1 //===-- MachException.cpp ---------------------------------------*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // Created by Greg Clayton on 6/18/07. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "MachException.h" 15 #include "MachProcess.h" 16 #include "DNB.h" 17 #include "DNBError.h" 18 #include <sys/types.h> 19 #include "DNBLog.h" 20 #include "PThreadMutex.h" 21 #include "SysSignal.h" 22 #include <errno.h> 23 #include <sys/ptrace.h> 24 25 // Routine mach_exception_raise 26 extern "C" 27 kern_return_t catch_mach_exception_raise 28 ( 29 mach_port_t exception_port, 30 mach_port_t thread, 31 mach_port_t task, 32 exception_type_t exception, 33 mach_exception_data_t code, 34 mach_msg_type_number_t codeCnt 35 ); 36 37 extern "C" 38 kern_return_t catch_mach_exception_raise_state 39 ( 40 mach_port_t exception_port, 41 exception_type_t exception, 42 const mach_exception_data_t code, 43 mach_msg_type_number_t codeCnt, 44 int *flavor, 45 const thread_state_t old_state, 46 mach_msg_type_number_t old_stateCnt, 47 thread_state_t new_state, 48 mach_msg_type_number_t *new_stateCnt 49 ); 50 51 // Routine mach_exception_raise_state_identity 52 extern "C" 53 kern_return_t catch_mach_exception_raise_state_identity 54 ( 55 mach_port_t exception_port, 56 mach_port_t thread, 57 mach_port_t task, 58 exception_type_t exception, 59 mach_exception_data_t code, 60 mach_msg_type_number_t codeCnt, 61 int *flavor, 62 thread_state_t old_state, 63 mach_msg_type_number_t old_stateCnt, 64 thread_state_t new_state, 65 mach_msg_type_number_t *new_stateCnt 66 ); 67 68 extern "C" boolean_t mach_exc_server( 69 mach_msg_header_t *InHeadP, 70 mach_msg_header_t *OutHeadP); 71 72 // Any access to the g_message variable should be done by locking the 73 // g_message_mutex first, using the g_message variable, then unlocking 74 // the g_message_mutex. See MachException::Message::CatchExceptionRaise() 75 // for sample code. 76 77 static MachException::Data *g_message = NULL; 78 //static pthread_mutex_t g_message_mutex = PTHREAD_MUTEX_INITIALIZER; 79 80 81 extern "C" 82 kern_return_t 83 catch_mach_exception_raise_state 84 ( 85 mach_port_t exc_port, 86 exception_type_t exc_type, 87 const mach_exception_data_t exc_data, 88 mach_msg_type_number_t exc_data_count, 89 int * flavor, 90 const thread_state_t old_state, 91 mach_msg_type_number_t old_stateCnt, 92 thread_state_t new_state, 93 mach_msg_type_number_t * new_stateCnt 94 ) 95 { 96 if (DNBLogCheckLogBit(LOG_EXCEPTIONS)) 97 { 98 DNBLogThreaded ("::%s ( exc_port = 0x%4.4x, exc_type = %d ( %s ), exc_data = 0x%llx, exc_data_count = %d)", 99 __FUNCTION__, 100 exc_port, 101 exc_type, MachException::Name(exc_type), 102 (uint64_t)exc_data, 103 exc_data_count); 104 } 105 return KERN_FAILURE; 106 } 107 108 extern "C" 109 kern_return_t 110 catch_mach_exception_raise_state_identity 111 ( 112 mach_port_t exc_port, 113 mach_port_t thread_port, 114 mach_port_t task_port, 115 exception_type_t exc_type, 116 mach_exception_data_t exc_data, 117 mach_msg_type_number_t exc_data_count, 118 