| 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/> |
| 6 |
* |
| 7 |
* Basilisk II (C) 1997-2001 Christian Bauer |
| 8 |
* |
| 9 |
* This program is free software; you can redistribute it and/or modify |
| 10 |
* it under the terms of the GNU General Public License as published by |
| 11 |
* the Free Software Foundation; either version 2 of the License, or |
| 12 |
* (at your option) any later version. |
| 13 |
* |
| 14 |
* This program is distributed in the hope that it will be useful, |
| 15 |
* but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 16 |
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 17 |
* GNU General Public License for more details. |
| 18 |
* |
| 19 |
* You should have received a copy of the GNU General Public License |
| 20 |
* along with this program; if not, write to the Free Software |
| 21 |
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 22 |
*/ |
| 23 |
|
| 24 |
#ifdef HAVE_UNISTD_H |
| 25 |
#include <unistd.h> |
| 26 |
#endif |
| 27 |
|
| 28 |
#ifdef HAVE_CONFIG_H |
| 29 |
#include "config.h" |
| 30 |
#endif |
| 31 |
|
| 32 |
#include <signal.h> |
| 33 |
#include "sigsegv.h" |
| 34 |
|
| 35 |
// Return value type of a signal handler (standard type if not defined) |
| 36 |
#ifndef RETSIGTYPE |
| 37 |
#define RETSIGTYPE void |
| 38 |
#endif |
| 39 |
|
| 40 |
// Type of the system signal handler |
| 41 |
typedef RETSIGTYPE (*signal_handler)(int); |
| 42 |
|
| 43 |
// User's SIGSEGV handler |
| 44 |
static sigsegv_handler_t sigsegv_user_handler = 0; |
| 45 |
|
| 46 |
// Actual SIGSEGV handler installer |
| 47 |
static bool sigsegv_do_install_handler(int sig); |
| 48 |
|
| 49 |
|
| 50 |
/* |
| 51 |
* OS-dependant SIGSEGV signals support section |
| 52 |
*/ |
| 53 |
|
| 54 |
#if HAVE_SIGINFO_T |
| 55 |
// Generic extended signal handler |
| 56 |
#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV) |
| 57 |
#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, siginfo_t *sip, void *scp |
| 58 |
#define SIGSEGV_FAULT_ADDRESS sip->si_addr |
| 59 |
#if defined(__linux__) |
| 60 |
#if (defined(ia64) || defined(__ia64__)) |
| 61 |
#define SIGSEGV_FAULT_INSTRUCTION (((struct sigcontext *)scp)->sc_ip & ~0x3ULL) /* slot number is in bits 0 and 1 */ |
| 62 |
#endif |
| 63 |
#endif |
| 64 |
#endif |
| 65 |
|
| 66 |
#if HAVE_SIGCONTEXT_SUBTERFUGE |
| 67 |
// Linux kernels prior to 2.4 ? |
| 68 |
#if defined(__linux__) |
| 69 |
#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV) |
| 70 |
#if (defined(i386) || defined(__i386__)) |
| 71 |
#include <asm/sigcontext.h> |
| 72 |
#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, struct sigcontext scs |
| 73 |
#define SIGSEGV_FAULT_ADDRESS scs.cr2 |
| 74 |
#define SIGSEGV_FAULT_INSTRUCTION scs.eip |
| 75 |
#endif |
| 76 |
#if (defined(sparc) || defined(__sparc__)) |
| 77 |
#include <asm/sigcontext.h> |
| 78 |
#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp, char *addr |
| 79 |
#define SIGSEGV_FAULT_ADDRESS addr |
