| 1 |
/* |
| 2 |
* sigsegv.cpp - SIGSEGV signals support |
| 3 |
* |
| 4 |
* Derived from Bruno Haible's work on his SIGSEGV library for clisp |
| 5 |
* <http://clisp.sourceforge.net/> |
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* |
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* MacOS X support derived from the post by Timothy J. Wood to the |
| 8 |
* omnigroup macosx-dev list: |
| 9 |
* Mach Exception Handlers 101 (Was Re: ptrace, gdb) |
| 10 |
* tjw@omnigroup.com Sun, 4 Jun 2000 |
| 11 |
* www.omnigroup.com/mailman/archive/macosx-dev/2000-June/002030.html |
| 12 |
* |
| 13 |
* 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 |
| 16 |
* it under the terms of the GNU General Public License as published by |
| 17 |
* the Free Software Foundation; either version 2 of the License, or |
| 18 |
* (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, |
| 21 |
* but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 22 |
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 23 |
* GNU General Public License for more details. |
| 24 |
* |
| 25 |
* You should have received a copy of the GNU General Public License |
| 26 |
* along with this program; if not, write to the Free Software |
| 27 |
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 28 |
*/ |
| 29 |
|
| 30 |
#ifdef HAVE_UNISTD_H |
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#include <unistd.h> |
| 32 |
#endif |
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|
| 34 |
#ifdef HAVE_CONFIG_H |
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#include "config.h" |
| 36 |
#endif |
| 37 |
|
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#include <list> |
| 39 |
#include <signal.h> |
| 40 |
#include "sigsegv.h" |
| 41 |
|
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#ifndef NO_STD_NAMESPACE |
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using std::list; |
| 44 |
#endif |
| 45 |
|
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// Return value type of a signal handler (standard type if not defined) |
| 47 |
#ifndef RETSIGTYPE |
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#define RETSIGTYPE void |
| 49 |
#endif |
| 50 |
|
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// Type of the system signal handler |
| 52 |
typedef RETSIGTYPE (*signal_handler)(int); |
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|
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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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|
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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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|
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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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|
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/* |
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* Instruction decoding aids |
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*/ |
| 67 |
|
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// Transfer size |
| 69 |
enum transfer_size_t { |
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SIZE_UNKNOWN, |
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SIZE_BYTE, |
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SIZE_WORD, // 2 bytes |
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SIZE_LONG, // 4 bytes |
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SIZE_QUAD, // 8 bytes |
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}; |
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|
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// Transfer type |
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typedef sigsegv_transfer_type_t transfer_type_t; |
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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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|
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// Decoded instruction |
| 91 |
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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|
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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 |
| 102 |
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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|
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// Analyze opcode |
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transfer_type_t transfer_type = SIGSEGV_TRANSFER_UNKNOWN; |
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transfer_size_t transfer_size = SIZE_UNKNOWN; |
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addressing_mode_t addr_mode = MODE_UNKNOWN; |
| 114 |
switch (primop) { |
| 115 |
case 31: |
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switch (exop) { |
| 117 |
case 23: // lwzx |
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transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_LONG; addr_mode = MODE_X; break; |
| 119 |
case 55: // lwzux |
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transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_LONG; addr_mode = MODE_UX; break; |
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case 87: // lbzx |
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transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_BYTE; addr_mode = MODE_X; break; |
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case 119: // lbzux |
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transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_BYTE; addr_mode = MODE_UX; break; |
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case 151: // stwx |
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transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_LONG; addr_mode = MODE_X; break; |
| 127 |
case 183: // stwux |
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transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_LONG; addr_mode = MODE_UX; break; |
| 129 |
case 215: // stbx |
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transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_BYTE; addr_mode = MODE_X; break; |
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case 247: // stbux |
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transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_BYTE; addr_mode = MODE_UX; break; |
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case 279: // lhzx |
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transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_X; break; |
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case 311: // lhzux |
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transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_UX; break; |
| 137 |
case 343: // lhax |
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transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_X; break; |
| 139 |
case 375: // lhaux |
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transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_UX; break; |
| 141 |
case 407: // sthx |
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transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_WORD; addr_mode = MODE_X; break; |
| 143 |
case 439: // sthux |
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transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_WORD; addr_mode = MODE_UX; break; |
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} |
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break; |
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|
| 148 |
case 32: // lwz |
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transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_LONG; addr_mode = MODE_NORM; break; |