int * flavor, 119 thread_state_t old_state, 120 mach_msg_type_number_t old_stateCnt, 121 thread_state_t new_state, 122 mach_msg_type_number_t *new_stateCnt 123 ) 124 { 125 if (DNBLogCheckLogBit(LOG_EXCEPTIONS)) 126 { 127 DNBLogThreaded("::%s ( exc_port = 0x%4.4x, thd_port = 0x%4.4x, tsk_port = 0x%4.4x, exc_type = %d ( %s ), exc_data[%d] = { 0x%llx, 0x%llx })", 128 __FUNCTION__, 129 exc_port, 130 thread_port, 131 task_port, 132 exc_type, MachException::Name(exc_type), 133 exc_data_count, 134 (uint64_t)(exc_data_count > 0 ? exc_data[0] : 0xBADDBADD), 135 (uint64_t)(exc_data_count > 1 ? exc_data[1] : 0xBADDBADD)); 136 } 137 mach_port_deallocate (mach_task_self (), task_port); 138 mach_port_deallocate (mach_task_self (), thread_port); 139 140 return KERN_FAILURE; 141 } 142 143 extern "C" 144 kern_return_t 145 catch_mach_exception_raise 146 ( 147 mach_port_t exc_port, 148 mach_port_t thread_port, 149 mach_port_t task_port, 150 exception_type_t exc_type, 151 mach_exception_data_t exc_data, 152 mach_msg_type_number_t exc_data_count) 153 { 154 if (DNBLogCheckLogBit(LOG_EXCEPTIONS)) 155 { 156 DNBLogThreaded ("::%s ( exc_port = 0x%4.4x, thd_port = 0x%4.4x, tsk_port = 0x%4.4x, exc_type = %d ( %s ), exc_data[%d] = { 0x%llx, 0x%llx })", 157 __FUNCTION__, 158 exc_port, 159 thread_port, 160 task_port, 161 exc_type, MachException::Name(exc_type), 162 exc_data_count, 163 (uint64_t)(exc_data_count > 0 ? exc_data[0] : 0xBADDBADD), 164 (uint64_t)(exc_data_count > 1 ? exc_data[1] : 0xBADDBADD)); 165 } 166 167 if (task_port == g_message->task_port) 168 { 169 g_message->task_port = task_port; 170 g_message->thread_port = thread_port; 171 g_message->exc_type = exc_type; 172 g_message->exc_data.resize(exc_data_count); 173 ::memcpy (&g_message->exc_data[0], exc_data, g_message->exc_data.size() * sizeof (mach_exception_data_type_t)); 174 return KERN_SUCCESS; 175 } 176 return KERN_FAILURE; 177 } 178 179 180 void 181 MachException::Message::Dump() const 182 { 183 DNBLogThreadedIf(LOG_EXCEPTIONS, 184 " exc_msg { bits = 0x%8.8x size = 0x%8.8x remote-port = 0x%8.8x local-port = 0x%8.8x reserved = 0x%8.8x id = 0x%8.8x } ", 185 exc_msg.hdr.msgh_bits, 186 exc_msg.hdr.msgh_size, 187 exc_msg.hdr.msgh_remote_port, 188 exc_msg.hdr.msgh_local_port, 189 exc_msg.hdr.msgh_reserved, 190 exc_msg.hdr.msgh_id); 191 192 DNBLogThreadedIf(LOG_EXCEPTIONS, 193 "reply_msg { bits = 0x%8.8x size = 0x%8.8x remote-port = 0x%8.8x local-port = 0x%8.8x reserved = 0x%8.8x id = 0x%8.8x }", 194 reply_msg.hdr.msgh_bits, 195 reply_msg.hdr.msgh_size, 196 reply_msg.hdr.msgh_remote_port, 197 reply_msg.hdr.msgh_local_port, 198 reply_msg.hdr.msgh_reserved, 199 reply_msg.hdr.msgh_id); 200 201 state.Dump(); 202 } 203 204 bool 205 MachException::Data::GetStopInfo(struct DNBThreadStopInfo *stop_info) const 206 { 207 // Zero out the structure. 