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