/* $Id: exception.c,v 1.4 2004/01/23 14:33:26 monaka Exp $ */
/*
* Copyright (c) 2003 NONAKA Kimihiro
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "compiler.h"
#include "cpu.h"
#include "ia32.mcr"
const char *exception_str[EXCEPTION_NUM] = {
"DE_EXCEPTION",
"DB_EXCEPTION",
"NMI_EXCEPTION",
"BP_EXCEPTION",
"OF_EXCEPTION",
"BR_EXCEPTION",
"UD_EXCEPTION",
"NM_EXCEPTION",
"DF_EXCEPTION",
"CoProcesser Segment Overrun",
"TS_EXCEPTION",
"NP_EXCEPTION",
"SS_EXCEPTION",
"GP_EXCEPTION",
"PF_EXCEPTION",
"Reserved",
"MF_EXCEPTION",
"AC_EXCEPTION",
"MC_EXCEPTION",
"XF_EXCEPTION",
};
static const int exctype[EXCEPTION_NUM] = {
1, 0, 0, 0, 0, 0, 0, 0, 3, 0, 1, 1, 1, 1, 2, 0, 0, 0, 0, 0,
};
static const int dftable[4][4] = {
{ 0, 0, 0, 1, },
{ 0, 1, 0, 1, },
{ 0, 1, 1, 1, },
{ 1, 1, 1, 1, },
};
void
exception(int num, int error_code)
{
int errorp = 0;
__ASSERT((unsigned int)num < EXCEPTION_NUM);
VERBOSE(("exception: %s, error_code = %x at %04x:%08x", exception_str[num], error_code, CPU_CS, CPU_PREV_EIP));
CPU_STAT_NERROR++;
if ((CPU_STAT_NERROR >= 3)
|| (CPU_STAT_NERROR == 2 && CPU_STAT_PREV_EXCEPTION == DF_EXCEPTION)) {
/* Triple fault */
ia32_panic("exception: catch triple fault!");
}
switch (num) {
case DE_EXCEPTION: /* (F) 除算エラー */
case BR_EXCEPTION: /* (F) BOUND の範囲外 */
case UD_EXCEPTION: /* (F) 無効オペコード */
case NM_EXCEPTION: /* (F) デバイス使用不可 (FPU が無い) */
CPU_EIP = CPU_PREV_EIP;
/*FALLTHROUGH*/
case DB_EXCEPTION: /* (F/T) デバッグ */
case NMI_EXCEPTION: /* (I) NMI 割り込み */
case BP_EXCEPTION: /* (T) ブレークポイント */
case OF_EXCEPTION: /* (T) オーバーフロー */
errorp = 0;
break;
case DF_EXCEPTION: /* (A) ダブルフォルト (errcode: 0) */
errorp = 1;
error_code = 0;
break;
case AC_EXCEPTION: /* (F) アラインメントチェック (errcode: 0) */
error_code = 0;
/*FALLTHROUGH*/
case TS_EXCEPTION: /* (F) 無効 TSS (errcode) */
case NP_EXCEPTION: /* (F) セグメント不在 (errcode) */
case SS_EXCEPTION: /* (F) スタックセグメントフォルト (errcode) */
case GP_EXCEPTION: /* (F) 一般保護例外 (errcode) */
case PF_EXCEPTION: /* (F) ページフォルト (errcode) */
CPU_EIP = CPU_PREV_EIP;
errorp = 1;
break;
case MF_EXCEPTION: /* (F) 浮動小数点エラー */
CPU_EIP = CPU_PREV_EIP;
errorp = 0;
break;
case MC_EXCEPTION: /* (A) マシンチェック */
CPU_EIP = CPU_PREV_EIP;
errorp = 0;
break;
case XF_EXCEPTION: /* (F) ストリーミング SIMD 拡張命令 */
CPU_EIP = CPU_PREV_EIP;
errorp = 0;
break;
default:
ia32_panic("exception: unknown exception (%d)", num);
break;
}
#if defined(DEBUG)
if (num == PF_EXCEPTION) {
VERBOSE(("exception: CPU_CR2 = %08x", CPU_CR2));
}
#endif
