mirror of
https://github.com/kanjitalk755/macemu.git
synced 2024-09-30 13:56:16 +00:00
797 lines
22 KiB
C++
797 lines
22 KiB
C++
/*
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* sigsegv.cpp - SIGSEGV signals support
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*
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* Derived from Bruno Haible's work on his SIGSEGV library for clisp
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* <http://clisp.sourceforge.net/>
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*
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* Basilisk II (C) 1997-2002 Christian Bauer
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#ifdef HAVE_UNISTD_H
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#include <unistd.h>
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#endif
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#ifdef HAVE_CONFIG_H
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#include "config.h"
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#endif
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#include <signal.h>
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#include "sigsegv.h"
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// Return value type of a signal handler (standard type if not defined)
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#ifndef RETSIGTYPE
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#define RETSIGTYPE void
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#endif
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// Type of the system signal handler
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typedef RETSIGTYPE (*signal_handler)(int);
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// Is the fault to be ignored?
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static bool sigsegv_ignore_fault = false;
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// User's SIGSEGV handler
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static sigsegv_fault_handler_t sigsegv_fault_handler = 0;
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// Function called to dump state if we can't handle the fault
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static sigsegv_state_dumper_t sigsegv_state_dumper = 0;
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// Actual SIGSEGV handler installer
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static bool sigsegv_do_install_handler(int sig);
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/*
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* Instruction decoding aids
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*/
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// Transfer type
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enum transfer_type_t {
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TYPE_UNKNOWN,
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TYPE_LOAD,
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TYPE_STORE
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};
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// Transfer size
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enum transfer_size_t {
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SIZE_UNKNOWN,
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SIZE_BYTE,
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SIZE_WORD,
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SIZE_LONG
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};
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#if (defined(powerpc) || defined(__powerpc__) || defined(__ppc__))
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// Addressing mode
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enum addressing_mode_t {
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MODE_UNKNOWN,
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MODE_NORM,
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MODE_U,
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MODE_X,
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MODE_UX
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};
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// Decoded instruction
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struct instruction_t {
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transfer_type_t transfer_type;
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transfer_size_t transfer_size;
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addressing_mode_t addr_mode;
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unsigned int addr;
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char ra, rd;
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};
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static void powerpc_decode_instruction(instruction_t *instruction, unsigned int nip, unsigned int * gpr)
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{
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// Get opcode and divide into fields
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unsigned int opcode = *((unsigned int *)nip);
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unsigned int primop = opcode >> 26;
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unsigned int exop = (opcode >> 1) & 0x3ff;
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unsigned int ra = (opcode >> 16) & 0x1f;
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unsigned int rb = (opcode >> 11) & 0x1f;
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unsigned int rd = (opcode >> 21) & 0x1f;
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signed int imm = (signed short)(opcode & 0xffff);
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// Analyze opcode
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transfer_type_t transfer_type = TYPE_UNKNOWN;
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transfer_size_t transfer_size = SIZE_UNKNOWN;
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addressing_mode_t addr_mode = MODE_UNKNOWN;
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switch (primop) {
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case 31:
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switch (exop) {
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case 23: // lwzx
