK)) {
raise_exception_err_ra(env, EXCP0D_GPF, new_cs & 0xfffc, GETPC());
}
dpl = (e2 >> DESC_DPL_SHIFT) & 3;
if (e2 & DESC_C_MASK) {
/* conforming code segment */
if (dpl > cpl) {
raise_exception_err_ra(env, EXCP0D_GPF, new_cs & 0xfffc, GETPC());
}
} else {
/* non conforming code segment */
rpl = new_cs & 3;
if (rpl > cpl) {
raise_exception_err_ra(env, EXCP0D_GPF, new_cs & 0xfffc, GETPC());
}
if (dpl != cpl) {
raise_exception_err_ra(env, EXCP0D_GPF, new_cs & 0xfffc, GETPC());
}
}
if (!(e2 & DESC_P_MASK)) {
raise_exception_err_ra(env, EXCP0B_NOSEG, new_cs & 0xfffc, GETPC());
}
limit = get_seg_limit(e1, e2);
if (new_eip > limit &&
(!(env->hflags & HF_LMA_MASK) || !(e2 & DESC_L_MASK))) {
raise_exception_err_ra(env, EXCP0D_GPF, 0, GETPC());
}
cpu_x86_load_seg_cache(env, R_CS, (new_cs & 0xfffc) | cpl,
get_seg_base(e1, e2), limit, e2);
env->eip = new_eip;
} else {
/* jump to call or task gate */
dpl = (e2 >> DESC_DPL_SHIFT) & 3;
rpl = new_cs & 3;
cpl = env->hflags & HF_CPL_MASK;
type = (e2 >> DESC_TYPE_SHIFT) & 0xf;
#ifdef TARGET_X86_64
if (env->efer & MSR_EFER_LMA) {
if (type != 12) {
raise_exception_err_ra(env, EXCP0D_GPF, new_cs & 0xfffc, GETPC());
}
}
#endif
switch (type) {
case 1: /* 286 TSS */
case 9: /* 386 TSS */
case 5: /* task gate */
if (dpl < cpl || dpl < rpl) {
raise_exception_err_ra(env, EXCP0D_GPF, new_cs & 0xfffc, GETPC());
}
switch_tss_ra(env, new_cs, e1, e2, SWITCH_TSS_JMP, next_eip, GETPC());
break;
case 4: /* 286 call gate */
case 12: /* 386 call gate */
if ((dpl < cpl) || (dpl < rpl)) {
raise_exception_err_ra(env, EXCP0D_GPF, new_cs & 0xfffc, GETPC());
}
if (!(e2 & DESC_P_MASK)) {
raise_exception_err_ra(env, EXCP0B_NOSEG, new_cs & 0xfffc, GETPC());
}
gate_cs = e1 >> 16;
new_eip = (e1 & 0xffff);
if (type == 12) {
new_eip |= (e2 & 0xffff0000);
}
#ifdef TARGET_X86_64
if (env->efer & MSR_EFER_LMA) {
/* load the upper 8 bytes of the 64-bit call gate */
if (load_segment_ra(env, &e1, &e2, new_cs + 8, GETPC())) {
raise_exception_err_ra(env, EXCP0D_GPF, new_cs & 0xfffc,
GETPC());
}
type = (e2 >> DESC_TYPE_SHIFT) & 0x1f;
if (type != 0) {
raise_exception_err_ra(env, EXCP0D_GPF, new_cs & 0xfffc,
GETPC());
}
new_eip |= ((target_ulong)e1) << 32;
}
#endif
if (load_segment_ra(env, &e1, &e2, gate_cs, GETPC()) != 0) {
raise_exception_err_ra(env, EXCP0D_GPF, gate_cs & 0xfffc, GETPC());
}
dpl = (e2 >> DESC_DPL_SHIFT) & 3;
/* must be code segment */
if (((e2 & (DESC_S_MASK | DESC_CS_MASK)) !=
(DESC_S_MASK | DESC_CS_MASK))) {
raise_exception_err_ra(env, EXCP0D_GPF, gate_cs & 0xfffc, GETPC());
}
if (((e2 & DESC_C_MASK) && (dpl > cpl)) ||
(!(e2 & DESC_C_MASK) && (dpl != cpl))) {
raise_exception_err_ra(env, EXCP0D_GPF, gate_cs & 0xfffc, GETPC());
}
#ifdef TARGET_X86_64
if (env->efer & MSR_EFER_LMA) {
if (!(e2 & DESC_L_MASK)) {
raise_exception_err_ra(env, EXCP0D_GPF, gate_cs & 0xfffc, GETPC());
}
if (e2 & DESC_B_MASK) {
raise_exception_err_ra(env, EXCP0D_GPF, gate_cs & 0xfffc, GETPC());
}
}
#endif
if (!(e2 & DESC_P_MASK)) {
raise_exception_err_ra(env, EXCP0D_GPF, gate_cs & 0xfffc, GETPC());
}
limit = get_seg_limit(e1, e2);
if (new_eip > limit &&
(!(env->hflags & HF_LMA_MASK) || !(e2 & DESC_L_MASK))) {
raise_exception_err_ra(env, EXCP0D_GPF, 0, GETPC());
