1 //===-- StopInfoMachException.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 #include "StopInfoMachException.h" 11 12 13 #if defined(__APPLE__) 14 // Needed for the EXC_RESOURCE interpretation macros 15 #include <kern/exc_resource.h> 16 #endif 17 18 #include "lldb/Breakpoint/Watchpoint.h" 19 #include "lldb/Symbol/Symbol.h" 20 #include "lldb/Target/DynamicLoader.h" 21 #include "lldb/Target/ExecutionContext.h" 22 #include "lldb/Target/Process.h" 23 #include "lldb/Target/RegisterContext.h" 24 #include "lldb/Target/Target.h" 25 #include "lldb/Target/Thread.h" 26 #include "lldb/Target/ThreadPlan.h" 27 #include "lldb/Target/UnixSignals.h" 28 #include "lldb/Utility/StreamString.h" 29 30 using namespace lldb; 31 using namespace lldb_private; 32 33 const char *StopInfoMachException::GetDescription() { 34 if (m_description.empty() && m_value != 0) { 35 ExecutionContext exe_ctx(m_thread_wp.lock()); 36 Target *target = exe_ctx.GetTargetPtr(); 37 const llvm::Triple::ArchType cpu = 38 target ? target->GetArchitecture().GetMachine() 39 : llvm::Triple::UnknownArch; 40 41 const char *exc_desc = NULL; 42 const char *code_label = "code"; 43 const char *code_desc = NULL; 44 const char *subcode_label = "subcode"; 45 const char *subcode_desc = NULL; 46 47 char code_desc_buf[32]; 48 char subcode_desc_buf[32]; 49 50 switch (m_value) { 51 case 1: // EXC_BAD_ACCESS 52 exc_desc = "EXC_BAD_ACCESS"; 53 subcode_label = "address"; 54 switch (cpu) { 55 case llvm::Triple::x86: 56 case llvm::Triple::x86_64: 57 switch (m_exc_code) { 58 case 0xd: 59 code_desc = "EXC_I386_GPFLT"; 60 m_exc_data_count = 1; 61 break; 62 } 63 break; 64 case llvm::Triple::arm: 65 case llvm::Triple::thumb: 66 switch (m_exc_code) { 67 case 0x101: 68 code_desc = "EXC_ARM_DA_ALIGN"; 69 break; 70 case 0x102: 71 code_desc = "EXC_ARM_DA_DEBUG"; 72 break; 73 } 74 break; 75 76 case llvm::Triple::ppc: 77 case llvm::Triple::ppc64: 78 switch (m_exc_code) { 79 case 0x101: 80 code_desc = "EXC_PPC_VM_PROT_READ"; 81 break; 82 case 0x102: 83 code_desc = "EXC_PPC_BADSPACE"; 84 break; 85 case 0x103: 86 code_desc = "EXC_PPC_UNALIGNED"; 87 break; 88 } 89 break; 90 91 default: 92 break; 93 } 94 break; 95 96 case 2: // EXC_BAD_INSTRUCTION 97 exc_desc = "EXC_BAD_INSTRUCTION"; 98 switch (cpu) { 99 case llvm::Triple::x86: 100 case llvm::Triple::x86_64: 101 if (m_exc_code == 1) 102 code_desc = "EXC_I386_INVOP"; 103 break; 104 105 case llvm::Triple::ppc: 106 case llvm::Triple::ppc64: 107 switch (m_exc_code) { 108 case 1: 109 code_desc = "EXC_PPC_INVALID_SYSCALL"; 110 break; 111 case 2: 112 code_desc = "EXC_PPC_UNIPL_INST"; 113 break; 114 case 3: 115 code_desc = "EXC_PPC_PRIVINST"; 116 break; 117 case 4: 118 code_desc = "EXC_PPC_PRIVREG"; 119 break; 120 case 5: 121 code_desc = "EXC_PPC_TRACE"; 122 break; 123 case 6: 124 code_desc = "EXC_PPC_PERFMON"; 125 break; 126 } 127 break; 128 129 case llvm::Triple::arm: 130 case llvm::Triple::thumb: 131 if (m_exc_code == 1) 132 code_desc = "EXC_ARM_UNDEFINED"; 133 break; 134 135 default: 136 break; 137 } 138 break; 139 140 case 3: // EXC_ARITHMETIC 141 exc_desc = "EXC_ARITHMETIC"; 142 switch (cpu) { 143 case llvm::Triple::x86: 144 case llvm::Triple::x86_64: 145 switch (m_exc_code) { 146 case 1: 147 code_desc = "EXC_I386_DIV"; 148 break; 149 case 2: 150 code_desc = "EXC_I386_INTO"; 151 break; 152 case 3: 153 code_desc = "EXC_I386_NOEXT"; 154 break; 155 case 4: 156 code_desc = "EXC_I386_EXTOVR"; 157 break; 158 case 5: 159 code_desc = "EXC_I386_EXTERR"; 160 break; 161 case 6: 162 code_desc = "EXC_I386_EMERR"; 163 break; 164 case 7: 165 code_desc = "EXC_I386_BOUND"; 166 break; 167 case 8: 168 code_desc = "EXC_I386_SSEEXTERR"; 169 break; 170 } 171 break; 172 173 case llvm::Triple::ppc: 174 case llvm::Triple::ppc64: 175 switch (m_exc_code) { 176 case 1: 177 code_desc = "EXC_PPC_OVERFLOW"; 178 break; 179 case 2: 180 code_desc = "EXC_PPC_ZERO_DIVIDE"; 181 break; 182 case 3: 183 code_desc = "EXC_PPC_FLT_INEXACT"; 184 break; 185 case 4: 186 code_desc = "EXC_PPC_FLT_ZERO_DIVIDE"; 187 break; 188 case 5: 189 code_desc = "EXC_PPC_FLT_UNDERFLOW"; 190 break; 191 case 6: 192 code_desc = "EXC_PPC_FLT_OVERFLOW"; 193 break; 194 case 7: 195 code_desc = "EXC_PPC_FLT_NOT_A_NUMBER"; 196 break; 197 } 198 break; 199 200 default: 201 break; 202 } 203 break; 204 205 case 4: // EXC_EMULATION 206 exc_desc = "EXC_EMULATION"; 207 break; 208 209 case 5: // EXC_SOFTWARE 210 exc_desc = "EXC_SOFTWARE"; 211 if (m_exc_code == 0x10003) { 212 subcode_desc = "EXC_SOFT_SIGNAL"; 213 subcode_label = "signo"; 214 } 215 break; 216 217 case 6: // EXC_BREAKPOINT 218 { 219 exc_desc = "EXC_BREAKPOINT"; 220 switch (cpu) { 221 case llvm::Triple::x86: 222 case llvm::Triple::x86_64: 223 switch (m_exc_code) { 224 case 1: 225 code_desc = "EXC_I386_SGL"; 226 break; 227 case 2: 228 code_desc = "EXC_I386_BPT"; 229 break; 230 } 231 break; 232 233 case llvm::Triple::ppc: 234 case llvm::Triple::ppc64: 235 switch (m_exc_code) { 236 case 1: 237 code_desc = "EXC_PPC_BREAKPOINT"; 238 break; 239 } 240 break; 241 242 case llvm::Triple::arm: 243 case llvm::Triple::thumb: 244 switch (m_exc_code) { 245 case 0x101: 246 code_desc = "EXC_ARM_DA_ALIGN"; 247 break; 248 case 0x102: 249 code_desc = "EXC_ARM_DA_DEBUG"; 250 break; 251 case 1: 252 code_desc = "EXC_ARM_BREAKPOINT"; 253 break; 254 // FIXME temporary workaround, exc_code 0 does not really mean 255 // EXC_ARM_BREAKPOINT 256 case 0: 257 code_desc = "EXC_ARM_BREAKPOINT"; 258 break; 259 } 260 break; 261 262 default: 263 break; 264 } 265 } break; 266 267 case 7: 268 exc_desc = "EXC_SYSCALL"; 269 break; 270 271 case 8: 272 exc_desc = "EXC_MACH_SYSCALL"; 273 break; 274 275 case 9: 276 exc_desc = "EXC_RPC_ALERT"; 277 break; 278 279 case 10: 280 exc_desc = "EXC_CRASH"; 281 break; 282 case 11: 283 exc_desc = "EXC_RESOURCE"; 284 #if defined(__APPLE__) 285 { 286 int resource_type = EXC_RESOURCE_DECODE_RESOURCE_TYPE(m_exc_code); 287 288 code_label = "limit"; 289 code_desc = code_desc_buf; 290 subcode_label = "observed"; 291 subcode_desc = subcode_desc_buf; 292 293 switch (resource_type) { 294 case RESOURCE_TYPE_CPU: 295 exc_desc = "EXC_RESOURCE RESOURCE_TYPE_CPU"; 296 snprintf(code_desc_buf, sizeof(code_desc_buf), "%d%%", 297 (int)EXC_RESOURCE_CPUMONITOR_DECODE_PERCENTAGE(m_exc_code)); 298 snprintf(subcode_desc_buf, sizeof(subcode_desc_buf), "%d%%", 299 (int)EXC_RESOURCE_CPUMONITOR_DECODE_PERCENTAGE_OBSERVED(m_exc_subcode)); 300 break; 301 case RESOURCE_TYPE_WAKEUPS: 302 exc_desc = "EXC_RESOURCE RESOURCE_TYPE_WAKEUPS"; 303 snprintf(code_desc_buf, sizeof(code_desc_buf), "%d w/s", 304 (int)EXC_RESOURCE_CPUMONITOR_DECODE_WAKEUPS_PERMITTED(m_exc_code)); 305 snprintf(subcode_desc_buf, sizeof(subcode_desc_buf), "%d w/s", 306 (int)EXC_RESOURCE_CPUMONITOR_DECODE_WAKEUPS_OBSERVED(m_exc_subcode)); 307 break; 308 case RESOURCE_TYPE_MEMORY: 