208 memset(stop_info, 0, sizeof(struct DNBThreadStopInfo)); 209 // We always stop with a mach exceptions 210 stop_info->reason = eStopTypeException; 211 // Save the EXC_XXXX exception type 212 stop_info->details.exception.type = exc_type; 213 214 // Fill in a text description 215 const char * exc_name = MachException::Name(exc_type); 216 char *desc = stop_info->description; 217 const char *end_desc = desc + DNB_THREAD_STOP_INFO_MAX_DESC_LENGTH; 218 if (exc_name) 219 desc += snprintf(desc, DNB_THREAD_STOP_INFO_MAX_DESC_LENGTH, "%s", exc_name); 220 else 221 desc += snprintf(desc, DNB_THREAD_STOP_INFO_MAX_DESC_LENGTH, "%i", exc_type); 222 223 stop_info->details.exception.data_count = exc_data.size(); 224 225 int soft_signal = SoftSignal(); 226 if (soft_signal) 227 { 228 if (desc < end_desc) 229 { 230 const char *sig_str = SysSignal::Name(soft_signal); 231 snprintf(desc, end_desc - desc, " EXC_SOFT_SIGNAL( %i ( %s ))", soft_signal, sig_str ? sig_str : "unknown signal"); 232 } 233 } 234 else 235 { 236 // No special disassembly for exception data, just 237 size_t idx; 238 if (desc < end_desc) 239 { 240 desc += snprintf(desc, end_desc - desc, " data[%llu] = {", (uint64_t)stop_info->details.exception.data_count); 241 242 for (idx = 0; desc < end_desc && idx < stop_info->details.exception.data_count; ++idx) 243 desc += snprintf(desc, end_desc - desc, "0x%llx%c", (uint64_t)exc_data[idx], ((idx + 1 == stop_info->details.exception.data_count) ? '}' : ',')); 244 } 245 } 246 247 // Copy the exception data 248 size_t i; 249 for (i=0; i<stop_info->details.exception.data_count; i++) 250 stop_info->details.exception.data[i] = exc_data[i]; 251 252 return true; 253 } 254 255 256 void 257 MachException::Data::DumpStopReason() const 258 { 259 int soft_signal = SoftSignal(); 260 if (soft_signal) 261 { 262 const char *signal_str = SysSignal::Name(soft_signal); 263 if (signal_str) 264 DNBLog("signal(%s)", signal_str); 265 else 266 DNBLog("signal(%i)", soft_signal); 267 return; 268 } 269 DNBLog("%s", Name(exc_type)); 270 } 271 272 kern_return_t 273 MachException::Message::Receive(mach_port_t port, mach_msg_option_t options, mach_msg_timeout_t timeout, mach_port_t notify_port) 274 { 275 DNBError err; 276 const bool log_exceptions = DNBLogCheckLogBit(LOG_EXCEPTIONS); 277 mach_msg_timeout_t mach_msg_timeout = options & MACH_RCV_TIMEOUT ? timeout : 0; 278 if (log_exceptions && ((options & MACH_RCV_TIMEOUT) == 0)) 279 { 280 // Dump this log message if we have no timeout in case it never returns 281 DNBLogThreaded ("::mach_msg ( msg->{bits = %#x, size = %u remote_port = %#x, local_port = %#x, reserved = 0x%x, id = 0x%x}, option = %#x, send_size = 0, rcv_size = %llu, rcv_name = %#x, timeout = %u, notify = %#x)", 282 exc_msg.hdr.msgh_bits, 283 exc_msg.hdr.msgh_size, 284 exc_msg.hdr.msgh_remote_port, 285 exc_msg.hdr.msgh_local_port, 286 exc_msg.hdr.msgh_reserved, 287 exc_msg.hdr.msgh_id, 288 options, 289 (uint64_t)sizeof (exc_msg.data), 290 port, 291 mach_msg_timeout, 292 notify_port); 293 } 294 295 err = ::mach_msg (&exc_msg.hdr, 296 options, // options 297 0, // Send size 298 sizeof (exc_msg.data), // Receive size 299 port, // exception port to watch for exception on 300 mach_msg_timeout, // timeout in msec (obeyed only if MACH_RCV_TIMEOUT