void BX_CPU_C::protected_mode_int(Bit8u vector, unsigned soft_int, bx_bool push_error, Bit16u error_code) { bx_descriptor_t gate_descriptor, cs_descriptor; bx_selector_t cs_selector; Bit16u raw_tss_selector; bx_selector_t tss_selector; bx_descriptor_t tss_descriptor; Bit16u gate_dest_selector; Bit32u gate_dest_offset; // interrupt vector must be within IDT table limits, // else #GP(vector*8 + 2 + EXT) if ((vector*8 + 7) > BX_CPU_THIS_PTR idtr.limit) { BX_ERROR(("interrupt(): vector must be within IDT table limits, IDT.limit = 0x%x", BX_CPU_THIS_PTR idtr.limit)); exception(BX_GP_EXCEPTION, vector*8 + 2); } Bit64u desctmp = system_read_qword(BX_CPU_THIS_PTR idtr.base + vector*8); Bit32u dword1 = GET32L(desctmp); Bit32u dword2 = GET32H(desctmp); parse_descriptor(dword1, dword2, &gate_descriptor); if ((gate_descriptor.valid==0) || gate_descriptor.segment) { BX_ERROR(("interrupt(): gate descriptor is not valid sys seg (vector=0x%02x)", vector)); exception(BX_GP_EXCEPTION, vector*8 + 2); } // descriptor AR byte must indicate interrupt gate, trap gate, // or task gate, else #GP(vector*8 + 2 + EXT) switch (gate_descriptor.type) { case BX_TASK_GATE: case BX_286_INTERRUPT_GATE: case BX_286_TRAP_GATE: case BX_386_INTERRUPT_GATE: case BX_386_TRAP_GATE: break; default: BX_ERROR(("interrupt(): gate.type(%u) != {5,6,7,14,15}", (unsigned) gate_descriptor.type)); exception(BX_GP_EXCEPTION, vector*8 + 2); } // if software interrupt, then gate descripor DPL must be >= CPL, // else #GP(vector * 8 + 2 + EXT) if (soft_int && gate_descriptor.dpl < CPL) { BX_ERROR(("interrupt(): soft_int && (gate.dpl < CPL)")); exception(BX_GP_EXCEPTION, vector*8 + 2); } // Gate must be present, else #NP(vector * 8 + 2 + EXT) if (! IS_PRESENT(gate_descriptor)) { BX_ERROR(("interrupt(): gate not present")); exception(BX_NP_EXCEPTION, vector*8 + 2); } switch (gate_descriptor.type) { case BX_TASK_GATE: // examine selector to TSS, given in task gate descriptor raw_tss_selector = gate_descriptor.u.taskgate.tss_selector; parse_selector(raw_tss_selector, &tss_selector); // must specify global in the local/global bit, // else #GP(TSS selector) if (tss_selector.ti) { BX_ERROR(("interrupt(): tss_selector.ti=1 from gate descriptor - #GP(tss_selector)")); exception(BX_GP_EXCEPTION, raw_tss_selector & 0xfffc); } // index must be within GDT limits, else #TS(TSS selector) fetch_raw_descriptor(&tss_selector, &dword1, &dword2, BX_GP_EXCEPTION); parse_descriptor(dword1, dword2, &tss_descriptor); // AR byte must specify available TSS, // else #GP(TSS selector) if (tss_descriptor.valid==0 || tss_descriptor.segment) { BX_ERROR(("interrupt(): TSS selector points to invalid or bad TSS - #GP(tss_selector)")); exception(BX_GP_EXCEPTION, raw_tss_selector & 0xfffc); } if (tss_descriptor.type!=BX_SYS_SEGMENT_AVAIL_286_TSS && tss_descriptor.type!=BX_SYS_SEGMENT_AVAIL_386_TSS) { BX_ERROR(("interrupt(): TSS selector points to bad TSS - #GP(tss_selector)")); exception(BX_GP_EXCEPTION, raw_tss_selector & 0xfffc); } // TSS must be present, else #NP(TSS selector) if (! IS_PRESENT(tss_descriptor)) { BX_ERROR(("interrupt(): TSS descriptor.p == 0")); exception(BX_NP_EXCEPTION, raw_tss_selector & 0xfffc); } // switch tasks with nesting to TSS task_switch(0, &tss_selector, &tss_descriptor, BX_TASK_FROM_INT, dword1, dword2); RSP_SPECULATIVE; // if interrupt was caused by fault with error code // stack limits must allow push of 2 more bytes, else #SS(0) // push error code onto stack if (push_error) { if (tss_descriptor.type >= 9) // TSS386 push_32(error_code); else push_16(error_code); } // instruction pointer must be in CS limit, else #GP(0) if (EIP > BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS].cache.u.segment.limit_scaled) { BX_ERROR(("interrupt(): EIP > CS.limit")); exception(BX_GP_EXCEPTION, 0); } RSP_COMMIT; return; case BX_286_INTERRUPT_GATE: case BX_286_TRAP_GATE: case BX_386_INTERRUPT_GATE: case BX_386_TRAP_GATE: gate_dest_selector = gate_descriptor.u.gate.dest_selector; gate_dest_offset = gate_descriptor.u.gate.dest_offset; // examine CS selector and descriptor given in gate descriptor // selector must be non-null else #GP(EXT) if ((gate_dest_selector & 0xfffc) == 0) { BX_ERROR(("int_trap_gate(): selector null")); exception(BX_GP_EXCEPTION, 0); } parse_selector(gate_dest_selector, &cs_selector); // selector must be within its descriptor table limits // else #GP(selector+EXT) fetch_raw_descriptor(&cs_selector, &dword1, &dword2, BX_GP_EXCEPTION); parse_descriptor(dword1, dword2, &cs_descriptor); // descriptor AR byte must indicate code seg // and code segment descriptor DPL<=CPL, else #GP(selector+EXT) if (cs_descriptor.valid==0 || cs_descriptor.segment==0 || IS_DATA_SEGMENT(cs_descriptor.type) || cs_descriptor.dpl > CPL) { BX_ERROR(("interrupt(): not accessible or not code segment cs=0x%04x", cs_selector.value)); exception(BX_GP_EXCEPTION, cs_selector.value & 0xfffc); } // segment must be present, else #NP(selector + EXT) if (! IS_PRESENT(cs_descriptor)) { BX_ERROR(("interrupt(): segment not present")); exception(BX_NP_EXCEPTION, cs_selector.value & 0xfffc); } // if code segment is non-conforming and DPL < CPL then // INTERRUPT TO INNER PRIVILEGE if(IS_CODE_SEGMENT_NON_CONFORMING(cs_descriptor.type) && cs_descriptor.dpl < CPL) { Bit16u old_SS, old_CS, SS_for_cpl_x; Bit32u ESP_for_cpl_x, old_EIP, old_ESP; bx_descriptor_t ss_descriptor; bx_selector_t ss_selector; int is_v8086_mode = v8086_mode(); BX_DEBUG(("interrupt(): INTERRUPT TO INNER PRIVILEGE")); // check selector and descriptor for new stack in current TSS get_SS_ESP_from_TSS(cs_descriptor.dpl, &SS_for_cpl_x, &ESP_for_cpl_x); if (is_v8086_mode && cs_descriptor.dpl != 0) { // if code segment DPL != 0 then #GP(new code segment selector) BX_ERROR(("interrupt(): code segment DPL(%d) != 0 in v8086 mode", cs_descriptor.dpl)); exception(BX_GP_EXCEPTION, cs_selector.value & 0xfffc); } // Selector must be non-null else #TS(EXT) if ((SS_for_cpl_x & 0xfffc) == 0) { BX_ERROR(("interrupt(): SS selector null")); exception(BX_TS_EXCEPTION, 0); /* TS(ext) */ } // selector index must be within its descriptor table limits // else #TS(SS selector + EXT) parse_selector(SS_for_cpl_x, &ss_selector); // fetch 2 dwords of descriptor; call handles out of limits checks fetch_raw_descriptor(&ss_selector, &dword1, &dword2, BX_TS_EXCEPTION); parse_descriptor(dword1, dword2, &ss_descriptor); // selector rpl must = dpl of code segment, // else #TS(SS selector + ext) if (ss_selector.rpl != cs_descriptor.dpl) { BX_ERROR(("interrupt(): SS.rpl != CS.dpl")); exception(BX_TS_EXCEPTION, SS_for_cpl_x & 0xfffc); } // stack seg DPL must = DPL of code segment, // else #TS(SS selector + ext) if (ss_descriptor.dpl != cs_descriptor.dpl) { BX_ERROR(("interrupt(): SS.dpl != CS.dpl")); exception(BX_TS_EXCEPTION, SS_for_cpl_x & 0xfffc); } // descriptor must indicate writable data segment, // else #TS(SS selector + EXT) if (ss_descriptor.valid==0 || ss_descriptor.segment==0 || IS_CODE_SEGMENT(ss_descriptor.type) || !IS_DATA_SEGMENT_WRITEABLE(ss_descriptor.type)) { BX_ERROR(("interrupt(): SS is not writable data segment")); exception(BX_TS_EXCEPTION, SS_for_cpl_x & 0xfffc); } // seg must be present, else #SS(SS selector + ext) if (! IS_PRESENT(ss_descriptor)) { BX_ERROR(("interrupt(): SS not present")); exception(BX_SS_EXCEPTION, SS_for_cpl_x & 0xfffc); } // IP must be within CS segment boundaries, else #GP(0) if (gate_dest_offset > cs_descriptor.u.segment.limit_scaled) { BX_ERROR(("interrupt(): gate EIP > CS.limit")); exception(BX_GP_EXCEPTION, 0); } old_ESP = ESP; old_SS = BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS].selector.value; old_EIP = EIP; old_CS = BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS].selector.value; // Prepare new stack segment bx_segment_reg_t new_stack; new_stack.selector = ss_selector; new_stack.cache = ss_descriptor; new_stack.selector.rpl = cs_descriptor.dpl; // add cpl to the selector value new_stack.selector.value = (0xfffc & new_stack.selector.value) | new_stack.selector.rpl; if (ss_descriptor.u.segment.d_b) { Bit32u temp_ESP = ESP_for_cpl_x; if (is_v8086_mode) { if (gate_descriptor.type>=14) { // 386 int/trap gate