| 150 |
case 33: // lwzu |
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transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_LONG; addr_mode = MODE_U; break; |
| 152 |
case 34: // lbz |
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transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_BYTE; addr_mode = MODE_NORM; break; |
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case 35: // lbzu |
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transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_BYTE; addr_mode = MODE_U; break; |
| 156 |
case 36: // stw |
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transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_LONG; addr_mode = MODE_NORM; break; |
| 158 |
case 37: // stwu |
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transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_LONG; addr_mode = MODE_U; break; |
| 160 |
case 38: // stb |
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transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_BYTE; addr_mode = MODE_NORM; break; |
| 162 |
case 39: // stbu |
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transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_BYTE; addr_mode = MODE_U; break; |
| 164 |
case 40: // lhz |
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transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_NORM; break; |
| 166 |
case 41: // lhzu |
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transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_U; break; |
| 168 |
case 42: // lha |
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transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_NORM; break; |
| 170 |
case 43: // lhau |
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transfer_type = SIGSEGV_TRANSFER_LOAD; transfer_size = SIZE_WORD; addr_mode = MODE_U; break; |
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case 44: // sth |
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transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_WORD; addr_mode = MODE_NORM; break; |
| 174 |
case 45: // sthu |
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transfer_type = SIGSEGV_TRANSFER_STORE; transfer_size = SIZE_WORD; addr_mode = MODE_U; break; |
| 176 |
} |
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|
| 178 |
// Calculate effective address |
| 179 |
unsigned int addr = 0; |
| 180 |
switch (addr_mode) { |
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case MODE_X: |
| 182 |
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; |
| 197 |
} |
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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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|
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/* |
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* OS-dependant SIGSEGV signals support section |
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*/ |
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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_HANDLER_ARGLIST_1 siginfo_t *sip, void *scp |
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#define SIGSEGV_FAULT_HANDLER_ARGS sip, scp |
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#define SIGSEGV_FAULT_ADDRESS sip->si_addr |
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#if defined(__sun__) |
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#if (defined(sparc) || defined(__sparc__)) |
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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[REG_PC] |
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#endif |
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#endif |
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#if defined(__FreeBSD__) |
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#if (defined(i386) || defined(__i386__)) |
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#define SIGSEGV_FAULT_INSTRUCTION (((struct sigcontext *)scp)->sc_eip) |
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#define SIGSEGV_REGISTER_FILE ((unsigned long *)&(((struct sigcontext *)scp)->sc_edi)) /* EDI is the first GPR (even below EIP) in sigcontext */ |
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#define SIGSEGV_SKIP_INSTRUCTION ix86_skip_instruction |
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#endif |
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#endif |
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#if defined(__linux__) |
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#if (defined(i386) || defined(__i386__)) |
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#include <sys/ucontext.h> |
| 242 |
#define SIGSEGV_CONTEXT_REGS (((ucontext_t *)scp)->uc_mcontext.gregs) |
| 243 |
#define SIGSEGV_FAULT_INSTRUCTION SIGSEGV_CONTEXT_REGS[14] /* should use REG_EIP instead */ |
| 244 |
#define SIGSEGV_REGISTER_FILE (unsigned long *)SIGSEGV_CONTEXT_REGS |
| 245 |
#define SIGSEGV_SKIP_INSTRUCTION ix86_skip_instruction |
| 246 |
#endif |
| 247 |
#if (defined(x86_64) || defined(__x86_64__)) |
| 248 |
#include <sys/ucontext.h> |
| 249 |
#define SIGSEGV_CONTEXT_REGS (((ucontext_t *)scp)->uc_mcontext.gregs) |
| 250 |
#define SIGSEGV_FAULT_INSTRUCTION SIGSEGV_CONTEXT_REGS[16] /* should use REG_RIP instead */ |
| 251 |
#define SIGSEGV_REGISTER_FILE (unsigned long *)SIGSEGV_CONTEXT_REGS |
| 252 |
#define SIGSEGV_SKIP_INSTRUCTION ix86_skip_instruction |
| 253 |
#endif |
| 254 |
#if (defined(ia64) || defined(__ia64__)) |
| 255 |
#define SIGSEGV_FAULT_INSTRUCTION (((struct sigcontext *)scp)->sc_ip & ~0x3ULL) /* slot number is in bits 0 and 1 */ |
| 256 |
#endif |
| 257 |
#if (defined(powerpc) || defined(__powerpc__)) |
| 258 |
#include <sys/ucontext.h> |
| 259 |
#define SIGSEGV_CONTEXT_REGS (((ucontext_t *)scp)->uc_mcontext.regs) |
| 260 |
#define SIGSEGV_FAULT_INSTRUCTION (SIGSEGV_CONTEXT_REGS->nip) |
| 261 |
#define SIGSEGV_REGISTER_FILE (unsigned int *)&SIGSEGV_CONTEXT_REGS->nip, (unsigned int *)(SIGSEGV_CONTEXT_REGS->gpr) |
| 262 |
#define SIGSEGV_SKIP_INSTRUCTION powerpc_skip_instruction |
| 263 |
#endif |
| 264 |
#endif |
| 265 |
#endif |
| 266 |
|
| 267 |
#if HAVE_SIGCONTEXT_SUBTERFUGE |
| 268 |
// Linux kernels prior to 2.4 ? |
| 269 |
#if defined(__linux__) |
| 270 |
#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV) |
| 271 |
#if (defined(i386) || defined(__i386__)) |
| 272 |
#include <asm/sigcontext.h> |
| 273 |
#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, struct sigcontext scs |
| 274 |
#define SIGSEGV_FAULT_HANDLER_ARGLIST_1 struct sigcontext *scp |
| 275 |
#define SIGSEGV_FAULT_HANDLER_ARGS &scs |
| 276 |
#define SIGSEGV_FAULT_ADDRESS scp->cr2 |
| 277 |
#define SIGSEGV_FAULT_INSTRUCTION scp->eip |
| 278 |
#define SIGSEGV_REGISTER_FILE (unsigned long *)scp |
| 279 |
#define SIGSEGV_SKIP_INSTRUCTION ix86_skip_instruction |
| 280 |
#endif |
| 281 |
#if (defined(sparc) || defined(__sparc__)) |
| 282 |
#include <asm/sigcontext.h> |
| 283 |
#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp, char *addr |
| 284 |
#define SIGSEGV_FAULT_HANDLER_ARGS sig, code, scp, addr |
| 285 |
#define SIGSEGV_FAULT_ADDRESS addr |
| 286 |
#endif |
| 287 |
#if (defined(powerpc) || defined(__powerpc__)) |
| 288 |
#include <asm/sigcontext.h> |
| 289 |
#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, struct sigcontext *scp |
| 290 |
#define SIGSEGV_FAULT_HANDLER_ARGS sig, scp |
| 291 |
#define SIGSEGV_FAULT_ADDRESS scp->regs->dar |
| 292 |
#define SIGSEGV_FAULT_INSTRUCTION scp->regs->nip |
| 293 |
#define SIGSEGV_REGISTER_FILE (unsigned int *)&scp->regs->nip, (unsigned int *)(scp->regs->gpr) |
| 294 |
#define SIGSEGV_SKIP_INSTRUCTION powerpc_skip_instruction |
| 295 |
#endif |
| 296 |
#if (defined(alpha) || defined(__alpha__)) |
| 297 |
