| File: | build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/lldb/source/Plugins/Process/Utility/StopInfoMachException.cpp |
| Warning: | line 639, column 9 Value stored to 'is_actual_breakpoint' is never read |
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| 1 | //===-- StopInfoMachException.cpp -----------------------------------------===// |
| 2 | // |
| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| 4 | // See https://llvm.org/LICENSE.txt for license information. |
| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| 6 | // |
| 7 | //===----------------------------------------------------------------------===// |
| 8 | |
| 9 | #include "StopInfoMachException.h" |
| 10 | |
| 11 | #include "lldb/lldb-forward.h" |
| 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/ABI.h" |
| 21 | #include "lldb/Target/DynamicLoader.h" |
| 22 | #include "lldb/Target/ExecutionContext.h" |
| 23 | #include "lldb/Target/Process.h" |
| 24 | #include "lldb/Target/RegisterContext.h" |
| 25 | #include "lldb/Target/Target.h" |
| 26 | #include "lldb/Target/Thread.h" |
| 27 | #include "lldb/Target/ThreadPlan.h" |
| 28 | #include "lldb/Target/UnixSignals.h" |
| 29 | #include "lldb/Utility/StreamString.h" |
| 30 | |
| 31 | using namespace lldb; |
| 32 | using namespace lldb_private; |
| 33 | |
| 34 | /// Information about a pointer-authentication related instruction. |
| 35 | struct PtrauthInstructionInfo { |
| 36 | bool IsAuthenticated; |
| 37 | bool IsLoad; |
| 38 | bool DoesBranch; |
| 39 | }; |
| 40 | |
| 41 | /// Get any pointer-authentication related information about the instruction |
| 42 | /// at address \p at_addr. |
| 43 | static llvm::Optional<PtrauthInstructionInfo> |
| 44 | GetPtrauthInstructionInfo(Target &target, const ArchSpec &arch, |
| 45 | const Address &at_addr) { |
| 46 | const char *plugin_name = nullptr; |
| 47 | const char *flavor = nullptr; |
| 48 | AddressRange range_bounds(at_addr, 4); |
| 49 | const bool prefer_file_cache = true; |
| 50 | DisassemblerSP disassembler_sp = Disassembler::DisassembleRange( |
| 51 | arch, plugin_name, flavor, target, range_bounds, prefer_file_cache); |
| 52 | if (!disassembler_sp) |
| 53 | return llvm::None; |
| 54 | |
| 55 | InstructionList &insn_list = disassembler_sp->GetInstructionList(); |
| 56 | InstructionSP insn = insn_list.GetInstructionAtIndex(0); |
| 57 | if (!insn) |
| 58 | return llvm::None; |
| 59 | |
| 60 | return PtrauthInstructionInfo{insn->IsAuthenticated(), insn->IsLoad(), |
| 61 | insn->DoesBranch()}; |
| 62 | } |
| 63 | |
| 64 | /// Describe the load address of \p addr using the format filename:line:col. |
| 65 | static void DescribeAddressBriefly(Stream &strm, const Address &addr, |
| 66 | Target &target) { |
| 67 | strm.Printf("at address=0x%" PRIx64"l" "x", addr.GetLoadAddress(&target)); |
| 68 | StreamString s; |
| 69 | if (addr.GetDescription(s, target, eDescriptionLevelBrief)) |
| 70 | strm.Printf(" %s", s.GetString().data()); |
| 71 | strm.Printf(".\n"); |
| 72 | } |
| 73 | |
| 74 | bool StopInfoMachException::DeterminePtrauthFailure(ExecutionContext &exe_ctx) { |
| 75 | bool IsBreakpoint = m_value == 6; // EXC_BREAKPOINT |
| 76 | bool IsBadAccess = m_value == 1; // EXC_BAD_ACCESS |
| 77 | if (!IsBreakpoint && !IsBadAccess) |
| 78 | return false; |
| 79 | |
| 80 | // Check that we have a live process. |
| 81 | if (!exe_ctx.HasProcessScope() || !exe_ctx.HasThreadScope() || |
| 82 | !exe_ctx.HasTargetScope()) |
| 83 | return false; |
| 84 | |
