static void MEMCALL
cpu_memorywrite_check(descriptor_t *sdp, UINT32 offset, UINT len, int e)
{
__ASSERT(sdp != NULL);
__ASSERT(len > 0);
if (!SEG_IS_VALID(sdp)) {
e = GP_EXCEPTION;
goto exc;
}
if (!SEG_IS_PRESENT(sdp)
|| SEG_IS_SYSTEM(sdp)
|| SEG_IS_CODE(sdp)
|| (SEG_IS_DATA(sdp) && !SEG_IS_WRITABLE_DATA(sdp))) {
goto exc;
}
switch (sdp->type) {
case 2:
case 3: /* rw */
case 6:
case 7: /* rw (expand down) */
if (!check_limit_upstairs(sdp, offset, len, SEG_IS_32BIT(sdp)))
goto exc;
break;
default:
goto exc;
}
sdp->flag |= CPU_DESC_FLAG_WRITABLE | CPU_DESC_FLAG_READABLE;
return;
exc:
VERBOSE(("cpu_memorywrite_check: check failure: offset = 0x%08x, len = %d", offset, len));
#if defined(DEBUG)
segdesc_dump(sdp);
#endif
EXCEPTION(e, 0);
}
static int MEMCALL
check_limit_upstairs(descriptor_t *sdp, UINT32 offset, UINT len, BOOL is32bit)
{
UINT32 limit;
UINT32 end;
__ASSERT(sdp != NULL);
__ASSERT(len > 0);
len--;
end = offset + len;
if (SEG_IS_DATA(sdp) && SEG_IS_EXPANDDOWN_DATA(sdp)) {
/* expand-down data segment */
limit = SEG_IS_32BIT(sdp) ? 0xffffffff : 0x0000ffff;
if (sdp->u.seg.limit == 0) {
/*
* 32bit 16bit
* +-------+ +-------+ FFFFFFFFh
* | | | |
* | | + [1] + 0000FFFFh
* | valid | | |
* | | +-------+ 0000FFFFh - len -1
* | | | valid |
* +-------+ +-------+ 00000000h
*/
if (!SEG_IS_32BIT(sdp)) {
if ((len > limit) /* len check */
|| (end > limit)) { /* [1] */
goto exc;
}
} else {
sdp->flag |= CPU_DESC_FLAG_WHOLEADR;
}
} else {
/*
* 32bit 16bit
* +-------+ +-------+ FFFFFFFFh
* | [2] | | |
* +-------+ +.......+ FFFFFFFFh - len - 1
* | | | [2] |
* | | +.......+ 0000FFFFh
* | valid | | |
* | | +-------+ 0000FFFFh - len - 1
* | | | valid |
* +-------+ +-------+ seg.limit
* | [1] | | [1] |
* +-------+ +-------+ 00000000h
*/
if ((len > limit - sdp->u.seg.limit) /* len check */
|| (end < offset) /* wrap check */
|| (offset < sdp->u.seg.limit) /* [1] */
|| (end > limit)) { /* [2] */
goto exc;
}
}
} else {
/* expand-up data or code segment */
if (sdp->u.seg.limit == 0xffffffff) {
/*
* 16/32bit
* +-------+ FFFFFFFFh
* | |
* | |
* | valid |
* | |
* | |
* +-------+ 00000000h
*/
sdp->flag |= CPU_DESC_FLAG_WHOLEADR;
} else {
/*
* 16/32bit
* +-------+ FFFFFFFFh
* | |
* | |
* | [1] |
* +.......+ seg.limit
* | |
* +-------+ seg.limit - len - 1
* | valid |
* +-------+ 00000000h
*/
if ((len > sdp->u.seg.limit) /* len check */
|| (end < offset) /* wrap check */
|| (end > sdp->u.seg.limit + 1)) { /* [1] */
goto exc;
}
}
}
return 1; /* Ok! */
exc:
VERBOSE(("check_limit_upstairs: check failure: offset = 0x%08x, len = %d", offset, len + 1));
#if defined(DEBUG)
segdesc_dump(sdp);
#endif
return 0;
}
static void CPUCALL
interrupt_intr_or_trap(const descriptor_t *gsdp, int intrtype, int errorp, int error_code)
{
selector_t cs_sel, ss_sel;
UINT stacksize;
UINT32 old_flags;
UINT32 new_flags;
UINT32 mask;
UINT32 sp;
UINT32 new_ip, new_sp;
UINT32 old_ip, old_sp;
UINT16 old_cs, old_ss, new_ss;
BOOL is32bit;
int exc_errcode;
int rv;
new_ip = gsdp->u.gate.offset;