309 exc_desc = "EXC_RESOURCE RESOURCE_TYPE_MEMORY"; 310 snprintf(code_desc_buf, sizeof(code_desc_buf), "%d MB", 311 (int)EXC_RESOURCE_HWM_DECODE_LIMIT(m_exc_code)); 312 subcode_desc = nullptr; 313 subcode_label = "unused"; 314 break; 315 case RESOURCE_TYPE_IO: 316 exc_desc = "EXC_RESOURCE RESOURCE_TYPE_IO"; 317 snprintf(code_desc_buf, sizeof(code_desc_buf), "%d MB", 318 (int)EXC_RESOURCE_IO_DECODE_LIMIT(m_exc_code)); 319 snprintf(subcode_desc_buf, sizeof(subcode_desc_buf), "%d MB", 320 (int)EXC_RESOURCE_IO_OBSERVED(m_exc_subcode));; 321 break; 322 } 323 } 324 #endif 325 break; 326 case 12: 327 exc_desc = "EXC_GUARD"; 328 break; 329 } 330 331 StreamString strm; 332 333 if (exc_desc) 334 strm.PutCString(exc_desc); 335 else 336 strm.Printf("EXC_??? (%" PRIu64 ")", m_value); 337 338 if (m_exc_data_count >= 1) { 339 if (code_desc) 340 strm.Printf(" (%s=%s", code_label, code_desc); 341 else 342 strm.Printf(" (%s=%" PRIu64, code_label, m_exc_code); 343 } 344 345 if (m_exc_data_count >= 2) { 346 if (subcode_desc) 347 strm.Printf(", %s=%s", subcode_label, subcode_desc); 348 else 349 strm.Printf(", %s=0x%" PRIx64, subcode_label, m_exc_subcode); 350 } 351 352 if (m_exc_data_count > 0) 353 strm.PutChar(')'); 354 355 m_description = strm.GetString(); 356 } 357 return m_description.c_str(); 358 } 359 360 StopInfoSP StopInfoMachException::CreateStopReasonWithMachException( 361 Thread &thread, uint32_t exc_type, uint32_t exc_data_count, 362 uint64_t exc_code, uint64_t exc_sub_code, uint64_t exc_sub_sub_code, 363 bool pc_already_adjusted, bool adjust_pc_if_needed) { 364 if (exc_type != 0) { 365 uint32_t pc_decrement = 0; 366 ExecutionContext exe_ctx(thread.shared_from_this()); 367 Target *target = exe_ctx.GetTargetPtr(); 368 const llvm::Triple::ArchType cpu = 369 target ? target->GetArchitecture().GetMachine() 370 : llvm::Triple::UnknownArch; 371 372 switch (exc_type) { 373 case 1: // EXC_BAD_ACCESS 374 break; 375 376 case 2: // EXC_BAD_INSTRUCTION 377 switch (cpu) { 378 case llvm::Triple::ppc: 379 case llvm::Triple::ppc64: 380 switch (exc_code) { 381 case 1: // EXC_PPC_INVALID_SYSCALL 382 case 2: // EXC_PPC_UNIPL_INST 383 case 3: // EXC_PPC_PRIVINST 384 case 4: // EXC_PPC_PRIVREG 385 break; 386 case 5: // EXC_PPC_TRACE 387 return StopInfo::CreateStopReasonToTrace(thread); 388 case 6: // EXC_PPC_PERFMON 389 break; 390 } 391 break; 392 393 default: 394 break; 395 } 396 break; 397 398 case 3: // EXC_ARITHMETIC 399 case 4: // EXC_EMULATION 400 break; 401 402 case 5: // EXC_SOFTWARE 403 if (exc_code == 0x10003) // EXC_SOFT_SIGNAL 404 { 405 if (exc_sub_code == 5) { 406 // On MacOSX, a SIGTRAP can signify that a process has called exec, 407 // so we should check with our dynamic loader to verify. 408 ProcessSP process_sp(thread.GetProcess()); 409 if (process_sp) { 410 DynamicLoader *dynamic_loader = process_sp->GetDynamicLoader(); 411 if (dynamic_loader && dynamic_loader->ProcessDidExec()) { 412 // The program was re-exec'ed 413 return StopInfo::CreateStopReasonWithExec(thread); 414 } 415 // if (!process_did_exec) 416 // { 417 // // We have a SIGTRAP, make sure we 418 // didn't exec by checking 419 // // for the PC being at 420 // "_dyld_start"... 