write_new_stack_dword_32(&new_stack, temp_ESP-4, cs_descriptor.dpl, BX_CPU_THIS_PTR sregs[BX_SEG_REG_GS].selector.value); write_new_stack_dword_32(&new_stack, temp_ESP-8, cs_descriptor.dpl, BX_CPU_THIS_PTR sregs[BX_SEG_REG_FS].selector.value); write_new_stack_dword_32(&new_stack, temp_ESP-12, cs_descriptor.dpl, BX_CPU_THIS_PTR sregs[BX_SEG_REG_DS].selector.value); write_new_stack_dword_32(&new_stack, temp_ESP-16, cs_descriptor.dpl, BX_CPU_THIS_PTR sregs[BX_SEG_REG_ES].selector.value); temp_ESP -= 16; } else { write_new_stack_word_32(&new_stack, temp_ESP-2, cs_descriptor.dpl, BX_CPU_THIS_PTR sregs[BX_SEG_REG_GS].selector.value); write_new_stack_word_32(&new_stack, temp_ESP-4, cs_descriptor.dpl, BX_CPU_THIS_PTR sregs[BX_SEG_REG_FS].selector.value); write_new_stack_word_32(&new_stack, temp_ESP-6, cs_descriptor.dpl, BX_CPU_THIS_PTR sregs[BX_SEG_REG_DS].selector.value); write_new_stack_word_32(&new_stack, temp_ESP-8, cs_descriptor.dpl, BX_CPU_THIS_PTR sregs[BX_SEG_REG_ES].selector.value); temp_ESP -= 8; } } if (gate_descriptor.type>=14) { // 386 int/trap gate // push long pointer to old stack onto new stack write_new_stack_dword_32(&new_stack, temp_ESP-4, cs_descriptor.dpl, old_SS); write_new_stack_dword_32(&new_stack, temp_ESP-8, cs_descriptor.dpl, old_ESP); write_new_stack_dword_32(&new_stack, temp_ESP-12, cs_descriptor.dpl, read_eflags()); write_new_stack_dword_32(&new_stack, temp_ESP-16, cs_descriptor.dpl, old_CS); write_new_stack_dword_32(&new_stack, temp_ESP-20, cs_descriptor.dpl, old_EIP); temp_ESP -= 20; if (push_error) { temp_ESP -= 4; write_new_stack_dword_32(&new_stack, temp_ESP, cs_descriptor.dpl, error_code); } } else { // 286 int/trap gate // push long pointer to old stack onto new stack write_new_stack_word_32(&new_stack, temp_ESP-2, cs_descriptor.dpl, old_SS); write_new_stack_word_32(&new_stack, temp_ESP-4, cs_descriptor.dpl, (Bit16u) old_ESP); write_new_stack_word_32(&new_stack, temp_ESP-6, cs_descriptor.dpl, (Bit16u) read_eflags()); write_new_stack_word_32(&new_stack, temp_ESP-8, cs_descriptor.dpl, old_CS); write_new_stack_word_32(&new_stack, temp_ESP-10, cs_descriptor.dpl, (Bit16u) old_EIP); temp_ESP -= 10; if (push_error) { temp_ESP -= 2; write_new_stack_word_32(&new_stack, temp_ESP, cs_descriptor.dpl, error_code); } } ESP = temp_ESP; } else { Bit16u temp_SP = (Bit16u) ESP_for_cpl_x; if (is_v8086_mode) { if (gate_descriptor.type>=14) { // 386 int/trap gate write_new_stack_dword_32(&new_stack, (Bit16u)(temp_SP-4), cs_descriptor.dpl, BX_CPU_THIS_PTR sregs[BX_SEG_REG_GS].selector.value); write_new_stack_dword_32(&new_stack, (Bit16u)(temp_SP-8), cs_descriptor.dpl, BX_CPU_THIS_PTR sregs[BX_SEG_REG_FS].selector.value); write_new_stack_dword_32(&new_stack, (Bit16u)(temp_SP-12), cs_descriptor.dpl, BX_CPU_THIS_PTR sregs[BX_SEG_REG_DS].selector.value); write_new_stack_dword_32(&new_stack, (Bit16u)(temp_SP-16), cs_descriptor.dpl, BX_CPU_THIS_PTR sregs[BX_SEG_REG_ES].selector.value); temp_SP -= 16; } else { write_new_stack_word_32(&new_stack, (Bit16u)(temp_SP-2), cs_descriptor.dpl, BX_CPU_THIS_PTR sregs[BX_SEG_REG_GS].selector.value); write_new_stack_word_32(&new_stack, (Bit16u)(temp_SP-4), cs_descriptor.dpl, BX_CPU_THIS_PTR sregs[BX_SEG_REG_FS].selector.value); write_new_stack_word_32(&new_stack, (Bit16u)(temp_SP-6), cs_descriptor.dpl, BX_CPU_THIS_PTR sregs[BX_SEG_REG_DS].selector.value); write_new_stack_word_32(&new_stack, (Bit16u)(temp_SP-8), cs_descriptor.dpl, BX_CPU_THIS_PTR sregs[BX_SEG_REG_ES].selector.value); temp_SP -= 8; } } if (gate_descriptor.type>=14) { // 386 int/trap gate // push long pointer to old stack onto new stack write_new_stack_dword_32(&new_stack, (Bit16u)(temp_SP-4), cs_descriptor.dpl, old_SS); write_new_stack_dword_32(&new_stack, (Bit16u)(temp_SP-8), cs_descriptor.dpl, old_ESP); write_new_stack_dword_32(&new_stack, (Bit16u)(temp_SP-12), cs_descriptor.dpl, read_eflags()); write_new_stack_dword_32(&new_stack, (Bit16u)(temp_SP-16), cs_descriptor.dpl, old_CS); write_new_stack_dword_32(&new_stack, (Bit16u)(temp_SP-20), cs_descriptor.dpl, old_EIP); temp_SP -= 20; if (push_error) { temp_SP -= 4; write_new_stack_dword_32(&new_stack, temp_SP, cs_descriptor.dpl, error_code); } } else { // 286 int/trap gate // push long pointer to old stack onto new stack write_new_stack_word_32(&new_stack, (Bit16u)(temp_SP-2), cs_descriptor.dpl, old_SS); write_new_stack_word_32(&new_stack, (Bit16u)(temp_SP-4), cs_descriptor.dpl, (Bit16u) old_ESP); write_new_stack_word_32(&new_stack, (Bit16u)(temp_SP-6), cs_descriptor.dpl, (Bit16u) read_eflags()); write_new_stack_word_32(&new_stack, (Bit16u)(temp_SP-8), cs_descriptor.dpl, old_CS); write_new_stack_word_32(&new_stack, (Bit16u)(temp_SP-10), cs_descriptor.dpl, (Bit16u) old_EIP); temp_SP -= 10; if (push_error) { temp_SP -= 2; write_new_stack_word_32(&new_stack, temp_SP, cs_descriptor.dpl, error_code); } } SP = temp_SP; } // load new CS:eIP values from gate // set CPL to new code segment DPL // set RPL of CS to CPL load_cs(&cs_selector, &cs_descriptor, cs_descriptor.dpl); // load new SS:eSP values from TSS load_ss(&ss_selector, &ss_descriptor, cs_descriptor.dpl); if (is_v8086_mode) { BX_CPU_THIS_PTR sregs[BX_SEG_REG_GS].cache.valid = 0; BX_CPU_THIS_PTR sregs[BX_SEG_REG_GS].selector.value = 0; BX_CPU_THIS_PTR sregs[BX_SEG_REG_FS].cache.valid = 0; BX_CPU_THIS_PTR sregs[BX_SEG_REG_FS].selector.value = 0; BX_CPU_THIS_PTR sregs[BX_SEG_REG_DS].cache.valid = 0; BX_CPU_THIS_PTR sregs[BX_SEG_REG_DS].selector.value = 0; BX_CPU_THIS_PTR sregs[BX_SEG_REG_ES].cache.valid = 0; BX_CPU_THIS_PTR sregs[BX_SEG_REG_ES].selector.value = 0; } } else { BX_DEBUG(("interrupt(): INTERRUPT TO SAME PRIVILEGE")); if (v8086_mode() && (IS_CODE_SEGMENT_CONFORMING(cs_descriptor.type) || cs_descriptor.dpl != 0)) { // if code segment DPL != 0 then #GP(new code segment selector) BX_ERROR(("interrupt(): code segment conforming or DPL(%d) != 0 in v8086 mode", cs_descriptor.dpl)); exception(BX_GP_EXCEPTION, cs_selector.value & 0xfffc); } // EIP must be in CS limit else #GP(0) if (gate_dest_offset > cs_descriptor.u.segment.limit_scaled) { BX_ERROR(("interrupt(): IP > CS descriptor limit")); exception(BX_GP_EXCEPTION, 0); } // push flags onto stack // push current CS selector onto stack // push return offset onto stack if (gate_descriptor.type >= 14) { // 386 gate push_32(read_eflags()); push_32(BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS].selector.value); push_32(EIP); if (push_error) push_32(error_code); } else { // 286 gate push_16((Bit16u) read_eflags()); push_16(BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS].selector.value); push_16(IP); if (push_error) push_16(error_code); } // load CS:IP from gate // load CS descriptor // set the RPL field of CS to CPL load_cs(&cs_selector, &cs_descriptor, CPL); } EIP = gate_dest_offset; // if interrupt gate then set IF to 0 if (!(gate_descriptor.type & 1)) // even is int-gate BX_CPU_THIS_PTR clear_IF(); BX_CPU_THIS_PTR clear_TF(); BX_CPU_THIS_PTR clear_NT(); BX_CPU_THIS_PTR clear_VM(); BX_CPU_THIS_PTR clear_RF(); return; default: BX_PANIC(("bad descriptor type in interrupt()!")); break; } }