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transfer_type = TYPE_LOAD; transfer_size = SIZE_LONG; addr_mode = MODE_X; break;
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case 55: // lwzux
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transfer_type = TYPE_LOAD; transfer_size = SIZE_LONG; addr_mode = MODE_UX; break;
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case 87: // lbzx
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transfer_type = TYPE_LOAD; transfer_size = SIZE_BYTE; addr_mode = MODE_X; break;
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case 119: // lbzux
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transfer_type = TYPE_LOAD; transfer_size = SIZE_BYTE; addr_mode = MODE_UX; break;
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case 151: // stwx
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transfer_type = TYPE_STORE; transfer_size = SIZE_LONG; addr_mode = MODE_X; break;
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case 183: // stwux
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transfer_type = TYPE_STORE; transfer_size = SIZE_LONG; addr_mode = MODE_UX; break;
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case 215: // stbx
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transfer_type = TYPE_STORE; transfer_size = SIZE_BYTE; addr_mode = MODE_X; break;
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case 247: // stbux
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transfer_type = TYPE_STORE; transfer_size = SIZE_BYTE; addr_mode = MODE_UX; break;
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case 279: // lhzx
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transfer_type = TYPE_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_X; break;
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case 311: // lhzux
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transfer_type = TYPE_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_UX; break;
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case 343: // lhax
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transfer_type = TYPE_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_X; break;
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case 375: // lhaux
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transfer_type = TYPE_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_UX; break;
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case 407: // sthx
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transfer_type = TYPE_STORE; transfer_size = SIZE_WORD; addr_mode = MODE_X; break;
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case 439: // sthux
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transfer_type = TYPE_STORE; transfer_size = SIZE_WORD; addr_mode = MODE_UX; break;
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}
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break;
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case 32: // lwz
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transfer_type = TYPE_LOAD; transfer_size = SIZE_LONG; addr_mode = MODE_NORM; break;
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case 33: // lwzu
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transfer_type = TYPE_LOAD; transfer_size = SIZE_LONG; addr_mode = MODE_U; break;
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case 34: // lbz
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transfer_type = TYPE_LOAD; transfer_size = SIZE_BYTE; addr_mode = MODE_NORM; break;
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case 35: // lbzu
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transfer_type = TYPE_LOAD; transfer_size = SIZE_BYTE; addr_mode = MODE_U; break;
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case 36: // stw
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transfer_type = TYPE_STORE; transfer_size = SIZE_LONG; addr_mode = MODE_NORM; break;
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case 37: // stwu
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transfer_type = TYPE_STORE; transfer_size = SIZE_LONG; addr_mode = MODE_U; break;
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case 38: // stb
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transfer_type = TYPE_STORE; transfer_size = SIZE_BYTE; addr_mode = MODE_NORM; break;
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case 39: // stbu
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transfer_type = TYPE_STORE; transfer_size = SIZE_BYTE; addr_mode = MODE_U; break;
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case 40: // lhz
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transfer_type = TYPE_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_NORM; break;
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case 41: // lhzu
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transfer_type = TYPE_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_U; break;
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case 42: // lha
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transfer_type = TYPE_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_NORM; break;
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case 43: // lhau
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transfer_type = TYPE_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_U; break;
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case 44: // sth
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transfer_type = TYPE_STORE; transfer_size = SIZE_WORD; addr_mode = MODE_NORM; break;
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case 45: // sthu
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transfer_type = TYPE_STORE; transfer_size = SIZE_WORD; addr_mode = MODE_U; break;
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}
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// Calculate effective address
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unsigned int addr = 0;
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switch (addr_mode) {
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case MODE_X:
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case MODE_UX:
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if (ra == 0)
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addr = gpr[rb];
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else