| 85 | Thread &thread = *exe_ctx.GetThreadPtr(); |
| 86 | StackFrameSP current_frame = thread.GetStackFrameAtIndex(0); |
| 87 | if (!current_frame) |
| 88 | return false; |
| 89 | |
| 90 | Target &target = *exe_ctx.GetTargetPtr(); |
| 91 | Process &process = *exe_ctx.GetProcessPtr(); |
| 92 | ABISP abi_sp = process.GetABI(); |
| 93 | const ArchSpec &arch = target.GetArchitecture(); |
| 94 | assert(abi_sp && "Missing ABI info")(static_cast <bool> (abi_sp && "Missing ABI info" ) ? void (0) : __assert_fail ("abi_sp && \"Missing ABI info\"" , "lldb/source/Plugins/Process/Utility/StopInfoMachException.cpp" , 94, __extension__ __PRETTY_FUNCTION__)); |
| 95 | |
| 96 | // Check for a ptrauth-enabled target. |
| 97 | const bool ptrauth_enabled_target = |
| 98 | arch.GetCore() == ArchSpec::eCore_arm_arm64e; |
| 99 | if (!ptrauth_enabled_target) |
| 100 | return false; |
| 101 | |
| 102 | // Set up a stream we can write a diagnostic into. |
| 103 | StreamString strm; |
| 104 | auto emit_ptrauth_prologue = [&](uint64_t at_address) { |
| 105 | strm.Printf("EXC_BAD_ACCESS (code=%" PRIu64"l" "u" ", address=0x%" PRIx64"l" "x" ")\n", |
| 106 | m_exc_code, at_address); |
| 107 | strm.Printf("Note: Possible pointer authentication failure detected.\n"); |
| 108 | }; |
| 109 | |
| 110 | // Check if we have a "brk 0xc47x" trap, where the value that failed to |
| 111 | // authenticate is in x16. |
| 112 | Address current_address = current_frame->GetFrameCodeAddress(); |
| 113 | if (IsBreakpoint) { |
| 114 | RegisterContext *reg_ctx = exe_ctx.GetRegisterContext(); |
| 115 | if (!reg_ctx) |
| 116 | return false; |
| 117 | |
| 118 | const RegisterInfo *X16Info = reg_ctx->GetRegisterInfoByName("x16"); |
| 119 | RegisterValue X16Val; |
| 120 | if (!reg_ctx->ReadRegister(X16Info, X16Val)) |
| 121 | return false; |
| 122 | uint64_t bad_address = X16Val.GetAsUInt64(); |
| 123 | |
| 124 | uint64_t fixed_bad_address = abi_sp->FixCodeAddress(bad_address); |
| 125 | Address brk_address; |
| 126 | if (!target.ResolveLoadAddress(fixed_bad_address, brk_address)) |
| 127 | return false; |
| 128 | |
| 129 | auto brk_ptrauth_info = |
| 130 | GetPtrauthInstructionInfo(target, arch, current_address); |
| 131 | if (brk_ptrauth_info && brk_ptrauth_info->IsAuthenticated) { |
| 132 | emit_ptrauth_prologue(bad_address); |
| 133 | strm.Printf("Found value that failed to authenticate "); |
| 134 | DescribeAddressBriefly(strm, brk_address, target); |
| 135 | m_description = std::string(strm.GetString()); |
| 136 | return true; |
| 137 | } |
| 138 | return false; |
| 139 | } |
| 140 | |
| 141 | assert(IsBadAccess && "Handle EXC_BAD_ACCESS only after this point")(static_cast <bool> (IsBadAccess && "Handle EXC_BAD_ACCESS only after this point" ) ? void (0) : __assert_fail ("IsBadAccess && \"Handle EXC_BAD_ACCESS only after this point\"" , "lldb/source/Plugins/Process/Utility/StopInfoMachException.cpp" , 141, __extension__ __PRETTY_FUNCTION__)); |
| 142 | |
| 143 | // Check that we have the "bad address" from an EXC_BAD_ACCESS. |
| 144 | if (m_exc_data_count < 2) |
| 145 | return false; |
| 146 | |
| 147 | // Ok, we know the Target is valid and that it describes a ptrauth-enabled |
| 148 | // device. Now, we need to determine whether this exception was caused by a |
| 149 | // ptrauth failure. |
| 150 | |
| 151 | uint64_t bad_address = m_exc_subcode; |
| 152 | uint64_t fixed_bad_address = abi_sp->FixCodeAddress(bad_address); |
| 153 | uint64_t current_pc = current_address.GetLoadAddress(&target); |