| 80 |
#endif |
| 81 |
#if (defined(powerpc) || defined(__powerpc__)) |
| 82 |
#include <asm/sigcontext.h> |
| 83 |
#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, struct sigcontext *scp |
| 84 |
#define SIGSEGV_FAULT_ADDRESS scp->regs->dar |
| 85 |
#define SIGSEGV_FAULT_INSTRUCTION scp->regs->nip |
| 86 |
#endif |
| 87 |
#if (defined(alpha) || defined(__alpha__)) |
| 88 |
#include <asm/sigcontext.h> |
| 89 |
#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp |
| 90 |
#define SIGSEGV_FAULT_ADDRESS get_fault_address(scp) |
| 91 |
#define SIGSEGV_FAULT_INSTRUCTION scp->sc_pc |
| 92 |
|
| 93 |
// From Boehm's GC 6.0alpha8 |
| 94 |
static sigsegv_address_t get_fault_address(struct sigcontext *scp) |
| 95 |
{ |
| 96 |
unsigned int instruction = *((unsigned int *)(scp->sc_pc)); |
| 97 |
unsigned long fault_address = scp->sc_regs[(instruction >> 16) & 0x1f]; |
| 98 |
fault_address += (signed long)(signed short)(instruction & 0xffff); |
| 99 |
return (sigsegv_address_t)fault_address; |
| 100 |
} |
| 101 |
#endif |
| 102 |
#endif |
| 103 |
|
| 104 |
// Irix 5 or 6 on MIPS |
| 105 |
#if (defined(sgi) || defined(__sgi)) && (defined(SYSTYPE_SVR4) || defined(__SYSTYPE_SVR4)) |
| 106 |
#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp |
| 107 |
#define SIGSEGV_FAULT_ADDRESS scp->sc_badvaddr |
| 108 |
#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV) |
| 109 |
#endif |
| 110 |
|
| 111 |
// OSF/1 on Alpha |
| 112 |
#if defined(__osf__) |
| 113 |
#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp |
| 114 |
#define SIGSEGV_FAULT_ADDRESS scp->sc_traparg_a0 |
| 115 |
#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV) |
| 116 |
#endif |
| 117 |
|
| 118 |
// AIX |
| 119 |
#if defined(_AIX) |
| 120 |
#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp |
| 121 |
#define SIGSEGV_FAULT_ADDRESS scp->sc_jmpbuf.jmp_context.o_vaddr |
| 122 |
#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV) |
| 123 |
#endif |
| 124 |
|
| 125 |
// NetBSD or FreeBSD |
| 126 |
#if defined(__NetBSD__) || defined(__FreeBSD__) |
| 127 |
#if (defined(m68k) || defined(__m68k__)) |
| 128 |
#include <m68k/frame.h> |
| 129 |
#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp |
| 130 |
#define SIGSEGV_FAULT_ADDRESS ({ \ |
| 131 |
struct sigstate { \ |
| 132 |
int ss_flags; \ |
| 133 |
struct frame ss_frame; \ |
| 134 |
}; \ |
| 135 |
struct sigstate *state = (struct sigstate *)scp->sc_ap; \ |
| 136 |
char *fault_addr; \ |
| 137 |
switch (state->ss_frame.f_format) { \ |
| 138 |
case 7: /* 68040 access error */ \ |
| 139 |
/* "code" is sometimes unreliable (i.e. contains NULL or a bogus address), reason unknown */ \ |
| 140 |
fault_addr = state->ss_frame.f_fmt7.f_fa; \ |
| 141 |
break; \ |
| 142 |
default: \ |
| 143 |
fault_addr = (char *)code; \ |
| 144 |
break; \ |
| 145 |
} \ |
| 146 |
fault_addr; \ |
| 147 |
}) |
| 148 |
#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGSEGV) |
| 149 |
#else |