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addr = gpr[ra] + gpr[rb];
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break;
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case MODE_NORM:
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case MODE_U:
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if (ra == 0)
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addr = (signed int)(signed short)imm;
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else
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addr = gpr[ra] + (signed int)(signed short)imm;
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break;
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default:
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break;
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}
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// Commit decoded instruction
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instruction->addr = addr;
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instruction->addr_mode = addr_mode;
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instruction->transfer_type = transfer_type;
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instruction->transfer_size = transfer_size;
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instruction->ra = ra;
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instruction->rd = rd;
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}
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#endif
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/*
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* OS-dependant SIGSEGV signals support section
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*/
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#if HAVE_SIGINFO_T
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// Generic extended signal handler
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#if defined(__NetBSD__) || defined(__FreeBSD__)
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#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGBUS)
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#else
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#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV)
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#endif
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#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, siginfo_t *sip, void *scp
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#define SIGSEGV_FAULT_ADDRESS sip->si_addr
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#if defined(__linux__)
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#if (defined(i386) || defined(__i386__))
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#include <sys/ucontext.h>
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#define SIGSEGV_CONTEXT_REGS (((ucontext_t *)scp)->uc_mcontext.gregs)
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#define SIGSEGV_FAULT_INSTRUCTION SIGSEGV_CONTEXT_REGS[14] /* should use REG_EIP instead */
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#define SIGSEGV_REGISTER_FILE (unsigned int *)SIGSEGV_CONTEXT_REGS
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#define SIGSEGV_SKIP_INSTRUCTION ix86_skip_instruction
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#endif
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#if (defined(ia64) || defined(__ia64__))
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#define SIGSEGV_FAULT_INSTRUCTION (((struct sigcontext *)scp)->sc_ip & ~0x3ULL) /* slot number is in bits 0 and 1 */
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#endif
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#if (defined(powerpc) || defined(__powerpc__))
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#include <sys/ucontext.h>
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#define SIGSEGV_CONTEXT_REGS (((ucontext_t *)scp)->uc_mcontext.regs)
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#define SIGSEGV_FAULT_INSTRUCTION (SIGSEGV_CONTEXT_REGS->nip)
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#define SIGSEGV_REGISTER_FILE (unsigned int *)&SIGSEGV_CONTEXT_REGS->nip, (unsigned int *)(SIGSEGV_CONTEXT_REGS->gpr)
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#define SIGSEGV_SKIP_INSTRUCTION powerpc_skip_instruction
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#endif
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#endif
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#endif
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#if HAVE_SIGCONTEXT_SUBTERFUGE
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// Linux kernels prior to 2.4 ?
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#if defined(__linux__)
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#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV)
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#if (defined(i386) || defined(__i386__))
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#include <asm/sigcontext.h>
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#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, struct sigcontext scs
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#define SIGSEGV_FAULT_ADDRESS scs.cr2
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#define SIGSEGV_FAULT_INSTRUCTION scs.eip
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#define SIGSEGV_REGISTER_FILE (unsigned long *)(&scs)
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#define SIGSEGV_SKIP_INSTRUCTION ix86_skip_instruction
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#endif
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#if (defined(sparc) || defined(__sparc__))
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#include <asm/sigcontext.h>
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#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp, char *addr
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#define SIGSEGV_FAULT_ADDRESS addr
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#endif
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#if (defined(powerpc) || defined(__powerpc__))
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#include <asm/sigcontext.h>
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#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, struct sigcontext *scp