421 // lldb::StackFrameSP frame_sp 422 // (thread.GetStackFrameAtIndex(0)); 423 // if (frame_sp) 424 // { 425 // const Symbol *symbol = 426 // frame_sp->GetSymbolContext(eSymbolContextSymbol).symbol; 427 // if (symbol) 428 // { 429 // if (symbol->GetName() == 430 // ConstString("_dyld_start")) 431 // process_did_exec = true; 432 // } 433 // } 434 // } 435 } 436 } 437 return StopInfo::CreateStopReasonWithSignal(thread, exc_sub_code); 438 } 439 break; 440 441 case 6: // EXC_BREAKPOINT 442 { 443 bool is_actual_breakpoint = false; 444 bool is_trace_if_actual_breakpoint_missing = false; 445 switch (cpu) { 446 case llvm::Triple::x86: 447 case llvm::Triple::x86_64: 448 if (exc_code == 1) // EXC_I386_SGL 449 { 450 if (!exc_sub_code) { 451 // This looks like a plain trap. 452 // Have to check if there is a breakpoint here as well. When you 453 // single-step onto a trap, the single step stops you not to trap. 454 // Since we also do that check below, let's just use that logic. 455 is_actual_breakpoint = true; 456 is_trace_if_actual_breakpoint_missing = true; 457 } else { 458 459 // It's a watchpoint, then. 460 // The exc_sub_code indicates the data break address. 461 lldb::WatchpointSP wp_sp; 462 if (target) 463 wp_sp = target->GetWatchpointList().FindByAddress( 464 (lldb::addr_t)exc_sub_code); 465 if (wp_sp && wp_sp->IsEnabled()) { 466 // Debugserver may piggyback the hardware index of the fired 467 // watchpoint in the exception data. Set the hardware index if 468 // that's the case. 469 if (exc_data_count >= 3) 470 wp_sp->SetHardwareIndex((uint32_t)exc_sub_sub_code); 471 return StopInfo::CreateStopReasonWithWatchpointID(thread, 472 wp_sp->GetID()); 473 } 474 } 475 } else if (exc_code == 2 || // EXC_I386_BPT 476 exc_code == 3) // EXC_I386_BPTFLT 477 { 478 // KDP returns EXC_I386_BPTFLT for trace breakpoints 479 if (exc_code == 3) 480 is_trace_if_actual_breakpoint_missing = true; 481 482 is_actual_breakpoint = true; 483 if (!pc_already_adjusted) 484 pc_decrement = 1; 485 } 486 break; 487 488 case llvm::Triple::ppc: 489 case llvm::Triple::ppc64: 490 is_actual_breakpoint = exc_code == 1; // EXC_PPC_BREAKPOINT 491 break; 492 493 case llvm::Triple::arm: 494 case llvm::Triple::thumb: 495 if (exc_code == 0x102) // EXC_ARM_DA_DEBUG 496 { 497 // It's a watchpoint, then, if the exc_sub_code indicates a 498 // known/enabled data break address from our watchpoint list. 499 lldb::WatchpointSP wp_sp; 500 if (target) 501 wp_sp = target->GetWatchpointList().FindByAddress( 502 (lldb::addr_t)exc_sub_code); 503 if (wp_sp && wp_sp->IsEnabled()) { 504 // Debugserver may piggyback the hardware index of the fired 505 // watchpoint in the exception data. Set the hardware index if 506 // that's the case. 507 if (exc_data_count >= 3) 508 wp_sp->SetHardwareIndex((uint32_t)exc_sub_sub_code); 509 return StopInfo::CreateStopReasonWithWatchpointID(thread, 510 wp_sp->GetID()); 511 } else { 512 is_actual_breakpoint = true; 513 is_trace_if_actual_breakpoint_missing = true; 514 } 515 } else if (exc_code == 1) // EXC_ARM_BREAKPOINT 516 { 517 is_actual_breakpoint = true; 518 is_trace_if_actual_breakpoint_missing = true; 519 } else if (exc_code == 0) // FIXME not EXC_ARM_BREAKPOINT but a kernel 520 // is currently returning this so accept it 521 // as indicating a breakpoint until the 522 // kernel is fixed 523 { 524 is_actual_breakpoint = true; 525 is_trace_if_actual_breakpoint_missing = true; 526 } 527 break; 528 529 case llvm::Triple::aarch64: { 530 if (exc_code == 1 && exc_sub_code == 0) // EXC_ARM_BREAKPOINT 531 { 532 // This is hit when we single instruction step aka