}
cpu_x86_load_seg_cache(env, R_CS, (gate_cs & 0xfffc) | cpl,
get_seg_base(e1, e2), limit, e2);
env->eip = new_eip;
break;
default:
raise_exception_err_ra(env, EXCP0D_GPF, new_cs & 0xfffc, GETPC());
break;
}
}
}
/* real mode call */
void helper_lcall_real(CPUX86State *env, uint32_t new_cs, uint32_t new_eip,
int shift, uint32_t next_eip)
{
uint32_t esp, esp_mask;
target_ulong ssp;
esp = env->regs[R_ESP];
esp_mask = get_sp_mask(env->segs[R_SS].flags);
ssp = env->segs[R_SS].base;
if (shift) {
PUSHL_RA(ssp, esp, esp_mask, env->segs[R_CS].selector, GETPC());
PUSHL_RA(ssp, esp, esp_mask, next_eip, GETPC());
} else {
PUSHW_RA(ssp, esp, esp_mask, env->segs[R_CS].selector, GETPC());
PUSHW_RA(ssp, esp, esp_mask, next_eip, GETPC());
}
SET_ESP(esp, esp_mask);
env->eip = new_eip;
env->segs[R_CS].selector = new_cs;
env->segs[R_CS].base = (new_cs << 4);
}
/* protected mode call */
void helper_lcall_protected(CPUX86State *env, int new_cs, target_ulong new_eip,
int shift, target_ulong next_eip)
{
int new_stack, i;
uint32_t e1, e2, cpl, dpl, rpl, selector, param_count;
uint32_t ss = 0, ss_e1 = 0, ss_e2 = 0, type, ss_dpl, sp_mask;
uint32_t val, limit, old_sp_mask;
target_ulong ssp, old_ssp, offset, sp;
LOG_PCALL("lcall %04x:" TARGET_FMT_lx " s=%d\n", new_cs, new_eip, shift);
LOG_PCALL_STATE(env_cpu(env));
if ((new_cs & 0xfffc) == 0) {
raise_exception_err_ra(env, EXCP0D_GPF, 0, GETPC());
}
if (load_segment_ra(env, &e1, &e2, new_cs, GETPC()) != 0) {
raise_exception_err_ra(env, EXCP0D_GPF, new_cs & 0xfffc, GETPC());
}
cpl = env->hflags & HF_CPL_MASK;
LOG_PCALL("desc=%08x:%08x\n", e1, e2);
if (e2 & DESC_S_MASK) {
if (!(e2 & DESC_CS_MASK)) {
raise_exception_err_ra(env, EXCP0D_GPF, new_cs & 0xfffc, GETPC());
}
dpl = (e2 >> DESC_DPL_SHIFT) & 3;
if (e2 & DESC_C_MASK) {
/* conforming code segment */
if (dpl > cpl) {
raise_exception_err_ra(env, EXCP0D_GPF, new_cs & 0xfffc, GETPC());
}
} else {
/* non conforming code segment */
rpl = new_cs & 3;
if (rpl > cpl) {
raise_exception_err_ra(env, EXCP0D_GPF, new_cs & 0xfffc, GETPC());
}
if (dpl != cpl) {
raise_exception_err_ra(env, EXCP0D_GPF, new_cs & 0xfffc, GETPC());
}
}
if (!(e2 & DESC_P_MASK)) {
raise_exception_err_ra(env, EXCP0B_NOSEG, new_cs & 0xfffc, GETPC());
}
#ifdef TARGET_X86_64
/* XXX: check 16/32 bit cases in long mode */
if (shift == 2) {
target_ulong rsp;
/* 64 bit case */
rsp = env->regs[R_ESP];
PUSHQ_RA(rsp, env->segs[R_CS].selector, GETPC());
PUSHQ_RA(rsp, next_eip, GETPC());
/* from this point, not restartable */
env->regs[R_ESP] = rsp;
cpu_x86_load_seg_cache(env, R_CS, (new_cs & 0xfffc) | cpl,
get_seg_base(e1, e2),
get_seg_limit(e1, e2), e2);
env->eip = new_eip;
} else
#endif
{
sp = env->regs[R_ESP];
sp_mask = get_sp_mask(env->segs[R_SS].flags);
ssp = env->segs[R_SS].base;
if (shift) {
PUSHL_RA(ssp, sp, sp_mask, env->segs[R_CS].selector, GETPC());
PUSHL_RA(ssp, sp, sp_mask, next_eip, GETPC());
} else {
PUSHW_RA(ssp, sp, sp_mask, env->segs[R_CS].selector, GETPC());
PUSHW_RA(ssp, sp, sp_mask, next_eip, GETPC());
}
limit = get_seg_limit(e1, e2);
if (new_eip > limit) {
raise_exception_err_ra(env, EXCP0D_GPF, new_cs & 0xfffc, GETPC());
}
/* from this point, not restartable */