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#define SIGSEGV_FAULT_ADDRESS scp->regs->dar
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#define SIGSEGV_FAULT_INSTRUCTION scp->regs->nip
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#define SIGSEGV_REGISTER_FILE (unsigned int *)&scp->regs->nip, (unsigned int *)(scp->regs->gpr)
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#define SIGSEGV_SKIP_INSTRUCTION powerpc_skip_instruction
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#endif
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#if (defined(alpha) || defined(__alpha__))
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#include <asm/sigcontext.h>
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#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
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#define SIGSEGV_FAULT_ADDRESS get_fault_address(scp)
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#define SIGSEGV_FAULT_INSTRUCTION scp->sc_pc
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// From Boehm's GC 6.0alpha8
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static sigsegv_address_t get_fault_address(struct sigcontext *scp)
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{
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unsigned int instruction = *((unsigned int *)(scp->sc_pc));
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unsigned long fault_address = scp->sc_regs[(instruction >> 16) & 0x1f];
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fault_address += (signed long)(signed short)(instruction & 0xffff);
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return (sigsegv_address_t)fault_address;
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}
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#endif
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#endif
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// Irix 5 or 6 on MIPS
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#if (defined(sgi) || defined(__sgi)) && (defined(SYSTYPE_SVR4) || defined(__SYSTYPE_SVR4))
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#include <ucontext.h>
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#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
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#define SIGSEGV_FAULT_ADDRESS scp->sc_badvaddr
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#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV)
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#endif
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// HP-UX
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#if (defined(hpux) || defined(__hpux__))
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#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
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#define SIGSEGV_FAULT_ADDRESS scp->sc_sl.sl_ss.ss_narrow.ss_cr21
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#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV) FAULT_HANDLER(SIGBUS)
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#endif
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// OSF/1 on Alpha
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#if defined(__osf__)
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#include <ucontext.h>
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#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
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#define SIGSEGV_FAULT_ADDRESS scp->sc_traparg_a0
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#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV)
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#endif
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// AIX
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#if defined(_AIX)
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#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
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#define SIGSEGV_FAULT_ADDRESS scp->sc_jmpbuf.jmp_context.o_vaddr
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#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV)
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#endif
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// NetBSD or FreeBSD
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#if defined(__NetBSD__) || defined(__FreeBSD__)
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#if (defined(m68k) || defined(__m68k__))
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#include <m68k/frame.h>
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#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
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#define SIGSEGV_FAULT_ADDRESS get_fault_address(scp)
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#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV)
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// Use decoding scheme from BasiliskII/m68k native
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static sigsegv_address_t get_fault_address(struct sigcontext *scp)
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{
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struct sigstate {
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int ss_flags;
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struct frame ss_frame;
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};
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struct sigstate *state = (struct sigstate *)scp->sc_ap;
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char *fault_addr;
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switch (state->ss_frame.f_format) {
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case 7: /* 68040 access error */
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/* "code" is sometimes unreliable (i.e. contains NULL or a bogus address), reason unknown */
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fault_addr = state->ss_frame.f_fmt7.f_fa;
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break;
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default:
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fault_addr = (char *)code;
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break;
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}
