Bochs/bochs/cpu/jmp_far.cc
Stanislav Shwartsman d8ab4e3424 Fully implemented jump_far and ret_far in 64-bit mode.
Note that I am not sure about 100% correctness, I am just coding Intel specs ...
Code review and massive testing still required.
2005-08-02 18:44:20 +00:00

295 lines
9.6 KiB
C++
Executable File

////////////////////////////////////////////////////////////////////////
// $Id: jmp_far.cc,v 1.3 2005-08-02 18:44:20 sshwarts Exp $
/////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 2001 MandrakeSoft S.A.
//
// MandrakeSoft S.A.
// 43, rue d'Aboukir
// 75002 Paris - France
// http://www.linux-mandrake.com/
// http://www.mandrakesoft.com/
//
// 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 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, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
//
#define NEED_CPU_REG_SHORTCUTS 1
#include "bochs.h"
#define LOG_THIS BX_CPU_THIS_PTR
#if BX_SUPPORT_X86_64==0
// Make life easier merging cpu64 & cpu code.
#define RIP EIP
#endif
void BX_CPP_AttrRegparmN(3)
BX_CPU_C::jump_protected(bxInstruction_c *i, Bit16u cs_raw, bx_address disp)
{
bx_descriptor_t descriptor;
bx_selector_t selector;
Bit32u dword1, dword2;
/* destination selector is not null else #GP(0) */
if ((cs_raw & 0xfffc) == 0) {
BX_ERROR(("jump_protected: cs == 0"));
exception(BX_GP_EXCEPTION, 0, 0);
}
parse_selector(cs_raw, &selector);
/* destination selector index is whithin its descriptor table
limits else #GP(selector) */
fetch_raw_descriptor(&selector, &dword1, &dword2, BX_GP_EXCEPTION);
/* examine AR byte of destination selector for legal values: */
parse_descriptor(dword1, dword2, &descriptor);
if ( descriptor.segment ) {
check_cs(&descriptor, cs_raw, BX_SELECTOR_RPL(cs_raw), CPL);
branch_far64(&selector, &descriptor, disp, CPL);
return;
}
else {
// call gate DPL must be >= CPL else #GP(gate selector)
if (descriptor.dpl < CPL) {
BX_ERROR(("jump_protected: call gate.dpl < CPL"));
exception(BX_GP_EXCEPTION, cs_raw & 0xfffc, 0);
}
// call gate DPL must be >= gate selector RPL else #GP(gate selector)
if (descriptor.dpl < selector.rpl) {
BX_ERROR(("jump_protected: call gate.dpl < selector.rpl"));
exception(BX_GP_EXCEPTION, cs_raw & 0xfffc, 0);
}
// task gate must be present else #NP(gate selector)
if (! IS_PRESENT(descriptor)) {
BX_ERROR(("jump_protected: call gate.p == 0"));
exception(BX_NP_EXCEPTION, cs_raw & 0xfffc, 0);
}
#if BX_SUPPORT_X86_64
if (IsLongMode()) {
if (descriptor.type != BX_386_CALL_GATE) {
BX_ERROR(("jump_protected: gate type %u unsupported in long mode", (unsigned) descriptor.type));
exception(BX_GP_EXCEPTION, cs_raw & 0xfffc, 0);
}
else {
jmp_call_gate64(&descriptor);
return;
}
}
#endif
switch ( descriptor.type ) {
case BX_SYS_SEGMENT_AVAIL_286_TSS:
case BX_SYS_SEGMENT_AVAIL_386_TSS:
if ( descriptor.type==BX_SYS_SEGMENT_AVAIL_286_TSS )
BX_DEBUG(("jump to 286 TSS"));
else
BX_DEBUG(("jump to 386 TSS"));
// SWITCH_TASKS _without_ nesting to TSS