SET_ESP(sp, sp_mask);
cpu_x86_load_seg_cache(env, R_CS, (new_cs & 0xfffc) | cpl,
get_seg_base(e1, e2), limit, e2);
env->eip = new_eip;
}
} else {
/* check gate type */
type = (e2 >> DESC_TYPE_SHIFT) & 0x1f;
dpl = (e2 >> DESC_DPL_SHIFT) & 3;
rpl = new_cs & 3;
#ifdef TARGET_X86_64
if (env->efer & MSR_EFER_LMA) {
if (type != 12) {
raise_exception_err_ra(env, EXCP0D_GPF, new_cs & 0xfffc, GETPC());
}
}
#endif
switch (type) {
case 1: /* available 286 TSS */
case 9: /* available 386 TSS */
case 5: /* task gate */
if (dpl < cpl || dpl < rpl) {
raise_exception_err_ra(env, EXCP0D_GPF, new_cs & 0xfffc, GETPC());
}
switch_tss_ra(env, new_cs, e1, e2, SWITCH_TSS_CALL, next_eip, GETPC());
return;
case 4: /* 286 call gate */
case 12: /* 386 call gate */
break;
default:
raise_exception_err_ra(env, EXCP0D_GPF, new_cs & 0xfffc, GETPC());
break;
}
shift = type >> 3;
if (dpl < cpl || dpl < rpl) {
raise_exception_err_ra(env, EXCP0D_GPF, new_cs & 0xfffc, GETPC());
}
/* check valid bit */
if (!(e2 & DESC_P_MASK)) {
raise_exception_err_ra(env, EXCP0B_NOSEG, new_cs & 0xfffc, GETPC());
}
selector = e1 >> 16;
param_count = e2 & 0x1f;
offset = (e2 & 0xffff0000) | (e1 & 0x0000ffff);
#ifdef TARGET_X86_64
if (env->efer & MSR_EFER_LMA) {
/* load the upper 8 bytes of the 64-bit call gate */
if (load_segment_ra(env, &e1, &e2, new_cs + 8, GETPC())) {
raise_exception_err_ra(env, EXCP0D_GPF, new_cs & 0xfffc,
GETPC());
}
type = (e2 >> DESC_TYPE_SHIFT) & 0x1f;
if (type != 0) {
raise_exception_err_ra(env, EXCP0D_GPF, new_cs & 0xfffc,
GETPC());
}
offset |= ((target_ulong)e1) << 32;
}
#endif
if ((selector & 0xfffc) == 0) {
raise_exception_err_ra(env, EXCP0D_GPF, 0, GETPC());
}
if (load_segment_ra(env, &e1, &e2, selector, GETPC()) != 0) {
raise_exception_err_ra(env, EXCP0D_GPF, selector & 0xfffc, GETPC());
}
if (!(e2 & DESC_S_MASK) || !(e2 & (DESC_CS_MASK))) {
raise_exception_err_ra(env, EXCP0D_GPF, selector & 0xfffc, GETPC());
}
dpl = (e2 >> DESC_DPL_SHIFT) & 3;
if (dpl > cpl) {
raise_exception_err_ra(env, EXCP0D_GPF, selector & 0xfffc, GETPC());
}
#ifdef TARGET_X86_64
if (env->efer & MSR_EFER_LMA) {
if (!(e2 & DESC_L_MASK)) {
raise_exception_err_ra(env, EXCP0D_GPF, selector & 0xfffc, GETPC());
}
if (e2 & DESC_B_MASK) {
raise_exception_err_ra(env, EXCP0D_GPF, selector & 0xfffc, GETPC());
}
shift++;
}
#endif
if (!(e2 & DESC_P_MASK)) {
raise_exception_err_ra(env, EXCP0B_NOSEG, selector & 0xfffc, GETPC());
}
if (!(e2 & DESC_C_MASK) && dpl < cpl) {
/* to inner privilege */
#ifdef TARGET_X86_64
if (shift == 2) {
sp = get_rsp_from_tss(env, dpl);
ss = dpl; /* SS = NULL selector with RPL = new CPL */
new_stack = 1;
sp_mask = 0;
ssp = 0; /* SS base is always zero in IA-32e mode */
LOG_PCALL("new ss:rsp=%04x:%016llx env->regs[R_ESP]="
TARGET_FMT_lx "\n", ss, sp, env->regs[R_ESP]);
} else
#endif
{
uint32_t sp32;
get_ss_esp_from_tss(env, &ss, &sp32, dpl, GETPC());
LOG_PCALL("new ss:esp=%04x:%08x param_count=%d env->regs[R_ESP]="
TARGET_FMT_lx "\n", ss, sp32, param_count,
env->regs[R_ESP]);
sp = sp32;
if ((ss & 0xfffc) == 0) {
raise_exception_err_ra(env, EXCP0A_TSS, ss & 0xfffc, GETPC());
}
if ((ss & 3) != dpl) {
raise_exception_err_ra(env, EXCP0A_TSS, ss & 0xfffc, GETPC());
}