void RETfar_pm(UINT nbytes) { selector_t cs_sel, ss_sel, temp_sel; UINT32 sp; UINT32 new_ip, new_sp; UINT16 new_cs, new_ss; int rv; int i; VERBOSE(("RETfar_pm: old EIP = %04x:%08x, ESP = %04x:%08x, nbytes = %d", CPU_CS, CPU_PREV_EIP, CPU_SS, CPU_ESP, nbytes)); if (CPU_STAT_SS32) { sp = CPU_ESP; } else { sp = CPU_SP; } if (CPU_INST_OP32) { STACK_POP_CHECK(CPU_REGS_SREG(CPU_SS_INDEX), &CPU_STAT_SREG(CPU_SS_INDEX), sp, nbytes + 8); new_ip = cpu_vmemoryread_d(CPU_SS_INDEX, sp); new_cs = cpu_vmemoryread_w(CPU_SS_INDEX, sp + 4); } else { STACK_POP_CHECK(CPU_REGS_SREG(CPU_SS_INDEX), &CPU_STAT_SREG(CPU_SS_INDEX), sp, nbytes + 4); new_ip = cpu_vmemoryread_w(CPU_SS_INDEX, sp); new_cs = cpu_vmemoryread_w(CPU_SS_INDEX, sp + 2); } rv = parse_selector(&cs_sel, new_cs); if (rv < 0) { VERBOSE(("RETfar_pm: parse_selector (selector = %04x, rv = %d, %s)", cs_sel.selector, rv)); EXCEPTION(GP_EXCEPTION, cs_sel.idx); } /* check segment type */ if (!cs_sel.desc.s) { VERBOSE(("RETfar_pm: return to system segment")); EXCEPTION(GP_EXCEPTION, cs_sel.idx); } if (!cs_sel.desc.u.seg.c) { VERBOSE(("RETfar_pm: return to data segment")); EXCEPTION(GP_EXCEPTION, cs_sel.idx); } /* check privilege level */ if (cs_sel.rpl < CPU_STAT_CPL) { VERBOSE(("RETfar_pm: RPL(%d) < CPL(%d)", cs_sel.rpl, CPU_STAT_CPL)); EXCEPTION(GP_EXCEPTION, cs_sel.idx); } if (!cs_sel.desc.u.seg.ec && (cs_sel.desc.dpl > cs_sel.rpl)) { VERBOSE(("RETfar_pm: NON-COMFORMING-CODE-SEGMENT and DPL(%d) > RPL(%d)", cs_sel.desc.dpl, cs_sel.rpl)); EXCEPTION(GP_EXCEPTION, cs_sel.idx); } /* not present */ if (selector_is_not_present(&cs_sel)) { VERBOSE(("RETfar_pm: returned code segment is not present")); EXCEPTION(NP_EXCEPTION, cs_sel.idx); } if (cs_sel.rpl == CPU_STAT_CPL) { VERBOSE(("RETfar_pm: RETURN-TO-SAME-PRIVILEGE-LEVEL")); /* check code segment limit */ if (new_ip > cs_sel.desc.u.seg.limit) { VERBOSE(("RETfar_pm: new_ip is out of range. new_ip = %08x, limit = %08x", new_ip, cs_sel.desc.u.seg.limit)); EXCEPTION(GP_EXCEPTION, 0); } VERBOSE(("RETfar_pm: new_ip = %08x, new_cs = %04x", new_ip, cs_sel.selector)); if (CPU_INST_OP32) { nbytes += 8; } else { nbytes += 4; } if (CPU_STAT_SS32) { CPU_ESP += nbytes; } else { CPU_SP += (UINT16)nbytes; } load_cs(cs_sel.selector, &cs_sel.desc, CPU_STAT_CPL); SET_EIP(new_ip); } else { VERBOSE(("RETfar_pm: RETURN-OUTER-PRIVILEGE-LEVEL")); if (CPU_INST_OP32) { STACK_POP_CHECK(CPU_REGS_SREG(CPU_SS_INDEX), &CPU_STAT_SREG(CPU_SS_INDEX), sp, 8 + 8 + nbytes); new_sp = cpu_vmemoryread_d(CPU_SS_INDEX, sp + 8 + nbytes); new_ss = cpu_vmemoryread_w(CPU_SS_INDEX, sp + 8 + nbytes + 4); } else { STACK_POP_CHECK(CPU_REGS_SREG(CPU_SS_INDEX), &CPU_STAT_SREG(CPU_SS_INDEX), sp, 4 + 4 + nbytes); new_sp = cpu_vmemoryread_w(CPU_SS_INDEX, sp + 4 + nbytes); new_ss = cpu_vmemoryread_w(CPU_SS_INDEX, sp + 4 + nbytes + 2); } rv = parse_selector(&ss_sel, new_ss); if (rv < 0) { VERBOSE(("RETfar_pm: parse_selector (selector = %04x, rv = %d, %s)", ss_sel.selector, rv)); EXCEPTION(GP_EXCEPTION, ss_sel.idx); } /* check stack segment descriptor */ if (!ss_sel.desc.s) { VERBOSE(("RETfar_pm: stack segment is system segment")); EXCEPTION(GP_EXCEPTION, cs_sel.idx); } if (ss_sel.desc.u.seg.c) { VERBOSE(("RETfar_pm: stack segment is code segment")); EXCEPTION(GP_EXCEPTION, cs_sel.idx); } if (!ss_sel.desc.u.seg.wr) { VERBOSE(("RETfar_pm: stack segment is read-only data segment")); EXCEPTION(GP_EXCEPTION, cs_sel.idx); } /* check privilege level */ if (ss_sel.rpl != cs_sel.rpl) { VERBOSE(("RETfar_pm: RPL[SS](%d) != RPL[CS](%d)", ss_sel.rpl, cs_sel.rpl)); EXCEPTION(GP_EXCEPTION, cs_sel.idx); } if (ss_sel.desc.dpl != cs_sel.rpl) { VERBOSE(("RETfar_pm: DPL[SS](%d) != RPL[CS](%d)", ss_sel.desc.dpl, cs_sel.rpl)); EXCEPTION(GP_EXCEPTION, cs_sel.idx); } /* not present */ if (selector_is_not_present(&ss_sel)) { VERBOSE(("RETfar_pm: stack segment is not present")); EXCEPTION(SS_EXCEPTION, ss_sel.idx); } /* check code segment limit */ if (new_ip > cs_sel.desc.u.seg.limit) { VERBOSE(("RETfar_pm: new_ip is out of range. new_ip = %08x, limit = %08x", new_ip, cs_sel.desc.u.seg.limit)); EXCEPTION(GP_EXCEPTION, 0); } VERBOSE(("RETfar_pm: new_ip = %08x, new_cs = %04x", new_ip, cs_sel.selector)); VERBOSE(("RETfar_pm: new_sp = %08x, new_ss = %04x", new_sp, ss_sel.selector)); load_cs(cs_sel.selector, &cs_sel.desc, cs_sel.rpl); SET_EIP(new_ip); load_ss(ss_sel.selector, &ss_sel.desc, cs_sel.rpl); if (CPU_STAT_SS32) { CPU_ESP = new_sp + nbytes; } else { CPU_SP = (UINT16)(new_sp + nbytes); } /* check segment register */ for (i = 0; i < CPU_SEGREG_NUM; i++) { descriptor_t *dp; BOOL valid; dp = &CPU_STAT_SREG(i); if ((!dp->u.seg.c || !dp->u.seg.ec) && (CPU_STAT_SREG(i).dpl < CPU_STAT_CPL)) { /* segment register is invalid */ CPU_REGS_SREG(i) = 0; CPU_STAT_SREG_CLEAR(i); continue; } rv = parse_selector(&temp_sel, CPU_REGS_SREG(i)); if (rv < 0) { /* segment register is invalid */ CPU_REGS_SREG(i) = 0; CPU_STAT_SREG_CLEAR(i); continue; } valid = TRUE; if (!temp_sel.desc.s) { /* system segment */ valid = FALSE; } if (temp_sel.desc.u.seg.c && !temp_sel.desc.u.seg.wr) { /* execute-only code segment */ valid = FALSE; } if (!temp_sel.desc.u.seg.c || !temp_sel.desc.u.seg.ec) { if (CPU_STAT_CPL > temp_sel.desc.dpl) { valid = FALSE; } } if (!valid) { /* segment register is invalid */ CPU_REGS_SREG(i) = 0; CPU_STAT_SREG(i).valid = 0; } } } VERBOSE(("RETfar_pm: new EIP = %04x:%08x, ESP = %04x:%08x", CPU_CS, CPU_EIP, CPU_SS, CPU_ESP)); }
BX_CPU_C::return_protected(bxInstruction_c *i, Bit16u pop_bytes) { Bit16u raw_cs_selector, raw_ss_selector; bx_selector_t cs_selector, ss_selector; bx_descriptor_t cs_descriptor, ss_descriptor; Bit32u stack_param_offset; bx_address return_RIP, return_RSP, temp_RSP; Bit32u dword1, dword2; /* + 6+N*2: SS | +12+N*4: SS | +24+N*8 SS */ /* + 4+N*2: SP | + 8+N*4: ESP | +16+N*8 RSP */ /* parm N | + parm N | + parm N */ /* parm 3 | + parm 3 | + parm 3 */ /* parm 2 | + parm 2 | + parm 2 */ /* + 4: parm 1 | + 8: parm 1 | +16: parm 1 */ /* + 2: CS | + 4: CS | + 8: CS */ /* + 0: IP | + 0: EIP | + 0: RIP */ #if BX_SUPPORT_X86_64 if (StackAddrSize64()) temp_RSP = RSP; else #endif { if (BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS].cache.u.segment.d_b) temp_RSP = ESP; else temp_RSP = SP; } #if BX_SUPPORT_X86_64 if (i->os64L()) { raw_cs_selector = (Bit16u) read_virtual_qword_64(BX_SEG_REG_SS, temp_RSP + 8); return_RIP = read_virtual_qword_64(BX_SEG_REG_SS, temp_RSP); stack_param_offset = 16; } else #endif if (i->os32L()) { raw_cs_selector = (Bit16u) read_virtual_dword(BX_SEG_REG_SS, temp_RSP + 4); return_RIP = read_virtual_dword(BX_SEG_REG_SS, temp_RSP); stack_param_offset = 8; } else { raw_cs_selector = read_virtual_word(BX_SEG_REG_SS, temp_RSP + 2); return_RIP = read_virtual_word(BX_SEG_REG_SS, temp_RSP); stack_param_offset = 4; } // selector must be non-null else #GP(0) if ((raw_cs_selector & 0xfffc) == 0) { BX_ERROR(("return_protected: CS selector null")); exception(BX_GP_EXCEPTION, 0, 0); } parse_selector(raw_cs_selector, &cs_selector); // selector index must be within its descriptor table limits, // else #GP(selector) fetch_raw_descriptor(&cs_selector, &dword1, &dword2, BX_GP_EXCEPTION); // descriptor AR byte must indicate code segment, else #GP(selector) parse_descriptor(dword1, dword2, &cs_descriptor); // return selector RPL must be >= CPL, else #GP(return selector) if (cs_selector.rpl < CPL) { BX_ERROR(("return_protected: CS.rpl < CPL")); exception(BX_GP_EXCEPTION, raw_cs_selector & 0xfffc, 0); } // check code-segment descriptor check_cs(&cs_descriptor, raw_cs_selector, 0, cs_selector.rpl); // if return selector RPL == CPL then // RETURN TO SAME PRIVILEGE LEVEL if (cs_selector.rpl == CPL) { BX_DEBUG(("return_protected: return to SAME PRIVILEGE LEVEL")); branch_far64(&cs_selector, &cs_descriptor, return_RIP, CPL); #if BX_SUPPORT_X86_64 if (StackAddrSize64()) RSP += stack_param_offset + pop_bytes; else #endif { if (BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS].cache.u.segment.d_b) RSP = ESP + stack_param_offset + pop_bytes; else SP += stack_param_offset + pop_bytes; } return; } /* RETURN TO OUTER PRIVILEGE LEVEL */ else { /* + 6+N*2: SS | +12+N*4: SS | +24+N*8 SS */ /* + 4+N*2: SP | + 8+N*4: ESP | +16+N*8 RSP */ /* parm N | + parm N | + parm N */ /* parm 3 | + parm 3 | + parm 3 */ /* parm 2 | + parm 2 | + parm 2 */ /* + 4: parm 1 | + 8: parm 1 | +16: parm 1 */ /* + 2: CS | + 4: CS | + 8: CS */ /* + 0: IP | + 0: EIP | + 0: RIP */ BX_DEBUG(("return_protected: return to OUTER PRIVILEGE LEVEL")); #if BX_SUPPORT_X86_64 if (i->os64L()) { raw_ss_selector = read_virtual_word_64 (BX_SEG_REG_SS, temp_RSP + 24 + pop_bytes); return_RSP = read_virtual_qword_64(BX_SEG_REG_SS, temp_RSP + 16 + pop_bytes); } else #endif if (i->os32L()) { raw_ss_selector = read_virtual_word (BX_SEG_REG_SS, temp_RSP + 12 + pop_bytes); return_RSP = read_virtual_dword(BX_SEG_REG_SS, temp_RSP + 8 + pop_bytes); } else { raw_ss_selector = read_virtual_word(BX_SEG_REG_SS, temp_RSP + 6 + pop_bytes); return_RSP = read_virtual_word(BX_SEG_REG_SS, temp_RSP + 4 + pop_bytes); } /* selector index must be within its descriptor table limits, * else #GP(selector) */ parse_selector(raw_ss_selector, &ss_selector); if ((raw_ss_selector & 0xfffc) == 0) { if (long_mode()) { if (! IS_LONG64_SEGMENT(cs_descriptor) || (cs_selector.rpl == 3)) { BX_ERROR(("return_protected: SS selector