old_ss = CPU_SS;
old_cs = CPU_CS;
old_ip = CPU_EIP;
old_sp = CPU_ESP;
old_flags = REAL_EFLAGREG;
new_flags = REAL_EFLAGREG & ~(T_FLAG|RF_FLAG|NT_FLAG|VM_FLAG);
mask = T_FLAG|RF_FLAG|NT_FLAG|VM_FLAG;
switch (gsdp->type) {
case CPU_SYSDESC_TYPE_INTR_16:
case CPU_SYSDESC_TYPE_INTR_32:
VERBOSE(("interrupt: INTERRUPT-GATE"));
new_flags &= ~I_FLAG;
mask |= I_FLAG;
break;
case CPU_SYSDESC_TYPE_TRAP_16:
case CPU_SYSDESC_TYPE_TRAP_32:
VERBOSE(("interrupt: TRAP-GATE"));
break;
default:
ia32_panic("interrupt: gate descriptor type is invalid (type = %d)", gsdp->type);
break;
}
exc_errcode = gsdp->u.gate.selector & ~3;
if (intrtype == INTR_TYPE_EXTINTR)
exc_errcode++;
rv = parse_selector(&cs_sel, gsdp->u.gate.selector);
if (rv < 0) {
VERBOSE(("interrupt: parse_selector (selector = %04x, rv = %d)", gsdp->u.gate.selector, rv));
EXCEPTION(GP_EXCEPTION, exc_errcode);
}
/* check segment type */
if (SEG_IS_SYSTEM(&cs_sel.desc)) {
VERBOSE(("interrupt: code segment is system segment"));
EXCEPTION(GP_EXCEPTION, exc_errcode);
}
if (SEG_IS_DATA(&cs_sel.desc)) {
VERBOSE(("interrupt: code segment is data segment"));
EXCEPTION(GP_EXCEPTION, exc_errcode);
}
/* check privilege level */
if (cs_sel.desc.dpl > CPU_STAT_CPL) {
VERBOSE(("interrupt: DPL(%d) > CPL(%d)", cs_sel.desc.dpl, CPU_STAT_CPL));
EXCEPTION(GP_EXCEPTION, exc_errcode);
}
/* not present */
if (selector_is_not_present(&cs_sel)) {
VERBOSE(("interrupt: selector is not present"));
EXCEPTION(NP_EXCEPTION, exc_errcode);
}
is32bit = gsdp->type & CPU_SYSDESC_TYPE_32BIT;
if (!SEG_IS_CONFORMING_CODE(&cs_sel.desc) && (cs_sel.desc.dpl < CPU_STAT_CPL)) {
stacksize = errorp ? 12 : 10;
if (!CPU_STAT_VM86) {
VERBOSE(("interrupt: INTER-PRIVILEGE-LEVEL-INTERRUPT"));
} else {
/* VM86 */
VERBOSE(("interrupt: INTERRUPT-FROM-VIRTUAL-8086-MODE"));
if (cs_sel.desc.dpl != 0) {
/* 16.3.1.1 */
VERBOSE(("interrupt: DPL[CS](%d) != 0", cs_sel.desc.dpl));
EXCEPTION(GP_EXCEPTION, exc_errcode);
}
stacksize += 8;
}
if (is32bit) {
stacksize *= 2;
}
/* get stack pointer from TSS */
get_stack_pointer_from_tss(cs_sel.desc.dpl, &new_ss, &new_sp);
/* parse stack segment descriptor */
rv = parse_selector(&ss_sel, new_ss);
/* update exception error code */
exc_errcode = ss_sel.idx;
if (intrtype == INTR_TYPE_EXTINTR)
exc_errcode++;
if (rv < 0) {
VERBOSE(("interrupt: parse_selector (selector = %04x, rv = %d)", new_ss, rv));
EXCEPTION(TS_EXCEPTION, exc_errcode);
}
/* check privilege level */
if (ss_sel.rpl != cs_sel.desc.dpl) {
VERBOSE(("interrupt: selector RPL[SS](%d) != DPL[CS](%d)", ss_sel.rpl, cs_sel.desc.dpl));
EXCEPTION(TS_EXCEPTION, exc_errcode);
}
if (ss_sel.desc.dpl != cs_sel.desc.dpl) {
VERBOSE(("interrupt: descriptor DPL[SS](%d) != DPL[CS](%d)", ss_sel.desc.dpl, cs_sel.desc.dpl));
EXCEPTION(TS_EXCEPTION, exc_errcode);
}
/* stack segment must be writable data segment. */
if (SEG_IS_SYSTEM(&ss_sel.desc)) {
VERBOSE(("interrupt: stack segment is system segment"));
EXCEPTION(TS_EXCEPTION, exc_errcode);
}
if (SEG_IS_CODE(&ss_sel.desc)) {