if (load_segment_ra(env, &ss_e1, &ss_e2, ss, GETPC()) != 0) {
raise_exception_err_ra(env, EXCP0A_TSS, ss & 0xfffc, GETPC());
}
ss_dpl = (ss_e2 >> DESC_DPL_SHIFT) & 3;
if (ss_dpl != dpl) {
raise_exception_err_ra(env, EXCP0A_TSS, ss & 0xfffc, GETPC());
}
if (!(ss_e2 & DESC_S_MASK) ||
(ss_e2 & DESC_CS_MASK) ||
!(ss_e2 & DESC_W_MASK)) {
raise_exception_err_ra(env, EXCP0A_TSS, ss & 0xfffc, GETPC());
}
if (!(ss_e2 & DESC_P_MASK)) {
raise_exception_err_ra(env, EXCP0A_TSS, ss & 0xfffc, GETPC());
}
sp_mask = get_sp_mask(ss_e2);
ssp = get_seg_base(ss_e1, ss_e2);
}
/* push_size = ((param_count * 2) + 8) << shift; */
old_sp_mask = get_sp_mask(env->segs[R_SS].flags);
old_ssp = env->segs[R_SS].base;
#ifdef TARGET_X86_64
if (shift == 2) {
/* XXX: verify if new stack address is canonical */
PUSHQ_RA(sp, env->segs[R_SS].selector, GETPC());
PUSHQ_RA(sp, env->regs[R_ESP], GETPC());
/* parameters aren't supported for 64-bit call gates */
} else
#endif
if (shift == 1) {
PUSHL_RA(ssp, sp, sp_mask, env->segs[R_SS].selector, GETPC());
PUSHL_RA(ssp, sp, sp_mask, env->regs[R_ESP], GETPC());
for (i = param_count - 1; i >= 0; i--) {
val = cpu_ldl_kernel_ra(env, old_ssp +
((env->regs[R_ESP] + i * 4) &
old_sp_mask), GETPC());
PUSHL_RA(ssp, sp, sp_mask, val, GETPC());
}
} else {
PUSHW_RA(ssp, sp, sp_mask, env->segs[R_SS].selector, GETPC());
PUSHW_RA(ssp, sp, sp_mask, env->regs[R_ESP], GETPC());
for (i = param_count - 1; i >= 0; i--) {
val = cpu_lduw_kernel_ra(env, old_ssp +
((env->regs[R_ESP] + i * 2) &
old_sp_mask), GETPC());
PUSHW_RA(ssp, sp, sp_mask, val, GETPC());
}
}
new_stack = 1;
} else {
/* to same privilege */
sp = env->regs[R_ESP];
sp_mask = get_sp_mask(env->segs[R_SS].flags);
ssp = env->segs[R_SS].base;
/* push_size = (4 << shift); */
new_stack = 0;
}
#ifdef TARGET_X86_64
if (shift == 2) {
PUSHQ_RA(sp, env->segs[R_CS].selector, GETPC());
PUSHQ_RA(sp, next_eip, GETPC());
} else
#endif
if (shift == 1) {
PUSHL_RA(ssp, sp, sp_mask, env->segs[R_CS].selector, GETPC());
PUSHL_RA(ssp, sp, sp_mask, next_eip, GETPC());
} else {
PUSHW_RA(ssp, sp, sp_mask, env->segs[R_CS].selector, GETPC());
PUSHW_RA(ssp, sp, sp_mask, next_eip, GETPC());
}
/* from this point, not restartable */
if (new_stack) {
#ifdef TARGET_X86_64
if (shift == 2) {
cpu_x86_load_seg_cache(env, R_SS, ss, 0, 0, 0);
} else
#endif
{
ss = (ss & ~3) | dpl;
cpu_x86_load_seg_cache(env, R_SS, ss,
ssp,
get_seg_limit(ss_e1, ss_e2),
ss_e2);
}
}
selector = (selector & ~3) | dpl;
cpu_x86_load_seg_cache(env, R_CS, selector,
get_seg_base(e1, e2),
get_seg_limit(e1, e2),
e2);
SET_ESP(sp, sp_mask);
env->eip = offset;
}
}
/* real and vm86 mode iret */
void helper_iret_real(CPUX86State *env, int shift)
{
uint32_t sp, new_cs, new_eip, new_eflags, sp_mask;
target_ulong ssp;
int eflags_mask;
sp_mask = 0xffff; /* XXXX: use SS segment size? */
sp = env->regs[R_ESP];
ssp = env->segs[R_SS].base;
if (shift == 1) {
/* 32 bits */
POPL_RA(ssp, sp, sp_mask, new_eip, GETPC());
POPL_RA(ssp, sp, sp_mask, new_cs, GETPC());
new_cs &= 0xffff;
POPL_RA(ssp, sp, sp_mask, new_eflags, GETPC());
} else {
/* 16 bits */
POPW_RA(ssp, sp, sp_mask, new_eip, GETPC());
POPW_RA(ssp, sp, sp_mask, new_cs, GETPC());
POPW_RA(ssp, sp, sp_mask, new_eflags, GETPC());