null")); exception(BX_GP_EXCEPTION, 0, 0); } } else // not in long or compatibility mode { BX_ERROR(("return_protected: SS selector null")); exception(BX_GP_EXCEPTION, 0, 0); } } fetch_raw_descriptor(&ss_selector, &dword1, &dword2, BX_GP_EXCEPTION); parse_descriptor(dword1, dword2, &ss_descriptor); /* selector RPL must = RPL of the return CS selector, * else #GP(selector) */ if (ss_selector.rpl != cs_selector.rpl) { BX_ERROR(("return_protected: ss.rpl != cs.rpl")); exception(BX_GP_EXCEPTION, raw_ss_selector & 0xfffc, 0); } /* descriptor AR byte must indicate a writable data segment, * else #GP(selector) */ if (ss_descriptor.valid==0 || ss_descriptor.segment==0 || IS_CODE_SEGMENT(ss_descriptor.type) || !IS_DATA_SEGMENT_WRITEABLE(ss_descriptor.type)) { BX_ERROR(("return_protected: SS.AR byte not writable data")); exception(BX_GP_EXCEPTION, raw_ss_selector & 0xfffc, 0); } /* descriptor dpl must = RPL of the return CS selector, * else #GP(selector) */ if (ss_descriptor.dpl != cs_selector.rpl) { BX_ERROR(("return_protected: SS.dpl != cs.rpl")); exception(BX_GP_EXCEPTION, raw_ss_selector & 0xfffc, 0); } /* segment must be present else #SS(selector) */ if (! IS_PRESENT(ss_descriptor)) { BX_ERROR(("return_protected: ss.present == 0")); exception(BX_SS_EXCEPTION, raw_ss_selector & 0xfffc, 0); } branch_far64(&cs_selector, &cs_descriptor, return_RIP, cs_selector.rpl); /* load SS:SP from stack */ /* load SS-cache with return SS descriptor */ load_ss(&ss_selector, &ss_descriptor, cs_selector.rpl); #if BX_SUPPORT_X86_64 if (StackAddrSize64()) RSP = return_RSP + pop_bytes; else #endif if (ss_descriptor.u.segment.d_b) RSP = (Bit32u) return_RSP + pop_bytes; else SP = (Bit16u) return_RSP + pop_bytes; /* check ES, DS, FS, GS for validity */ validate_seg_regs(); } }
/*--- * IRET_pm: OUTER-PRIVILEGE */ static void IRET_pm_protected_mode_return_outer_privilege(const selector_t *cs_sel, UINT32 new_ip, UINT32 new_flags) { descriptor_t *dp; selector_t ss_sel; UINT32 mask; UINT32 sp; UINT32 new_sp; UINT16 new_ss; int rv; int i; VERBOSE(("IRET_pm: RETURN-OUTER-PRIVILEGE-LEVEL")); if (CPU_STAT_SS32) { sp = CPU_ESP; } else { sp = CPU_SP; } if (CPU_INST_OP32) { STACK_POP_CHECK(CPU_REGS_SREG(CPU_SS_INDEX), &CPU_STAT_SREG(CPU_SS_INDEX), sp, 20); new_sp = cpu_vmemoryread_d(CPU_SS_INDEX, sp + 12); new_ss = cpu_vmemoryread_w(CPU_SS_INDEX, sp + 16); } else { STACK_POP_CHECK(CPU_REGS_SREG(CPU_SS_INDEX), &CPU_STAT_SREG(CPU_SS_INDEX), sp, 10); new_sp = cpu_vmemoryread_w(CPU_SS_INDEX, sp + 6); new_ss = cpu_vmemoryread_w(CPU_SS_INDEX, sp + 8); } VERBOSE(("IRET_pm: new_sp = 0x%08x, new_ss = 0x%04x", new_sp, new_ss)); rv = parse_selector(&ss_sel, new_ss); if (rv < 0) { VERBOSE(("IRET_pm: parse_selector (selector = %04x, rv = %d)", ss_sel.selector, rv)); EXCEPTION(GP_EXCEPTION, ss_sel.idx); } /* check privilege level */ if (ss_sel.rpl != cs_sel->rpl) { VERBOSE(("IRET_pm: RPL[SS](%d) != RPL[CS](%d)", ss_sel.rpl, cs_sel->rpl)); EXCEPTION(GP_EXCEPTION, ss_sel.idx); } if (ss_sel.desc.dpl != cs_sel->rpl) { VERBOSE(("IRET_pm: DPL[SS](%d) != RPL[CS](%d)", ss_sel.desc.dpl, cs_sel->rpl)); EXCEPTION(GP_EXCEPTION, ss_sel.idx); } /* check stack segment descriptor */ if (!ss_sel.desc.s) { VERBOSE(("IRET_pm: stack segment is system segment")); EXCEPTION(GP_EXCEPTION, ss_sel.idx); } if (ss_sel.desc.u.seg.c) { VERBOSE(("IRET_pm: stack segment is code segment")); EXCEPTION(GP_EXCEPTION, ss_sel.idx); } if (!ss_sel.desc.u.seg.wr) { VERBOSE(("IRET_pm: stack segment is read-only data segment")); EXCEPTION(GP_EXCEPTION, ss_sel.idx); } /* not present */ if (selector_is_not_present(&ss_sel)) { VERBOSE(("IRET_pm: stack segment is not present")); EXCEPTION(SS_EXCEPTION, ss_sel.idx); } /* check code segment limit */ if (new_ip > cs_sel->desc.u.seg.limit) { VERBOSE(("IRET_pm: new_ip is out of range. new_ip = %08x, limit = %08x", new_ip, cs_sel->desc.u.seg.limit)); EXCEPTION(GP_EXCEPTION, 0); } mask = 0; if (CPU_INST_OP32) mask |= RF_FLAG; if (CPU_STAT_CPL <= CPU_STAT_IOPL) mask |= I_FLAG; if (CPU_STAT_CPL == 0) { mask |= IOPL_FLAG; if (CPU_INST_OP32) { mask |= VM_FLAG|VIF_FLAG|VIP_FLAG; } } /* set new register */ load_cs(cs_sel->selector, &cs_sel->desc, cs_sel->rpl); SET_EIP(new_ip); set_eflags(new_flags, mask); load_ss(ss_sel.selector, &ss_sel.desc, cs_sel->rpl); if (CPU_STAT_SS32) { CPU_ESP = new_sp; } else { CPU_SP = (UINT16)new_sp; } /* check segment register */ for (i = 0; i < CPU_SEGREG_NUM; i++) { if ((i != CPU_CS_INDEX) && (i != CPU_SS_INDEX)) { dp = &CPU_STAT_SREG(i); if ((!dp->u.seg.c || !dp->u.seg.ec) && (CPU_STAT_SREG(i).dpl < CPU_STAT_CPL)) { /* segment register is invalid */ CPU_REGS_SREG(i) = 0; CPU_STAT_SREG_CLEAR(i); } } } }
/*--- * CALLfar_pm: call gate (MORE-PRIVILEGE) */ static void CALLfar_pm_call_gate_more_privilege(const selector_t *callgate_sel, selector_t *cs_sel) { UINT32 param[32]; /* copy param */ selector_t ss_sel; UINT32 old_eip, old_esp; UINT32 new_esp; UINT16 old_cs, old_ss; UINT16 new_ss; int param_count; int i; int rv; VERBOSE(("CALLfar_pm: MORE-PRIVILEGE")); /* save register */ old_cs = CPU_CS; old_ss = CPU_SS; old_eip = CPU_EIP; old_esp = CPU_ESP; if (!CPU_STAT_SS32) { old_esp &= 0xffff; } /* get stack pointer from TSS */ get_stack_pointer_from_tss(cs_sel->desc.dpl, &new_ss, &new_esp); /* parse stack segment descriptor */ rv = parse_selector(&ss_sel, new_ss); if (rv < 0) { VERBOSE(("CALLfar_pm: parse_selector (selector = %04x, rv = %d)", new_ss, rv)); EXCEPTION(TS_EXCEPTION, ss_sel.idx); } /* check privilege level */ if (ss_sel.rpl != cs_sel->desc.dpl) { VERBOSE(("CALLfar_pm: RPL[SS](%d) != DPL[CS](%d)", ss_sel.rpl, cs_sel->desc.dpl)); EXCEPTION(TS_EXCEPTION, ss_sel.idx); } if (ss_sel.desc.dpl != cs_sel->desc.dpl) { VERBOSE(("CALLfar_pm: DPL[SS](%d) != DPL[CS](%d)", ss_sel.desc.dpl, cs_sel->desc.dpl)); EXCEPTION(TS_EXCEPTION, ss_sel.idx); } /* stack segment must be writable data segment. */ if (!ss_sel.desc.s) { VERBOSE(("CALLfar_pm: stack segment is system segment")); EXCEPTION(TS_EXCEPTION, ss_sel.idx); } if (ss_sel.desc.u.seg.c) { VERBOSE(("CALLfar_pm: stack segment is code segment")); EXCEPTION(TS_EXCEPTION, ss_sel.idx); } if (!ss_sel.desc.u.seg.wr) { VERBOSE(("CALLfar_pm: stack segment is read-only data segment")); EXCEPTION(TS_EXCEPTION, ss_sel.idx); } /* not present */ if (selector_is_not_present(&ss_sel)) { VERBOSE(("CALLfar_pm: stack segment selector is not present")); EXCEPTION(SS_EXCEPTION, ss_sel.idx); } param_count = callgate_sel->desc.u.gate.count; VERBOSE(("CALLfar_pm: param_count = %d", param_count)); if (callgate_sel->desc.type == CPU_SYSDESC_TYPE_CALL_32) { STACK_PUSH_CHECK(ss_sel.idx, &ss_sel.desc, new_esp, 16 + param_count * 4); /* dump param */ for (i = 0; i < param_count; i++) { param[i] = cpu_vmemoryread_d(CPU_SS_INDEX, old_esp + i * 4); VERBOSE(("CALLfar_pm: get param[%d] = %08x", i, param[i])); } load_ss(ss_sel.selector, &ss_sel.desc, ss_sel.desc.dpl); if (CPU_STAT_SS32) { CPU_ESP = new_esp; } else { CPU_SP = (UINT16)new_esp; } load_cs(cs_sel->selector, &cs_sel->desc, cs_sel->desc.dpl); SET_EIP(callgate_sel->desc.u.gate.offset); PUSH0_32(old_ss); PUSH0_32(old_esp); /* restore param */ for (i = param_count; i > 0; i--) { PUSH0_32(param[i - 1]); VERBOSE(("CALLfar_pm: set param[%d] = %08x", i - 1, param[i - 1])); } PUSH0_32(old_cs); PUSH0_32(old_eip); } else { STACK_PUSH_CHECK(ss_sel.idx, &ss_sel.desc, new_esp, 8 + param_count * 2); /* dump param */ for (i = 0; i < param_count; i++) { param[i] = cpu_vmemoryread_w(CPU_SS_INDEX, old_esp + i * 2); VERBOSE(("CALLfar_pm: get param[%d] = %04x", i, param[i])); } load_ss(ss_sel.selector, &ss_sel.desc, ss_sel.desc.dpl); if (CPU_STAT_SS32) { CPU_ESP = new_esp; } else { CPU_SP = (UINT16)new_esp; } load_cs(cs_sel->selector, &cs_sel->desc, cs_sel->desc.dpl); SET_EIP(callgate_sel->desc.u.gate.offset); PUSH0_16(old_ss); PUSH0_16(old_esp); /* restore param */ for (i = param_count; i > 0; i--) { PUSH0_16(param[i - 1]); VERBOSE(("CALLfar_pm: set param[%d] = %04x", i - 1, param[i - 1])); } PUSH0_16(old_cs); PUSH0_16(old_eip); } }