task_switch(&selector, &descriptor, BX_TASK_FROM_JUMP, dword1, dword2);
// EIP must be in code seg limit, else #GP(0)
if (EIP > BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS].cache.u.segment.limit_scaled) {
BX_ERROR(("jump_protected: EIP not within CS limits"));
exception(BX_GP_EXCEPTION, 0, 0);
}
return;
case BX_286_CALL_GATE:
jmp_call_gate16(&descriptor);
return;
case BX_TASK_GATE:
jmp_task_gate(&descriptor);
return;
case BX_386_CALL_GATE:
jmp_call_gate32(&descriptor);
return;
default:
BX_ERROR(("jump_protected: gate type %u unsupported", (unsigned) descriptor.type));
exception(BX_GP_EXCEPTION, cs_raw & 0xfffc, 0);
}
}
}
void BX_CPP_AttrRegparmN(1)
BX_CPU_C::jmp_task_gate(bx_descriptor_t *gate_descriptor)
{
Bit16u raw_tss_selector;
bx_selector_t tss_selector;
bx_descriptor_t tss_descriptor;
Bit32u dword1, dword2;
Bit32u temp_eIP;
// examine selector to TSS, given in Task Gate descriptor
// must specify global in the local/global bit else #GP(TSS selector)
raw_tss_selector = gate_descriptor->u.taskgate.tss_selector;
parse_selector(raw_tss_selector, &tss_selector);
if (tss_selector.ti) {
BX_ERROR(("jump_protected: tss_selector.ti=1"));
exception(BX_GP_EXCEPTION, raw_tss_selector & 0xfffc, 0);
}
// index must be within GDT limits else #GP(TSS selector)
fetch_raw_descriptor(&tss_selector, &dword1, &dword2, BX_GP_EXCEPTION);
// descriptor AR byte must specify available TSS
// else #GP(TSS selector)
parse_descriptor(dword1, dword2, &tss_descriptor);
if (tss_descriptor.valid==0 || tss_descriptor.segment) {
BX_ERROR(("jump_protected: TSS selector points to bad TSS"));
exception(BX_GP_EXCEPTION, raw_tss_selector & 0xfffc, 0);
}
if (tss_descriptor.type!=9 && tss_descriptor.type!=1) {
BX_ERROR(("jump_protected: TSS selector points to bad TSS"));
exception(BX_GP_EXCEPTION, raw_tss_selector & 0xfffc, 0);
}
// task state segment must be present, else #NP(tss selector)
if (! IS_PRESENT(tss_descriptor)) {
BX_ERROR(("jump_protected: TSS descriptor.p == 0"));
exception(BX_NP_EXCEPTION, raw_tss_selector & 0xfffc, 0);
}
// SWITCH_TASKS _without_ nesting to TSS
task_switch(&tss_selector, &tss_descriptor, BX_TASK_FROM_JUMP, dword1, dword2);
// EIP must be within code segment limit, else #GP(0)
if (BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS].cache.u.segment.d_b)
temp_eIP = EIP;
else
temp_eIP = IP;
if (temp_eIP > BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS].cache.u.segment.limit_scaled) {
BX_ERROR(("jump_protected: EIP > CS.limit"));
exception(BX_GP_EXCEPTION, 0, 0);
}
}
void BX_CPP_AttrRegparmN(1)
BX_CPU_C::jmp_call_gate16(bx_descriptor_t *gate_descriptor)
{
bx_selector_t gate_cs_selector;
bx_descriptor_t gate_cs_descriptor;
Bit32u dword1, dword2;
BX_DEBUG(("jump_protected: JUMP TO 286 CALL GATE"));
// examine selector to code segment given in call gate descriptor
// selector must not be null, else #GP(0)
Bit16u gate_cs_raw = gate_descriptor->u.gate286.dest_selector;
if ((gate_cs_raw & 0xfffc) == 0) {