#include <asm/sigcontext.h> |
| 298 |
#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp |
| 299 |
#define SIGSEGV_FAULT_HANDLER_ARGS sig, code, scp |
| 300 |
#define SIGSEGV_FAULT_ADDRESS get_fault_address(scp) |
| 301 |
#define SIGSEGV_FAULT_INSTRUCTION scp->sc_pc |
| 302 |
#endif |
| 303 |
#endif |
| 304 |
|
| 305 |
// Irix 5 or 6 on MIPS |
| 306 |
#if (defined(sgi) || defined(__sgi)) && (defined(SYSTYPE_SVR4) || defined(__SYSTYPE_SVR4)) |
| 307 |
#include <ucontext.h> |
| 308 |
#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp |
| 309 |
#define SIGSEGV_FAULT_HANDLER_ARGS sig, code, scp |
| 310 |
#define SIGSEGV_FAULT_ADDRESS scp->sc_badvaddr |
| 311 |
#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV) |
| 312 |
#endif |
| 313 |
|
| 314 |
// HP-UX |
| 315 |
#if (defined(hpux) || defined(__hpux__)) |
| 316 |
#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp |
| 317 |
#define SIGSEGV_FAULT_HANDLER_ARGS sig, code, scp |
| 318 |
#define SIGSEGV_FAULT_ADDRESS scp->sc_sl.sl_ss.ss_narrow.ss_cr21 |
| 319 |
#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV) FAULT_HANDLER(SIGBUS) |
| 320 |
#endif |
| 321 |
|
| 322 |
// OSF/1 on Alpha |
| 323 |
#if defined(__osf__) |
| 324 |
#include <ucontext.h> |
| 325 |
#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp |
| 326 |
#define SIGSEGV_FAULT_HANDLER_ARGS sig, code, scp |
| 327 |
#define SIGSEGV_FAULT_ADDRESS scp->sc_traparg_a0 |
| 328 |
#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV) |
| 329 |
#endif |
| 330 |
|
| 331 |
// AIX |
| 332 |
#if defined(_AIX) |
| 333 |
#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp |
| 334 |
#define SIGSEGV_FAULT_HANDLER_ARGS sig, code, scp |
| 335 |
#define SIGSEGV_FAULT_ADDRESS scp->sc_jmpbuf.jmp_context.o_vaddr |
| 336 |
#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV) |
| 337 |
#endif |
| 338 |
|
| 339 |
// NetBSD |
| 340 |
#if defined(__NetBSD__) |
| 341 |
#if (defined(m68k) || defined(__m68k__)) |
| 342 |
#include <m68k/frame.h> |
| 343 |
#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp |
| 344 |
#define SIGSEGV_FAULT_HANDLER_ARGS sig, code, scp |
| 345 |
#define SIGSEGV_FAULT_ADDRESS get_fault_address(scp) |
| 346 |
#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV) |
| 347 |
|
| 348 |
// Use decoding scheme from BasiliskII/m68k native |
| 349 |
static sigsegv_address_t get_fault_address(struct sigcontext *scp) |
| 350 |
{ |
| 351 |
struct sigstate { |
| 352 |
int ss_flags; |
| 353 |
struct frame ss_frame; |
| 354 |
}; |
| 355 |
struct sigstate *state = (struct sigstate *)scp->sc_ap; |
| 356 |
char *fault_addr; |
| 357 |
switch (state->ss_frame.f_format) { |
| 358 |
case 7: /* 68040 access error */ |
| 359 |
/* "code" is sometimes unreliable (i.e. contains NULL or a bogus address), reason unknown */ |
| 360 |
fault_addr = state->ss_frame.f_fmt7.f_fa; |
| 361 |
break; |
| 362 |
default: |
| 363 |
fault_addr = (char *)code; |
| 364 |
break; |
| 365 |
} |
| 366 |
return (sigsegv_address_t)fault_addr; |
| 367 |
} |
| 368 |
#endif |
| 369 |
#if (defined(alpha) || defined(__alpha__)) |
| 370 |
#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp |
| 371 |
#define SIGSEGV_FAULT_HANDLER_ARGS sig, code, scp |
| 372 |
#define SIGSEGV_FAULT_ADDRESS get_fault_address(scp) |
| 373 |
#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGBUS) |
| 374 |
#endif |
| 375 |
#if (defined(i386) || defined(__i386__)) |
| 376 |
#error "FIXME: need to decode instruction and compute EA" |
| 377 |
#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp |
| 378 |
#define SIGSEGV_FAULT_HANDLER_ARGS sig, code, scp |
| 379 |
#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV) |
| 380 |
#endif |
| 381 |
#endif |
| 382 |
#if defined(__FreeBSD__) |
| 383 |
#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGBUS) |
| 384 |
#if (defined(i386) || defined(__i386__)) |
| 385 |
#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp, char *addr |
| 386 |
#define SIGSEGV_FAULT_HANDLER_ARGS sig, code, scp, addr |
| 387 |
#define SIGSEGV_FAULT_ADDRESS addr |
| 388 |
#define SIGSEGV_FAULT_INSTRUCTION scp->sc_eip |
| 389 |
#define SIGSEGV_REGISTER_FILE ((unsigned long *)&scp->sc_edi) |
| 390 |
#define SIGSEGV_SKIP_INSTRUCTION ix86_skip_instruction |
| 391 |
#endif |
| 392 |
#endif |
| 393 |
|
| 394 |
// Extract fault address out of a sigcontext |
| 395 |
#if (defined(alpha) || defined(__alpha__)) |
| 396 |
// From Boehm's GC 6.0alpha8 |
| 397 |
static sigsegv_address_t get_fault_address(struct sigcontext *scp) |
| 398 |
{ |
| 399 |
unsigned int instruction = *((unsigned int *)(scp->sc_pc)); |
| 400 |
unsigned long fault_address = scp->sc_regs[(instruction >> 16) & 0x1f]; |
| 401 |
fault_address += (signed long)(signed short)(instruction & 0xffff); |
| 402 |
return (sigsegv_address_t)fault_address; |
| 403 |
} |
| 404 |
#endif |
| 405 |
|
| 406 |
|
| 407 |
// MacOS X, not sure which version this works in. Under 10.1 |
| 408 |
// vm_protect does not appear to work from a signal handler. Under |
| 409 |
// 10.2 signal handlers get siginfo type arguments but the si_addr |
| 410 |
// field is the address of the faulting instruction and not the |
| 411 |
// address that caused the SIGBUS. Maybe this works in 10.0? In any |
| 412 |
// case with Mach exception handlers there is a way to do what this |
| 413 |
// was meant to do. |
| 414 |
#ifndef HAVE_MACH_EXCEPTIONS |
| 415 |
#if defined(__APPLE__) && defined(__MACH__) |
| 416 |
#if (defined(ppc) || defined(__ppc__)) |
| 417 |
#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp |
| 418 |
#define SIGSEGV_FAULT_HANDLER_ARGS sig, code, scp |
| 419 |
#define SIGSEGV_FAULT_ADDRESS get_fault_address(scp) |
| 420 |
#define SIGSEGV_FAULT_INSTRUCTION scp->sc_ir |
| 421 |
#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGBUS) |
| 422 |
#define SIGSEGV_REGISTER_FILE (unsigned int *)&scp->sc_ir, &((unsigned int *) scp->sc_regs)[2] |
| 423 |
#define SIGSEGV_SKIP_INSTRUCTION powerpc_skip_instruction |
| 424 |
|
| 425 |
// Use decoding scheme from SheepShaver |
| 426 |
static sigsegv_address_t get_fault_address(struct sigcontext *scp) |
| 427 |
{ |
| 428 |
unsigned int nip = (unsigned int) scp->sc_ir; |
| 429 |
unsigned int * gpr = &((unsigned int *) scp->sc_regs)[2]; |
| 430 |
instruction_t instr; |
| 431 |
|
| 432 |
powerpc_decode_instruction(&instr, nip, gpr); |
| 433 |
return (sigsegv_address_t)instr.addr; |
| 434 |
} |
| 435 |
#endif |
| 436 |
#endif |
| 437 |
#endif |
| 438 |
#endif |
| 439 |
|
| 440 |
#if HAVE_MACH_EXCEPTIONS |
| 441 |
|
| 442 |
// This can easily be extended to other Mach systems, but really who |
| 443 |
// uses HURD (oops GNU/HURD), Darwin/x86, NextStep, Rhapsody, or CMU |
| 444 |
// Mach 2.5/3.0? |
| 445 |
#if defined(__APPLE__) && defined(__MACH__) |
| 446 |
|
| 447 |
#include <sys/types.h> |
| 448 |
#include <stdlib.h> |
| 449 |
#include <stdio.h> |
| 450 |
#include <pthread.h> |
| 451 |
|
| 452 |
/* |
| 453 |
* If you are familiar with MIG then you will understand the frustration |
| 454 |
* that was necessary to get these embedded into C++ code by hand. |
| 455 |
*/ |
| 456 |
extern "C" { |
| 457 |
#include <mach/mach.h> |
| 458 |
#include <mach/mach_error.h> |
| 459 |
|
| 460 |
extern boolean_t exc_server(mach_msg_header_t *, mach_msg_header_t *); |
| 461 |
extern kern_return_t catch_exception_raise(mach_port_t, mach_port_t, |
| 462 |
mach_port_t, exception_type_t, exception_data_t, mach_msg_type_number_t); |
| 463 |
extern kern_return_t exception_raise(mach_port_t, mach_port_t, mach_port_t, |
| 464 |
exception_type_t, exception_data_t, mach_msg_type_number_t); |
| 465 |
extern kern_return_t exception_raise_state(mach_port_t, exception_type_t, |
| 466 |
exception_data_t, mach_msg_type_number_t, thread_state_flavor_t *, |
| 467 |
thread_state_t, mach_msg_type_number_t, thread_state_t, mach_msg_type_number_t *); |
| 468 |