void BX_CPU_C::long_mode_int(Bit8u vector, bx_bool is_INT, bx_bool is_error_code, Bit16u error_code) { // long mode interrupt Bit64u tmp1, tmp2; bx_descriptor_t gate_descriptor, cs_descriptor; bx_selector_t cs_selector; // interrupt vector must be within IDT table limits, // else #GP(vector number*16 + 2 + EXT) if ((vector*16 + 15) > BX_CPU_THIS_PTR idtr.limit) { BX_ERROR(("interrupt(long mode): vector must be within IDT table limits, IDT.limit = 0x%x", BX_CPU_THIS_PTR idtr.limit)); exception(BX_GP_EXCEPTION, vector*16 + 2, 0); } access_read_linear(BX_CPU_THIS_PTR idtr.base + vector*16, 8, 0, BX_READ, &tmp1); access_read_linear(BX_CPU_THIS_PTR idtr.base + vector*16 + 8, 8, 0, BX_READ, &tmp2); if (tmp2 & BX_CONST64(0x00001F0000000000)) { BX_ERROR(("interrupt(long mode): IDT entry extended attributes DWORD4 TYPE != 0")); exception(BX_GP_EXCEPTION, vector*16 + 2, 0); } Bit32u dword1 = GET32L(tmp1); Bit32u dword2 = GET32H(tmp1); Bit32u dword3 = GET32L(tmp2); parse_descriptor(dword1, dword2, &gate_descriptor); if ((gate_descriptor.valid==0) || gate_descriptor.segment) { BX_ERROR(("interrupt(long mode): gate descriptor is not valid sys seg")); exception(BX_GP_EXCEPTION, vector*16 + 2, 0); } // descriptor AR byte must indicate interrupt gate, trap gate, // or task gate, else #GP(vector*16 + 2 + EXT) if (gate_descriptor.type != BX_386_INTERRUPT_GATE && gate_descriptor.type != BX_386_TRAP_GATE) { BX_ERROR(("interrupt(long mode): unsupported gate type %u", (unsigned) gate_descriptor.type)); exception(BX_GP_EXCEPTION, vector*16 + 2, 0); } // if software interrupt, then gate descripor DPL must be >= CPL, // else #GP(vector * 16 + 2 + EXT) if (is_INT && (gate_descriptor.dpl < CPL)) { BX_ERROR(("interrupt(long mode): is_INT && (dpl < CPL)")); exception(BX_GP_EXCEPTION, vector*16 + 2, 0); } // Gate must be present, else #NP(vector * 16 + 2 + EXT) if (! IS_PRESENT(gate_descriptor)) { BX_ERROR(("interrupt(long mode): p == 0")); exception(BX_NP_EXCEPTION, vector*16 + 2, 0); } Bit16u gate_dest_selector = gate_descriptor.u.gate.dest_selector; Bit64u gate_dest_offset = ((Bit64u)dword3 << 32) | gate_descriptor.u.gate.dest_offset; unsigned ist = gate_descriptor.u.gate.param_count & 0x7; // examine CS selector and descriptor given in gate descriptor // selector must be non-null else #GP(EXT) if ((gate_dest_selector & 0xfffc) == 0) { BX_ERROR(("int_trap_gate(long mode): selector null")); exception(BX_GP_EXCEPTION, 0, 0); } parse_selector(gate_dest_selector, &cs_selector); // selector must be within its descriptor table limits // else #GP(selector+EXT) fetch_raw_descriptor(&cs_selector, &dword1, &dword2, BX_GP_EXCEPTION); parse_descriptor(dword1, dword2, &cs_descriptor); // descriptor AR byte must indicate code seg // and code segment descriptor DPL<=CPL, else #GP(selector+EXT) if (cs_descriptor.valid==0 || cs_descriptor.segment==0 || IS_DATA_SEGMENT(cs_descriptor.type) || cs_descriptor.dpl>CPL) { BX_ERROR(("interrupt(long mode): not accessable or not code segment")); exception(BX_GP_EXCEPTION, cs_selector.value & 0xfffc, 0); } // check that it's a 64 bit segment if (! IS_LONG64_SEGMENT(cs_descriptor) || cs_descriptor.u.segment.d_b) { BX_ERROR(("interrupt(long mode): must be 64 bit segment")); exception(BX_GP_EXCEPTION, cs_selector.value & 0xfffc, 0); } // segment must be present, else #NP(selector + EXT) if (! IS_PRESENT(cs_descriptor)) { BX_ERROR(("interrupt(long mode): segment not present")); exception(BX_NP_EXCEPTION, cs_selector.value & 0xfffc, 0); } // if code segment is non-conforming and DPL < CPL then // INTERRUPT TO INNER PRIVILEGE: if (IS_CODE_SEGMENT_NON_CONFORMING(cs_descriptor.type) && cs_descriptor.dpl<CPL) { Bit64u RSP_for_cpl_x; BX_DEBUG(("interrupt(long mode): INTERRUPT TO INNER PRIVILEGE")); // check selector and descriptor for new stack in current TSS if (ist != 0) { BX_DEBUG(("interrupt(long mode): trap to IST, vector = %d", ist)); get_RSP_from_TSS(ist+3, &RSP_for_cpl_x); } else { get_RSP_from_TSS(cs_descriptor.dpl, &RSP_for_cpl_x); } RSP_for_cpl_x &= BX_CONST64(0xfffffffffffffff0); Bit64u old_CS = BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS].selector.value; Bit64u old_RIP = RIP; Bit64u old_SS = BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS].selector.value; Bit64u old_RSP = RSP; if (! IsCanonical(RSP_for_cpl_x)) { // #SS(selector) when changing priviledge level BX_ERROR(("interrupt(long mode): canonical address failure %08x%08x", GET32H(RSP_for_cpl_x), GET32L(RSP_for_cpl_x))); exception(BX_SS_EXCEPTION, old_SS & 0xfffc, 0); } // push old stack long pointer onto new stack write_new_stack_qword_64(RSP_for_cpl_x - 8, cs_descriptor.dpl, old_SS); write_new_stack_qword_64(RSP_for_cpl_x - 16, cs_descriptor.dpl, old_RSP); write_new_stack_qword_64(RSP_for_cpl_x - 24, cs_descriptor.dpl, read_eflags()); // push long pointer to return address onto new stack write_new_stack_qword_64(RSP_for_cpl_x - 32, cs_descriptor.dpl, old_CS); write_new_stack_qword_64(RSP_for_cpl_x - 40, cs_descriptor.dpl, old_RIP); RSP_for_cpl_x -= 40; if (is_error_code) { RSP_for_cpl_x -= 8; write_new_stack_qword_64(RSP_for_cpl_x, cs_descriptor.dpl, error_code); } bx_selector_t ss_selector; bx_descriptor_t ss_descriptor; // set up a null descriptor parse_selector(0, &ss_selector); parse_descriptor(0, 0, &ss_descriptor); // load CS:RIP (guaranteed to be in 64 bit mode) branch_far64(&cs_selector, &cs_descriptor, gate_dest_offset, cs_descriptor.dpl); // set up null SS descriptor load_ss(&ss_selector, &ss_descriptor, cs_descriptor.dpl); RSP = RSP_for_cpl_x; // if INTERRUPT GATE set IF to 0 if (!(gate_descriptor.type & 1)) // even is int-gate BX_CPU_THIS_PTR clear_IF(); BX_CPU_THIS_PTR clear_TF(); BX_CPU_THIS_PTR clear_VM(); BX_CPU_THIS_PTR clear_RF(); BX_CPU_THIS_PTR clear_NT(); return; } // if code segment is conforming OR code segment DPL = CPL then // INTERRUPT TO SAME PRIVILEGE LEVEL: if (IS_CODE_SEGMENT_CONFORMING(cs_descriptor.type) || cs_descriptor.dpl==CPL) { BX_DEBUG(("interrupt(long mode): INTERRUPT TO SAME PRIVILEGE")); Bit64u old_RSP = RSP; // check selector and descriptor for new stack in current TSS if (ist > 0) { BX_DEBUG(("interrupt(long mode): trap to IST, vector = %d", ist)); get_RSP_from_TSS(ist+3, &RSP); } // align stack RSP &= BX_CONST64(0xfffffffffffffff0); // push flags onto stack // push current CS selector onto stack // push return offset onto stack write_new_stack_qword_64(RSP - 8, cs_descriptor.dpl, BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS].selector.value); write_new_stack_qword_64(RSP - 16, cs_descriptor.dpl, old_RSP); write_new_stack_qword_64(RSP - 24, cs_descriptor.dpl, read_eflags()); write_new_stack_qword_64(RSP - 32, cs_descriptor.dpl, BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS].selector.value); write_new_stack_qword_64(RSP - 40, cs_descriptor.dpl, RIP); RSP -= 40; if (is_error_code) { RSP -= 8; write_new_stack_qword_64(RSP, cs_descriptor.dpl, error_code); } // set the RPL field of CS to CPL branch_far64(&cs_selector, &cs_descriptor, gate_dest_offset, CPL); // if interrupt gate then set IF to 0 if (!(gate_descriptor.type & 1)) // even is int-gate BX_CPU_THIS_PTR clear_IF(); BX_CPU_THIS_PTR clear_TF(); BX_CPU_THIS_PTR clear_VM(); BX_CPU_THIS_PTR clear_RF(); BX_CPU_THIS_PTR clear_NT(); return; } // else #GP(CS selector + ext) BX_ERROR(("interrupt(long mode): bad descriptor type=%u, descriptor.dpl=%u, CPL=%u", (unsigned) cs_descriptor.type, (unsigned) cs_descriptor.dpl, (unsigned) CPL)); BX_ERROR(("cs.segment = %u", (unsigned) cs_descriptor.segment)); exception(BX_GP_EXCEPTION, cs_selector.value & 0xfffc, 0); }