is ORed into the options parameter) 301 notify_port); 302 303 // Dump any errors we get 304 if (log_exceptions) 305 { 306 err.LogThreaded("::mach_msg ( msg->{bits = %#x, size = %u remote_port = %#x, local_port = %#x, reserved = 0x%x, id = 0x%x}, option = %#x, send_size = %u, rcv_size = %u, rcv_name = %#x, timeout = %u, notify = %#x)", 307 exc_msg.hdr.msgh_bits, 308 exc_msg.hdr.msgh_size, 309 exc_msg.hdr.msgh_remote_port, 310 exc_msg.hdr.msgh_local_port, 311 exc_msg.hdr.msgh_reserved, 312 exc_msg.hdr.msgh_id, 313 options, 314 0, 315 sizeof (exc_msg.data), 316 port, 317 mach_msg_timeout, 318 notify_port); 319 } 320 return err.Error(); 321 } 322 323 bool 324 MachException::Message::CatchExceptionRaise(task_t task) 325 { 326 bool success = false; 327 // locker will keep a mutex locked until it goes out of scope 328 // PThreadMutex::Locker locker(&g_message_mutex); 329 // DNBLogThreaded("calling mach_exc_server"); 330 state.task_port = task; 331 g_message = &state; 332 // The exc_server function is the MIG generated server handling function 333 // to handle messages from the kernel relating to the occurrence of an 334 // exception in a thread. Such messages are delivered to the exception port 335 // set via thread_set_exception_ports or task_set_exception_ports. When an 336 // exception occurs in a thread, the thread sends an exception message to 337 // its exception port, blocking in the kernel waiting for the receipt of a 338 // reply. The exc_server function performs all necessary argument handling 339 // for this kernel message and calls catch_exception_raise, 340 // catch_exception_raise_state or catch_exception_raise_state_identity, 341 // which should handle the exception. If the called routine returns 342 // KERN_SUCCESS, a reply message will be sent, allowing the thread to 343 // continue from the point of the exception; otherwise, no reply message 344 // is sent and the called routine must have dealt with the exception 345 // thread directly. 346 if (mach_exc_server (&exc_msg.hdr, &reply_msg.hdr)) 347 { 348 success = true; 349 } 350 else if (DNBLogCheckLogBit(LOG_EXCEPTIONS)) 351 { 352 DNBLogThreaded("mach_exc_server returned zero..."); 353 } 354 g_message = NULL; 355 return success; 356 } 357 358 359 360 kern_return_t 361 MachException::Message::Reply(MachProcess *process, int signal) 362 { 363 // Reply to the exception... 364 DNBError err; 365 366 // If we had a soft signal, we need to update the thread first so it can 367 // continue without signaling 368 int soft_signal = state.SoftSignal(); 369 if (soft_signal) 370 { 371 int state_pid = -1; 372 if (process->Task().TaskPort() == state.task_port) 373 { 374 // This is our task, so we can update the signal to send to it 375 state_pid = process->ProcessID(); 376 soft_signal = signal; 377 } 378 else 379 { 380 err = ::pid_for_task(state.task_port, &state_pid); 381 } 382 383 assert (state_pid != -1); 384 if (state_pid != -1) 385 { 386 errno = 0; 387 if (::ptrace (PT_THUPDATE, state_pid, (caddr_t)((uintptr_t)state.thread_port), soft_signal) != 