extern kern_return_t exception_raise_state_identity(mach_port_t, mach_port_t, mach_port_t, |
| 469 |
exception_type_t, exception_data_t, mach_msg_type_number_t, thread_state_flavor_t *, |
| 470 |
thread_state_t, mach_msg_type_number_t, thread_state_t, mach_msg_type_number_t *); |
| 471 |
} |
| 472 |
|
| 473 |
// Could make this dynamic by looking for a result of MIG_ARRAY_TOO_LARGE |
| 474 |
#define HANDLER_COUNT 64 |
| 475 |
|
| 476 |
// structure to tuck away existing exception handlers |
| 477 |
typedef struct _ExceptionPorts { |
| 478 |
mach_msg_type_number_t maskCount; |
| 479 |
exception_mask_t masks[HANDLER_COUNT]; |
| 480 |
exception_handler_t handlers[HANDLER_COUNT]; |
| 481 |
exception_behavior_t behaviors[HANDLER_COUNT]; |
| 482 |
thread_state_flavor_t flavors[HANDLER_COUNT]; |
| 483 |
} ExceptionPorts; |
| 484 |
|
| 485 |
// exception handler thread |
| 486 |
static pthread_t exc_thread; |
| 487 |
|
| 488 |
// place where old exception handler info is stored |
| 489 |
static ExceptionPorts ports; |
| 490 |
|
| 491 |
// our exception port |
| 492 |
static mach_port_t _exceptionPort = MACH_PORT_NULL; |
| 493 |
|
| 494 |
#define MACH_CHECK_ERROR(name,ret) \ |
| 495 |
if (ret != KERN_SUCCESS) { \ |
| 496 |
mach_error(#name, ret); \ |
| 497 |
exit (1); \ |
| 498 |
} |
| 499 |
|
| 500 |
#define SIGSEGV_FAULT_ADDRESS code[1] |
| 501 |
#define SIGSEGV_FAULT_INSTRUCTION get_fault_instruction(thread, state) |
| 502 |
#define SIGSEGV_FAULT_HANDLER_INVOKE(ADDR, IP) ((code[0] == KERN_PROTECTION_FAILURE) ? sigsegv_fault_handler(ADDR, IP) : SIGSEGV_RETURN_FAILURE) |
| 503 |
#define SIGSEGV_FAULT_HANDLER_ARGLIST mach_port_t thread, exception_data_t code, ppc_thread_state_t *state |
| 504 |
#define SIGSEGV_FAULT_HANDLER_ARGS thread, code, &state |
| 505 |
#define SIGSEGV_SKIP_INSTRUCTION powerpc_skip_instruction |
| 506 |
#define SIGSEGV_REGISTER_FILE &state->srr0, &state->r0 |
| 507 |
|
| 508 |
// Given a suspended thread, stuff the current instruction and |
| 509 |
// registers into state. |
| 510 |
// |
| 511 |
// It would have been nice to have this be ppc/x86 independant which |
| 512 |
// could have been done easily with a thread_state_t instead of |
| 513 |
// ppc_thread_state_t, but because of the way this is called it is |
| 514 |
// easier to do it this way. |
| 515 |
#if (defined(ppc) || defined(__ppc__)) |
| 516 |
static inline sigsegv_address_t get_fault_instruction(mach_port_t thread, ppc_thread_state_t *state) |
| 517 |
{ |
| 518 |
kern_return_t krc; |
| 519 |
mach_msg_type_number_t count; |
| 520 |
|
| 521 |
count = MACHINE_THREAD_STATE_COUNT; |
| 522 |
krc = thread_get_state(thread, MACHINE_THREAD_STATE, (thread_state_t)state, &count); |
| 523 |
MACH_CHECK_ERROR (thread_get_state, krc); |
| 524 |
|
| 525 |
return (sigsegv_address_t)state->srr0; |
| 526 |
} |
| 527 |
#endif |
| 528 |
|
| 529 |
// Since there can only be one exception thread running at any time |
| 530 |
// this is not a problem. |
| 531 |
#define MSG_SIZE 512 |
| 532 |
static char msgbuf[MSG_SIZE]; |
| 533 |
static char replybuf[MSG_SIZE]; |
| 534 |
|
| 535 |
/* |
| 536 |
* This is the entry point for the exception handler thread. The job |
| 537 |
* of this thread is to wait for exception messages on the exception |
| 538 |
* port that was setup beforehand and to pass them on to exc_server. |
| 539 |
* exc_server is a MIG generated function that is a part of Mach. |
| 540 |
* Its job is to decide what to do with the exception message. In our |
| 541 |
* case exc_server calls catch_exception_raise on our behalf. After |
| 542 |
* exc_server returns, it is our responsibility to send the reply. |
| 543 |
*/ |
| 544 |
static void * |
| 545 |
handleExceptions(void *priv) |
| 546 |
{ |
| 547 |
mach_msg_header_t *msg, *reply; |
| 548 |
kern_return_t krc; |
| 549 |
|
| 550 |
msg = (mach_msg_header_t *)msgbuf; |
| 551 |
reply = (mach_msg_header_t *)replybuf; |
| 552 |
|
| 553 |
for (;;) { |
| 554 |
krc = mach_msg(msg, MACH_RCV_MSG, MSG_SIZE, MSG_SIZE, |
| 555 |
_exceptionPort, 0, MACH_PORT_NULL); |
| 556 |
MACH_CHECK_ERROR(mach_msg, krc); |
| 557 |
|
| 558 |
if (!exc_server(msg, reply)) { |
| 559 |
fprintf(stderr, "exc_server hated the message\n"); |
| 560 |
exit(1); |
| 561 |
} |
| 562 |
|
| 563 |
krc = mach_msg(reply, MACH_SEND_MSG, reply->msgh_size, 0, |
| 564 |
msg->msgh_local_port, 0, MACH_PORT_NULL); |
| 565 |
if (krc != KERN_SUCCESS) { |
| 566 |
fprintf(stderr, "Error sending message to original reply port, krc = %d, %s", |
| 567 |
krc, mach_error_string(krc)); |
| 568 |
exit(1); |
| 569 |
} |
| 570 |
} |
| 571 |
} |
| 572 |
#endif |
| 573 |
#endif |
| 574 |
|
| 575 |
|
| 576 |
/* |
| 577 |
* Instruction skipping |
| 578 |
*/ |
| 579 |
|
| 580 |
#ifdef HAVE_SIGSEGV_SKIP_INSTRUCTION |
| 581 |
// Decode and skip X86 instruction |
| 582 |
#if (defined(i386) || defined(__i386__)) || defined(__x86_64__) |
| 583 |
#if defined(__linux__) |
| 584 |
enum { |
| 585 |
#if (defined(i386) || defined(__i386__)) |
| 586 |
X86_REG_EIP = 14, |
| 587 |
X86_REG_EAX = 11, |
| 588 |
X86_REG_ECX = 10, |
| 589 |
X86_REG_EDX = 9, |
| 590 |
X86_REG_EBX = 8, |
| 591 |
X86_REG_ESP = 7, |
| 592 |
X86_REG_EBP = 6, |
| 593 |
X86_REG_ESI = 5, |
| 594 |
X86_REG_EDI = 4 |
| 595 |
#endif |
| 596 |
#if defined(__x86_64__) |
| 597 |
X86_REG_R8 = 0, |
| 598 |
X86_REG_R9 = 1, |
| 599 |
X86_REG_R10 = 2, |
| 600 |
X86_REG_R11 = 3, |
| 601 |
X86_REG_R12 = 4, |
| 602 |
X86_REG_R13 = 5, |
| 603 |
X86_REG_R14 = 6, |
| 604 |
X86_REG_R15 = 7, |
| 605 |
X86_REG_EDI = 8, |
| 606 |
X86_REG_ESI = 9, |
| 607 |
X86_REG_EBP = 10, |
| 608 |
X86_REG_EBX = 11, |
| 609 |
X86_REG_EDX = 12, |
| 610 |
X86_REG_EAX = 13, |
| 611 |
X86_REG_ECX = 14, |
| 612 |
X86_REG_ESP = 15, |
| 613 |
X86_REG_EIP = 16 |
| 614 |
#endif |
| 615 |
}; |
| 616 |
#endif |
| 617 |
#if defined(__NetBSD__) || defined(__FreeBSD__) |
| 618 |
enum { |
| 619 |
#if (defined(i386) || defined(__i386__)) |
| 620 |
X86_REG_EIP = 10, |
| 621 |
X86_REG_EAX = 7, |
| 622 |
X86_REG_ECX = 6, |
| 623 |
X86_REG_EDX = 5, |
| 624 |
X86_REG_EBX = 4, |
| 625 |
X86_REG_ESP = 13, |
| 626 |
X86_REG_EBP = 2, |
| 627 |
X86_REG_ESI = 1, |
| 628 |
X86_REG_EDI = 0 |
| 629 |
#endif |
| 630 |
}; |
| 631 |
#endif |
| 632 |
// FIXME: this is partly redundant with the instruction decoding phase |
| 633 |
// to discover transfer type and register number |
| 634 |
static inline int ix86_step_over_modrm(unsigned char * p) |
| 635 |
{ |
| 636 |
int mod = (p[0] >> 6) & 3; |
| 637 |
int rm = p[0] & 7; |
| 638 |
int offset = 0; |
| 639 |
|
| 640 |
// ModR/M Byte |
| 641 |
switch (mod) { |
| 642 |
case 0: // [reg] |
| 643 |
if (rm == 5) return 4; // disp32 |
| 644 |
break; |
| 645 |
case 1: // disp8[reg] |
| 646 |
offset = 1; |
| 647 |
break; |
| 648 |
case 2: // disp32[reg] |
| 649 |
offset = 4; |
| 650 |
break; |
| 651 |
case 3: // register |
| 652 |
return 0; |
| 653 |
} |
| 654 |
|
| 655 |
// SIB Byte |
| 656 |
if (rm == 4) { |
| 657 |
if (mod == 0 && (p[1] & 7) == 5) |
| 658 |
offset = 5; // disp32[index] |
| 659 |
else |
| 660 |
offset++; |
| 661 |
} |
| 662 |
|
| 663 |
return offset; |
| 664 |
} |
| 665 |
|
| 666 |
static bool ix86_skip_instruction(unsigned long * regs) |
| 667 |
{ |
| 668 |
unsigned char * eip = (unsigned char *)regs[X86_REG_EIP]; |
| 669 |
|
| 670 |
if (eip == 0) |
| 671 |
return false; |
| 672 |
|
| 673 |
transfer_type_t transfer_type = SIGSEGV_TRANSFER_UNKNOWN; |
| 674 |
transfer_size_t transfer_size = SIZE_LONG; |
| 675 |
|
| 676 |
int reg = -1; |
| 677 |
int len = 0; |
| 678 |
|
| 679 |
#if DEBUG |
| 680 |
printf("IP: %p [%02x %02x %02x %02x...]\n", |
| 681 |
eip, eip[0], eip[1], eip[2], eip[3]); |
| 682 |
#endif |
| 683 |
|
| 684 |
// Operand size prefix |
| 685 |
if (*eip == 0x66) { |
| 686 |
eip++; |
| 687 |
len++; |
| 688 |
transfer_size = SIZE_WORD; |
| 689 |
} |
| 690 |
|
| 691 |
// REX prefix |
| 692 |
#if defined(__x86_64__) |
| 693 |
struct rex_t { |
| 694 |
unsigned char W; |
| 695 |