BX_CPU_C::call_gate64(bx_selector_t *gate_selector) { bx_selector_t cs_selector; Bit32u dword1, dword2, dword3; bx_descriptor_t cs_descriptor; bx_descriptor_t gate_descriptor; // examine code segment selector in call gate descriptor BX_DEBUG(("call_gate64: CALL 64bit call gate")); fetch_raw_descriptor_64(gate_selector, &dword1, &dword2, &dword3, BX_GP_EXCEPTION); parse_descriptor(dword1, dword2, &gate_descriptor); Bit16u dest_selector = gate_descriptor.u.gate.dest_selector; // selector must not be null else #GP(0) if ((dest_selector & 0xfffc) == 0) { BX_ERROR(("call_gate64: selector in gate null")); exception(BX_GP_EXCEPTION, 0, 0); } parse_selector(dest_selector, &cs_selector); // selector must be within its descriptor table limits, // else #GP(code segment selector) fetch_raw_descriptor(&cs_selector, &dword1, &dword2, BX_GP_EXCEPTION); parse_descriptor(dword1, dword2, &cs_descriptor); // find the RIP in the gate_descriptor Bit64u new_RIP = gate_descriptor.u.gate.dest_offset; new_RIP |= ((Bit64u)dword3 << 32); // AR byte of selected descriptor must indicate code segment, // else #GP(code segment selector) // DPL of selected descriptor must be <= CPL, // else #GP(code segment selector) if (cs_descriptor.valid==0 || cs_descriptor.segment==0 || IS_DATA_SEGMENT(cs_descriptor.type) || cs_descriptor.dpl > CPL) { BX_ERROR(("call_gate64: selected descriptor is not code")); exception(BX_GP_EXCEPTION, dest_selector & 0xfffc, 0); } // 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(cs_descriptor) || cs_descriptor.u.segment.d_b) { BX_ERROR(("call_gate64: not 64-bit code segment in call gate 64")); exception(BX_GP_EXCEPTION, dest_selector & 0xfffc, 0); } // code segment must be present else #NP(selector) if (! IS_PRESENT(cs_descriptor)) { BX_ERROR(("call_gate64: code segment not present !")); exception(BX_NP_EXCEPTION, dest_selector & 0xfffc, 0); } Bit64u old_CS = BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS].selector.value; Bit64u old_RIP = RIP; // CALL GATE TO MORE PRIVILEGE // if non-conforming code segment and DPL < CPL then if (IS_CODE_SEGMENT_NON_CONFORMING(cs_descriptor.type) && (cs_descriptor.dpl < CPL)) { Bit64u RSP_for_cpl_x; BX_DEBUG(("CALL GATE TO MORE PRIVILEGE LEVEL")); // get new RSP for new privilege level from TSS get_RSP_from_TSS(cs_descriptor.dpl, &RSP_for_cpl_x); Bit64u old_SS = BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS].selector.value; Bit64u old_RSP = RSP; if (! IsCanonical(RSP_for_cpl_x)) { // #SS(selector) when changing priviledge level BX_ERROR(("call_gate64: canonical address failure %08x%08x", GET32H(RSP_for_cpl_x), GET32L(RSP_for_cpl_x))); exception(BX_SS_EXCEPTION, old_SS & 0xfffc, 0); } // push old stack long pointer onto new stack write_new_stack_qword_64(RSP_for_cpl_x - 8, cs_descriptor.dpl, old_SS); write_new_stack_qword_64(RSP_for_cpl_x - 16, cs_descriptor.dpl, old_RSP); // push long pointer to return address onto new stack write_new_stack_qword_64(RSP_for_cpl_x - 24, cs_descriptor.dpl, old_CS); write_new_stack_qword_64(RSP_for_cpl_x - 32, cs_descriptor.dpl, old_RIP); RSP_for_cpl_x -= 32; // prepare new stack null SS selector bx_selector_t ss_selector; bx_descriptor_t ss_descriptor; // set up a null descriptor parse_selector(0, &ss_selector); parse_descriptor(0, 0, &ss_descriptor); // load CS:RIP (guaranteed to be in 64 bit mode) branch_far64(&cs_selector, &cs_descriptor, new_RIP, cs_descriptor.dpl); // set up null SS descriptor load_ss(&ss_selector, &ss_descriptor, cs_descriptor.dpl); RSP = RSP_for_cpl_x; } else { BX_DEBUG(("CALL GATE TO SAME PRIVILEGE")); // push to 64-bit stack, switch to long64 guaranteed write_new_stack_qword_64(RSP - 8, CPL, old_CS); write_new_stack_qword_64(RSP - 16, CPL, old_RIP); RSP -= 16; // load CS:RIP (guaranteed to be in 64 bit mode) branch_far64(&cs_selector, &cs_descriptor, new_RIP, CPL); } }
BX_CPU_C::call_protected(bxInstruction_c *i, Bit16u cs_raw, bx_address disp) { bx_selector_t cs_selector; Bit32u dword1, dword2; bx_descriptor_t cs_descriptor; /* new cs selector must not be null, else #GP(0) */ if ((cs_raw & 0xfffc) == 0) { BX_ERROR(("call_protected: CS selector null")); exception(BX_GP_EXCEPTION, 0, 0); } parse_selector(cs_raw, &cs_selector); // check new CS selector index within its descriptor limits, // else #GP(new CS selector) fetch_raw_descriptor(&cs_selector, &dword1, &dword2, BX_GP_EXCEPTION); parse_descriptor(dword1, dword2, &cs_descriptor); // examine AR byte of selected descriptor for various legal values if (cs_descriptor.valid==0) { BX_ERROR(("call_protected: invalid CS descriptor")); exception(BX_GP_EXCEPTION, cs_raw & 0xfffc, 0); } if (cs_descriptor.segment) // normal segment { check_cs(&cs_descriptor, cs_raw, BX_SELECTOR_RPL(cs_raw), CPL); #if BX_SUPPORT_X86_64 if (i->os64L()) { // push return address onto stack (CS padded to 64bits) push_64((Bit64u) BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS].selector.value); push_64(RIP); } else #endif if (i->os32L()) { // push return address onto stack (CS padded to 32bits) push_32((Bit32u) BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS].selector.value); push_32(EIP); } else { // push return address onto stack push_16(BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS].selector.value); push_16(IP); } // load code segment descriptor into CS cache // load CS with new code segment selector // set RPL of CS to CPL branch_far64(&cs_selector, &cs_descriptor, disp, CPL); return; } else { // gate & special segment bx_descriptor_t gate_descriptor = cs_descriptor; bx_selector_t gate_selector = cs_selector; Bit32u new_EIP; Bit16u dest_selector; Bit16u raw_tss_selector; bx_selector_t tss_selector; bx_descriptor_t tss_descriptor; Bit32u temp_eIP; // descriptor DPL must be >= CPL else #GP(gate selector) if (gate_descriptor.dpl < CPL) { BX_ERROR(("call_protected: descriptor.dpl < CPL")); exception(BX_GP_EXCEPTION, cs_raw & 0xfffc, 0); } // descriptor DPL must be >= gate selector RPL else #GP(gate selector) if (gate_descriptor.dpl < gate_selector.rpl) { BX_ERROR(("call_protected: descriptor.dpl < selector.rpl")); exception(BX_GP_EXCEPTION, cs_raw & 0xfffc, 0); } #if BX_SUPPORT_X86_64 if (long_mode()) { // call gate type is higher priority than non-present bit check if (gate_descriptor.type != BX_386_CALL_GATE) { BX_ERROR(("call_protected: gate type %u unsupported in long mode", (unsigned) gate_descriptor.type)); exception(BX_GP_EXCEPTION, cs_raw & 0xfffc, 0); } } else #endif { switch (gate_descriptor.type) { case BX_SYS_SEGMENT_AVAIL_286_TSS: case BX_SYS_SEGMENT_AVAIL_386_TSS: case BX_TASK_GATE: case BX_286_CALL_GATE: case BX_386_CALL_GATE: break; default: BX_ERROR(("call_protected(): gate.type(%u) unsupported", (unsigned) gate_descriptor.type)); exception(BX_GP_EXCEPTION, cs_raw & 0xfffc, 0); } } // gate descriptor must be present else #NP(gate selector) if (! IS_PRESENT(gate_descriptor)) { BX_ERROR(("call_protected: gate not present")); exception(BX_NP_EXCEPTION, cs_raw & 0xfffc, 0); } #if BX_SUPPORT_X86_64 if (long_mode()) { call_gate64(&gate_selector); return; } #endif switch (gate_descriptor.type) { case BX_SYS_SEGMENT_AVAIL_286_TSS: case BX_SYS_SEGMENT_AVAIL_386_TSS: if (gate_descriptor.type==BX_SYS_SEGMENT_AVAIL_286_TSS) BX_DEBUG(("call_protected: 16bit available TSS")); else BX_DEBUG(("call_protected: 32bit available TSS")); // SWITCH_TASKS _without_ nesting to TSS task_switch(&gate_selector, &gate_descriptor, BX_TASK_FROM_CALL_OR_INT, 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(("call_protected: EIP not within CS limits")); exception(BX_GP_EXCEPTION, 0, 0); } return; case BX_TASK_GATE: // examine selector to TSS, given in Task Gate descriptor // must specify global in the local/global bit else #TS(TSS selector) raw_tss_selector = gate_descriptor.u.taskgate.tss_selector; parse_selector(raw_tss_selector, &tss_selector); if (tss_selector.ti) { BX_ERROR(("call_protected: tss_selector.ti=1")); exception(BX_GP_EXCEPTION, raw_tss_selector & 0xfffc, 0); } // index must be within GDT limits else #TS(TSS selector) fetch_raw_descriptor(&tss_selector, &dword1, &dword2, BX_GP_EXCEPTION); parse_descriptor(dword1, dword2, &tss_descriptor); // descriptor AR byte must specify available TSS // else #GP(TSS selector) if (tss_descriptor.valid==0 || tss_descriptor.segment) { BX_ERROR(("call_protected: TSS selector points to bad TSS")); exception(BX_GP_EXCEPTION, raw_tss_selector & 0xfffc, 0); } if (tss_descriptor.type!=BX_SYS_SEGMENT_AVAIL_286_TSS && tss_descriptor.type!