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return (sigsegv_address_t)fault_addr;
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}
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#else
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#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, void *scp, char *addr
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#define SIGSEGV_FAULT_ADDRESS addr
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#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGBUS)
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#endif
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#endif
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// MacOS X
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#if defined(__APPLE__) && defined(__MACH__)
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#if (defined(ppc) || defined(__ppc__))
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#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp
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#define SIGSEGV_FAULT_ADDRESS get_fault_address(scp)
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#define SIGSEGV_FAULT_INSTRUCTION scp->sc_ir
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#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGBUS)
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#define SIGSEGV_REGISTER_FILE (unsigned int *)&scp->sc_ir, &((unsigned int *) scp->sc_regs)[2]
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#define SIGSEGV_SKIP_INSTRUCTION powerpc_skip_instruction
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// Use decoding scheme from SheepShaver
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static sigsegv_address_t get_fault_address(struct sigcontext *scp)
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{
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unsigned int nip = (unsigned int) scp->sc_ir;
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unsigned int * gpr = &((unsigned int *) scp->sc_regs)[2];
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instruction_t instr;
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powerpc_decode_instruction(&instr, nip, gpr);
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return (sigsegv_address_t)instr.addr;
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}
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#endif
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#endif
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#endif
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/*
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* Instruction skipping
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*/
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#ifdef HAVE_SIGSEGV_SKIP_INSTRUCTION
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// Decode and skip X86 instruction
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#if (defined(i386) || defined(__i386__))
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#if defined(__linux__)
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enum {
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X86_REG_EIP = 14,
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X86_REG_EAX = 11,
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X86_REG_ECX = 10,
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X86_REG_EDX = 9,
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X86_REG_EBX = 8,
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X86_REG_ESP = 7,
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X86_REG_EBP = 6,
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X86_REG_ESI = 5,
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X86_REG_EDI = 4
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};
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#endif
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// FIXME: this is partly redundant with the instruction decoding phase
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// to discover transfer type and register number
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static inline int ix86_step_over_modrm(unsigned char * p)
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{
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int mod = (p[0] >> 6) & 3;
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int rm = p[0] & 7;
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int offset = 0;
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// ModR/M Byte
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switch (mod) {
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case 0: // [reg]
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if (rm == 5) return 4; // disp32
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break;
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case 1: // disp8[reg]
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offset = 1;
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break;
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case 2: // disp32[reg]
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offset = 4;
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break;
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case 3: // register
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return 0;
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}
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// SIB Byte
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if (rm == 4) {
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if (mod == 0 && (p[1] & 7) == 5)
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offset = 5; // disp32[index]
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else
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offset++;
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}
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return offset;
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}
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static bool ix86_skip_instruction(unsigned int * regs)
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{
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unsigned char * eip = (unsigned char *)regs[X86_REG_EIP];
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if (eip == 0)