| 154 | |
| 155 | // Detect: LDRAA, LDRAB (Load Register, with pointer authentication). |
| 156 | // |
| 157 | // If an authenticated load results in an exception, the instruction at the |
| 158 | // current PC should be one of LDRAx. |
| 159 | if (bad_address != current_pc && fixed_bad_address != current_pc) { |
| 160 | auto ptrauth_info = |
| 161 | GetPtrauthInstructionInfo(target, arch, current_address); |
| 162 | if (ptrauth_info && ptrauth_info->IsAuthenticated && ptrauth_info->IsLoad) { |
| 163 | emit_ptrauth_prologue(bad_address); |
| 164 | strm.Printf("Found authenticated load instruction "); |
| 165 | DescribeAddressBriefly(strm, current_address, target); |
| 166 | m_description = std::string(strm.GetString()); |
| 167 | return true; |
| 168 | } |
| 169 | } |
| 170 | |
| 171 | // Detect: BLRAA, BLRAAZ, BLRAB, BLRABZ (Branch with Link to Register, with |
| 172 | // pointer authentication). |
| 173 | // |
| 174 | // TODO: Detect: BRAA, BRAAZ, BRAB, BRABZ (Branch to Register, with pointer |
| 175 | // authentication). At a minimum, this requires call site info support for |
| 176 | // indirect calls. |
| 177 | // |
| 178 | // If an authenticated call or tail call results in an exception, stripping |
| 179 | // the bad address should give the current PC, which points to the address |
| 180 | // we tried to branch to. |
| 181 | if (bad_address != current_pc && fixed_bad_address == current_pc) { |
| 182 | if (StackFrameSP parent_frame = thread.GetStackFrameAtIndex(1)) { |
| 183 | addr_t return_pc = |
| 184 | parent_frame->GetFrameCodeAddress().GetLoadAddress(&target); |
| 185 | Address blr_address; |
| 186 | if (!target.ResolveLoadAddress(return_pc - 4, blr_address)) |
| 187 | return false; |
| 188 | |
| 189 | auto blr_ptrauth_info = |
| 190 | GetPtrauthInstructionInfo(target, arch, blr_address); |
| 191 | if (blr_ptrauth_info && blr_ptrauth_info->IsAuthenticated && |
| 192 | blr_ptrauth_info->DoesBranch) { |
| 193 | emit_ptrauth_prologue(bad_address); |
| 194 | strm.Printf("Found authenticated indirect branch "); |
| 195 | DescribeAddressBriefly(strm, blr_address, target); |
| 196 | m_description = std::string(strm.GetString()); |
| 197 | return true; |
| 198 | } |
| 199 | } |
| 200 | } |
| 201 | |
| 202 | // TODO: Detect: RETAA, RETAB (Return from subroutine, with pointer |
| 203 | // authentication). |
| 204 | // |
| 205 | // Is there a motivating, non-malicious code snippet that corrupts LR? |
| 206 | |
| 207 | return false; |
| 208 | } |
| 209 | |
| 210 | const char *StopInfoMachException::GetDescription() { |
| 211 | if (!m_description.empty()) |
| 212 | return m_description.c_str(); |
| 213 | if (GetValue() == eStopReasonInvalid) |
| 214 | return "invalid stop reason!"; |
| 215 | |
| 216 | ExecutionContext exe_ctx(m_thread_wp.lock()); |
| 217 | Target *target = exe_ctx.GetTargetPtr(); |
| 218 | const llvm::Triple::ArchType cpu = |
| 219 | target ? target->GetArchitecture().GetMachine() |
| 220 | : llvm::Triple::UnknownArch; |
| 221 | |
| 222 | const char *exc_desc = nullptr; |
| 223 | const char *code_label = "code"; |
| 224 | const char *code_desc = nullptr; |
| 225 | const char *subcode_label = "subcode"; |
| 226 | const char *subcode_desc = nullptr; |
| 227 | |
| 228 | #if defined(__APPLE__) |
| 229 | char code_desc_buf[32]; |
| 230 | char subcode_desc_buf[32]; |
| 231 | #endif |
| 232 | |
| 233 | switch (m_value) { |
| 234 | case 1: // EXC_BAD_ACCESS |
| 235 | exc_desc = "EXC_BAD_ACCESS"; |