}
env->regs[R_ESP] = (env->regs[R_ESP] & ~sp_mask) | (sp & sp_mask);
env->segs[R_CS].selector = new_cs;
env->segs[R_CS].base = (new_cs << 4);
env->eip = new_eip;
if (env->eflags & VM_MASK) {
eflags_mask = TF_MASK | AC_MASK | ID_MASK | IF_MASK | RF_MASK |
NT_MASK;
} else {
eflags_mask = TF_MASK | AC_MASK | ID_MASK | IF_MASK | IOPL_MASK |
RF_MASK | NT_MASK;
}
if (shift == 0) {
eflags_mask &= 0xffff;
}
cpu_load_eflags(env, new_eflags, eflags_mask);
env->hflags2 &= ~HF2_NMI_MASK;
}
static inline void validate_seg(CPUX86State *env, X86Seg seg_reg, int cpl)
{
int dpl;
uint32_t e2;
/* XXX: on x86_64, we do not want to nullify FS and GS because
they may still contain a valid base. I would be interested to
know how a real x86_64 CPU behaves */
if ((seg_reg == R_FS || seg_reg == R_GS) &&
(env->segs[seg_reg].selector & 0xfffc) == 0) {
return;
}
e2 = env->segs[seg_reg].flags;
dpl = (e2 >> DESC_DPL_SHIFT) & 3;
if (!(e2 & DESC_CS_MASK) || !(e2 & DESC_C_MASK)) {
/* data or non conforming code segment */
if (dpl < cpl) {
cpu_x86_load_seg_cache(env, seg_reg, 0,
env->segs[seg_reg].base,
env->segs[seg_reg].limit,
env->segs[seg_reg].flags & ~DESC_P_MASK);
}
}
}
/* protected mode iret */
static inline void helper_ret_protected(CPUX86State *env, int shift,
int is_iret, int addend,
uintptr_t retaddr)
{
uint32_t new_cs, new_eflags, new_ss;
uint32_t new_es, new_ds, new_fs, new_gs;
uint32_t e1, e2, ss_e1, ss_e2;
int cpl, dpl, rpl, eflags_mask, iopl;
target_ulong ssp, sp, new_eip, new_esp, sp_mask;
#ifdef TARGET_X86_64
if (shift == 2) {
sp_mask = -1;
} else
#endif
{
sp_mask = get_sp_mask(env->segs[R_SS].flags);
}
sp = env->regs[R_ESP];
ssp = env->segs[R_SS].base;
new_eflags = 0; /* avoid warning */
#ifdef TARGET_X86_64
if (shift == 2) {
POPQ_RA(sp, new_eip, retaddr);
POPQ_RA(sp, new_cs, retaddr);
new_cs &= 0xffff;
if (is_iret) {
POPQ_RA(sp, new_eflags, retaddr);
}
} else
#endif
{
if (shift == 1) {
/* 32 bits */
POPL_RA(ssp, sp, sp_mask, new_eip, retaddr);
POPL_RA(ssp, sp, sp_mask, new_cs, retaddr);
new_cs &= 0xffff;
if (is_iret) {
POPL_RA(ssp, sp, sp_mask, new_eflags, retaddr);
if (new_eflags & VM_MASK) {
goto return_to_vm86;
}
}
} else {
/* 16 bits */
POPW_RA(ssp, sp, sp_mask, new_eip, retaddr);
POPW_RA(ssp, sp, sp_mask, new_cs, retaddr);
if (is_iret) {
POPW_RA(ssp, sp, sp_mask, new_eflags, retaddr);
}
}
}
LOG_PCALL("lret new %04x:" TARGET_FMT_lx " s=%d addend=0x%x\n",
new_cs, new_eip, shift, addend);
LOG_PCALL_STATE(env_cpu(env));
if ((new_cs & 0xfffc) == 0) {
raise_exception_err_ra(env, EXCP0D_GPF, new_cs & 0xfffc, retaddr);
}
if (load_segment_ra(env, &e1, &e2, new_cs, retaddr) != 0) {
raise_exception_err_ra(env, EXCP0D_GPF, new_cs & 0xfffc, retaddr);
}
if (!(e2 & DESC_S_MASK) ||
!(e2 & DESC_CS_MASK)) {
raise_exception_err_ra(env, EXCP0D_GPF, new_cs & 0xfffc, retaddr);
}
cpl = env->hflags & HF_CPL_MASK;
rpl = new_cs & 3;
if (rpl < cpl) {
raise_exception_err_ra(env, EXCP0D_GPF, new_cs & 0xfffc, retaddr);
}
dpl = (e2 >> DESC_DPL_SHIFT) & 3;
if (e2 & DESC_C_MASK) {
if (dpl > rpl) {
raise_exception_err_ra(env, EXCP0D_GPF, new_cs & 0xfffc, retaddr);
}
} else {
if (dpl != rpl) {
raise_exception_err_ra(env, EXCP0D_GPF, new_cs & 0xfffc, retaddr);
}
}