if (CPU_STAT_NERROR >= 2) {
if (dftable[exctype[CPU_STAT_PREV_EXCEPTION]][exctype[num]]) {
num = DF_EXCEPTION;
}
}
CPU_STAT_PREV_EXCEPTION = num;
INTERRUPT(num, FALSE, errorp, error_code);
CPU_STAT_NERROR = 0;
siglongjmp(exec_1step_jmpbuf, 1);
}
/*
* コール・ゲート・ディスクリプタ
*
* 31 16 15 14 13 12 8 7 5 4 0
* +------------------------------------+--+-----+----------+-----+---------+
* | オフセット 31..16 | P| DPL | 0 D 1 0 0|0 0 0|カウント | 4
* +------------------------------------+--+-----+----------+-----+---------+
* 31 16 15 0
* +------------------------------------+-----------------------------------+
* | セグメント・セレクタ | オフセット 15..0 | 0
* +------------------------------------+-----------------------------------+
*/
/*
* 割り込みディスクリプタ
*--
* タスク・ゲート
*
* 31 16 15 14 13 12 8 7 0
* +------------------------------------+--+-----+----------+---------------+
* | Reserved | P| DPL | 0 0 1 0 1| Reserved | 4
* +------------------------------------+--+-----+----------+---------------+
* 31 16 15 0
* +------------------------------------+-----------------------------------+
* | TSS セグメント・セレクタ | Reserved | 0
* +------------------------------------+-----------------------------------+
*--
* 割り込み・ゲート
*
* 31 16 15 14 13 12 8 7 5 4 0
* +------------------------------------+--+-----+----------+-----+---------+
* | オフセット 31..16 | P| DPL | 0 D 1 1 0|0 0 0|Reserved | 4
* +------------------------------------+--+-----+----------+-----+---------+
* 31 16 15 0
* +------------------------------------+-----------------------------------+
* | セグメント・セレクタ | オフセット 15..0 | 0
* +------------------------------------+-----------------------------------+
*--
* トラップ・ゲート
*
* 31 16 15 14 13 12 8 7 5 4 0
* +------------------------------------+--+-----+----------+-----+---------+
* | オフセット 31..16 | P| DPL | 0 D 1 1 1|0 0 0|Reserved | 4
* +------------------------------------+--+-----+----------+-----+---------+
* 31 16 15 0
* +------------------------------------+-----------------------------------+
* | セグメント・セレクタ | オフセット 15..0 | 0
* +------------------------------------+-----------------------------------+
*--
* DPL : ディスクリプタ特権レベル
* オフセット : プロシージャ・エントリ・ポイントまでのオフセット
* P : セグメント存在フラグ
* セレクタ : ディスティネーション・コード・セグメントのセグメント・セレクタ
* D : ゲートのサイズ．0 = 16 bit, 1 = 32 bit
*/
static void interrupt_task(descriptor_t *gdp, int softintp, int errorp, int error_code);
static void interrupt_intr_or_trap(descriptor_t *gdp, int softintp, int errorp, int error_code);
void
interrupt(int num, int softintp, int errorp, int error_code)