MDSCR_EL1 SS bit 0 533 // is set 534 is_actual_breakpoint = false; 535 is_trace_if_actual_breakpoint_missing = true; 536 } 537 if (exc_code == 0x102) // EXC_ARM_DA_DEBUG 538 { 539 // It's a watchpoint, then, if the exc_sub_code indicates a 540 // known/enabled data break address from our watchpoint list. 541 lldb::WatchpointSP wp_sp; 542 if (target) 543 wp_sp = target->GetWatchpointList().FindByAddress( 544 (lldb::addr_t)exc_sub_code); 545 if (wp_sp && wp_sp->IsEnabled()) { 546 // Debugserver may piggyback the hardware index of the fired 547 // watchpoint in the exception data. Set the hardware index if 548 // that's the case. 549 if (exc_data_count >= 3) 550 wp_sp->SetHardwareIndex((uint32_t)exc_sub_sub_code); 551 return StopInfo::CreateStopReasonWithWatchpointID(thread, 552 wp_sp->GetID()); 553 } 554 // EXC_ARM_DA_DEBUG seems to be reused for EXC_BREAKPOINT as well as 555 // EXC_BAD_ACCESS 556 if (thread.GetTemporaryResumeState() == eStateStepping) 557 return StopInfo::CreateStopReasonToTrace(thread); 558 } 559 // It looks like exc_sub_code has the 4 bytes of the instruction that 560 // triggered the exception, i.e. our breakpoint opcode 561 is_actual_breakpoint = exc_code == 1; 562 break; 563 } 564 565 default: 566 break; 567 } 568 569 if (is_actual_breakpoint) { 570 RegisterContextSP reg_ctx_sp(thread.GetRegisterContext()); 571 addr_t pc = reg_ctx_sp->GetPC() - pc_decrement; 572 573 ProcessSP process_sp(thread.CalculateProcess()); 574 575 lldb::BreakpointSiteSP bp_site_sp; 576 if (process_sp) 577 bp_site_sp = process_sp->GetBreakpointSiteList().FindByAddress(pc); 578 if (bp_site_sp && bp_site_sp->IsEnabled()) { 579 // Update the PC if we were asked to do so, but only do so if we find 580 // a breakpoint that we know about cause this could be a trap 581 // instruction in the code 582 if (pc_decrement > 0 && adjust_pc_if_needed) 583 reg_ctx_sp->SetPC(pc); 584 585 // If the breakpoint is for this thread, then we'll report the hit, 586 // but if it is for another thread, we can just report no reason. We 587 // don't need to worry about stepping over the breakpoint here, that 588 // will be taken care of when the thread resumes and notices that 589 // there's a breakpoint under the pc. If we have an operating system 590 // plug-in, we might have set a thread specific breakpoint using the 591 // operating system thread ID, so we can't make any assumptions about 592 // the thread ID so we must always report the breakpoint regardless 593 // of the thread. 594 if (bp_site_sp->ValidForThisThread(&thread) || 595 thread.GetProcess()->GetOperatingSystem() != NULL) 596 return StopInfo::CreateStopReasonWithBreakpointSiteID( 597 thread, bp_site_sp->GetID()); 598 else if (is_trace_if_actual_breakpoint_missing) 599 return StopInfo::CreateStopReasonToTrace(thread); 600 else 601 return StopInfoSP(); 602 } 603 604 // Don't call this a trace if we weren't single stepping this thread. 605 if (is_trace_if_actual_breakpoint_missing && 606 thread.GetTemporaryResumeState() == eStateStepping) { 607 return StopInfo::CreateStopReasonToTrace(thread); 608 } 609 } 610 } break; 611 612 case 7: // EXC_SYSCALL 613 case 8: // EXC_MACH_SYSCALL 614 case 9: // EXC_RPC_ALERT 615 case 10: // EXC_CRASH 616 break; 617 } 618 619 return StopInfoSP(new StopInfoMachException( 620 thread, exc_type, exc_data_count, exc_code, exc_sub_code)); 621 } 622 return StopInfoSP(); 623 } 624