| 150 |
#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, void *scp, char *addr |
| 151 |
#define SIGSEGV_FAULT_ADDRESS addr |
| 152 |
#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGBUS) |
| 153 |
#endif |
| 154 |
#endif |
| 155 |
|
| 156 |
// MacOS X |
| 157 |
#if defined(__APPLE__) && defined(__MACH__) |
| 158 |
#if (defined(ppc) || defined(__ppc__)) |
| 159 |
#define SIGSEGV_FAULT_HANDLER_ARGLIST int sig, int code, struct sigcontext *scp |
| 160 |
#define SIGSEGV_FAULT_ADDRESS get_fault_address(scp) |
| 161 |
#define SIGSEGV_FAULT_INSTRUCTION scp->sc_ir |
| 162 |
#define SIGSEGV_ALL_SIGNALS FAULT_HANDLER(SIGBUS) |
| 163 |
|
| 164 |
// From Boehm's GC 6.0alpha8 |
| 165 |
#define EXTRACT_OP1(iw) (((iw) & 0xFC000000) >> 26) |
| 166 |
#define EXTRACT_OP2(iw) (((iw) & 0x000007FE) >> 1) |
| 167 |
#define EXTRACT_REGA(iw) (((iw) & 0x001F0000) >> 16) |
| 168 |
#define EXTRACT_REGB(iw) (((iw) & 0x03E00000) >> 21) |
| 169 |
#define EXTRACT_REGC(iw) (((iw) & 0x0000F800) >> 11) |
| 170 |
#define EXTRACT_DISP(iw) ((short *) &(iw))[1] |
| 171 |
|
| 172 |
static sigsegv_address_t get_fault_address(struct sigcontext *scp) |
| 173 |
{ |
| 174 |
unsigned int instr = *((unsigned int *) scp->sc_ir); |
| 175 |
unsigned int * regs = &((unsigned int *) scp->sc_regs)[2]; |
| 176 |
int disp = 0, tmp; |
| 177 |
unsigned int baseA = 0, baseB = 0; |
| 178 |
unsigned int addr, alignmask = 0xFFFFFFFF; |
| 179 |
|
| 180 |
switch(EXTRACT_OP1(instr)) { |
| 181 |
case 38: /* stb */ |
| 182 |
case 39: /* stbu */ |
| 183 |
case 54: /* stfd */ |
| 184 |
case 55: /* stfdu */ |
| 185 |
case 52: /* stfs */ |
| 186 |
case 53: /* stfsu */ |
| 187 |
case 44: /* sth */ |
| 188 |
case 45: /* sthu */ |
| 189 |
case 47: /* stmw */ |
| 190 |
case 36: /* stw */ |
| 191 |
case 37: /* stwu */ |
| 192 |
tmp = EXTRACT_REGA(instr); |
| 193 |
if(tmp > 0) |
| 194 |
baseA = regs[tmp]; |
| 195 |
disp = EXTRACT_DISP(instr); |
| 196 |
break; |
| 197 |
case 31: |
| 198 |
switch(EXTRACT_OP2(instr)) { |
| 199 |
case 86: /* dcbf */ |
| 200 |
case 54: /* dcbst */ |
| 201 |
case 1014: /* dcbz */ |
| 202 |
case 247: /* stbux */ |
| 203 |
case 215: /* stbx */ |
| 204 |
case 759: /* stfdux */ |
| 205 |
case 727: /* stfdx */ |
| 206 |
case 983: /* stfiwx */ |
| 207 |
case 695: /* stfsux */ |
| 208 |
case 663: /* stfsx */ |
| 209 |
case 918: /* sthbrx */ |
| 210 |
case 439: /* sthux */ |
| 211 |
case 407: /* sthx */ |
| 212 |
case 661: /* stswx */ |
| 213 |
case 662: /* stwbrx */ |
| 214 |
case 150: /* stwcx. */ |
| 215 |
case 183: /* stwux */ |
| 216 |
case 151: /* stwx */ |
| 217 |
case 135: /* stvebx */ |
| 218 |
case 167: /* stvehx */ |
| 219 |
case 199: /* stvewx */ |
| 220 |
case 231: /* stvx */ |
| 221 |
case 487: /* stvxl */ |
| 222 |
tmp = EXTRACT_REGA(instr); |
| 223 |
if(tmp > 0) |
| 224 |
baseA = regs[tmp]; |
| 225 |
baseB = regs[EXTRACT_REGC(instr)]; |
| 226 |
/* determine Altivec alignment mask */ |
| 227 |
switch(EXTRACT_OP2(instr)) { |