unsigned char R; |
| 696 |
unsigned char X; |
| 697 |
unsigned char B; |
| 698 |
}; |
| 699 |
rex_t rex = { 0, 0, 0, 0 }; |
| 700 |
bool has_rex = false; |
| 701 |
if ((*eip & 0xf0) == 0x40) { |
| 702 |
has_rex = true; |
| 703 |
const unsigned char b = *eip; |
| 704 |
rex.W = b & (1 << 3); |
| 705 |
rex.R = b & (1 << 2); |
| 706 |
rex.X = b & (1 << 1); |
| 707 |
rex.B = b & (1 << 0); |
| 708 |
#if DEBUG |
| 709 |
printf("REX: %c,%c,%c,%c\n", |
| 710 |
rex.W ? 'W' : '_', |
| 711 |
rex.R ? 'R' : '_', |
| 712 |
rex.X ? 'X' : '_', |
| 713 |
rex.B ? 'B' : '_'); |
| 714 |
#endif |
| 715 |
eip++; |
| 716 |
len++; |
| 717 |
if (rex.W) |
| 718 |
transfer_size = SIZE_QUAD; |
| 719 |
} |
| 720 |
#else |
| 721 |
const bool has_rex = false; |
| 722 |
#endif |
| 723 |
|
| 724 |
// Decode instruction |
| 725 |
switch (eip[0]) { |
| 726 |
case 0x0f: |
| 727 |
switch (eip[1]) { |
| 728 |
case 0xb6: // MOVZX r32, r/m8 |
| 729 |
case 0xb7: // MOVZX r32, r/m16 |
| 730 |
switch (eip[2] & 0xc0) { |
| 731 |
case 0x80: |
| 732 |
reg = (eip[2] >> 3) & 7; |
| 733 |
transfer_type = SIGSEGV_TRANSFER_LOAD; |
| 734 |
break; |
| 735 |
case 0x40: |
| 736 |
reg = (eip[2] >> 3) & 7; |
| 737 |
transfer_type = SIGSEGV_TRANSFER_LOAD; |
| 738 |
break; |
| 739 |
case 0x00: |
| 740 |
reg = (eip[2] >> 3) & 7; |
| 741 |
transfer_type = SIGSEGV_TRANSFER_LOAD; |
| 742 |
break; |
| 743 |
} |
| 744 |
len += 3 + ix86_step_over_modrm(eip + 2); |
| 745 |
break; |
| 746 |
} |
| 747 |
break; |
| 748 |
case 0x8a: // MOV r8, r/m8 |
| 749 |
transfer_size = SIZE_BYTE; |
| 750 |
case 0x8b: // MOV r32, r/m32 (or 16-bit operation) |
| 751 |
switch (eip[1] & 0xc0) { |
| 752 |
case 0x80: |
| 753 |
reg = (eip[1] >> 3) & 7; |
| 754 |
transfer_type = SIGSEGV_TRANSFER_LOAD; |
| 755 |
break; |
| 756 |
case 0x40: |
| 757 |
reg = (eip[1] >> 3) & 7; |
| 758 |
transfer_type = SIGSEGV_TRANSFER_LOAD; |
| 759 |
break; |
| 760 |
case 0x00: |
| 761 |
reg = (eip[1] >> 3) & 7; |
| 762 |
transfer_type = SIGSEGV_TRANSFER_LOAD; |
| 763 |
break; |
| 764 |
} |
| 765 |
len += 2 + ix86_step_over_modrm(eip + 1); |
| 766 |
break; |
| 767 |
case 0x88: // MOV r/m8, r8 |
| 768 |
transfer_size = SIZE_BYTE; |
| 769 |
case 0x89: // MOV r/m32, r32 (or 16-bit operation) |
| 770 |
switch (eip[1] & 0xc0) { |
| 771 |
case 0x80: |
| 772 |
reg = (eip[1] >> 3) & 7; |
| 773 |
transfer_type = SIGSEGV_TRANSFER_STORE; |
| 774 |
break; |
| 775 |
case 0x40: |
| 776 |
reg = (eip[1] >> 3) & 7; |
| 777 |
transfer_type = SIGSEGV_TRANSFER_STORE; |
| 778 |
break; |
| 779 |
case 0x00: |
| 780 |
reg = (eip[1] >> 3) & 7; |
| 781 |
transfer_type = SIGSEGV_TRANSFER_STORE; |
| 782 |
break; |
| 783 |
} |
| 784 |
len += 2 + ix86_step_over_modrm(eip + 1); |
| 785 |
break; |
| 786 |
} |
| 787 |
|
| 788 |
if (transfer_type == SIGSEGV_TRANSFER_UNKNOWN) { |
| 789 |
// Unknown machine code, let it crash. Then patch the decoder |
| 790 |
return false; |
| 791 |
} |
| 792 |
|
| 793 |
#if defined(__x86_64__) |
| 794 |
if (rex.R) |
| 795 |
reg += 8; |
| 796 |
#endif |
| 797 |
|
| 798 |
if (transfer_type == SIGSEGV_TRANSFER_LOAD && reg != -1) { |
| 799 |
static const int x86_reg_map[] = { |
| 800 |
X86_REG_EAX, X86_REG_ECX, X86_REG_EDX, X86_REG_EBX, |
| 801 |
X86_REG_ESP, X86_REG_EBP, X86_REG_ESI, X86_REG_EDI, |
| 802 |
#if defined(__x86_64__) |
| 803 |
X86_REG_R8, X86_REG_R9, X86_REG_R10, X86_REG_R11, |
| 804 |
X86_REG_R12, X86_REG_R13, X86_REG_R14, X86_REG_R15, |
| 805 |
#endif |
| 806 |
}; |
| 807 |
|
| 808 |
if (reg < 0 || reg >= (sizeof(x86_reg_map)/sizeof(x86_reg_map[0]) - 1)) |
| 809 |
return false; |
| 810 |
|
| 811 |
// Set 0 to the relevant register part |
| 812 |
// NOTE: this is only valid for MOV alike instructions |
| 813 |
int rloc = x86_reg_map[reg]; |
| 814 |
switch (transfer_size) { |
| 815 |
case SIZE_BYTE: |
| 816 |
if (has_rex || reg < 4) |
| 817 |
regs[rloc] = (regs[rloc] & ~0x00ffL); |
| 818 |
else { |
| 819 |
rloc = x86_reg_map[reg - 4]; |
| 820 |
regs[rloc] = (regs[rloc] & ~0xff00L); |
| 821 |
} |
| 822 |
break; |
| 823 |
case SIZE_WORD: |
| 824 |
regs[rloc] = (regs[rloc] & ~0xffffL); |
| 825 |
break; |
| 826 |
case SIZE_LONG: |
| 827 |
case SIZE_QUAD: // zero-extension |
| 828 |
regs[rloc] = 0; |
| 829 |
break; |
| 830 |
} |
| 831 |
} |
| 832 |
|
| 833 |
#if DEBUG |
| 834 |
printf("%08x: %s %s access", regs[X86_REG_EIP], |
| 835 |
transfer_size == SIZE_BYTE ? "byte" : |
| 836 |
transfer_size == SIZE_WORD ? "word" : |
| 837 |
transfer_size == SIZE_LONG ? "long" : |
| 838 |
transfer_size == SIZE_QUAD ? "quad" : "unknown", |
| 839 |
transfer_type == SIGSEGV_TRANSFER_LOAD ? "read" : "write"); |
| 840 |
|
| 841 |
if (reg != -1) { |
| 842 |
static const char * x86_byte_reg_str_map[] = { |
| 843 |
"al", "cl", "dl", "bl", |
| 844 |
"spl", "bpl", "sil", "dil", |
| 845 |
"r8b", "r9b", "r10b", "r11b", |
| 846 |
"r12b", "r13b", "r14b", "r15b", |
| 847 |
"ah", "ch", "dh", "bh", |
| 848 |
}; |
| 849 |
static const char * x86_word_reg_str_map[] = { |
| 850 |
"ax", "cx", "dx", "bx", |
| 851 |
"sp", "bp", "si", "di", |
| 852 |
"r8w", "r9w", "r10w", "r11w", |
| 853 |
"r12w", "r13w", "r14w", "r15w", |
| 854 |
}; |
| 855 |
static const char *x86_long_reg_str_map[] = { |
| 856 |
"eax", "ecx", "edx", "ebx", |
| 857 |
"esp", "ebp", "esi", "edi", |
| 858 |
"r8d", "r9d", "r10d", "r11d", |
| 859 |
"r12d", "r13d", "r14d", "r15d", |
| 860 |
}; |
| 861 |
static const char *x86_quad_reg_str_map[] = { |
| 862 |
"rax", "rcx", "rdx", "rbx", |
| 863 |
"rsp", "rbp", "rsi", "rdi", |
| 864 |
"r8", "r9", "r10", "r11", |
| 865 |
"r12", "r13", "r14", "r15", |
| 866 |
}; |
| 867 |
const char * reg_str = NULL; |
| 868 |
switch (transfer_size) { |
| 869 |
case SIZE_BYTE: |
| 870 |
reg_str = x86_byte_reg_str_map[(!has_rex && reg >= 4 ? 12 : 0) + reg]; |
| 871 |
break; |
| 872 |
case SIZE_WORD: reg_str = x86_word_reg_str_map[reg]; break; |
| 873 |
case SIZE_LONG: reg_str = x86_long_reg_str_map[reg]; break; |
| 874 |
case SIZE_QUAD: reg_str = x86_quad_reg_str_map[reg]; break; |
| 875 |
} |
| 876 |
if (reg_str) |
| 877 |
printf(" %s register %%%s", |
| 878 |
transfer_type == SIGSEGV_TRANSFER_LOAD ? "to" : "from", |
| 879 |
reg_str); |
| 880 |
} |
| 881 |
printf(", %d bytes instruction\n", len); |
| 882 |
#endif |
| 883 |
|
| 884 |
regs[X86_REG_EIP] += len; |
| 885 |
return true; |
| 886 |
} |
| 887 |
#endif |
| 888 |
|
| 889 |
// Decode and skip PPC instruction |
| 890 |
#if (defined(powerpc) || defined(__powerpc__) || defined(__ppc__)) |
| 891 |
static bool powerpc_skip_instruction(unsigned int * nip_p, unsigned int * regs) |
| 892 |
{ |
| 893 |
instruction_t instr; |
| 894 |
powerpc_decode_instruction(&instr, *nip_p, regs); |
| 895 |
|
| 896 |
if (instr.transfer_type == SIGSEGV_TRANSFER_UNKNOWN) { |
| 897 |
// Unknown machine code, let it crash. Then patch the decoder |
| 898 |
return false; |
| 899 |
} |
| 900 |
|
| 901 |
#if DEBUG |
| 902 |
printf("%08x: %s %s access", *nip_p, |
| 903 |
instr.transfer_size == SIZE_BYTE ? "byte" : instr.transfer_size == SIZE_WORD ? "word" : "long", |
| 904 |
instr.transfer_type == SIGSEGV_TRANSFER_LOAD ? "read" : "write"); |
| 905 |
|
| 906 |
if (instr.addr_mode == MODE_U || instr.addr_mode == MODE_UX) |
| 907 |
printf(" r%d (ra = %08x)\n", instr.ra, instr.addr); |
| 908 |
if (instr.transfer_type == SIGSEGV_TRANSFER_LOAD) |
| 909 |
printf(" r%d (rd = 0)\n", instr.rd); |
| 910 |
#endif |
| 911 |
|
| 912 |
if (instr.addr_mode == MODE_U || instr.addr_mode == MODE_UX) |
| 913 |
regs[instr.ra] = instr.addr; |
| 914 |
if (instr.transfer_type == SIGSEGV_TRANSFER_LOAD) |
| 915 |
regs[instr.rd] = 0; |
| 916 |
|
| 917 |
*nip_p += 4; |
| 918 |
return true; |
| 919 |
} |
| 920 |
#endif |
| 921 |
#endif |
| 922 |
|
| 923 |
// Fallbacks |
| 924 |
#ifndef SIGSEGV_FAULT_INSTRUCTION |
| 925 |
#define SIGSEGV_FAULT_INSTRUCTION SIGSEGV_INVALID_PC |
| 926 |
#endif |
| 927 |
#ifndef SIGSEGV_FAULT_HANDLER_ARGLIST_1 |
| 928 |
#define SIGSEGV_FAULT_HANDLER_ARGLIST_1 SIGSEGV_FAULT_HANDLER_ARGLIST |