| 236 | subcode_label = "address"; |
| 237 | switch (cpu) { |
| 238 | case llvm::Triple::x86: |
| 239 | case llvm::Triple::x86_64: |
| 240 | switch (m_exc_code) { |
| 241 | case 0xd: |
| 242 | code_desc = "EXC_I386_GPFLT"; |
| 243 | m_exc_data_count = 1; |
| 244 | break; |
| 245 | } |
| 246 | break; |
| 247 | case llvm::Triple::arm: |
| 248 | case llvm::Triple::thumb: |
| 249 | switch (m_exc_code) { |
| 250 | case 0x101: |
| 251 | code_desc = "EXC_ARM_DA_ALIGN"; |
| 252 | break; |
| 253 | case 0x102: |
| 254 | code_desc = "EXC_ARM_DA_DEBUG"; |
| 255 | break; |
| 256 | } |
| 257 | break; |
| 258 | |
| 259 | case llvm::Triple::aarch64: |
| 260 | if (DeterminePtrauthFailure(exe_ctx)) |
| 261 | return m_description.c_str(); |
| 262 | break; |
| 263 | |
| 264 | default: |
| 265 | break; |
| 266 | } |
| 267 | break; |
| 268 | |
| 269 | case 2: // EXC_BAD_INSTRUCTION |
| 270 | exc_desc = "EXC_BAD_INSTRUCTION"; |
| 271 | switch (cpu) { |
| 272 | case llvm::Triple::x86: |
| 273 | case llvm::Triple::x86_64: |
| 274 | if (m_exc_code == 1) |
| 275 | code_desc = "EXC_I386_INVOP"; |
| 276 | break; |
| 277 | |
| 278 | case llvm::Triple::arm: |
| 279 | case llvm::Triple::thumb: |
| 280 | if (m_exc_code == 1) |
| 281 | code_desc = "EXC_ARM_UNDEFINED"; |
| 282 | break; |
| 283 | |
| 284 | default: |
| 285 | break; |
| 286 | } |
| 287 | break; |
| 288 | |
| 289 | case 3: // EXC_ARITHMETIC |
| 290 | exc_desc = "EXC_ARITHMETIC"; |
| 291 | switch (cpu) { |
| 292 | case llvm::Triple::x86: |
| 293 | case llvm::Triple::x86_64: |
| 294 | switch (m_exc_code) { |
| 295 | case 1: |
| 296 | code_desc = "EXC_I386_DIV"; |
| 297 | break; |
| 298 | case 2: |
| 299 | code_desc = "EXC_I386_INTO"; |
| 300 | break; |
| 301 | case 3: |
| 302 | code_desc = "EXC_I386_NOEXT"; |
| 303 | break; |
| 304 | case 4: |
| 305 | code_desc = "EXC_I386_EXTOVR"; |
| 306 | break; |
| 307 | case 5: |
| 308 | code_desc = "EXC_I386_EXTERR"; |
| 309 | break; |
| 310 | case 6: |
| 311 | code_desc = "EXC_I386_EMERR"; |
| 312 | break; |
| 313 | case 7: |
| 314 | code_desc = "EXC_I386_BOUND"; |
| 315 | break; |
| 316 | case 8: |
| 317 | code_desc = "EXC_I386_SSEEXTERR"; |
| 318 | break; |
| 319 | } |
| 320 | break; |
| 321 | |
| 322 | default: |
| 323 | break; |
| 324 | } |
| 325 | break; |
| 326 | |
| 327 | case 4: // EXC_EMULATION |
| 328 | exc_desc = "EXC_EMULATION"; |
| 329 | break; |
| 330 | |
| 331 | case 5: // EXC_SOFTWARE |
| 332 | exc_desc = "EXC_SOFTWARE"; |
| 333 | if (m_exc_code == 0x10003) { |
| 334 | subcode_desc = "EXC_SOFT_SIGNAL"; |
| 335 | subcode_label = "signo"; |
| 336 | } |
| 337 | break; |
| 338 | |
| 339 | case 6: // EXC_BREAKPOINT |
| 340 | { |
| 341 | exc_desc = "EXC_BREAKPOINT"; |
| 342 | switch (cpu) { |
| 343 | case llvm::Triple::x86: |
| 344 | case llvm::Triple::x86_64: |
| 345 | switch (m_exc_code) { |
| 346 | case 1: |
| 347 | code_desc = "EXC_I386_SGL"; |
| 348 | break; |
| 349 | case 2: |
| 350 | code_desc = "EXC_I386_BPT"; |
| 351 | break; |
| 352 | } |
| 353 | break; |
| 354 | |
| 355 | case llvm::Triple::arm: |
| 356 | case llvm::Triple::thumb: |
| 357 | switch (m_exc_code) { |
| 358 | case 0x101: |
| 359 | code_desc = "EXC_ARM_DA_ALIGN"; |
| 360 | break; |
| 361 | case 0x102: |
| 362 | code_desc = "EXC_ARM_DA_DEBUG"; |
| 363 | break; |
| 364 | case 1: |
| 365 | code_desc = "EXC_ARM_BREAKPOINT"; |
| 366 | break; |
| 367 | // FIXME temporary workaround, exc_code 0 does not really mean |
| 368 | // EXC_ARM_BREAKPOINT |
| 369 | case 0: |