{
descriptor_t gd;
DWORD idt_idx;
DWORD new_ip;
WORD new_cs;
VERBOSE(("interrupt: num = 0x%02x, softintp = %s, errorp = %s, error_code = %02x", num, softintp ? "on" : "off", errorp ? "on" : "off", error_code));
if (!CPU_STAT_PM) {
/* real mode */
idt_idx = num * 4;
if (idt_idx + 3 > CPU_IDTR_LIMIT) {
VERBOSE(("interrupt: real-mode IDTR limit check failure (idx = 0x%04x, limit = 0x%08x", idt_idx, CPU_IDTR_LIMIT));
EXCEPTION(GP_EXCEPTION, num * 4 | 2);
}
if (!softintp) {
BYTE op = cpu_codefetch(CPU_IP);
if (op == 0xf4) { /* hlt */
CPU_EIP++;
}
}
REGPUSH0(REAL_FLAGREG);
REGPUSH0(CPU_CS);
REGPUSH0(CPU_IP);
CPU_EFLAG &= ~(T_FLAG | I_FLAG | AC_FLAG | RF_FLAG);
CPU_TRAP = 0;
new_ip = cpu_memoryread_w(CPU_IDTR_BASE + num * 4);
new_cs = cpu_memoryread_w(CPU_IDTR_BASE + num * 4 + 2);
CPU_SET_SEGREG(CPU_CS_INDEX, new_cs);
SET_EIP(new_ip);
CPU_WORKCLOCK(20);
} else {
/* protected mode */
/* VM86 && IOPL < 3 && interrupt cause == INTn */
if (CPU_STAT_VM86 && (CPU_STAT_IOPL < CPU_IOPL3) && (softintp == -1)) {
VERBOSE(("interrupt: VM86 && IOPL < 3 && INTn"));
EXCEPTION(GP_EXCEPTION, 0);
}
idt_idx = num * 8;
if (idt_idx + 7 > CPU_IDTR_LIMIT) {
VERBOSE(("interrupt: IDTR limit check failure (idx = 0x%04x, limit = 0x%08x", idt_idx, CPU_IDTR_LIMIT));
EXCEPTION(GP_EXCEPTION, num * 8 | 2 | !softintp);
}
memset(&gd, 0, sizeof(gd));
CPU_SET_GATEDESC(&gd, CPU_IDTR_BASE + idt_idx);
if (!gd.valid || !gd.p) {
VERBOSE(("interrupt: gate descripter is invalid."));
EXCEPTION(GP_EXCEPTION, num * 8 | 2 | !softintp);
}
switch (gd.type) {
case CPU_SYSDESC_TYPE_TASK:
case CPU_SYSDESC_TYPE_INTR_16:
case CPU_SYSDESC_TYPE_INTR_32:
case CPU_SYSDESC_TYPE_TRAP_16:
case CPU_SYSDESC_TYPE_TRAP_32:
break;
default:
VERBOSE(("interrupt: invalid gate type (%d)", gd.type));
EXCEPTION(GP_EXCEPTION, num * 8 | 2 | !softintp);
break;
}
/* 5.10.1.1. 例外／割り込みハンドラ・プロシージャの保護 */
if (softintp && (gd.dpl < CPU_STAT_CPL)) {
VERBOSE(("interrupt: softintp && DPL(%d) < CPL(%d)", gd.dpl, CPU_STAT_CPL));
EXCEPTION(GP_EXCEPTION, num * 8 | 2);
}
switch (gd.type) {
case CPU_SYSDESC_TYPE_TASK:
interrupt_task(&gd, softintp, errorp, error_code);
break;
case CPU_SYSDESC_TYPE_INTR_16:
case CPU_SYSDESC_TYPE_INTR_32:
case CPU_SYSDESC_TYPE_TRAP_16:
case CPU_SYSDESC_TYPE_TRAP_32:
interrupt_intr_or_trap(&gd, softintp, errorp, error_code);
break;
default:
EXCEPTION(GP_EXCEPTION, num * 8 | 2 | !softintp);
break;
}
}
}
static void
interrupt_task(descriptor_t *gdp, int softintp, int errorp, int error_code)