| 929 |
#endif |
| 930 |
#ifndef SIGSEGV_FAULT_HANDLER_INVOKE |
| 931 |
#define SIGSEGV_FAULT_HANDLER_INVOKE(ADDR, IP) sigsegv_fault_handler(ADDR, IP) |
| 932 |
#endif |
| 933 |
|
| 934 |
// SIGSEGV recovery supported ? |
| 935 |
#if defined(SIGSEGV_ALL_SIGNALS) && defined(SIGSEGV_FAULT_HANDLER_ARGLIST) && defined(SIGSEGV_FAULT_ADDRESS) |
| 936 |
#define HAVE_SIGSEGV_RECOVERY |
| 937 |
#endif |
| 938 |
|
| 939 |
|
| 940 |
/* |
| 941 |
* SIGSEGV global handler |
| 942 |
*/ |
| 943 |
|
| 944 |
#if defined(HAVE_SIGSEGV_RECOVERY) || defined(HAVE_MACH_EXCEPTIONS) |
| 945 |
// This function handles the badaccess to memory. |
| 946 |
// It is called from the signal handler or the exception handler. |
| 947 |
static bool handle_badaccess(SIGSEGV_FAULT_HANDLER_ARGLIST_1) |
| 948 |
{ |
| 949 |
sigsegv_address_t fault_address = (sigsegv_address_t)SIGSEGV_FAULT_ADDRESS; |
| 950 |
sigsegv_address_t fault_instruction = (sigsegv_address_t)SIGSEGV_FAULT_INSTRUCTION; |
| 951 |
|
| 952 |
// Call user's handler and reinstall the global handler, if required |
| 953 |
switch (SIGSEGV_FAULT_HANDLER_INVOKE(fault_address, fault_instruction)) { |
| 954 |
case SIGSEGV_RETURN_SUCCESS: |
| 955 |
return true; |
| 956 |
|
| 957 |
#if HAVE_SIGSEGV_SKIP_INSTRUCTION |
| 958 |
case SIGSEGV_RETURN_SKIP_INSTRUCTION: |
| 959 |
// Call the instruction skipper with the register file |
| 960 |
// available |
| 961 |
if (SIGSEGV_SKIP_INSTRUCTION(SIGSEGV_REGISTER_FILE)) { |
| 962 |
#ifdef HAVE_MACH_EXCEPTIONS |
| 963 |
// Unlike UNIX signals where the thread state |
| 964 |
// is modified off of the stack, in Mach we |
| 965 |
// need to actually call thread_set_state to |
| 966 |
// have the register values updated. |
| 967 |
kern_return_t krc; |
| 968 |
|
| 969 |
krc = thread_set_state(thread, |
| 970 |
MACHINE_THREAD_STATE, (thread_state_t)state, |
| 971 |
MACHINE_THREAD_STATE_COUNT); |
| 972 |
MACH_CHECK_ERROR (thread_get_state, krc); |
| 973 |
#endif |
| 974 |
return true; |
| 975 |
} |
| 976 |
break; |
| 977 |
#endif |
| 978 |
} |
| 979 |
|
| 980 |
// We can't do anything with the fault_address, dump state? |
| 981 |
if (sigsegv_state_dumper != 0) |
| 982 |
sigsegv_state_dumper(fault_address, fault_instruction); |
| 983 |
|
| 984 |
return false; |
| 985 |
} |
| 986 |
#endif |
| 987 |
|
| 988 |
|
| 989 |
/* |
| 990 |
* There are two mechanisms for handling a bad memory access, |
| 991 |
* Mach exceptions and UNIX signals. The implementation specific |
| 992 |
* code appears below. Its reponsibility is to call handle_badaccess |
| 993 |
* which is the routine that handles the fault in an implementation |
| 994 |
* agnostic manner. The implementation specific code below is then |
| 995 |
* reponsible for checking whether handle_badaccess was able |
| 996 |
* to handle the memory access error and perform any implementation |
| 997 |
* specific tasks necessary afterwards. |
| 998 |
*/ |
| 999 |
|
| 1000 |
#ifdef HAVE_MACH_EXCEPTIONS |
| 1001 |
/* |
| 1002 |
* We need to forward all exceptions that we do not handle. |
| 1003 |
* This is important, there are many exceptions that may be |
| 1004 |
* handled by other exception handlers. For example debuggers |
| 1005 |
* use exceptions and the exception hander is in another |
| 1006 |
* process in such a case. (Timothy J. Wood states in his |
| 1007 |
* message to the list that he based this code on that from |
| 1008 |
* gdb for Darwin.) |
| 1009 |
*/ |
| 1010 |
static inline kern_return_t |
| 1011 |
forward_exception(mach_port_t thread_port, |
| 1012 |
mach_port_t task_port, |
| 1013 |
exception_type_t exception_type, |
| 1014 |
exception_data_t exception_data, |
| 1015 |
mach_msg_type_number_t data_count, |
| 1016 |
ExceptionPorts *oldExceptionPorts) |
| 1017 |
{ |
| 1018 |
kern_return_t kret; |
| 1019 |
unsigned int portIndex; |
| 1020 |
mach_port_t port; |
| 1021 |
exception_behavior_t behavior; |
| 1022 |
thread_state_flavor_t flavor; |
| 1023 |
thread_state_t thread_state; |
| 1024 |
mach_msg_type_number_t thread_state_count; |
| 1025 |
|
| 1026 |
for (portIndex = 0; portIndex < oldExceptionPorts->maskCount; portIndex++) { |
| 1027 |
if (oldExceptionPorts->masks[portIndex] & (1 << exception_type)) { |
| 1028 |
// This handler wants the exception |
| 1029 |
break; |
| 1030 |
} |
| 1031 |
} |
| 1032 |
|
| 1033 |
if (portIndex >= oldExceptionPorts->maskCount) { |
| 1034 |
fprintf(stderr, "No handler for exception_type = %d. Not fowarding\n", exception_type); |
| 1035 |
return KERN_FAILURE; |
| 1036 |
} |
| 1037 |
|
| 1038 |
port = oldExceptionPorts->handlers[portIndex]; |
| 1039 |
behavior = oldExceptionPorts->behaviors[portIndex]; |
| 1040 |
flavor = oldExceptionPorts->flavors[portIndex]; |
| 1041 |
|
| 1042 |
/* |
| 1043 |
fprintf(stderr, "forwarding exception, port = 0x%x, behaviour = %d, flavor = %d\n", port, behavior, flavor); |
| 1044 |
*/ |
| 1045 |
|
| 1046 |
if (behavior != EXCEPTION_DEFAULT) { |
| 1047 |
thread_state_count = THREAD_STATE_MAX; |
| 1048 |
kret = thread_get_state (thread_port, flavor, thread_state, |
| 1049 |
&thread_state_count); |
| 1050 |
MACH_CHECK_ERROR (thread_get_state, kret); |
| 1051 |
} |
| 1052 |
|
| 1053 |
switch (behavior) { |
| 1054 |
case EXCEPTION_DEFAULT: |
| 1055 |
// fprintf(stderr, "forwarding to exception_raise\n"); |
| 1056 |
kret = exception_raise(port, thread_port, task_port, exception_type, |
| 1057 |
exception_data, data_count); |
| 1058 |
MACH_CHECK_ERROR (exception_raise, kret); |
| 1059 |
break; |
| 1060 |
case EXCEPTION_STATE: |
| 1061 |
// fprintf(stderr, "forwarding to exception_raise_state\n"); |
| 1062 |
kret = exception_raise_state(port, exception_type, exception_data, |
| 1063 |
data_count, &flavor, |
| 1064 |
thread_state, thread_state_count, |
| 1065 |
thread_state, &thread_state_count); |
| 1066 |
MACH_CHECK_ERROR (exception_raise_state, kret); |
| 1067 |
break; |
| 1068 |
case EXCEPTION_STATE_IDENTITY: |
| 1069 |
// fprintf(stderr, "forwarding to exception_raise_state_identity\n"); |
| 1070 |
kret = exception_raise_state_identity(port, thread_port, task_port, |
| 1071 |
exception_type, exception_data, |
| 1072 |
data_count, &flavor, |
| 1073 |
thread_state, thread_state_count, |
| 1074 |
thread_state, &thread_state_count); |
| 1075 |
MACH_CHECK_ERROR (exception_raise_state_identity, kret); |
| 1076 |
break; |
| 1077 |
default: |
| 1078 |
fprintf(stderr, "forward_exception got unknown behavior\n"); |
| 1079 |
break; |
| 1080 |
} |
| 1081 |
|
| 1082 |
if (behavior != EXCEPTION_DEFAULT) { |
| 1083 |
kret = thread_set_state (thread_port, flavor, thread_state, |
| 1084 |
thread_state_count); |
| 1085 |
MACH_CHECK_ERROR (thread_set_state, kret); |
| 1086 |
} |
| 1087 |
|
| 1088 |
return KERN_SUCCESS; |
| 1089 |
} |
| 1090 |
|
| 1091 |
/* |
| 1092 |
* This is the code that actually handles the exception. |
| 1093 |
* It is called by exc_server. For Darwin 5 Apple changed |
| 1094 |
* this a bit from how this family of functions worked in |
| 1095 |
* Mach. If you are familiar with that it is a little |
| 1096 |
* different. The main variation that concerns us here is |
| 1097 |
* that code is an array of exception specific codes and |
| 1098 |
* codeCount is a count of the number of codes in the code |
| 1099 |
* array. In typical Mach all exceptions have a code |
| 1100 |
* and sub-code. It happens to be the case that for a |
| 1101 |
* EXC_BAD_ACCESS exception the first entry is the type of |
| 1102 |
* bad access that occurred and the second entry is the |
| 1103 |
* faulting address so these entries correspond exactly to |
| 1104 |
* how the code and sub-code are used on Mach. |
| 1105 |
* |
| 1106 |
* This is a MIG interface. No code in Basilisk II should |
| 1107 |
* call this directley. This has to have external C |
| 1108 |
* linkage because that is what exc_server expects. |
| 1109 |
*/ |
| 1110 |
kern_return_t |
| 1111 |