0) 388 err.SetError(errno, DNBError::POSIX); 389 else 390 err.Clear(); 391 392 if (DNBLogCheckLogBit(LOG_EXCEPTIONS) || err.Fail()) 393 err.LogThreaded("::ptrace (request = PT_THUPDATE, pid = 0x%4.4x, tid = 0x%4.4x, signal = %i)", state_pid, state.thread_port, soft_signal); 394 } 395 } 396 397 DNBLogThreadedIf(LOG_EXCEPTIONS, "::mach_msg ( msg->{bits = %#x, size = %u, remote_port = %#x, local_port = %#x, reserved = 0x%x, id = 0x%x}, option = %#x, send_size = %u, rcv_size = %u, rcv_name = %#x, timeout = %u, notify = %#x)", 398 reply_msg.hdr.msgh_bits, 399 reply_msg.hdr.msgh_size, 400 reply_msg.hdr.msgh_remote_port, 401 reply_msg.hdr.msgh_local_port, 402 reply_msg.hdr.msgh_reserved, 403 reply_msg.hdr.msgh_id, 404 MACH_SEND_MSG | MACH_SEND_INTERRUPT, 405 reply_msg.hdr.msgh_size, 406 0, 407 MACH_PORT_NULL, 408 MACH_MSG_TIMEOUT_NONE, 409 MACH_PORT_NULL); 410 411 err = ::mach_msg ( &reply_msg.hdr, 412 MACH_SEND_MSG | MACH_SEND_INTERRUPT, 413 reply_msg.hdr.msgh_size, 414 0, 415 MACH_PORT_NULL, 416 MACH_MSG_TIMEOUT_NONE, 417 MACH_PORT_NULL); 418 419 if (err.Fail()) 420 { 421 if (err.Error() == MACH_SEND_INTERRUPTED) 422 { 423 if (DNBLogCheckLogBit(LOG_EXCEPTIONS)) 424 err.LogThreaded("::mach_msg() - send interrupted"); 425 // TODO: keep retrying to reply??? 426 } 427 else 428 { 429 if (state.task_port == process->Task().TaskPort()) 430 { 431 if (DNBLogCheckLogBit(LOG_EXCEPTIONS)) 432 err.LogThreaded("::mach_msg() - failed (task)"); 433 abort (); 434 } 435 else 436 { 437 if (DNBLogCheckLogBit(LOG_EXCEPTIONS)) 438 err.LogThreaded("::mach_msg() - failed (child of task)"); 439 } 440 } 441 } 442 443 return err.Error(); 444 } 445 446 447 void 448 MachException::Data::Dump() const 449 { 450 const char *exc_type_name = MachException::Name(exc_type); 451 DNBLogThreadedIf(LOG_EXCEPTIONS, " state { task_port = 0x%4.4x, thread_port = 0x%4.4x, exc_type = %i (%s) ...", task_port, thread_port, exc_type, exc_type_name ? exc_type_name : "???"); 452 453 const size_t exc_data_count = exc_data.size(); 454 // Dump any special exception data contents 455 int soft_signal = SoftSignal(); 456 if (soft_signal != 0) 457 { 458 const char *sig_str = SysSignal::Name(soft_signal); 459 DNBLogThreadedIf(LOG_EXCEPTIONS, " exc_data: EXC_SOFT_SIGNAL (%i (%s))", soft_signal, sig_str ? sig_str : "unknown signal"); 460 } 461 else 462 { 463 // No special disassembly for this data, just dump the data 464 size_t idx; 465 for (idx = 0; idx < exc_data_count; ++idx) 466 { 467 DNBLogThreadedIf(LOG_EXCEPTIONS, " exc_data[%llu]: 0x%llx", (uint64_t)idx, (uint64_t)exc_data[idx]); 468 } 469 } 470 } 471 472 #define PREV_EXC_MASK_ALL (EXC_MASK_BAD_ACCESS | \ 473 EXC_MASK_BAD_INSTRUCTION | \ 474 EXC_MASK_ARITHMETIC | \ 475 EXC_MASK_EMULATION | \ 476 EXC_MASK_SOFTWARE | \ 477 EXC_MASK_BREAKPOINT | \ 478 EXC_MASK_SYSCALL | \ 479 EXC_MASK_MACH_SYSCALL | \ 480 EXC_MASK_RPC_ALERT | \ 481 EXC_MASK_MACHINE) 482 483 // Don't listen for EXC_RESOURCE, it should really get handled by the system handler. 