| 370 | code_desc = "EXC_ARM_BREAKPOINT"; |
| 371 | break; |
| 372 | } |
| 373 | break; |
| 374 | |
| 375 | case llvm::Triple::aarch64: |
| 376 | if (DeterminePtrauthFailure(exe_ctx)) |
| 377 | return m_description.c_str(); |
| 378 | break; |
| 379 | |
| 380 | default: |
| 381 | break; |
| 382 | } |
| 383 | } break; |
| 384 | |
| 385 | case 7: |
| 386 | exc_desc = "EXC_SYSCALL"; |
| 387 | break; |
| 388 | |
| 389 | case 8: |
| 390 | exc_desc = "EXC_MACH_SYSCALL"; |
| 391 | break; |
| 392 | |
| 393 | case 9: |
| 394 | exc_desc = "EXC_RPC_ALERT"; |
| 395 | break; |
| 396 | |
| 397 | case 10: |
| 398 | exc_desc = "EXC_CRASH"; |
| 399 | break; |
| 400 | case 11: |
| 401 | exc_desc = "EXC_RESOURCE"; |
| 402 | #if defined(__APPLE__) |
| 403 | { |
| 404 | int resource_type = EXC_RESOURCE_DECODE_RESOURCE_TYPE(m_exc_code); |
| 405 | |
| 406 | code_label = "limit"; |
| 407 | code_desc = code_desc_buf; |
| 408 | subcode_label = "observed"; |
| 409 | subcode_desc = subcode_desc_buf; |
| 410 | |
| 411 | switch (resource_type) { |
| 412 | case RESOURCE_TYPE_CPU: |
| 413 | exc_desc = "EXC_RESOURCE RESOURCE_TYPE_CPU"; |
| 414 | snprintf(code_desc_buf, sizeof(code_desc_buf), "%d%%", |
| 415 | (int)EXC_RESOURCE_CPUMONITOR_DECODE_PERCENTAGE(m_exc_code)); |
| 416 | snprintf(subcode_desc_buf, sizeof(subcode_desc_buf), "%d%%", |
| 417 | (int)EXC_RESOURCE_CPUMONITOR_DECODE_PERCENTAGE_OBSERVED( |
| 418 | m_exc_subcode)); |
| 419 | break; |
| 420 | case RESOURCE_TYPE_WAKEUPS: |
| 421 | exc_desc = "EXC_RESOURCE RESOURCE_TYPE_WAKEUPS"; |
| 422 | snprintf( |
| 423 | code_desc_buf, sizeof(code_desc_buf), "%d w/s", |
| 424 | (int)EXC_RESOURCE_CPUMONITOR_DECODE_WAKEUPS_PERMITTED(m_exc_code)); |
| 425 | snprintf(subcode_desc_buf, sizeof(subcode_desc_buf), "%d w/s", |
| 426 | (int)EXC_RESOURCE_CPUMONITOR_DECODE_WAKEUPS_OBSERVED( |
| 427 | m_exc_subcode)); |
| 428 | break; |
| 429 | case RESOURCE_TYPE_MEMORY: |
| 430 | exc_desc = "EXC_RESOURCE RESOURCE_TYPE_MEMORY"; |
| 431 | snprintf(code_desc_buf, sizeof(code_desc_buf), "%d MB", |
| 432 | (int)EXC_RESOURCE_HWM_DECODE_LIMIT(m_exc_code)); |
| 433 | subcode_desc = nullptr; |
| 434 | subcode_label = "unused"; |
| 435 | break; |
| 436 | #if defined(RESOURCE_TYPE_IO) |
| 437 | // RESOURCE_TYPE_IO is introduced in macOS SDK 10.12. |
| 438 | case RESOURCE_TYPE_IO: |
| 439 | exc_desc = "EXC_RESOURCE RESOURCE_TYPE_IO"; |
| 440 | snprintf(code_desc_buf, sizeof(code_desc_buf), "%d MB", |
| 441 | (int)EXC_RESOURCE_IO_DECODE_LIMIT(m_exc_code)); |
| 442 | snprintf(subcode_desc_buf, sizeof(subcode_desc_buf), "%d MB", |
| 443 | (int)EXC_RESOURCE_IO_OBSERVED(m_exc_subcode)); |
| 444 | ; |
| 445 | break; |
| 446 | #endif |
| 447 | } |
| 448 | } |
| 449 | #endif |
| 450 | break; |
| 451 | case 12: |
| 452 | exc_desc = "EXC_GUARD"; |
| 453 | break; |
| 454 | } |
| 455 | |
| 456 | StreamString strm; |
| 457 | |
| 458 | if (exc_desc) |
| 459 | strm.PutCString(exc_desc); |
| 460 | else |
| 461 | strm.Printf("EXC_??? (%" PRIu64"l" "u" ")", m_value); |
| 462 | |
| 463 | if (m_exc_data_count >= 1) { |
| 464 | if (code_desc) |
| 465 | strm.Printf(" (%s=%s", code_label, code_desc); |
| 466 | else |
| 467 | strm.Printf(" (%s=%" PRIu64"l" "u", code_label, m_exc_code); |
| 468 | } |
| 469 | |
| 470 | if (m_exc_data_count >= 2) { |
| 471 | if (subcode_desc) |
| 472 | strm.Printf(", %s=%s", subcode_label, subcode_desc); |
| 473 | else |
| 474 | strm.Printf(", %s=0x%" PRIx64"l" "x", subcode_label, m_exc_subcode); |
| 475 | } |
| 476 | |
| 477 | if (m_exc_data_count > 0) |