catch_exception_raise(mach_port_t exception_port, |
| 1112 |
mach_port_t thread, |
| 1113 |
mach_port_t task, |
| 1114 |
exception_type_t exception, |
| 1115 |
exception_data_t code, |
| 1116 |
mach_msg_type_number_t codeCount) |
| 1117 |
{ |
| 1118 |
ppc_thread_state_t state; |
| 1119 |
kern_return_t krc; |
| 1120 |
|
| 1121 |
if ((exception == EXC_BAD_ACCESS) && (codeCount >= 2)) { |
| 1122 |
if (handle_badaccess(SIGSEGV_FAULT_HANDLER_ARGS)) |
| 1123 |
return KERN_SUCCESS; |
| 1124 |
} |
| 1125 |
|
| 1126 |
// In Mach we do not need to remove the exception handler. |
| 1127 |
// If we forward the exception, eventually some exception handler |
| 1128 |
// will take care of this exception. |
| 1129 |
krc = forward_exception(thread, task, exception, code, codeCount, &ports); |
| 1130 |
|
| 1131 |
return krc; |
| 1132 |
} |
| 1133 |
#endif |
| 1134 |
|
| 1135 |
#ifdef HAVE_SIGSEGV_RECOVERY |
| 1136 |
// Handle bad memory accesses with signal handler |
| 1137 |
static void sigsegv_handler(SIGSEGV_FAULT_HANDLER_ARGLIST) |
| 1138 |
{ |
| 1139 |
// Call handler and reinstall the global handler, if required |
| 1140 |
if (handle_badaccess(SIGSEGV_FAULT_HANDLER_ARGS)) { |
| 1141 |
#if (defined(HAVE_SIGACTION) ? defined(SIGACTION_NEED_REINSTALL) : defined(SIGNAL_NEED_REINSTALL)) |
| 1142 |
sigsegv_do_install_handler(sig); |
| 1143 |
#endif |
| 1144 |
return; |
| 1145 |
} |
| 1146 |
|
| 1147 |
// Failure: reinstall default handler for "safe" crash |
| 1148 |
#define FAULT_HANDLER(sig) signal(sig, SIG_DFL); |
| 1149 |
SIGSEGV_ALL_SIGNALS |
| 1150 |
#undef FAULT_HANDLER |
| 1151 |
} |
| 1152 |
#endif |
| 1153 |
|
| 1154 |
|
| 1155 |
/* |
| 1156 |
* SIGSEGV handler initialization |
| 1157 |
*/ |
| 1158 |
|
| 1159 |
#if defined(HAVE_SIGINFO_T) |
| 1160 |
static bool sigsegv_do_install_handler(int sig) |
| 1161 |
{ |
| 1162 |
// Setup SIGSEGV handler to process writes to frame buffer |
| 1163 |
#ifdef HAVE_SIGACTION |
| 1164 |
struct sigaction sigsegv_sa; |
| 1165 |
sigemptyset(&sigsegv_sa.sa_mask); |
| 1166 |
sigsegv_sa.sa_sigaction = sigsegv_handler; |
| 1167 |
sigsegv_sa.sa_flags = SA_SIGINFO; |
| 1168 |
return (sigaction(sig, &sigsegv_sa, 0) == 0); |
| 1169 |
#else |
| 1170 |
return (signal(sig, (signal_handler)sigsegv_handler) != SIG_ERR); |
| 1171 |
#endif |
| 1172 |
} |
| 1173 |
#endif |
| 1174 |
|
| 1175 |
#if defined(HAVE_SIGCONTEXT_SUBTERFUGE) |
| 1176 |
static bool sigsegv_do_install_handler(int sig) |
| 1177 |
{ |
| 1178 |
// Setup SIGSEGV handler to process writes to frame buffer |
| 1179 |
#ifdef HAVE_SIGACTION |
| 1180 |
struct sigaction sigsegv_sa; |
| 1181 |
sigemptyset(&sigsegv_sa.sa_mask); |
| 1182 |
sigsegv_sa.sa_handler = (signal_handler)sigsegv_handler; |
| 1183 |
sigsegv_sa.sa_flags = 0; |
| 1184 |
#if !EMULATED_68K && defined(__NetBSD__) |
| 1185 |
sigaddset(&sigsegv_sa.sa_mask, SIGALRM); |
| 1186 |
sigsegv_sa.sa_flags |= SA_ONSTACK; |
| 1187 |
#endif |
| 1188 |
return (sigaction(sig, &sigsegv_sa, 0) == 0); |
| 1189 |
#else |
| 1190 |
return (signal(sig, (signal_handler)sigsegv_handler) != SIG_ERR); |
| 1191 |
#endif |
| 1192 |
} |
| 1193 |
#endif |
| 1194 |
|
| 1195 |
#if defined(HAVE_MACH_EXCEPTIONS) |
| 1196 |
static bool sigsegv_do_install_handler(sigsegv_fault_handler_t handler) |
| 1197 |
{ |
| 1198 |
/* |
| 1199 |
* Except for the exception port functions, this should be |
| 1200 |
* pretty much stock Mach. If later you choose to support |
| 1201 |
* other Mach's besides Darwin, just check for __MACH__ |
| 1202 |
* here and __APPLE__ where the actual differences are. |
| 1203 |
*/ |
| 1204 |
#if defined(__APPLE__) && defined(__MACH__) |
| 1205 |
if (sigsegv_fault_handler != NULL) { |
| 1206 |
sigsegv_fault_handler = handler; |
| 1207 |
return true; |
| 1208 |
} |
| 1209 |
|
| 1210 |
kern_return_t krc; |
| 1211 |
|
| 1212 |
// create the the exception port |
| 1213 |
krc = mach_port_allocate(mach_task_self(), |
| 1214 |
MACH_PORT_RIGHT_RECEIVE, &_exceptionPort); |
| 1215 |
if (krc != KERN_SUCCESS) { |
| 1216 |
mach_error("mach_port_allocate", krc); |
| 1217 |
return false; |
| 1218 |
} |
| 1219 |
|
| 1220 |
// add a port send right |
| 1221 |
krc = mach_port_insert_right(mach_task_self(), |
| 1222 |
_exceptionPort, _exceptionPort, |
| 1223 |
MACH_MSG_TYPE_MAKE_SEND); |
| 1224 |
if (krc != KERN_SUCCESS) { |
| 1225 |
mach_error("mach_port_insert_right", krc); |
| 1226 |
return false; |
| 1227 |
} |
| 1228 |
|
| 1229 |
// get the old exception ports |
| 1230 |
ports.maskCount = sizeof (ports.masks) / sizeof (ports.masks[0]); |
| 1231 |
krc = thread_get_exception_ports(mach_thread_self(), EXC_MASK_BAD_ACCESS, ports.masks, |
| 1232 |
&ports.maskCount, ports.handlers, ports.behaviors, ports.flavors); |
| 1233 |
if (krc != KERN_SUCCESS) { |
| 1234 |
mach_error("thread_get_exception_ports", krc); |
| 1235 |
return false; |
| 1236 |
} |
| 1237 |
|
| 1238 |
// set the new exception port |
| 1239 |
// |
| 1240 |
// We could have used EXCEPTION_STATE_IDENTITY instead of |
| 1241 |
// EXCEPTION_DEFAULT to get the thread state in the initial |
| 1242 |
// message, but it turns out that in the common case this is not |
| 1243 |
// neccessary. If we need it we can later ask for it from the |
| 1244 |
// suspended thread. |
| 1245 |
// |
| 1246 |
// Even with THREAD_STATE_NONE, Darwin provides the program |
| 1247 |
// counter in the thread state. The comments in the header file |
| 1248 |
// seem to imply that you can count on the GPR's on an exception |
| 1249 |
// as well but just to be safe I use MACHINE_THREAD_STATE because |
| 1250 |
// you have to ask for all of the GPR's anyway just to get the |
| 1251 |
// program counter. In any case because of update effective |
| 1252 |
// address from immediate and update address from effective |
| 1253 |
// addresses of ra and rb modes (as good an name as any for these |
| 1254 |
// addressing modes) used in PPC instructions, you will need the |
| 1255 |
// GPR state anyway. |
| 1256 |
krc = thread_set_exception_ports(mach_thread_self(), EXC_MASK_BAD_ACCESS, _exceptionPort, |
| 1257 |
EXCEPTION_DEFAULT, MACHINE_THREAD_STATE); |
| 1258 |
if (krc != KERN_SUCCESS) { |
| 1259 |
mach_error("thread_set_exception_ports", krc); |
| 1260 |
return false; |
| 1261 |
} |
| 1262 |
|
| 1263 |
// create the exception handler thread |
| 1264 |
if (pthread_create(&exc_thread, NULL, &handleExceptions, NULL) != 0) { |
| 1265 |
(void)fprintf(stderr, "creation of exception thread failed\n"); |
| 1266 |
return false; |
| 1267 |
} |
| 1268 |
|
| 1269 |
// do not care about the exception thread any longer, let is run standalone |
| 1270 |
(void)pthread_detach(exc_thread); |
| 1271 |
|
| 1272 |
sigsegv_fault_handler = handler; |
| 1273 |
return true; |
| 1274 |
#else |
| 1275 |
return false; |
| 1276 |
#endif |
| 1277 |
} |
| 1278 |
#endif |
| 1279 |
|
| 1280 |
bool sigsegv_install_handler(sigsegv_fault_handler_t handler) |
| 1281 |
{ |
| 1282 |
#if defined(HAVE_SIGSEGV_RECOVERY) |
| 1283 |
bool success = true; |
| 1284 |
#define FAULT_HANDLER(sig) success = success && sigsegv_do_install_handler(sig); |
| 1285 |
SIGSEGV_ALL_SIGNALS |
| 1286 |
#undef FAULT_HANDLER |
| 1287 |
if (success) |
| 1288 |
sigsegv_fault_handler = handler; |
| 1289 |
return success; |
| 1290 |
#elif defined(HAVE_MACH_EXCEPTIONS) |
| 1291 |
return sigsegv_do_install_handler(handler); |
| 1292 |
#else |
| 1293 |
// FAIL: no siginfo_t nor sigcontext subterfuge is available |
| 1294 |
return false; |
| 1295 |
#endif |
| 1296 |
} |
| 1297 |
|
| 1298 |
|
| 1299 |
/* |
| 1300 |
* SIGSEGV handler deinitialization |
| 1301 |
*/ |
| 1302 |
|
| 1303 |
void sigsegv_deinstall_handler(void) |
| 1304 |
{ |
| 1305 |
// We do nothing for Mach exceptions, the thread would need to be |
| 1306 |
// suspended if not already so, and we might mess with other |
| 1307 |
// exception handlers that came after we registered ours. There is |
| 1308 |