VERBOSE(("interrupt: stack segment is code segment"));
EXCEPTION(TS_EXCEPTION, exc_errcode);
}
if (!SEG_IS_WRITABLE_DATA(&ss_sel.desc)) {
VERBOSE(("interrupt: stack segment is read-only data segment"));
EXCEPTION(TS_EXCEPTION, exc_errcode);
}
/* not present */
if (selector_is_not_present(&ss_sel)) {
VERBOSE(("interrupt: selector is not present"));
EXCEPTION(SS_EXCEPTION, exc_errcode);
}
/* check stack room size */
cpu_stack_push_check(ss_sel.idx, &ss_sel.desc, new_sp, stacksize, ss_sel.desc.d);
/* out of range */
if (new_ip > cs_sel.desc.u.seg.limit) {
VERBOSE(("interrupt: new_ip is out of range. new_ip = %08x, limit = %08x", new_ip, cs_sel.desc.u.seg.limit));
EXCEPTION(GP_EXCEPTION, 0);
}
load_ss(ss_sel.selector, &ss_sel.desc, cs_sel.desc.dpl);
CPU_ESP = new_sp;
load_cs(cs_sel.selector, &cs_sel.desc, cs_sel.desc.dpl);
CPU_EIP = new_ip;
if (is32bit) {
if (CPU_STAT_VM86) {
PUSH0_32(CPU_GS);
PUSH0_32(CPU_FS);
PUSH0_32(CPU_DS);
PUSH0_32(CPU_ES);
LOAD_SEGREG(CPU_GS_INDEX, 0);
CPU_STAT_SREG(CPU_GS_INDEX).valid = 0;
LOAD_SEGREG(CPU_FS_INDEX, 0);
CPU_STAT_SREG(CPU_FS_INDEX).valid = 0;
LOAD_SEGREG(CPU_DS_INDEX, 0);
CPU_STAT_SREG(CPU_DS_INDEX).valid = 0;
LOAD_SEGREG(CPU_ES_INDEX, 0);
CPU_STAT_SREG(CPU_ES_INDEX).valid = 0;
}
PUSH0_32(old_ss);
PUSH0_32(old_sp);
PUSH0_32(old_flags);
PUSH0_32(old_cs);
PUSH0_32(old_ip);
if (errorp) {
PUSH0_32(error_code);
}
} else {
if (CPU_STAT_VM86) {
ia32_panic("interrupt: 16bit gate && VM86");
}
PUSH0_16(old_ss);
PUSH0_16(old_sp);
PUSH0_16(old_flags);
PUSH0_16(old_cs);
PUSH0_16(old_ip);
if (errorp) {
PUSH0_16(error_code);
}
}
} else {
if (CPU_STAT_VM86) {
VERBOSE(("interrupt: VM86"));
EXCEPTION(GP_EXCEPTION, exc_errcode);
}
if (!SEG_IS_CONFORMING_CODE(&cs_sel.desc) && (cs_sel.desc.dpl != CPU_STAT_CPL)) {
VERBOSE(("interrupt: %sCONFORMING-CODE-SEGMENT(%d) && DPL[CS](%d) != CPL", SEG_IS_CONFORMING_CODE(&cs_sel.desc) ? "" : "NON-", cs_sel.desc.dpl, CPU_STAT_CPL));
EXCEPTION(GP_EXCEPTION, exc_errcode);
}
VERBOSE(("interrupt: INTRA-PRIVILEGE-LEVEL-INTERRUPT"));
stacksize = errorp ? 8 : 6;
if (is32bit) {
stacksize *= 2;
}
/* check stack room size */
if (CPU_STAT_SS32) {
sp = CPU_ESP;
} else {
sp = CPU_SP;
}
/*
* 17.1
* コールゲート、割り込みゲート、またはトラップゲートを通じて
* プログラムの制御を他のコード・セグメントに移行するときは、
* 移行中に使用されるオペランド・サイズは使用されるゲートの
* タイプ（16 ビットまたは32 ビット）によって決まる（移行命
* 令のD フラグ、プリフィックスのいずれにもよらない）。
*/
SS_PUSH_CHECK1(sp, stacksize, is32bit);
/* out of range */
if (new_ip > cs_sel.desc.u.seg.limit) {
VERBOSE(("interrupt: new_ip is out of range. new_ip = %08x, limit = %08x", new_ip, cs_sel.desc.u.seg.limit));
EXCEPTION(GP_EXCEPTION, 0);
}
load_cs(cs_sel.selector, &cs_sel.desc, CPU_STAT_CPL);
CPU_EIP = new_ip;
if (is32bit) {
PUSH0_32(old_flags);
PUSH0_32(old_cs);
PUSH0_32(old_ip);
if (errorp) {
PUSH0_32(error_code);
}
} else {
PUSH0_16(old_flags);
PUSH0_16(old_cs);
PUSH0_16(old_ip);
if (errorp) {
PUSH0_16(error_code);
}
}
}
set_eflags(new_flags, mask);
VERBOSE(("interrupt: new EIP = %04x:%08x, ESP = %04x:%08x", CPU_CS, CPU_EIP, CPU_SS, CPU_ESP));
}