{
selector_t task_sel;
int rv;
VERBOSE(("interrupt: TASK-GATE"));
(void)softintp;
rv = parse_selector(&task_sel, gdp->u.gate.selector);
if (rv < 0 || task_sel.ldt) {
VERBOSE(("interrupt: parse_selector (selector = %04x, rv = %d, %cDT)", gdp->u.gate.selector, rv, task_sel.ldt ? 'L' : 'G'));
EXCEPTION(TS_EXCEPTION, task_sel.idx);
}
/* check gate type */
switch (task_sel.desc.type) {
case CPU_SYSDESC_TYPE_TSS_16:
case CPU_SYSDESC_TYPE_TSS_32:
break;
case CPU_SYSDESC_TYPE_TSS_BUSY_16:
case CPU_SYSDESC_TYPE_TSS_BUSY_32:
VERBOSE(("interrupt: task is busy."));
/*FALLTHROUGH*/
default:
VERBOSE(("interrupt: invalid gate type (%d)", task_sel.desc.type));
EXCEPTION(TS_EXCEPTION, task_sel.idx);
break;
}
/* not present */
if (selector_is_not_present(&task_sel)) {
VERBOSE(("interrupt: selector is not present"));
EXCEPTION(NP_EXCEPTION, task_sel.idx);
}
task_switch(&task_sel, TASK_SWITCH_INTR);
if (errorp) {
XPUSH0(error_code);
}
}
static void
interrupt_intr_or_trap(descriptor_t *gdp, int softintp, int errorp, int error_code)
{
selector_t intr_sel, ss_sel;
DWORD flags = REAL_EFLAGREG;
DWORD mask = 0;
DWORD stacksize;
DWORD new_ip, new_sp;
DWORD old_ip, old_sp;
WORD old_cs, old_ss, new_ss;
int rv;
switch (gdp->type) {
case CPU_SYSDESC_TYPE_INTR_16:
case CPU_SYSDESC_TYPE_INTR_32:
VERBOSE(("interrupt: INTERRUPT-GATE"));
flags &= ~I_FLAG;
mask |= I_FLAG;
break;
case CPU_SYSDESC_TYPE_TRAP_16:
case CPU_SYSDESC_TYPE_TRAP_32:
VERBOSE(("interrupt: TRAP-GATE"));
break;
}
flags &= ~(T_FLAG|RF_FLAG|NT_FLAG|VM_FLAG);
mask |= T_FLAG|RF_FLAG|NT_FLAG|VM_FLAG;
new_ip = gdp->u.gate.offset;
old_ss = CPU_SS;
old_cs = CPU_CS;
old_ip = CPU_EIP;
old_sp = CPU_ESP;
switch (gdp->type) {
case CPU_SYSDESC_TYPE_INTR_16:
case CPU_SYSDESC_TYPE_TRAP_16:
old_ip &= 0xffff;
old_sp &= 0xffff;
break;
}
VERBOSE(("interrupt: old EIP = %04x:%08x, old ESP = %04x:%08x", old_cs, old_ip, old_ss, old_sp));
rv = parse_selector(&intr_sel, gdp->u.gate.selector);
if (rv < 0) {
VERBOSE(("interrupt: parse_selector (selector = %04x, rv = %d)", gdp->u.gate.selector, rv));
EXCEPTION(GP_EXCEPTION, intr_sel.idx | !softintp);
}
/* check segment type */
if (!intr_sel.desc.s) {
VERBOSE(("interrupt: code segment is system segment"));
EXCEPTION(GP_EXCEPTION, intr_sel.idx | !softintp);
}
if (!intr_sel.desc.u.seg.c) {
VERBOSE(("interrupt: code segment is data segment"));
EXCEPTION(GP_EXCEPTION, intr_sel.idx | !softintp);
}
/* check privilege level */
if (intr_sel.desc.dpl > CPU_STAT_CPL) {