if (!(e2 & DESC_P_MASK)) {
raise_exception_err_ra(env, EXCP0B_NOSEG, new_cs & 0xfffc, retaddr);
}
sp += addend;
if (rpl == cpl && (!(env->hflags & HF_CS64_MASK) ||
((env->hflags & HF_CS64_MASK) && !is_iret))) {
/* return to same privilege level */
cpu_x86_load_seg_cache(env, R_CS, new_cs,
get_seg_base(e1, e2),
get_seg_limit(e1, e2),
e2);
} else {
/* return to different privilege level */
#ifdef TARGET_X86_64
if (shift == 2) {
POPQ_RA(sp, new_esp, retaddr);
POPQ_RA(sp, new_ss, retaddr);
new_ss &= 0xffff;
} else
#endif
{
if (shift == 1) {
/* 32 bits */
POPL_RA(ssp, sp, sp_mask, new_esp, retaddr);
POPL_RA(ssp, sp, sp_mask, new_ss, retaddr);
new_ss &= 0xffff;
} else {
/* 16 bits */
POPW_RA(ssp, sp, sp_mask, new_esp, retaddr);
POPW_RA(ssp, sp, sp_mask, new_ss, retaddr);
}
}
LOG_PCALL("new ss:esp=%04x:" TARGET_FMT_lx "\n",
new_ss, new_esp);
if ((new_ss & 0xfffc) == 0) {
#ifdef TARGET_X86_64
/* NULL ss is allowed in long mode if cpl != 3 */
/* XXX: test CS64? */
if ((env->hflags & HF_LMA_MASK) && rpl != 3) {
cpu_x86_load_seg_cache(env, R_SS, new_ss,
0, 0xffffffff,
DESC_G_MASK | DESC_B_MASK | DESC_P_MASK |
DESC_S_MASK | (rpl << DESC_DPL_SHIFT) |
DESC_W_MASK | DESC_A_MASK);
ss_e2 = DESC_B_MASK; /* XXX: should not be needed? */
} else
#endif
{
raise_exception_err_ra(env, EXCP0D_GPF, 0, retaddr);
}
} else {
if ((new_ss & 3) != rpl) {
raise_exception_err_ra(env, EXCP0D_GPF, new_ss & 0xfffc, retaddr);
}
if (load_segment_ra(env, &ss_e1, &ss_e2, new_ss, retaddr) != 0) {
raise_exception_err_ra(env, EXCP0D_GPF, new_ss & 0xfffc, retaddr);
}
if (!(ss_e2 & DESC_S_MASK) ||
(ss_e2 & DESC_CS_MASK) ||
!(ss_e2 & DESC_W_MASK)) {
raise_exception_err_ra(env, EXCP0D_GPF, new_ss & 0xfffc, retaddr);
}
dpl = (ss_e2 >> DESC_DPL_SHIFT) & 3;
if (dpl != rpl) {
raise_exception_err_ra(env, EXCP0D_GPF, new_ss & 0xfffc, retaddr);
}
if (!(ss_e2 & DESC_P_MASK)) {
raise_exception_err_ra(env, EXCP0B_NOSEG, new_ss & 0xfffc, retaddr);
}
cpu_x86_load_seg_cache(env, R_SS, new_ss,
get_seg_base(ss_e1, ss_e2),
get_seg_limit(ss_e1, ss_e2),
ss_e2);
}
cpu_x86_load_seg_cache(env, R_CS, new_cs,
get_seg_base(e1, e2),
get_seg_limit(e1, e2),
e2);
sp = new_esp;
#ifdef TARGET_X86_64
if (env->hflags & HF_CS64_MASK) {
sp_mask = -1;
} else
#endif
{
sp_mask = get_sp_mask(ss_e2);
}
/* validate data segments */
validate_seg(env, R_ES, rpl);
validate_seg(env, R_DS, rpl);
validate_seg(env, R_FS, rpl);
validate_seg(env, R_GS, rpl);
sp += addend;
}
SET_ESP(sp, sp_mask);
env->eip = new_eip;
if (is_iret) {
/* NOTE: 'cpl' is the _old_ CPL */
eflags_mask = TF_MASK | AC_MASK | ID_MASK | RF_MASK | NT_MASK;
if (cpl == 0) {
eflags_mask |= IOPL_MASK;
}
iopl = (env->eflags >> IOPL_SHIFT) & 3;
if (cpl <= iopl) {
eflags_mask |= IF_MASK;
}
if (shift == 0) {
eflags_mask &= 0xffff;
}
cpu_load_eflags(env, new_eflags, eflags_mask);
}
return;
return_to_vm86:
POPL_RA(ssp, sp, sp_mask, new_esp, retaddr);
POPL_RA(ssp, sp, sp_mask, new_ss, retaddr);
POPL_RA(ssp, sp, sp_mask, new_es, retaddr);
POPL_RA(ssp, sp, sp_mask, new_ds, retaddr);
POPL_RA(ssp, sp, sp_mask, new_fs, retaddr);
POPL_RA(ssp, sp, sp_mask, new_gs, retaddr);
/* modify processor state */
cpu_load_eflags(env, new_eflags, TF_MASK | AC_MASK | ID_MASK |