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return false;
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transfer_type_t transfer_type = TYPE_UNKNOWN;
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transfer_size_t transfer_size = SIZE_LONG;
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int reg = -1;
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int len = 0;
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// Operand size prefix
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if (*eip == 0x66) {
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eip++;
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len++;
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transfer_size = SIZE_WORD;
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}
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// Decode instruction
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switch (eip[0]) {
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case 0x8a: // MOV r8, r/m8
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transfer_size = SIZE_BYTE;
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case 0x8b: // MOV r32, r/m32 (or 16-bit operation)
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switch (eip[1] & 0xc0) {
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case 0x80:
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reg = (eip[1] >> 3) & 7;
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transfer_type = TYPE_LOAD;
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break;
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case 0x40:
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reg = (eip[1] >> 3) & 7;
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transfer_type = TYPE_LOAD;
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break;
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case 0x00:
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reg = (eip[1] >> 3) & 7;
|
|
transfer_type = TYPE_LOAD;
|
|
break;
|
|
}
|
|
len += 2 + ix86_step_over_modrm(eip + 1);
|
|
break;
|
|
case 0x88: // MOV r/m8, r8
|
|
transfer_size = SIZE_BYTE;
|
|
case 0x89: // MOV r/m32, r32 (or 16-bit operation)
|
|
switch (eip[1] & 0xc0) {
|
|
case 0x80:
|
|
reg = (eip[1] >> 3) & 7;
|
|
transfer_type = TYPE_STORE;
|
|
break;
|
|
case 0x40:
|
|
reg = (eip[1] >> 3) & 7;
|
|
transfer_type = TYPE_STORE;
|
|
break;
|
|
case 0x00:
|
|
reg = (eip[1] >> 3) & 7;
|
|
transfer_type = TYPE_STORE;
|
|
break;
|
|
}
|
|
len += 2 + ix86_step_over_modrm(eip + 1);
|
|
break;
|
|
}
|
|
|
|
if (transfer_type == TYPE_UNKNOWN) {
|
|
// Unknown machine code, let it crash. Then patch the decoder
|
|
return false;
|
|
}
|
|
|
|
if (transfer_type == TYPE_LOAD && reg != -1) {
|
|
static const int x86_reg_map[8] = {
|
|
X86_REG_EAX, X86_REG_ECX, X86_REG_EDX, X86_REG_EBX,
|
|
X86_REG_ESP, X86_REG_EBP, X86_REG_ESI, X86_REG_EDI
|
|
};
|
|
|
|
if (reg < 0 || reg >= 8)
|
|
return false;
|
|
|
|
int rloc = x86_reg_map[reg];
|
|
switch (transfer_size) {
|
|
case SIZE_BYTE:
|
|
regs[rloc] = (regs[rloc] & ~0xff);
|
|
break;
|
|
case SIZE_WORD:
|
|
regs[rloc] = (regs[rloc] & ~0xffff);
|
|
break;
|
|
case SIZE_LONG:
|
|
regs[rloc] = 0;
|
|
break;
|
|
}
|
|
}
|
|
|
|
#if DEBUG
|
|
printf("%08x: %s %s access", regs[X86_REG_EIP],
|
|
transfer_size == SIZE_BYTE ? "byte" : transfer_size == SIZE_WORD ? "word" : "long",
|
|
transfer_type == TYPE_LOAD ? "read" : "write");
|
|
|
|
if (reg != -1) {
|
|
static const char * x86_reg_str_map[8] = {
|
|
"eax", "ecx", "edx", "ebx",
|
|
"esp", "ebp", "esi", "edi"
|
|
};
|
|
printf(" %s register %%%s", transfer_type == TYPE_LOAD ? "to" : "from", x86_reg_str_map[reg]);
|
|
}
|
|
printf(", %d bytes instruction\n", len);
|
|
#endif
|
|
|
|
regs[X86_REG_EIP] += len;
|
|
return true;
|
|
}
|
|
#endif
|
|
|
|
// Decode and skip PPC instruction
|
|
#if (defined(powerpc) || defined(__powerpc__) || defined(__ppc__))
|
|
static bool powerpc_skip_instruction(unsigned int * nip_p, unsigned int * regs)
|
|
{
|
|
instruction_t instr;
|
|
powerpc_decode_instruction(&instr, *nip_p, regs);
|
|
|
|
if (instr.transfer_type == TYPE_UNKNOWN) {
|
|
// Unknown machine code, let it crash. Then patch the decoder
|
|
return false;
|
|
}
|
|
|
|
#if DEBUG
|
|
printf("%08x: %s %s access", *nip_p,
|
|
instr.transfer_size == SIZE_BYTE ? "byte" : instr.transfer_size == SIZE_WORD ? "word" : "long",
|
|
instr.transfer_type == TYPE_LOAD ? "read" : "write");
|
|
|
|
if (instr.addr_mode == MODE_U || instr.addr_mode == MODE_UX)
|
|
printf(" r%d (ra = %08x)\n", instr.ra, instr.addr);
|
|
if (instr.transfer_type == TYPE_LOAD)
|
|
printf(" r%d (rd = 0)\n", instr.rd);
|
|
#endif
|
|
|
|
if (instr.addr_mode == MODE_U || instr.addr_mode == MODE_UX)
|
|
regs[instr.ra] = instr.addr;
|
|
if (instr.transfer_type == TYPE_LOAD)
|
|
regs[instr.rd] = 0;
|
|
|
|
*nip_p += 4;
|
|
return true;
|
|
}
|
|
#endif
|
|
#endif
|
|
|
|
// Fallbacks
|
|
#ifndef SIGSEGV_FAULT_INSTRUCTION
|
|
#define SIGSEGV_FAULT_INSTRUCTION SIGSEGV_INVALID_PC
|
|
#endif
|
|
|
|
// SIGSEGV recovery supported ?
|
|
#if defined(SIGSEGV_ALL_SIGNALS) && defined(SIGSEGV_FAULT_HANDLER_ARGLIST) && defined(SIGSEGV_FAULT_ADDRESS)
|
|
#define HAVE_SIGSEGV_RECOVERY
|
|
#endif
|
|
|
|
|
|
/*
|
|
* SIGSEGV global handler
|
|
*/
|
|
|
|
#ifdef HAVE_SIGSEGV_RECOVERY
|
|
static void sigsegv_handler(SIGSEGV_FAULT_HANDLER_ARGLIST)
|
|
{
|
|
sigsegv_address_t fault_address = (sigsegv_address_t)SIGSEGV_FAULT_ADDRESS;
|
|
sigsegv_address_t fault_instruction = (sigsegv_address_t)SIGSEGV_FAULT_INSTRUCTION;
|
|
bool fault_recovered = false;
|
|
|
|
// Call user's handler and reinstall the global handler, if required
|
|
if (sigsegv_fault_handler(fault_address, fault_instruction)) {
|
|
#if (defined(HAVE_SIGACTION) ? defined(SIGACTION_NEED_REINSTALL) : defined(SIGNAL_NEED_REINSTALL))
|
|
sigsegv_do_install_handler(sig);
|
|
#endif
|
|
fault_recovered = true;
|
|
}
|
|
#if HAVE_SIGSEGV_SKIP_INSTRUCTION
|
|
else if (sigsegv_ignore_fault) {
|
|
// Call the instruction skipper with the register file available
|
|
if (SIGSEGV_SKIP_INSTRUCTION(SIGSEGV_REGISTER_FILE))
|
|
fault_recovered = true;
|
|
}
|
|
#endif
|
|
|
|
if (!fault_recovered) {
|
|
// FAIL: reinstall default handler for "safe" crash
|
|
#define FAULT_HANDLER(sig) signal(sig, SIG_DFL);
|
|
SIGSEGV_ALL_SIGNALS
|
|
#undef FAULT_HANDLER
|
|
|
|
// We can't do anything with the fault_address, dump state?