VERBOSE(("interrupt: DPL(%d) > CPL(%d)", intr_sel.desc.dpl, CPU_STAT_CPL));
EXCEPTION(GP_EXCEPTION, intr_sel.idx | !softintp);
}
/* not present */
if (selector_is_not_present(&intr_sel)) {
VERBOSE(("interrupt: selector is not present"));
EXCEPTION(NP_EXCEPTION, intr_sel.idx | !softintp);
}
if (!intr_sel.desc.u.seg.ec
&& (intr_sel.desc.dpl < CPU_STAT_CPL)) {
if (!CPU_STAT_VM86) {
VERBOSE(("interrupt: INTER-PRIVILEGE-LEVEL-INTERRUPT"));
stacksize = errorp ? 12 : 10;
} else {
/* VM86 */
if (intr_sel.desc.dpl != 0) {
/* 16.3.1.1 */
VERBOSE(("interrupt: DPL[CS](%d) != 0", intr_sel.desc.dpl));
EXCEPTION(GP_EXCEPTION, intr_sel.idx);
}
VERBOSE(("interrupt: INTERRUPT-FROM-VIRTUAL-8086-MODE"));
stacksize = errorp ? 20 : 18;
}
switch (gdp->type) {
case CPU_SYSDESC_TYPE_INTR_32:
case CPU_SYSDESC_TYPE_TRAP_32:
stacksize *= 2;
break;
}
get_stack_from_tss(intr_sel.desc.dpl, &new_ss, &new_sp);
rv = parse_selector(&ss_sel, new_ss);
if (rv < 0) {
VERBOSE(("interrupt: parse_selector (selector = %04x, rv = %d)", new_ss, rv));
EXCEPTION(TS_EXCEPTION, ss_sel.idx | !softintp);
}
/* check privilege level */
if (ss_sel.rpl != intr_sel.desc.dpl) {
VERBOSE(("interrupt: RPL[SS](%d) != DPL[CS](%d)", ss_sel.rpl, intr_sel.desc.dpl));
EXCEPTION(TS_EXCEPTION, ss_sel.idx | !softintp);
}
if (ss_sel.desc.dpl != intr_sel.desc.dpl) {
VERBOSE(("interrupt: DPL[SS](%d) != DPL[CS](%d)", ss_sel.desc.dpl, intr_sel.desc.dpl));
EXCEPTION(TS_EXCEPTION, ss_sel.idx | !softintp);
}
/* check segment type */
if (!ss_sel.desc.s) {
VERBOSE(("interrupt: stack segment is system segment"));
EXCEPTION(TS_EXCEPTION, ss_sel.idx | !softintp);
}
if (ss_sel.desc.u.seg.c) {
VERBOSE(("interrupt: stack segment is code segment"));
EXCEPTION(TS_EXCEPTION, ss_sel.idx | !softintp);
}
if (!ss_sel.desc.u.seg.wr) {
VERBOSE(("interrupt: stack segment is read-only data segment"));
EXCEPTION(TS_EXCEPTION, ss_sel.idx | !softintp);
}
/* not present */
if (selector_is_not_present(&ss_sel)) {
VERBOSE(("interrupt: selector is not present"));
EXCEPTION(SS_EXCEPTION, ss_sel.idx | !softintp);
}
/* check stack room size */
CHECK_STACK_PUSH(&ss_sel.desc, new_sp, stacksize);
/* out of range */
if (new_ip > intr_sel.desc.u.seg.limit) {
VERBOSE(("interrupt: new_ip is out of range. new_ip = %08x, limit = %08x", new_ip, intr_sel.desc.u.seg.limit));
EXCEPTION(GP_EXCEPTION, 0);
}
load_ss(new_ss, &ss_sel.desc, intr_sel.desc.dpl);
if (CPU_STAT_SS32) {
CPU_ESP = new_sp;
} else {
CPU_SP = new_sp;
}