IF_MASK | IOPL_MASK | VM_MASK | NT_MASK | VIF_MASK |
VIP_MASK);
load_seg_vm(env, R_CS, new_cs & 0xffff);
load_seg_vm(env, R_SS, new_ss & 0xffff);
load_seg_vm(env, R_ES, new_es & 0xffff);
load_seg_vm(env, R_DS, new_ds & 0xffff);
load_seg_vm(env, R_FS, new_fs & 0xffff);
load_seg_vm(env, R_GS, new_gs & 0xffff);
env->eip = new_eip & 0xffff;
env->regs[R_ESP] = new_esp;
}
void helper_iret_protected(CPUX86State *env, int shift, int next_eip)
{
int tss_selector, type;
uint32_t e1, e2;
/* specific case for TSS */
if (env->eflags & NT_MASK) {
#ifdef TARGET_X86_64
if (env->hflags & HF_LMA_MASK) {
raise_exception_err_ra(env, EXCP0D_GPF, 0, GETPC());
}
#endif
tss_selector = cpu_lduw_kernel_ra(env, env->tr.base + 0, GETPC());
if (tss_selector & 4) {
raise_exception_err_ra(env, EXCP0A_TSS, tss_selector & 0xfffc, GETPC());
}
if (load_segment_ra(env, &e1, &e2, tss_selector, GETPC()) != 0) {
raise_exception_err_ra(env, EXCP0A_TSS, tss_selector & 0xfffc, GETPC());
}
type = (e2 >> DESC_TYPE_SHIFT) & 0x17;
/* NOTE: we check both segment and busy TSS */
if (type != 3) {
raise_exception_err_ra(env, EXCP0A_TSS, tss_selector & 0xfffc, GETPC());
}
switch_tss_ra(env, tss_selector, e1, e2, SWITCH_TSS_IRET, next_eip, GETPC());
} else {
helper_ret_protected(env, shift, 1, 0, GETPC());
}
env->hflags2 &= ~HF2_NMI_MASK;
}
void helper_lret_protected(CPUX86State *env, int shift, int addend)
{
helper_ret_protected(env, shift, 0, addend, GETPC());
}
void helper_sysenter(CPUX86State *env)
{
if (env->sysenter_cs == 0) {
raise_exception_err_ra(env, EXCP0D_GPF, 0, GETPC());
}
env->eflags &= ~(VM_MASK | IF_MASK | RF_MASK);
#ifdef TARGET_X86_64
if (env->hflags & HF_LMA_MASK) {
cpu_x86_load_seg_cache(env, R_CS, env->sysenter_cs & 0xfffc,
0, 0xffffffff,
DESC_G_MASK | DESC_B_MASK | DESC_P_MASK |
DESC_S_MASK |
DESC_CS_MASK | DESC_R_MASK | DESC_A_MASK |
DESC_L_MASK);
} else
#endif
{
cpu_x86_load_seg_cache(env, R_CS, env->sysenter_cs & 0xfffc,
0, 0xffffffff,
DESC_G_MASK | DESC_B_MASK | DESC_P_MASK |
DESC_S_MASK |
DESC_CS_MASK | DESC_R_MASK | DESC_A_MASK);
}
cpu_x86_load_seg_cache(env, R_SS, (env->sysenter_cs + 8) & 0xfffc,
0, 0xffffffff,
DESC_G_MASK | DESC_B_MASK | DESC_P_MASK |
DESC_S_MASK |
DESC_W_MASK | DESC_A_MASK);
env->regs[R_ESP] = env->sysenter_esp;
env->eip = env->sysenter_eip;
}
void helper_sysexit(CPUX86State *env, int dflag)
{
int cpl;
cpl = env->hflags & HF_CPL_MASK;
if (env->sysenter_cs == 0 || cpl != 0) {
raise_exception_err_ra(env, EXCP0D_GPF, 0, GETPC());
}
#ifdef TARGET_X86_64
if (dflag == 2) {
cpu_x86_load_seg_cache(env, R_CS, ((env->sysenter_cs + 32) & 0xfffc) |
3, 0, 0xffffffff,
DESC_G_MASK | DESC_B_MASK | DESC_P_MASK |
DESC_S_MASK | (3 << DESC_DPL_SHIFT) |
DESC_CS_MASK | DESC_R_MASK | DESC_A_MASK |
DESC_L_MASK);
cpu_x86_load_seg_cache(env, R_SS, ((env->sysenter_cs + 40) & 0xfffc) |
3, 0, 0xffffffff,
DESC_G_MASK | DESC_B_MASK | DESC_P_MASK |
DESC_S_MASK | (3 << DESC_DPL_SHIFT) |
DESC_W_MASK | DESC_A_MASK);
} else
#endif
{
cpu_x86_load_seg_cache(env, R_CS, ((env->sysenter_cs + 16) & 0xfffc) |
3, 0, 0xffffffff,
DESC_G_MASK | DESC_B_MASK | DESC_P_MASK |
DESC_S_MASK | (3 << DESC_DPL_SHIFT) |
DESC_CS_MASK | DESC_R_MASK | DESC_A_MASK);