|
|
if (sigsegv_state_dumper != 0)
|
|
sigsegv_state_dumper(fault_address, fault_instruction);
|
|
}
|
|
}
|
|
#endif
|
|
|
|
|
|
/*
|
|
* SIGSEGV handler initialization
|
|
*/
|
|
|
|
#if defined(HAVE_SIGINFO_T)
|
|
static bool sigsegv_do_install_handler(int sig)
|
|
{
|
|
// Setup SIGSEGV handler to process writes to frame buffer
|
|
#ifdef HAVE_SIGACTION
|
|
struct sigaction vosf_sa;
|
|
sigemptyset(&vosf_sa.sa_mask);
|
|
vosf_sa.sa_sigaction = sigsegv_handler;
|
|
vosf_sa.sa_flags = SA_SIGINFO;
|
|
return (sigaction(sig, &vosf_sa, 0) == 0);
|
|
#else
|
|
return (signal(sig, (signal_handler)sigsegv_handler) != SIG_ERR);
|
|
#endif
|
|
}
|
|
#endif
|
|
|
|
#if defined(HAVE_SIGCONTEXT_SUBTERFUGE)
|
|
static bool sigsegv_do_install_handler(int sig)
|
|
{
|
|
// Setup SIGSEGV handler to process writes to frame buffer
|
|
#ifdef HAVE_SIGACTION
|
|
struct sigaction vosf_sa;
|
|
sigemptyset(&vosf_sa.sa_mask);
|
|
vosf_sa.sa_handler = (signal_handler)sigsegv_handler;
|
|
#if !EMULATED_68K && defined(__NetBSD__)
|
|
sigaddset(&vosf_sa.sa_mask, SIGALRM);
|
|
vosf_sa.sa_flags = SA_ONSTACK;
|
|
#else
|
|
vosf_sa.sa_flags = 0;
|
|
#endif
|
|
return (sigaction(sig, &vosf_sa, 0) == 0);
|
|
#else
|
|
return (signal(sig, (signal_handler)sigsegv_handler) != SIG_ERR);
|
|
#endif
|
|
}
|
|
#endif
|
|
|
|
bool sigsegv_install_handler(sigsegv_fault_handler_t handler)
|
|
{
|
|
#ifdef HAVE_SIGSEGV_RECOVERY
|
|
sigsegv_fault_handler = handler;
|
|
bool success = true;
|
|
#define FAULT_HANDLER(sig) success = success && sigsegv_do_install_handler(sig);
|
|
SIGSEGV_ALL_SIGNALS
|
|
#undef FAULT_HANDLER
|
|
return success;
|
|
#else
|
|
// FAIL: no siginfo_t nor sigcontext subterfuge is available
|
|
return false;
|
|
#endif
|
|
}
|
|
|
|
|
|
/*
|
|
* SIGSEGV handler deinitialization
|
|
*/
|
|
|
|
void sigsegv_deinstall_handler(void)
|
|
{
|
|
#ifdef HAVE_SIGSEGV_RECOVERY
|
|
sigsegv_fault_handler = 0;
|
|
#define FAULT_HANDLER(sig) signal(sig, SIG_DFL);
|
|
SIGSEGV_ALL_SIGNALS
|
|
#undef FAULT_HANDLER
|
|
#endif
|
|
}
|
|
|
|
|
|
/*
|
|
* SIGSEGV ignore state modifier
|
|
*/
|
|
|
|
void sigsegv_set_ignore_state(bool ignore_fault)
|
|
{
|
|
sigsegv_ignore_fault = ignore_fault;
|
|
}
|
|
|
|
|
|
/*
|
|
* Set callback function when we cannot handle the fault