| 478 | strm.PutChar(')'); |
| 479 | |
| 480 | m_description = std::string(strm.GetString()); |
| 481 | return m_description.c_str(); |
| 482 | } |
| 483 | |
| 484 | static StopInfoSP GetStopInfoForHardwareBP(Thread &thread, Target *target, |
| 485 | uint32_t exc_data_count, |
| 486 | uint64_t exc_sub_code, |
| 487 | uint64_t exc_sub_sub_code) { |
| 488 | // Try hardware watchpoint. |
| 489 | if (target) { |
| 490 | // The exc_sub_code indicates the data break address. |
| 491 | lldb::WatchpointSP wp_sp = |
| 492 | target->GetWatchpointList().FindByAddress((lldb::addr_t)exc_sub_code); |
| 493 | if (wp_sp && wp_sp->IsEnabled()) { |
| 494 | // Debugserver may piggyback the hardware index of the fired watchpoint |
| 495 | // in the exception data. Set the hardware index if that's the case. |
| 496 | if (exc_data_count >= 3) |
| 497 | wp_sp->SetHardwareIndex((uint32_t)exc_sub_sub_code); |
| 498 | return StopInfo::CreateStopReasonWithWatchpointID(thread, wp_sp->GetID()); |
| 499 | } |
| 500 | } |
| 501 | |
| 502 | // Try hardware breakpoint. |
| 503 | ProcessSP process_sp(thread.GetProcess()); |
| 504 | if (process_sp) { |
| 505 | // The exc_sub_code indicates the data break address. |
| 506 | lldb::BreakpointSiteSP bp_sp = |
| 507 | process_sp->GetBreakpointSiteList().FindByAddress( |
| 508 | (lldb::addr_t)exc_sub_code); |
| 509 | if (bp_sp && bp_sp->IsEnabled()) { |
| 510 | // Debugserver may piggyback the hardware index of the fired breakpoint |
| 511 | // in the exception data. Set the hardware index if that's the case. |
| 512 | if (exc_data_count >= 3) |
| 513 | bp_sp->SetHardwareIndex((uint32_t)exc_sub_sub_code); |
| 514 | return StopInfo::CreateStopReasonWithBreakpointSiteID(thread, |
| 515 | bp_sp->GetID()); |
| 516 | } |
| 517 | } |
| 518 | |
| 519 | return nullptr; |
| 520 | } |
| 521 | |
| 522 | StopInfoSP StopInfoMachException::CreateStopReasonWithMachException( |
| 523 | Thread &thread, uint32_t exc_type, uint32_t exc_data_count, |
| 524 | uint64_t exc_code, uint64_t exc_sub_code, uint64_t exc_sub_sub_code, |
| 525 | bool pc_already_adjusted, bool adjust_pc_if_needed) { |
| 526 | if (exc_type == 0) |
| 527 | return StopInfoSP(); |
| 528 | |
| 529 | uint32_t pc_decrement = 0; |
| 530 | ExecutionContext exe_ctx(thread.shared_from_this()); |
| 531 | Target *target = exe_ctx.GetTargetPtr(); |
| 532 | const llvm::Triple::ArchType cpu = |
| 533 | target ? target->GetArchitecture().GetMachine() |
| 534 | : llvm::Triple::UnknownArch; |
| 535 | |
| 536 | switch (exc_type) { |
| 537 | case 1: // EXC_BAD_ACCESS |
| 538 | case 2: // EXC_BAD_INSTRUCTION |
| 539 | case 3: // EXC_ARITHMETIC |
| 540 | case 4: // EXC_EMULATION |
| 541 | break; |
| 542 | |
| 543 | case 5: // EXC_SOFTWARE |
| 544 | if (exc_code == 0x10003) // EXC_SOFT_SIGNAL |
| 545 | { |
| 546 | if (exc_sub_code == 5) { |
| 547 | // On MacOSX, a SIGTRAP can signify that a process has called exec, |
| 548 | // so we should check with our dynamic loader to verify. |
| 549 | ProcessSP process_sp(thread.GetProcess()); |
| 550 | if (process_sp) { |
| 551 | DynamicLoader *dynamic_loader = process_sp->GetDynamicLoader(); |
| 552 | if (dynamic_loader && dynamic_loader->ProcessDidExec()) { |
| 553 | // The program was re-exec'ed |
| 554 | return StopInfo::CreateStopReasonWithExec(thread); |
| 555 | } |
| 556 | } |
| 557 | } |
| 558 | return StopInfo::CreateStopReasonWithSignal(thread, exc_sub_code); |
| 559 | } |
| 560 | break; |
| 561 | |
| 562 | case 6: // EXC_BREAKPOINT |