load_cs(intr_sel.selector, &intr_sel.desc, intr_sel.desc.dpl);
SET_EIP(new_ip);
if (CPU_STAT_VM86) {
switch (gdp->type) {
case CPU_SYSDESC_TYPE_INTR_32:
case CPU_SYSDESC_TYPE_TRAP_32:
PUSH0_32(CPU_GS);
PUSH0_32(CPU_FS);
PUSH0_32(CPU_DS);
PUSH0_32(CPU_ES);
break;
case CPU_SYSDESC_TYPE_INTR_16:
case CPU_SYSDESC_TYPE_TRAP_16:
ia32_panic("interrupt: 16bit gate");
break;
}
CPU_SET_SEGREG(CPU_GS_INDEX, 0);
CPU_SET_SEGREG(CPU_FS_INDEX, 0);
CPU_SET_SEGREG(CPU_DS_INDEX, 0);
CPU_SET_SEGREG(CPU_ES_INDEX, 0);
}
switch (gdp->type) {
case CPU_SYSDESC_TYPE_INTR_32:
case CPU_SYSDESC_TYPE_TRAP_32:
PUSH0_32(old_ss);
PUSH0_32(old_sp);
PUSH0_32(REAL_EFLAGREG);
PUSH0_32(old_cs);
PUSH0_32(old_ip);
if (errorp) {
PUSH0_32(error_code);
}
break;
case CPU_SYSDESC_TYPE_INTR_16:
case CPU_SYSDESC_TYPE_TRAP_16:
PUSH0_16(old_ss);
PUSH0_16(old_sp);
PUSH0_16(REAL_FLAGREG);
PUSH0_16(old_cs);
PUSH0_16(old_ip);
if (errorp) {
PUSH0_16(error_code);
}
break;
}
set_eflags(flags, mask);
} else {
if (CPU_STAT_VM86) {
VERBOSE(("interrupt: VM86"));
EXCEPTION(GP_EXCEPTION, intr_sel.idx);
}
if (!intr_sel.desc.u.seg.ec && (intr_sel.desc.dpl != CPU_STAT_CPL)) {
VERBOSE(("interrupt: NON-CONFORMING-CODE-SEGMENT(%s) and DPL[CS](%d) != CPL", intr_sel.desc.u.seg.ec ? "false" : "true", intr_sel.desc.dpl, CPU_STAT_CPL));
EXCEPTION(GP_EXCEPTION, intr_sel.idx);
}
VERBOSE(("interrupt: INTRA-PRIVILEGE-LEVEL-INTERRUPT"));
if (CPU_STAT_SS32) {
new_sp = CPU_ESP;
} else {
new_sp = CPU_SP;
}
stacksize = errorp ? 8 : 6;
switch (gdp->type) {
case CPU_SYSDESC_TYPE_INTR_32:
case CPU_SYSDESC_TYPE_TRAP_32:
stacksize *= 2;
break;
}
CHECK_STACK_PUSH(&CPU_STAT_SREG(CPU_SS_INDEX), new_sp, stacksize);
/* out of range */
if (new_ip > intr_sel.desc.u.seg.limit) {
VERBOSE(("interrupt: new_ip is out of range. new_ip = %08x, limit = %08x", new_ip, intr_sel.desc.u.seg.limit));
EXCEPTION(GP_EXCEPTION, 0);
}
switch (gdp->type) {
case CPU_SYSDESC_TYPE_INTR_32:
case CPU_SYSDESC_TYPE_TRAP_32:
PUSH0_32(REAL_EFLAGREG);
PUSH0_32(CPU_CS);
PUSH0_32(CPU_EIP);
if (errorp) {
PUSH0_32(error_code);
}
break;
case CPU_SYSDESC_TYPE_INTR_16:
case CPU_SYSDESC_TYPE_TRAP_16:
PUSH0_16(REAL_FLAGREG);
PUSH0_16(CPU_CS);
PUSH0_16(CPU_IP);
if (errorp) {
PUSH0_16(error_code);
}
break;
}
load_cs(intr_sel.selector, &intr_sel.desc, CPU_STAT_CPL);
SET_EIP(new_ip);
set_eflags(flags, mask);
}
VERBOSE(("interrupt: new EIP = %04x:%08x, new ESP = %04x:%08x", CPU_CS, CPU_EIP, CPU_SS, CPU_ESP));
}
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