|
|
*/
|
|
|
|
void sigsegv_set_dump_state(sigsegv_state_dumper_t handler)
|
|
{
|
|
sigsegv_state_dumper = handler;
|
|
}
|
|
|
|
|
|
/*
|
|
* Test program used for configure/test
|
|
*/
|
|
|
|
#ifdef CONFIGURE_TEST_SIGSEGV_RECOVERY
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <fcntl.h>
|
|
#include <sys/mman.h>
|
|
#include "vm_alloc.h"
|
|
|
|
static int page_size;
|
|
static volatile char * page = 0;
|
|
static volatile int handler_called = 0;
|
|
|
|
static bool sigsegv_test_handler(sigsegv_address_t fault_address, sigsegv_address_t instruction_address)
|
|
{
|
|
handler_called++;
|
|
if ((fault_address - 123) != page)
|
|
exit(1);
|
|
if (vm_protect((char *)((unsigned long)fault_address & -page_size), page_size, VM_PAGE_READ | VM_PAGE_WRITE) != 0)
|
|
exit(1);
|
|
return true;
|
|
}
|
|
|
|
#ifdef HAVE_SIGSEGV_SKIP_INSTRUCTION
|
|
static bool sigsegv_insn_handler(sigsegv_address_t fault_address, sigsegv_address_t instruction_address)
|
|
{
|
|
return false;
|
|
}
|
|
#endif
|
|
|
|
int main(void)
|
|
{
|
|
if (vm_init() < 0)
|
|
return 1;
|
|
|
|
page_size = getpagesize();
|
|
if ((page = (char *)vm_acquire(page_size)) == VM_MAP_FAILED)
|
|
return 1;
|
|
|
|
if (vm_protect((char *)page, page_size, VM_PAGE_READ) < 0)
|
|
return 1;
|
|
|
|
if (!sigsegv_install_handler(sigsegv_test_handler))
|
|
return 1;
|
|
|
|
page[123] = 45;
|
|
page[123] = 45;
|
|
|
|
if (handler_called != 1)
|
|
return 1;
|
|
|
|
#ifdef HAVE_SIGSEGV_SKIP_INSTRUCTION
|
|
if (!sigsegv_install_handler(sigsegv_insn_handler))
|
|
return 1;
|
|
|
|
if (vm_protect((char *)page, page_size, VM_PAGE_WRITE) < 0)
|
|
return 1;
|
|
|
|
for (int i = 0; i < page_size; i++)
|
|
page[i] = (i + 1) % page_size;
|
|
|
|
if (vm_protect((char *)page, page_size, VM_PAGE_NOACCESS) < 0)
|
|
return 1;
|
|
|
|
sigsegv_set_ignore_state(true);
|
|
|
|
#define TEST_SKIP_INSTRUCTION(TYPE) do { \
|
|
const unsigned int TAG = 0x12345678; \
|
|
TYPE data = *((TYPE *)(page + sizeof(TYPE))); \
|
|
volatile unsigned int effect = data + TAG; \
|
|
if (effect != TAG) \
|
|
return 1; \
|
|
} while (0)
|
|
|
|
TEST_SKIP_INSTRUCTION(unsigned char);
|
|
TEST_SKIP_INSTRUCTION(unsigned short);
|
|
TEST_SKIP_INSTRUCTION(unsigned int);
|
|
#endif
|
|
|
|
vm_exit();
|
|
return 0;
|
|
}
|
|
#endif
|