484 485 #ifndef EXC_RESOURCE 486 #define EXC_RESOURCE 11 487 #endif 488 489 #ifndef EXC_MASK_RESOURCE 490 #define EXC_MASK_RESOURCE (1 << EXC_RESOURCE) 491 #endif 492 493 #define LLDB_EXC_MASK (EXC_MASK_ALL & ~EXC_MASK_RESOURCE) 494 495 kern_return_t 496 MachException::PortInfo::Save (task_t task) 497 { 498 DNBLogThreadedIf(LOG_EXCEPTIONS | LOG_VERBOSE, "MachException::PortInfo::Save ( task = 0x%4.4x )", task); 499 // Be careful to be able to have debugserver built on a newer OS than what 500 // it is currently running on by being able to start with all exceptions 501 // and back off to just what is supported on the current system 502 DNBError err; 503 504 mask = LLDB_EXC_MASK; 505 506 count = (sizeof (ports) / sizeof (ports[0])); 507 err = ::task_get_exception_ports (task, mask, masks, &count, ports, behaviors, flavors); 508 if (DNBLogCheckLogBit(LOG_EXCEPTIONS) || err.Fail()) 509 err.LogThreaded("::task_get_exception_ports ( task = 0x%4.4x, mask = 0x%x, maskCnt => %u, ports, behaviors, flavors )", task, mask, count); 510 511 if (err.Error() == KERN_INVALID_ARGUMENT && mask != PREV_EXC_MASK_ALL) 512 { 513 mask = PREV_EXC_MASK_ALL; 514 count = (sizeof (ports) / sizeof (ports[0])); 515 err = ::task_get_exception_ports (task, mask, masks, &count, ports, behaviors, flavors); 516 if (DNBLogCheckLogBit(LOG_EXCEPTIONS) || err.Fail()) 517 err.LogThreaded("::task_get_exception_ports ( task = 0x%4.4x, mask = 0x%x, maskCnt => %u, ports, behaviors, flavors )", task, mask, count); 518 } 519 if (err.Fail()) 520 { 521 mask = 0; 522 count = 0; 523 } 524 return err.Error(); 525 } 526 527 kern_return_t 528 MachException::PortInfo::Restore (task_t task) 529 { 530 DNBLogThreadedIf(LOG_EXCEPTIONS | LOG_VERBOSE, "MachException::PortInfo::Restore( task = 0x%4.4x )", task); 531 uint32_t i = 0; 532 DNBError err; 533 if (count > 0) 534 { 535 for (i = 0; i < count; i++) 536 { 537 err = ::task_set_exception_ports (task, masks[i], ports[i], behaviors[i], flavors[i]); 538 if (DNBLogCheckLogBit(LOG_EXCEPTIONS) || err.Fail()) 539 { 540 err.LogThreaded("::task_set_exception_ports ( task = 0x%4.4x, exception_mask = 0x%8.8x, new_port = 0x%4.4x, behavior = 0x%8.8x, new_flavor = 0x%8.8x )", task, masks[i], ports[i], behaviors[i], flavors[i]); 541 // Bail if we encounter any errors 542 } 543 544 if (err.Fail()) 545 break; 546 } 547 } 548 count = 0; 549 return err.Error(); 550 } 551 552 const char * 553 MachException::Name(exception_type_t exc_type) 554 { 555 switch (exc_type) 556 { 557 case EXC_BAD_ACCESS: return "EXC_BAD_ACCESS"; 558 case EXC_BAD_INSTRUCTION: return "EXC_BAD_INSTRUCTION"; 559 case EXC_ARITHMETIC: return "EXC_ARITHMETIC"; 560 case EXC_EMULATION: return "EXC_EMULATION"; 561 case EXC_SOFTWARE: return "EXC_SOFTWARE"; 562 case EXC_BREAKPOINT: return "EXC_BREAKPOINT"; 563 case EXC_SYSCALL: return "EXC_SYSCALL"; 564 case EXC_MACH_SYSCALL: return "EXC_MACH_SYSCALL"; 565 case EXC_RPC_ALERT: return "EXC_RPC_ALERT"; 566 #ifdef EXC_CRASH 567 case EXC_CRASH: return "EXC_CRASH"; 568 #endif 569 default: 570 break; 571 } 572 return NULL; 573 } 574 575 576 577