| 563 | { |
| 564 | bool is_actual_breakpoint = false; |
| 565 | bool is_trace_if_actual_breakpoint_missing = false; |
| 566 | switch (cpu) { |
| 567 | case llvm::Triple::x86: |
| 568 | case llvm::Triple::x86_64: |
| 569 | if (exc_code == 1) // EXC_I386_SGL |
| 570 | { |
| 571 | if (!exc_sub_code) { |
| 572 | // This looks like a plain trap. |
| 573 | // Have to check if there is a breakpoint here as well. When you |
| 574 | // single-step onto a trap, the single step stops you not to trap. |
| 575 | // Since we also do that check below, let's just use that logic. |
| 576 | is_actual_breakpoint = true; |
| 577 | is_trace_if_actual_breakpoint_missing = true; |
| 578 | } else { |
| 579 | if (StopInfoSP stop_info = |
| 580 | GetStopInfoForHardwareBP(thread, target, exc_data_count, |
| 581 | exc_sub_code, exc_sub_sub_code)) |
| 582 | return stop_info; |
| 583 | } |
| 584 | } else if (exc_code == 2 || // EXC_I386_BPT |
| 585 | exc_code == 3) // EXC_I386_BPTFLT |
| 586 | { |
| 587 | // KDP returns EXC_I386_BPTFLT for trace breakpoints |
| 588 | if (exc_code == 3) |
| 589 | is_trace_if_actual_breakpoint_missing = true; |
| 590 | |
| 591 | is_actual_breakpoint = true; |
| 592 | if (!pc_already_adjusted) |
| 593 | pc_decrement = 1; |
| 594 | } |
| 595 | break; |
| 596 | |
| 597 | case llvm::Triple::arm: |
| 598 | case llvm::Triple::thumb: |
| 599 | if (exc_code == 0x102) // EXC_ARM_DA_DEBUG |
| 600 | { |
| 601 | // It's a watchpoint, then, if the exc_sub_code indicates a |
| 602 | // known/enabled data break address from our watchpoint list. |
| 603 | lldb::WatchpointSP wp_sp; |
| 604 | if (target) |
| 605 | wp_sp = target->GetWatchpointList().FindByAddress( |
| 606 | (lldb::addr_t)exc_sub_code); |
| 607 | if (wp_sp && wp_sp->IsEnabled()) { |
| 608 | // Debugserver may piggyback the hardware index of the fired |
| 609 | // watchpoint in the exception data. Set the hardware index if |
| 610 | // that's the case. |
| 611 | if (exc_data_count >= 3) |
| 612 | wp_sp->SetHardwareIndex((uint32_t)exc_sub_sub_code); |
| 613 | return StopInfo::CreateStopReasonWithWatchpointID(thread, |
| 614 | wp_sp->GetID()); |
| 615 | } else { |
| 616 | is_actual_breakpoint = true; |
| 617 | is_trace_if_actual_breakpoint_missing = true; |
| 618 | } |
| 619 | } else if (exc_code == 1) // EXC_ARM_BREAKPOINT |
| 620 | { |
| 621 | is_actual_breakpoint = true; |
| 622 | is_trace_if_actual_breakpoint_missing = true; |
| 623 | } else if (exc_code == 0) // FIXME not EXC_ARM_BREAKPOINT but a kernel |
| 624 | // is currently returning this so accept it |
| 625 | // as indicating a breakpoint until the |
| 626 | // kernel is fixed |
| 627 | { |
| 628 | is_actual_breakpoint = true; |
| 629 | is_trace_if_actual_breakpoint_missing = true; |
| 630 | } |
| 631 | break; |
| 632 | |
| 633 | case llvm::Triple::aarch64_32: |
| 634 | case llvm::Triple::aarch64: { |
| 635 | if (exc_code == 1 && exc_sub_code == 0) // EXC_ARM_BREAKPOINT |
| 636 | { |
| 637 | // This is hit when we single instruction step aka MDSCR_EL1 SS bit 0 |
| 638 | // is set |
| 639 | is_actual_breakpoint = false; |
Value stored to 'is_actual_breakpoint' is never read | |
| 640 | is_trace_if_actual_breakpoint_missing = true; |
| 641 | } |
| 642 | if (exc_code == 0x102) // EXC_ARM_DA_DEBUG |
| 643 | { |
| 644 | // It's a watchpoint, then, if the exc_sub_code indicates a |
| 645 | // known/enabled data break address from our watchpoint list. |
| 646 | lldb::WatchpointSP wp_sp; |
| 647 | if (target) |