=BX_SYS_SEGMENT_AVAIL_386_TSS) { BX_ERROR(("call_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(("call_protected: task 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_CALL_OR_INT, dword1, dword2); // EIP must be within code segment limit, else #TS(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(("call_protected: EIP > CS.limit")); exception(BX_GP_EXCEPTION, 0, 0); } return; case BX_286_CALL_GATE: case BX_386_CALL_GATE: // examine code segment selector in call gate descriptor BX_DEBUG(("call_protected: call gate")); dest_selector = gate_descriptor.u.gate.dest_selector; new_EIP = gate_descriptor.u.gate.dest_offset; // selector must not be null else #GP(0) if ((dest_selector & 0xfffc) == 0) { BX_ERROR(("call_protected: selector in gate null")); exception(BX_GP_EXCEPTION, 0, 0); } parse_selector(dest_selector, &cs_selector); // selector must be within its descriptor table limits, // else #GP(code segment selector) fetch_raw_descriptor(&cs_selector, &dword1, &dword2, BX_GP_EXCEPTION); parse_descriptor(dword1, dword2, &cs_descriptor); // AR byte of selected descriptor must indicate code segment, // else #GP(code segment selector) // DPL of selected descriptor must be <= CPL, // else #GP(code segment selector) if (cs_descriptor.valid==0 || cs_descriptor.segment==0 || IS_DATA_SEGMENT(cs_descriptor.type) || cs_descriptor.dpl > CPL) { BX_ERROR(("call_protected: selected descriptor is not code")); exception(BX_GP_EXCEPTION, dest_selector & 0xfffc, 0); } // code segment must be present else #NP(selector) if (! IS_PRESENT(cs_descriptor)) { BX_ERROR(("call_protected: code segment not present !")); exception(BX_NP_EXCEPTION, dest_selector & 0xfffc, 0); } // CALL GATE TO MORE PRIVILEGE // if non-conforming code segment and DPL < CPL then if (IS_CODE_SEGMENT_NON_CONFORMING(cs_descriptor.type) && (cs_descriptor.dpl < CPL)) { Bit16u SS_for_cpl_x; Bit32u ESP_for_cpl_x; bx_selector_t ss_selector; bx_descriptor_t ss_descriptor; Bit16u return_SS, return_CS; Bit32u return_ESP, return_EIP; Bit16u parameter_word[32]; Bit32u parameter_dword[32]; BX_DEBUG(("CALL GATE TO MORE PRIVILEGE LEVEL")); // get new SS selector for new privilege level from TSS get_SS_ESP_from_TSS(cs_descriptor.dpl, &SS_for_cpl_x, &ESP_for_cpl_x); // check selector & descriptor for new SS: // selector must not be null, else #TS(0) if ((SS_for_cpl_x & 0xfffc) == 0) { BX_ERROR(("call_protected: new SS null")); exception(BX_TS_EXCEPTION, 0, 0); } // selector index must be within its descriptor table limits, // else #TS(SS selector) parse_selector(SS_for_cpl_x, &ss_selector); fetch_raw_descriptor(&ss_selector, &dword1, &dword2, BX_TS_EXCEPTION); parse_descriptor(dword1, dword2, &ss_descriptor); // selector's RPL must equal DPL of code segment, // else #TS(SS selector) if (ss_selector.rpl != cs_descriptor.dpl) { BX_ERROR(("call_protected: SS selector.rpl != CS descr.dpl")); exception(BX_TS_EXCEPTION, SS_for_cpl_x & 0xfffc, 0); } // stack segment DPL must equal DPL of code segment, // else #TS(SS selector) if (ss_descriptor.dpl != cs_descriptor.dpl) { BX_ERROR(("call_protected: SS descr.rpl != CS descr.dpl")); exception(BX_TS_EXCEPTION, SS_for_cpl_x & 0xfffc, 0); } // descriptor must indicate writable data segment, // else #TS(SS selector) if (ss_descriptor.valid==0 || ss_descriptor.segment==0 || IS_CODE_SEGMENT(ss_descriptor.type) || !IS_DATA_SEGMENT_WRITEABLE(ss_descriptor.type)) { BX_ERROR(("call_protected: ss descriptor is not writable data seg")); exception(BX_TS_EXCEPTION, SS_for_cpl_x & 0xfffc, 0); } // segment must be present, else #SS(SS selector) if (! IS_PRESENT(ss_descriptor)) { BX_ERROR(("call_protected: ss descriptor not present")); exception(BX_SS_EXCEPTION, SS_for_cpl_x & 0xfffc, 0); } // get word count from call gate, mask to 5 bits unsigned param_count = gate_descriptor.u.gate.param_count & 0x1f; // save return SS:eSP to be pushed on new stack return_SS = BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS].selector.value; if (BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS].cache.u.segment.d_b) return_ESP = ESP; else return_ESP = SP; // save return CS:eIP to be pushed on new stack return_CS = BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS].selector.value; if (cs_descriptor.u.segment.d_b) return_EIP = EIP; else return_EIP = IP; if (gate_descriptor.type==BX_286_CALL_GATE) { for (unsigned i=0; i<param_count; i++) { parameter_word[i] = read_virtual_word(BX_SEG_REG_SS, return_ESP + i*2); } } else { for (unsigned i=0; i<param_count; i++) { parameter_dword[i] = read_virtual_dword(BX_SEG_REG_SS, return_ESP + i*4); } } // Prepare new stack segment bx_segment_reg_t new_stack; new_stack.selector = ss_selector; new_stack.cache = ss_descriptor; new_stack.selector.rpl = cs_descriptor.dpl; // add cpl to the selector value new_stack.selector.value = (0xfffc & new_stack.selector.value) | new_stack.selector.rpl; /* load new SS:SP value from TSS */ if (ss_descriptor.u.segment.d_b) { Bit32u temp_ESP = ESP_for_cpl_x; // push pointer of old stack onto new stack if (gate_descriptor.type==BX_386_CALL_GATE) { write_new_stack_dword_32(&new_stack, temp_ESP-4, cs_descriptor.dpl, return_SS); write_new_stack_dword_32(&new_stack, temp_ESP-8, cs_descriptor.dpl, return_ESP); temp_ESP -= 8; for (unsigned i=param_count; i>0; i--) { temp_ESP -= 4; write_new_stack_dword_32(&new_stack, temp_ESP, cs_descriptor.dpl, parameter_dword[i-1]); } // push return address onto new stack write_new_stack_dword_32(&new_stack, temp_ESP-4, cs_descriptor.dpl, return_CS); write_new_stack_dword_32(&new_stack, temp_ESP-8, cs_descriptor.dpl, return_EIP); temp_ESP -= 8; } else { write_new_stack_word_32(&new_stack, temp_ESP-2, cs_descriptor.dpl, return_SS); write_new_stack_word_32(&new_stack, temp_ESP-4, cs_descriptor.dpl, (Bit16u) return_ESP); temp_ESP -= 4; for (unsigned i=param_count; i>0; i--) { temp_ESP -= 2; write_new_stack_word_32(&new_stack, temp_ESP, cs_descriptor.dpl, parameter_word[i-1]); } // push return address onto new stack write_new_stack_word_32(&new_stack, temp_ESP-2, cs_descriptor.dpl, return_CS); write_new_stack_word_32(&new_stack, temp_ESP-4, cs_descriptor.dpl, (Bit16u) return_EIP); temp_ESP -= 4; } ESP = temp_ESP; } else { Bit16u temp_SP = (Bit16u) ESP_for_cpl_x; // push pointer of old stack onto new stack if (gate_descriptor.type==BX_386_CALL_GATE) { write_new_stack_dword_32(&new_stack, (Bit16u)(temp_SP-4), cs_descriptor.dpl, return_SS); write_new_stack_dword_32(&new_stack, (Bit16u)(temp_SP-8), cs_descriptor.dpl, return_ESP); temp_SP -= 8; for (unsigned i=param_count; i>0; i--) { temp_SP -= 4; write_new_stack_dword_32(&new_stack, temp_SP, cs_descriptor.dpl, parameter_dword[i-1]); } // push return address onto new stack write_new_stack_dword_32(&new_stack, (Bit16u)(temp_SP-4), cs_descriptor.dpl, return_CS); write_new_stack_dword_32(&new_stack, (Bit16u)(temp_SP-8), cs_descriptor.dpl, return_EIP); temp_SP -= 8; } else { write_new_stack_word_32(&new_stack, (Bit16u)(temp_SP-2), cs_descriptor.dpl, return_SS); write_new_stack_word_32(&new_stack, (Bit16u)(temp_SP-4), cs_descriptor.dpl, (Bit16u) return_ESP); temp_SP -= 4; for (unsigned i=param_count; i>0; i--) { temp_SP -= 2; write_new_stack_word_32(&new_stack, temp_SP, cs_descriptor.dpl, parameter_word[i-1]); } // push return address onto new stack write_new_stack_word_32(&new_stack, (Bit16u)(temp_SP-2), cs_descriptor.dpl, return_CS); write_new_stack_word_32(&new_stack, (Bit16u)(temp_SP-4), cs_descriptor.dpl, (Bit16u) return_EIP); temp_SP -= 4; } SP = temp_SP; } // new eIP must be in code segment limit else #GP(0) if (new_EIP > cs_descriptor.u.segment.limit_scaled) { BX_ERROR(("call_protected: EIP not within CS limits")); exception(BX_GP_EXCEPTION, 0, 0); } /* load SS descriptor */ load_ss(&ss_selector, &ss_descriptor, cs_descriptor.dpl); /* load new CS:IP value from gate */ /* load CS descriptor */ /* set CPL to stack segment DPL */ /* set RPL of CS to CPL */ load_cs(&cs_selector, &cs_descriptor, cs_descriptor.dpl); EIP = new_EIP; } else // CALL GATE TO SAME PRIVILEGE { BX_DEBUG(("CALL GATE TO SAME PRIVILEGE")); if (gate_descriptor.type == BX_386_CALL_GATE) { // call gate 32bit, push return address onto stack push_32(BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS].selector.value); push_32(EIP); } else { // call gate 16bit, push return address onto stack push_16(BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS].selector.value); push_16(IP); } // load CS:EIP from gate // load code segment descriptor into CS register // set RPL of CS to CPL branch_far32(&cs_selector, &cs_descriptor, new_EIP, CPL); } return; default: // can't get here BX_PANIC(("call_protected: gate type %u unsupported", (unsigned) cs_descriptor.type)); exception(BX_GP_EXCEPTION, cs_raw & 0xfffc, 0); } } }