| 228 |
case 167: /* stvehx */ |
| 229 |
alignmask = 0xFFFFFFFE; |
| 230 |
break; |
| 231 |
case 199: /* stvewx */ |
| 232 |
alignmask = 0xFFFFFFFC; |
| 233 |
break; |
| 234 |
case 231: /* stvx */ |
| 235 |
alignmask = 0xFFFFFFF0; |
| 236 |
break; |
| 237 |
case 487: /* stvxl */ |
| 238 |
alignmask = 0xFFFFFFF0; |
| 239 |
break; |
| 240 |
} |
| 241 |
break; |
| 242 |
case 725: /* stswi */ |
| 243 |
tmp = EXTRACT_REGA(instr); |
| 244 |
if(tmp > 0) |
| 245 |
baseA = regs[tmp]; |
| 246 |
break; |
| 247 |
default: /* ignore instruction */ |
| 248 |
return 0; |
| 249 |
break; |
| 250 |
} |
| 251 |
break; |
| 252 |
default: /* ignore instruction */ |
| 253 |
return 0; |
| 254 |
break; |
| 255 |
} |
| 256 |
|
| 257 |
addr = (baseA + baseB) + disp; |
| 258 |
addr &= alignmask; |
| 259 |
return (sigsegv_address_t)addr; |
| 260 |
} |
| 261 |
#endif |
| 262 |
#endif |
| 263 |
#endif |
| 264 |
|
| 265 |
// Fallbacks |
| 266 |
#ifndef SIGSEGV_FAULT_INSTRUCTION |
| 267 |
#define SIGSEGV_FAULT_INSTRUCTION SIGSEGV_INVALID_PC |
| 268 |
#endif |
| 269 |
|
| 270 |
// SIGSEGV recovery supported ? |
| 271 |
#if defined(SIGSEGV_ALL_SIGNALS) && defined(SIGSEGV_FAULT_HANDLER_ARGLIST) && defined(SIGSEGV_FAULT_ADDRESS) |
| 272 |
#define HAVE_SIGSEGV_RECOVERY |
| 273 |
#endif |
| 274 |
|
| 275 |
|
| 276 |
/* |
| 277 |
* SIGSEGV global handler |
| 278 |
*/ |
| 279 |
|
| 280 |
#ifdef HAVE_SIGSEGV_RECOVERY |
| 281 |
static void sigsegv_handler(SIGSEGV_FAULT_HANDLER_ARGLIST) |
| 282 |
{ |
| 283 |
// Call user's handler and reinstall the global handler, if required |
| 284 |
if (sigsegv_user_handler((sigsegv_address_t)SIGSEGV_FAULT_ADDRESS, (sigsegv_address_t)SIGSEGV_FAULT_INSTRUCTION)) { |
| 285 |
#if (defined(HAVE_SIGACTION) ? defined(SIGACTION_NEED_REINSTALL) : defined(SIGNAL_NEED_REINSTALL)) |
| 286 |
sigsegv_do_install_handler(sig); |
| 287 |
#endif |
| 288 |
} |
| 289 |
else { |
| 290 |
// FAIL: reinstall default handler for "safe" crash |
| 291 |
#define FAULT_HANDLER(sig) signal(sig, SIG_DFL); |
| 292 |
SIGSEGV_ALL_SIGNALS |
| 293 |
#undef FAULT_HANDLER |
| 294 |
} |
| 295 |
} |
| 296 |
#endif |
| 297 |
|
| 298 |
|
| 299 |
/* |
| 300 |
* SIGSEGV handler initialization |
| 301 |
*/ |
| 302 |
|
| 303 |
#if defined(HAVE_SIGINFO_T) |
| 304 |
static bool sigsegv_do_install_handler(int sig) |
| 305 |
{ |
| 306 |
// Setup SIGSEGV handler to process writes to frame buffer |
| 307 |
#ifdef HAVE_SIGACTION |
| 308 |
struct sigaction vosf_sa; |
| 309 |
sigemptyset(&vosf_sa.sa_mask); |
| 310 |
vosf_sa.sa_sigaction = sigsegv_handler; |
| 311 |
vosf_sa.sa_flags = SA_SIGINFO; |
| 312 |
return (sigaction(sig, &vosf_sa, 0) == 0); |
| 313 |
#else |
| 314 |
return (signal(sig, (signal_handler)sigsegv_handler) != SIG_ERR); |
| 315 |
#endif |
| 316 |
} |
| 317 |
#endif |
| 318 |
|
| 319 |
#if defined(HAVE_SIGCONTEXT_SUBTERFUGE) |
| 320 |
static bool sigsegv_do_install_handler(int sig) |
| 321 |
{ |
| 322 |
// Setup SIGSEGV handler to process writes to frame buffer |