| 648 | wp_sp = target->GetWatchpointList().FindByAddress( |
| 649 | (lldb::addr_t)exc_sub_code); |
| 650 | if (wp_sp && wp_sp->IsEnabled()) { |
| 651 | // Debugserver may piggyback the hardware index of the fired |
| 652 | // watchpoint in the exception data. Set the hardware index if |
| 653 | // that's the case. |
| 654 | if (exc_data_count >= 3) |
| 655 | wp_sp->SetHardwareIndex((uint32_t)exc_sub_sub_code); |
| 656 | return StopInfo::CreateStopReasonWithWatchpointID(thread, |
| 657 | wp_sp->GetID()); |
| 658 | } |
| 659 | // EXC_ARM_DA_DEBUG seems to be reused for EXC_BREAKPOINT as well as |
| 660 | // EXC_BAD_ACCESS |
| 661 | if (thread.GetTemporaryResumeState() == eStateStepping) |
| 662 | return StopInfo::CreateStopReasonToTrace(thread); |
| 663 | } |
| 664 | // It looks like exc_sub_code has the 4 bytes of the instruction that |
| 665 | // triggered the exception, i.e. our breakpoint opcode |
| 666 | is_actual_breakpoint = exc_code == 1; |
| 667 | break; |
| 668 | } |
| 669 | |
| 670 | default: |
| 671 | break; |
| 672 | } |
| 673 | |
| 674 | if (is_actual_breakpoint) { |
| 675 | RegisterContextSP reg_ctx_sp(thread.GetRegisterContext()); |
| 676 | addr_t pc = reg_ctx_sp->GetPC() - pc_decrement; |
| 677 | |
| 678 | ProcessSP process_sp(thread.CalculateProcess()); |
| 679 | |
| 680 | lldb::BreakpointSiteSP bp_site_sp; |
| 681 | if (process_sp) |
| 682 | bp_site_sp = process_sp->GetBreakpointSiteList().FindByAddress(pc); |
| 683 | if (bp_site_sp && bp_site_sp->IsEnabled()) { |
| 684 | // Update the PC if we were asked to do so, but only do so if we find |
| 685 | // a breakpoint that we know about cause this could be a trap |
| 686 | // instruction in the code |
| 687 | if (pc_decrement > 0 && adjust_pc_if_needed) |
| 688 | reg_ctx_sp->SetPC(pc); |
| 689 | |
| 690 | // If the breakpoint is for this thread, then we'll report the hit, |
| 691 | // but if it is for another thread, we can just report no reason. We |
| 692 | // don't need to worry about stepping over the breakpoint here, that |
| 693 | // will be taken care of when the thread resumes and notices that |
| 694 | // there's a breakpoint under the pc. If we have an operating system |
| 695 | // plug-in, we might have set a thread specific breakpoint using the |
| 696 | // operating system thread ID, so we can't make any assumptions about |
| 697 | // the thread ID so we must always report the breakpoint regardless |
| 698 | // of the thread. |
| 699 | if (bp_site_sp->ValidForThisThread(thread) || |
| 700 | thread.GetProcess()->GetOperatingSystem() != nullptr) |
| 701 | return StopInfo::CreateStopReasonWithBreakpointSiteID( |
| 702 | thread, bp_site_sp->GetID()); |
| 703 | else if (is_trace_if_actual_breakpoint_missing) |
| 704 | return StopInfo::CreateStopReasonToTrace(thread); |
| 705 | else |
| 706 | return StopInfoSP(); |
| 707 | } |
| 708 | |
| 709 | // Don't call this a trace if we weren't single stepping this thread. |
| 710 | if (is_trace_if_actual_breakpoint_missing && |
| 711 | thread.GetTemporaryResumeState() == eStateStepping) { |
| 712 | return StopInfo::CreateStopReasonToTrace(thread); |
| 713 | } |
| 714 | } |
| 715 | } break; |
| 716 | |
| 717 | case 7: // EXC_SYSCALL |
| 718 | case 8: // EXC_MACH_SYSCALL |
| 719 | case 9: // EXC_RPC_ALERT |
| 720 | case 10: // EXC_CRASH |
| 721 | break; |
| 722 | } |
| 723 | |
| 724 | return StopInfoSP(new StopInfoMachException(thread, exc_type, exc_data_count, |
| 725 | exc_code, exc_sub_code)); |
| 726 | } |