// no need to remove the exception handler, in fact this function is |
| 1309 |
// not called anywhere in Basilisk II. |
| 1310 |
#ifdef HAVE_SIGSEGV_RECOVERY |
| 1311 |
sigsegv_fault_handler = 0; |
| 1312 |
#define FAULT_HANDLER(sig) signal(sig, SIG_DFL); |
| 1313 |
SIGSEGV_ALL_SIGNALS |
| 1314 |
#undef FAULT_HANDLER |
| 1315 |
#endif |
| 1316 |
} |
| 1317 |
|
| 1318 |
|
| 1319 |
/* |
| 1320 |
* Set callback function when we cannot handle the fault |
| 1321 |
*/ |
| 1322 |
|
| 1323 |
void sigsegv_set_dump_state(sigsegv_state_dumper_t handler) |
| 1324 |
{ |
| 1325 |
sigsegv_state_dumper = handler; |
| 1326 |
} |
| 1327 |
|
| 1328 |
|
| 1329 |
/* |
| 1330 |
* Test program used for configure/test |
| 1331 |
*/ |
| 1332 |
|
| 1333 |
#ifdef CONFIGURE_TEST_SIGSEGV_RECOVERY |
| 1334 |
#include <stdio.h> |
| 1335 |
#include <stdlib.h> |
| 1336 |
#include <fcntl.h> |
| 1337 |
#include <sys/mman.h> |
| 1338 |
#include "vm_alloc.h" |
| 1339 |
|
| 1340 |
const int REF_INDEX = 123; |
| 1341 |
const int REF_VALUE = 45; |
| 1342 |
|
| 1343 |
static int page_size; |
| 1344 |
static volatile char * page = 0; |
| 1345 |
static volatile int handler_called = 0; |
| 1346 |
|
| 1347 |
#ifdef __GNUC__ |
| 1348 |
// Code range where we expect the fault to come from |
| 1349 |
static void *b_region, *e_region; |
| 1350 |
#endif |
| 1351 |
|
| 1352 |
static sigsegv_return_t sigsegv_test_handler(sigsegv_address_t fault_address, sigsegv_address_t instruction_address) |
| 1353 |
{ |
| 1354 |
handler_called++; |
| 1355 |
if ((fault_address - REF_INDEX) != page) |
| 1356 |
exit(10); |
| 1357 |
#ifdef __GNUC__ |
| 1358 |
// Make sure reported fault instruction address falls into |
| 1359 |
// expected code range |
| 1360 |
if (instruction_address != SIGSEGV_INVALID_PC |
| 1361 |
&& ((instruction_address < (sigsegv_address_t)b_region) || |
| 1362 |
(instruction_address >= (sigsegv_address_t)e_region))) |
| 1363 |
exit(11); |
| 1364 |
#endif |
| 1365 |
if (vm_protect((char *)((unsigned long)fault_address & -page_size), page_size, VM_PAGE_READ | VM_PAGE_WRITE) != 0) |
| 1366 |
exit(12); |
| 1367 |
return SIGSEGV_RETURN_SUCCESS; |
| 1368 |
} |
| 1369 |
|
| 1370 |
#ifdef HAVE_SIGSEGV_SKIP_INSTRUCTION |
| 1371 |
static sigsegv_return_t sigsegv_insn_handler(sigsegv_address_t fault_address, sigsegv_address_t instruction_address) |
| 1372 |
{ |
| 1373 |
if (((unsigned long)fault_address - (unsigned long)page) < page_size) { |
| 1374 |
#ifdef __GNUC__ |
| 1375 |
// Make sure reported fault instruction address falls into |
| 1376 |
// expected code range |
| 1377 |
if (instruction_address != SIGSEGV_INVALID_PC |
| 1378 |
&& ((instruction_address < (sigsegv_address_t)b_region) || |
| 1379 |
(instruction_address >= (sigsegv_address_t)e_region))) |
| 1380 |
return SIGSEGV_RETURN_FAILURE; |
| 1381 |
#endif |
| 1382 |
return SIGSEGV_RETURN_SKIP_INSTRUCTION; |
| 1383 |
} |
| 1384 |
|
| 1385 |
return SIGSEGV_RETURN_FAILURE; |
| 1386 |
} |
| 1387 |
|
| 1388 |
// More sophisticated tests for instruction skipper |
| 1389 |
static bool arch_insn_skipper_tests() |
| 1390 |
{ |
| 1391 |
#if (defined(i386) || defined(__i386__)) || defined(__x86_64__) |
| 1392 |
static const unsigned char code[] = { |
| 1393 |
0x8a, 0x00, // mov (%eax),%al |
| 1394 |
0x8a, 0x2c, 0x18, // mov (%eax,%ebx,1),%ch |
| 1395 |
0x88, 0x20, // mov %ah,(%eax) |
| 1396 |
0x88, 0x08, // mov %cl,(%eax) |
| 1397 |
0x66, 0x8b, 0x00, // mov (%eax),%ax |
| 1398 |
0x66, 0x8b, 0x0c, 0x18, // mov (%eax,%ebx,1),%cx |
| 1399 |
0x66, 0x89, 0x00, // mov %ax,(%eax) |
| 1400 |
0x66, 0x89, 0x0c, 0x18, // mov %cx,(%eax,%ebx,1) |
| 1401 |
0x8b, 0x00, // mov (%eax),%eax |
| 1402 |
0x8b, 0x0c, 0x18, // mov (%eax,%ebx,1),%ecx |
| 1403 |
0x89, 0x00, // mov %eax,(%eax) |
| 1404 |
0x89, 0x0c, 0x18, // mov %ecx,(%eax,%ebx,1) |
| 1405 |
#if defined(__x86_64__) |
| 1406 |
0x44, 0x8a, 0x00, // mov (%rax),%r8b |
| 1407 |
0x44, 0x8a, 0x20, // mov (%rax),%r12b |
| 1408 |
0x42, 0x8a, 0x3c, 0x10, // mov (%rax,%r10,1),%dil |
| 1409 |
0x44, 0x88, 0x00, // mov %r8b,(%rax) |
| 1410 |
0x44, 0x88, 0x20, // mov %r12b,(%rax) |
| 1411 |
0x42, 0x88, 0x3c, 0x10, // mov %dil,(%rax,%r10,1) |
| 1412 |
0x66, 0x44, 0x8b, 0x00, // mov (%rax),%r8w |
| 1413 |
0x66, 0x42, 0x8b, 0x0c, 0x10, // mov (%rax,%r10,1),%cx |
| 1414 |
0x66, 0x44, 0x89, 0x00, // mov %r8w,(%rax) |
| 1415 |
0x66, 0x42, 0x89, 0x0c, 0x10, // mov %cx,(%rax,%r10,1) |
| 1416 |
0x44, 0x8b, 0x00, // mov (%rax),%r8d |
| 1417 |
0x42, 0x8b, 0x0c, 0x10, // mov (%rax,%r10,1),%ecx |
| 1418 |
0x44, 0x89, 0x00, // mov %r8d,(%rax) |
| 1419 |
0x42, 0x89, 0x0c, 0x10, // mov %ecx,(%rax,%r10,1) |
| 1420 |
0x48, 0x8b, 0x08, // mov (%rax),%rcx |
| 1421 |
0x4c, 0x8b, 0x18, // mov (%rax),%r11 |
| 1422 |
0x4a, 0x8b, 0x0c, 0x10, // mov (%rax,%r10,1),%rcx |
| 1423 |
0x4e, 0x8b, 0x1c, 0x10, // mov (%rax,%r10,1),%r11 |
| 1424 |
0x48, 0x89, 0x08, // mov %rcx,(%rax) |
| 1425 |
0x4c, 0x89, 0x18, // mov %r11,(%rax) |
| 1426 |
0x4a, 0x89, 0x0c, 0x10, // mov %rcx,(%rax,%r10,1) |
| 1427 |
0x4e, 0x89, 0x1c, 0x10, // mov %r11,(%rax,%r10,1) |
| 1428 |
#endif |
| 1429 |
0 // end |
| 1430 |
}; |
| 1431 |
const int N_REGS = 20; |
| 1432 |
unsigned long regs[N_REGS]; |
| 1433 |
for (int i = 0; i < N_REGS; i++) |
| 1434 |
regs[i] = i; |
| 1435 |
const unsigned long start_code = (unsigned long)&code; |
| 1436 |
regs[X86_REG_EIP] = start_code; |
| 1437 |
while ((regs[X86_REG_EIP] - start_code) < (sizeof(code) - 1) |
| 1438 |
&& ix86_skip_instruction(regs)) |
| 1439 |
; /* simply iterate */ |
| 1440 |
return (regs[X86_REG_EIP] - start_code) == (sizeof(code) - 1); |
| 1441 |
#endif |
| 1442 |
return true; |
| 1443 |
} |
| 1444 |
#endif |
| 1445 |
|
| 1446 |
int main(void) |
| 1447 |
{ |
| 1448 |
if (vm_init() < 0) |
| 1449 |
return 1; |
| 1450 |
|
| 1451 |
page_size = getpagesize(); |
| 1452 |
if ((page = (char *)vm_acquire(page_size)) == VM_MAP_FAILED) |
| 1453 |
return 2; |
| 1454 |
|
| 1455 |
memset((void *)page, 0, page_size); |
| 1456 |
if (vm_protect((char *)page, page_size, VM_PAGE_READ) < 0) |
| 1457 |
return 3; |
| 1458 |
|
| 1459 |
if (!sigsegv_install_handler(sigsegv_test_handler)) |
| 1460 |
return 4; |
| 1461 |
|
| 1462 |
#ifdef __GNUC__ |
| 1463 |
b_region = &&L_b_region1; |
| 1464 |
e_region = &&L_e_region1; |
| 1465 |
#endif |
| 1466 |
L_b_region1: |
| 1467 |
page[REF_INDEX] = REF_VALUE; |
| 1468 |
if (page[REF_INDEX] != REF_VALUE) |
| 1469 |
exit(20); |
| 1470 |
page[REF_INDEX] = REF_VALUE; |
| 1471 |
L_e_region1: |
| 1472 |
|
| 1473 |
if (handler_called != 1) |
| 1474 |
return 5; |
| 1475 |
|
| 1476 |
#ifdef HAVE_SIGSEGV_SKIP_INSTRUCTION |
| 1477 |
if (!sigsegv_install_handler(sigsegv_insn_handler)) |
| 1478 |
return 6; |
| 1479 |
|
| 1480 |
if (vm_protect((char *)page, page_size, VM_PAGE_READ | VM_PAGE_WRITE) < 0) |
| 1481 |
return 7; |
| 1482 |
|
| 1483 |
for (int i = 0; i < page_size; i++) |
| 1484 |
page[i] = (i + 1) % page_size; |
| 1485 |
|
| 1486 |
if (vm_protect((char *)page, page_size, VM_PAGE_NOACCESS) < 0) |
| 1487 |
return 8; |
| 1488 |
|
| 1489 |
#define TEST_SKIP_INSTRUCTION(TYPE) do { \ |
| 1490 |
const unsigned long TAG = 0x12345678 | \ |
| 1491 |
(sizeof(long) == 8 ? 0x9abcdef0UL << 31 : 0); \ |
| 1492 |
TYPE data = *((TYPE *)(page + sizeof(TYPE))); \ |
| 1493 |
volatile unsigned long effect = data + TAG; \ |
| 1494 |
if (effect != TAG) \ |
| 1495 |
return 9; \ |
| 1496 |
} while (0) |
| 1497 |
|
| 1498 |
#ifdef __GNUC__ |
| 1499 |
b_region = &&L_b_region2; |
| 1500 |
e_region = &&L_e_region2; |
| 1501 |
#endif |
| 1502 |
L_b_region2: |
| 1503 |
TEST_SKIP_INSTRUCTION(unsigned char); |
| 1504 |
TEST_SKIP_INSTRUCTION(unsigned short); |
| 1505 |
TEST_SKIP_INSTRUCTION(unsigned int); |
| 1506 |
TEST_SKIP_INSTRUCTION(unsigned long); |
| 1507 |
L_e_region2: |
| 1508 |
|
| 1509 |
if (!arch_insn_skipper_tests()) |
| 1510 |
return 20; |
| 1511 |
#endif |
| 1512 |
|
| 1513 |
vm_exit(); |
| 1514 |
return 0; |
| 1515 |
} |
| 1516 |
#endif |