| 323 |
#ifdef HAVE_SIGACTION |
| 324 |
struct sigaction vosf_sa; |
| 325 |
sigemptyset(&vosf_sa.sa_mask); |
| 326 |
vosf_sa.sa_handler = (signal_handler)sigsegv_handler; |
| 327 |
#if !EMULATED_68K && defined(__NetBSD__) |
| 328 |
sigaddset(&vosf_sa.sa_mask, SIGALRM); |
| 329 |
vosf_sa.sa_flags = SA_ONSTACK; |
| 330 |
#else |
| 331 |
vosf_sa.sa_flags = 0; |
| 332 |
#endif |
| 333 |
return (sigaction(sig, &vosf_sa, 0) == 0); |
| 334 |
#else |
| 335 |
return (signal(sig, (signal_handler)sigsegv_handler) != SIG_ERR); |
| 336 |
#endif |
| 337 |
} |
| 338 |
#endif |
| 339 |
|
| 340 |
bool sigsegv_install_handler(sigsegv_handler_t handler) |
| 341 |
{ |
| 342 |
#ifdef HAVE_SIGSEGV_RECOVERY |
| 343 |
sigsegv_user_handler = handler; |
| 344 |
bool success = true; |
| 345 |
#define FAULT_HANDLER(sig) success = success && sigsegv_do_install_handler(sig); |
| 346 |
SIGSEGV_ALL_SIGNALS |
| 347 |
#undef FAULT_HANDLER |
| 348 |
return success; |
| 349 |
#else |
| 350 |
// FAIL: no siginfo_t nor sigcontext subterfuge is available |
| 351 |
return false; |
| 352 |
#endif |
| 353 |
} |
| 354 |
|
| 355 |
|
| 356 |
/* |
| 357 |
* SIGSEGV handler deinitialization |
| 358 |
*/ |
| 359 |
|
| 360 |
void sigsegv_deinstall_handler(void) |
| 361 |
{ |
| 362 |
#ifdef HAVE_SIGSEGV_RECOVERY |
| 363 |
sigsegv_user_handler = 0; |
| 364 |
#define FAULT_HANDLER(sig) signal(sig, SIG_DFL); |
| 365 |
SIGSEGV_ALL_SIGNALS |
| 366 |
#undef FAULT_HANDLER |
| 367 |
#endif |
| 368 |
} |
| 369 |
|
| 370 |
/* |
| 371 |
* Test program used for configure/test |
| 372 |
*/ |
| 373 |
|
| 374 |
#ifdef CONFIGURE_TEST_SIGSEGV_RECOVERY |
| 375 |
#include <stdio.h> |
| 376 |
#include <stdlib.h> |
| 377 |
#include <fcntl.h> |
| 378 |
#include <sys/mman.h> |
| 379 |
#include "vm_alloc.h" |
| 380 |
|
| 381 |
static int page_size; |
| 382 |
static volatile char * page = 0; |
| 383 |
static volatile int handler_called = 0; |
| 384 |
|
| 385 |
static bool sigsegv_test_handler(sigsegv_address_t fault_address, sigsegv_address_t instruction_address) |
| 386 |
{ |
| 387 |
handler_called++; |
| 388 |
if ((fault_address - 123) != page) |
| 389 |
exit(1); |
| 390 |
if (vm_protect((char *)((unsigned long)fault_address & -page_size), page_size, VM_PAGE_READ | VM_PAGE_WRITE) != 0) |
| 391 |
exit(1); |
| 392 |
return true; |
| 393 |
} |
| 394 |
|
| 395 |
int main(void) |
| 396 |
{ |
| 397 |
if (vm_init() < 0) |
| 398 |
return 1; |
| 399 |
|
| 400 |
page_size = getpagesize(); |
| 401 |
if ((page = (char *)vm_acquire(page_size)) == VM_MAP_FAILED) |
| 402 |
return 1; |
| 403 |
|
| 404 |
if (vm_protect((char *)page, page_size, VM_PAGE_READ) < 0) |
| 405 |
return 1; |
| 406 |
|
| 407 |
if (!sigsegv_install_handler(sigsegv_test_handler)) |
| 408 |
return 1; |
| 409 |
|
| 410 |
page[123] = 45; |
| 411 |
page[123] = 45; |
| 412 |
|
| 413 |
if (handler_called != 1) |
| 414 |
return 1; |
| 415 |
|
| 416 |
vm_exit(); |
| 417 |
return 0; |
| 418 |
} |
| 419 |
#endif |