BX_ERROR(("jump_protected: CS selector null"));
exception(BX_GP_EXCEPTION, 0, 0);
}
parse_selector(gate_cs_raw, &gate_cs_selector);
// selector must be within its descriptor table limits else #GP(CS selector)
fetch_raw_descriptor(&gate_cs_selector, &dword1, &dword2, BX_GP_EXCEPTION);
parse_descriptor(dword1, dword2, &gate_cs_descriptor);
// check code-segment descriptor
check_cs(&gate_cs_descriptor, gate_cs_raw, 0, CPL);
Bit16u temp_IP = gate_descriptor->u.gate286.dest_offset;
branch_far32(&gate_cs_selector, &gate_cs_descriptor, temp_IP, CPL);
}
void BX_CPP_AttrRegparmN(1)
BX_CPU_C::jmp_call_gate32(bx_descriptor_t *gate_descriptor)
{
bx_selector_t gate_cs_selector;
bx_descriptor_t gate_cs_descriptor;
Bit32u dword1, dword2;
BX_DEBUG(("jump_protected: JUMP TO 386 CALL GATE"));
// examine selector to code segment given in call gate descriptor
// selector must not be null, else #GP(0)
Bit16u gate_cs_raw = gate_descriptor->u.gate386.dest_selector;
if ((gate_cs_raw & 0xfffc) == 0) {
BX_ERROR(("jump_protected: CS selector null"));
exception(BX_GP_EXCEPTION, 0, 0);
}
parse_selector(gate_cs_raw, &gate_cs_selector);
// selector must be within its descriptor table limits else #GP(CS selector)
fetch_raw_descriptor(&gate_cs_selector, &dword1, &dword2, BX_GP_EXCEPTION);
parse_descriptor(dword1, dword2, &gate_cs_descriptor);
// check code-segment descriptor
check_cs(&gate_cs_descriptor, gate_cs_raw, 0, CPL);
Bit32u temp_EIP = gate_descriptor->u.gate386.dest_offset;
branch_far32(&gate_cs_selector, &gate_cs_descriptor, temp_EIP, CPL);
}
#if BX_SUPPORT_X86_64
void BX_CPP_AttrRegparmN(1)
BX_CPU_C::jmp_call_gate64(bx_descriptor_t *gate_descriptor)
{
bx_selector_t gate_cs_selector;
bx_descriptor_t gate_cs_descriptor;
Bit32u dword1, dword2, dword3;
Bit64u temp_RIP;
BX_DEBUG(("jump_protected: jump to CALL GATE 64"));
// examine selector to code segment given in call gate descriptor
// selector must not be null, else #GP(0)
Bit16u gate_cs_raw = gate_descriptor->u.gate386.dest_selector;
if ((gate_cs_raw & 0xfffc) == 0) {
BX_ERROR(("jump_protected: CS selector null"));
exception(BX_GP_EXCEPTION, 0, 0);
}
parse_selector(gate_cs_raw, &gate_cs_selector);
// selector must be within its descriptor table limits else #GP(CS selector)
fetch_raw_descriptor64(&gate_cs_selector, &dword1, &dword2, &dword3, BX_GP_EXCEPTION);
parse_descriptor(dword1, dword2, &gate_cs_descriptor);
// In long mode, only 64-bit call gates are allowed, and they must point
// to 64-bit code segments, else #GP(selector)
if (! IS_LONG64_SEGMENT(gate_cs_descriptor) || gate_cs_descriptor.u.segment.d_b)
{
BX_ERROR(("jump_protected: not 64-bit code segment in call gate 64"));
exception(BX_GP_EXCEPTION, gate_cs_raw & 0xfffc, 0);
}
// check code-segment descriptor
check_cs(&gate_cs_descriptor, gate_cs_raw, 0, CPL);
temp_RIP = gate_descriptor->u.gate386.dest_offset;
temp_RIP |= ((Bit64u)dword3 << 32);
branch_far64(&gate_cs_selector, &gate_cs_descriptor, temp_RIP, CPL);
}
#endif