cpu_x86_load_seg_cache(env, R_SS, ((env->sysenter_cs + 24) & 0xfffc) |
3, 0, 0xffffffff,
DESC_G_MASK | DESC_B_MASK | DESC_P_MASK |
DESC_S_MASK | (3 << DESC_DPL_SHIFT) |
DESC_W_MASK | DESC_A_MASK);
}
env->regs[R_ESP] = env->regs[R_ECX];
env->eip = env->regs[R_EDX];
}
target_ulong helper_lsl(CPUX86State *env, target_ulong selector1)
{
unsigned int limit;
uint32_t e1, e2, eflags, selector;
int rpl, dpl, cpl, type;
selector = selector1 & 0xffff;
eflags = cpu_cc_compute_all(env);
if ((selector & 0xfffc) == 0) {
goto fail;
}
if (load_segment_ra(env, &e1, &e2, selector, GETPC()) != 0) {
goto fail;
}
rpl = selector & 3;
dpl = (e2 >> DESC_DPL_SHIFT) & 3;
cpl = env->hflags & HF_CPL_MASK;
if (e2 & DESC_S_MASK) {
if ((e2 & DESC_CS_MASK) && (e2 & DESC_C_MASK)) {
/* conforming */
} else {
if (dpl < cpl || dpl < rpl) {
goto fail;
}
}
} else {
type = (e2 >> DESC_TYPE_SHIFT) & 0xf;
switch (type) {
case 1:
case 2:
case 3:
case 9:
case 11:
break;
default:
goto fail;
}
if (dpl < cpl || dpl < rpl) {
fail:
CC_SRC = eflags & ~CC_Z;
return 0;
}
}
limit = get_seg_limit(e1, e2);
CC_SRC = eflags | CC_Z;
return limit;
}
target_ulong helper_lar(CPUX86State *env, target_ulong selector1)
{
uint32_t e1, e2, eflags, selector;
int rpl, dpl, cpl, type;
selector = selector1 & 0xffff;
eflags = cpu_cc_compute_all(env);
if ((selector & 0xfffc) == 0) {
goto fail;
}
if (load_segment_ra(env, &e1, &e2, selector, GETPC()) != 0) {
goto fail;
}
rpl = selector & 3;
dpl = (e2 >> DESC_DPL_SHIFT) & 3;
cpl = env->hflags & HF_CPL_MASK;
if (e2 & DESC_S_MASK) {
if ((e2 & DESC_CS_MASK) && (e2 & DESC_C_MASK)) {
/* conforming */
} else {
if (dpl < cpl || dpl < rpl) {
goto fail;
}
}
} else {
type = (e2 >> DESC_TYPE_SHIFT) & 0xf;
switch (type) {
case 1:
case 2:
case 3:
case 4:
case 5:
case 9:
case 11:
case 12:
break;
default:
goto fail;
}
if (dpl < cpl || dpl < rpl) {
fail:
CC_SRC = eflags & ~CC_Z;
return 0;
}
}
CC_SRC = eflags | CC_Z;
return e2 & 0x00f0ff00;
}
void helper_verr(CPUX86State *env, target_ulong selector1)
{
uint32_t e1, e2, eflags, selector;
int rpl, dpl, cpl;
selector = selector1 & 0xffff;
eflags = cpu_cc_compute_all(env);
if ((selector & 0xfffc) == 0) {
goto fail;
}
if (load_segment_ra(env, &e1, &e2, selector, GETPC()) != 0) {
goto fail;
}
if (!(e2 & DESC_S_MASK)) {
goto fail;
}
rpl = selector & 3;
dpl = (e2 >> DESC_DPL_SHIFT) & 3;
cpl = env->hflags & HF_CPL_MASK;
if (e2 & DESC_CS_MASK) {
if (!(e2 & DESC_R_MASK)) {
goto fail;
}
if (!(e2 & DESC_C_MASK)) {
if (dpl < cpl || dpl < rpl) {
goto fail;
}
}
} else {
if (dpl < cpl || dpl < rpl) {
fail:
CC_SRC = eflags & ~CC_Z;
return;
}
}
CC_SRC = eflags | CC_Z;
}
void helper_verw(CPUX86State *env, target_ulong selector1)
{
uint32_t e1, e2, eflags, selector;
int rpl, dpl, cpl;
selector = selector1 & 0xffff;
eflags = cpu_cc_compute_all(env);
if ((selector & 0xfffc) == 0) {
goto fail;
}
if (load_segment_ra(env, &e1, &e2, selector, GETPC()) != 0) {
goto fail;
}
if (!(e2 & DESC_S_MASK)) {
goto fail;
}
rpl = selector & 3;
dpl = (e2 >> DESC_DPL_SHIFT) & 3;
cpl = env->hflags & HF_CPL_MASK;
if (e2 & DESC_CS_MASK) {
goto fail;
} else {
if (dpl < cpl || dpl < rpl) {
goto fail;
}
if (!(e2 & DESC_W_MASK)) {
fail:
CC_SRC = eflags & ~CC_Z;
return;
}
}
CC_SRC = eflags | CC_Z;
}