void BX_CPP_AttrRegparmN(1) BX_CPU_C::call_gate(bx_descriptor_t *gate_descriptor) { bx_selector_t cs_selector; Bit32u dword1, dword2; bx_descriptor_t cs_descriptor; // examine code segment selector in call gate descriptor BX_DEBUG(("call_protected: call gate")); Bit16u dest_selector = gate_descriptor->u.gate.dest_selector; Bit32u new_EIP = gate_descriptor->u.gate.dest_offset; // selector must not be null else #GP(0) if ((dest_selector & 0xfffc) == 0) { BX_ERROR(("call_protected: selector in gate null")); exception(BX_GP_EXCEPTION, 0); } parse_selector(dest_selector, &cs_selector); // selector must be within its descriptor table limits, // else #GP(code segment selector) fetch_raw_descriptor(&cs_selector, &dword1, &dword2, BX_GP_EXCEPTION); parse_descriptor(dword1, dword2, &cs_descriptor); // AR byte of selected descriptor must indicate code segment, // else #GP(code segment selector) // DPL of selected descriptor must be <= CPL, // else #GP(code segment selector) if (cs_descriptor.valid==0 || cs_descriptor.segment==0 || IS_DATA_SEGMENT(cs_descriptor.type) || cs_descriptor.dpl > CPL) { BX_ERROR(("call_protected: selected descriptor is not code")); exception(BX_GP_EXCEPTION, dest_selector & 0xfffc); } // code segment must be present else #NP(selector) if (! IS_PRESENT(cs_descriptor)) { BX_ERROR(("call_protected: code segment not present !")); exception(BX_NP_EXCEPTION, dest_selector & 0xfffc); } // CALL GATE TO MORE PRIVILEGE // if non-conforming code segment and DPL < CPL then if (IS_CODE_SEGMENT_NON_CONFORMING(cs_descriptor.type) && (cs_descriptor.dpl < CPL)) { Bit16u SS_for_cpl_x; Bit32u ESP_for_cpl_x; bx_selector_t ss_selector; bx_descriptor_t ss_descriptor; Bit16u return_SS, return_CS; Bit32u return_ESP, return_EIP; BX_DEBUG(("CALL GATE TO MORE PRIVILEGE LEVEL")); // get new SS selector for new privilege level from TSS get_SS_ESP_from_TSS(cs_descriptor.dpl, &SS_for_cpl_x, &ESP_for_cpl_x); // check selector & descriptor for new SS: // selector must not be null, else #TS(0) if ((SS_for_cpl_x & 0xfffc) == 0) { BX_ERROR(("call_protected: new SS null")); exception(BX_TS_EXCEPTION, 0); } // selector index must be within its descriptor table limits, // else #TS(SS selector) parse_selector(SS_for_cpl_x, &ss_selector); fetch_raw_descriptor(&ss_selector, &dword1, &dword2, BX_TS_EXCEPTION); parse_descriptor(dword1, dword2, &ss_descriptor); // selector's RPL must equal DPL of code segment, // else #TS(SS selector) if (ss_selector.rpl != cs_descriptor.dpl) { BX_ERROR(("call_protected: SS selector.rpl != CS descr.dpl")); exception(BX_TS_EXCEPTION, SS_for_cpl_x & 0xfffc); } // stack segment DPL must equal DPL of code segment, // else #TS(SS selector) if (ss_descriptor.dpl != cs_descriptor.dpl) { BX_ERROR(("call_protected: SS descr.rpl != CS descr.dpl")); exception(BX_TS_EXCEPTION, SS_for_cpl_x & 0xfffc); } // descriptor must indicate writable data segment, // else #TS(SS selector) if (ss_descriptor.valid==0 || ss_descriptor.segment==0 || IS_CODE_SEGMENT(ss_descriptor.type) || !IS_DATA_SEGMENT_WRITEABLE(ss_descriptor.type)) { BX_ERROR(("call_protected: ss descriptor is not writable data seg")); exception(BX_TS_EXCEPTION, SS_for_cpl_x & 0xfffc); } // segment must be present, else #SS(SS selector) if (! IS_PRESENT(ss_descriptor)) { BX_ERROR(("call_protected: ss descriptor not present")); exception(BX_SS_EXCEPTION, SS_for_cpl_x & 0xfffc); } // get word count from call gate, mask to 5 bits unsigned param_count = gate_descriptor->u.gate.param_count & 0x1f; // save return SS:eSP to be pushed on new stack return_SS = BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS].selector.value; if (BX_CPU_THIS_PTR sregs[BX_SEG_REG_SS].cache.u.segment.d_b) return_ESP = ESP; else return_ESP = SP; // save return CS:eIP to be pushed on new stack return_CS = BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS].selector.value; if (cs_descriptor.u.segment.d_b) return_EIP = EIP; else return_EIP = IP; // Prepare new stack segment bx_segment_reg_t new_stack; new_stack.selector = ss_selector; new_stack.cache = ss_descriptor; new_stack.selector.rpl = cs_descriptor.dpl; // add cpl to the selector value new_stack.selector.value = (0xfffc & new_stack.selector.value) | new_stack.selector.rpl; /* load new SS:SP value from TSS */ if (ss_descriptor.u.segment.d_b) { Bit32u temp_ESP = ESP_for_cpl_x; // push pointer of old stack onto new stack if (gate_descriptor->type==BX_386_CALL_GATE) { write_new_stack_dword_32(&new_stack, temp_ESP-4, cs_descriptor.dpl, return_SS); write_new_stack_dword_32(&new_stack, temp_ESP-8, cs_descriptor.dpl, return_ESP); temp_ESP -= 8; for (unsigned n=param_count; n>0; n--) { temp_ESP -= 4; Bit32u param = read_virtual_dword_32(BX_SEG_REG_SS, return_ESP + (n-1)*4); write_new_stack_dword_32(&new_stack, temp_ESP, cs_descriptor.dpl, param); } // push return address onto new stack write_new_stack_dword_32(&new_stack, temp_ESP-4, cs_descriptor.dpl, return_CS); write_new_stack_dword_32(&new_stack, temp_ESP-8, cs_descriptor.dpl, return_EIP); temp_ESP -= 8; } else { write_new_stack_word_32(&new_stack, temp_ESP-2, cs_descriptor.dpl, return_SS); write_new_stack_word_32(&new_stack, temp_ESP-4, cs_descriptor.dpl, (Bit16u) return_ESP); temp_ESP -= 4; for (unsigned n=param_count; n>0; n--) { temp_ESP -= 2; Bit16u param = read_virtual_word_32(BX_SEG_REG_SS, return_ESP + (n-1)*2); write_new_stack_word_32(&new_stack, temp_ESP, cs_descriptor.dpl, param); } // push return address onto new stack write_new_stack_word_32(&new_stack, temp_ESP-2, cs_descriptor.dpl, return_CS); write_new_stack_word_32(&new_stack, temp_ESP-4, cs_descriptor.dpl, (Bit16u) return_EIP); temp_ESP -= 4; } ESP = temp_ESP; } else { Bit16u temp_SP = (Bit16u) ESP_for_cpl_x; // push pointer of old stack onto new stack if (gate_descriptor->type==BX_386_CALL_GATE) { write_new_stack_dword_32(&new_stack, (Bit16u)(temp_SP-4), cs_descriptor.dpl, return_SS); write_new_stack_dword_32(&new_stack, (Bit16u)(temp_SP-8), cs_descriptor.dpl, return_ESP); temp_SP -= 8; for (unsigned n=param_count; n>0; n--) { temp_SP -= 4; Bit32u param = read_virtual_dword_32(BX_SEG_REG_SS, return_ESP + (n-1)*4); write_new_stack_dword_32(&new_stack, temp_SP, cs_descriptor.dpl, param); } // push return address onto new stack write_new_stack_dword_32(&new_stack, (Bit16u)(temp_SP-4), cs_descriptor.dpl, return_CS); write_new_stack_dword_32(&new_stack, (Bit16u)(temp_SP-8), cs_descriptor.dpl, return_EIP); temp_SP -= 8; } else { write_new_stack_word_32(&new_stack, (Bit16u)(temp_SP-2), cs_descriptor.dpl, return_SS); write_new_stack_word_32(&new_stack, (Bit16u)(temp_SP-4), cs_descriptor.dpl, (Bit16u) return_ESP); temp_SP -= 4; for (unsigned n=param_count; n>0; n--) { temp_SP -= 2; Bit16u param = read_virtual_word_32(BX_SEG_REG_SS, return_ESP + (n-1)*2); write_new_stack_word_32(&new_stack, temp_SP, cs_descriptor.dpl, param); } // push return address onto new stack write_new_stack_word_32(&new_stack, (Bit16u)(temp_SP-2), cs_descriptor.dpl, return_CS); write_new_stack_word_32(&new_stack, (Bit16u)(temp_SP-4), cs_descriptor.dpl, (Bit16u) return_EIP); temp_SP -= 4; } SP = temp_SP; } // new eIP must be in code segment limit else #GP(0) if (new_EIP > cs_descriptor.u.segment.limit_scaled) { BX_ERROR(("call_protected: EIP not within CS limits")); exception(BX_GP_EXCEPTION, 0); } /* load SS descriptor */ load_ss(&ss_selector, &ss_descriptor, cs_descriptor.dpl); /* load new CS:IP value from gate */ /* load CS descriptor */ /* set CPL to stack segment DPL */ /* set RPL of CS to CPL */ load_cs(&cs_selector, &cs_descriptor, cs_descriptor.dpl); EIP = new_EIP; } else // CALL GATE TO SAME PRIVILEGE { BX_DEBUG(("CALL GATE TO SAME PRIVILEGE")); if (gate_descriptor->type == BX_386_CALL_GATE) { // call gate 32bit, push return address onto stack push_32(BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS].selector.value); push_32(EIP); } else { // call gate 16bit, push return address onto stack push_16(BX_CPU_THIS_PTR sregs[BX_SEG_REG_CS].selector.value); push_16(IP); } // load CS:EIP from gate // load code segment descriptor into CS register // set RPL of CS to CPL branch_far32(&cs_selector, &cs_descriptor, new_EIP, CPL); } }
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)); }