lldb/source/Plugins/Platform/Linux/PlatformLinux.cpp

   1 //===-- PlatformLinux.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 "PlatformLinux.h"
  10 #include "lldb/Host/Config.h"
  11
  12 #include <cstdio>
  13 #if LLDB_ENABLE_POSIX
  14 #include <sys/utsname.h>
  15 #endif
  16
  17 #include "Utility/ARM64_DWARF_Registers.h"
  18 #include "lldb/Core/Debugger.h"
  19 #include "lldb/Core/PluginManager.h"
  20 #include "lldb/Host/HostInfo.h"
  21 #include "lldb/Symbol/UnwindPlan.h"
  22 #include "lldb/Target/Process.h"
  23 #include "lldb/Target/Target.h"
  24 #include "lldb/Utility/FileSpec.h"
  25 #include "lldb/Utility/LLDBLog.h"
  26 #include "lldb/Utility/Log.h"
  27 #include "lldb/Utility/State.h"
  28 #include "lldb/Utility/Status.h"
  29 #include "lldb/Utility/StreamString.h"
  30
  31 // Define these constants from Linux mman.h for use when targeting remote linux
  32 // systems even when host has different values.
  33 #define MAP_PRIVATE 2
  34 #define MAP_ANON 0x20
  35
  36 using namespace lldb;
  37 using namespace lldb_private;
  38 using namespace lldb_private::platform_linux;
  39
  40 LLDB_PLUGIN_DEFINE(PlatformLinux)
  41
  42 static uint32_t g_initialize_count = 0;
  43
  44
  45 PlatformSP PlatformLinux::CreateInstance(bool force, const ArchSpec *arch) {
  46   Log *log = GetLog(LLDBLog::Platform);
  47   LLDB_LOG(log, "force = {0}, arch=({1}, {2})", force,
  48            arch ? arch->GetArchitectureName() : "<null>",
  49            arch ? arch->GetTriple().getTriple() : "<null>");
  50
  51   bool create = force;
  52   if (!create && arch && arch->IsValid()) {
  53     const llvm::Triple &triple = arch->GetTriple();
  54     switch (triple.getOS()) {
  55     case llvm::Triple::Linux:
  56       create = true;
  57       break;
  58
  59 #if defined(__linux__)
  60     // Only accept "unknown" for the OS if the host is linux and it "unknown"
  61     // wasn't specified (it was just returned because it was NOT specified)
  62     case llvm::Triple::OSType::UnknownOS:
  63       create = !arch->TripleOSWasSpecified();
  64       break;
  65 #endif
  66     default:
  67       break;
  68     }
  69   }
  70
  71   LLDB_LOG(log, "create = {0}", create);
  72   if (create) {
  73     return PlatformSP(new PlatformLinux(false));
  74   }
  75   return PlatformSP();
  76 }
  77
  78 llvm::StringRef PlatformLinux::GetPluginDescriptionStatic(bool is_host) {
  79   if (is_host)
  80     return "Local Linux user platform plug-in.";
  81   return "Remote Linux user platform plug-in.";
  82 }
  83
  84 void PlatformLinux::Initialize() {
  85   PlatformPOSIX::Initialize();
  86
  87   if (g_initialize_count++ == 0) {
  88 #if defined(__linux__) && !defined(__ANDROID__)
  89     PlatformSP default_platform_sp(new PlatformLinux(true));
  90     default_platform_sp->SetSystemArchitecture(HostInfo::GetArchitecture());
  91     Platform::SetHostPlatform(default_platform_sp);
  92 #endif
  93     PluginManager::RegisterPlugin(
  94         PlatformLinux::GetPluginNameStatic(false),
  95         PlatformLinux::GetPluginDescriptionStatic(false),
  96         PlatformLinux::CreateInstance, nullptr);
  97   }
  98 }
  99
 100 void PlatformLinux::Terminate() {
 101   if (g_initialize_count > 0) {
 102     if (--g_initialize_count == 0) {
 103       PluginManager::UnregisterPlugin(PlatformLinux::CreateInstance);
 104     }
 105   }
 106
 107   PlatformPOSIX::Terminate();
 108 }
 109
 110 /// Default Constructor
 111 PlatformLinux::PlatformLinux(bool is_host)
 112     : PlatformPOSIX(is_host) // This is the local host platform
 113 {
 114   if (is_host) {
 115     ArchSpec hostArch = HostInfo::GetArchitecture(HostInfo::eArchKindDefault);
 116     m_supported_architectures.push_back(hostArch);
 117     if (hostArch.GetTriple().isArch64Bit()) {
 118       m_supported_architectures.push_back(
 119           HostInfo::GetArchitecture(HostInfo::eArchKind32));
 120     }
 121   } else {
 122     m_supported_architectures = CreateArchList(
 123         {llvm::Triple::x86_64, llvm::Triple::x86, llvm::Triple::arm,
 124          llvm::Triple::aarch64, llvm::Triple::mips64, llvm::Triple::mips64,
 125          llvm::Triple::hexagon, llvm::Triple::mips, llvm::Triple::mips64el,
 126          llvm::Triple::mipsel, llvm::Triple::msp430, llvm::Triple::systemz},
 127         llvm::Triple::Linux);
 128   }
 129 }
 130
 131 std::vector<ArchSpec>
 132 PlatformLinux::GetSupportedArchitectures(const ArchSpec &process_host_arch) {
 133   if (m_remote_platform_sp)
 134     return m_remote_platform_sp->GetSupportedArchitectures(process_host_arch);
 135   return m_supported_architectures;
 136 }
 137
 138 void PlatformLinux::GetStatus(Stream &strm) {
 139   Platform::GetStatus(strm);
 140
 141 #if LLDB_ENABLE_POSIX
 142   // Display local kernel information only when we are running in host mode.
 143   // Otherwise, we would end up printing non-Linux information (when running on
 144   // Mac OS for example).
 145   if (IsHost()) {
 146     struct utsname un;
 147
 148     if (uname(&un))
 149       return;
 150
 151     strm.Printf("    Kernel: %s\n", un.sysname);
 152     strm.Printf("   Release: %s\n", un.release);
 153     strm.Printf("   Version: %s\n", un.version);
 154   }
 155 #endif
 156 }
 157
 158 uint32_t
 159 PlatformLinux::GetResumeCountForLaunchInfo(ProcessLaunchInfo &launch_info) {
 160   uint32_t resume_count = 0;
 161
 162   // Always resume past the initial stop when we use eLaunchFlagDebug
 163   if (launch_info.GetFlags().Test(eLaunchFlagDebug)) {
 164     // Resume past the stop for the final exec into the true inferior.
 165     ++resume_count;
 166   }
 167
 168   // If we're not launching a shell, we're done.
 169   const FileSpec &shell = launch_info.GetShell();
 170   if (!shell)
 171     return resume_count;
 172
 173   std::string shell_string = shell.GetPath();
 174   // We're in a shell, so for sure we have to resume past the shell exec.
 175   ++resume_count;
 176
 177   // Figure out what shell we're planning on using.
 178   const char *shell_name = strrchr(shell_string.c_str(), '/');
 179   if (shell_name == nullptr)
 180     shell_name = shell_string.c_str();
 181   else
 182     shell_name++;
 183
 184   if (strcmp(shell_name, "csh") == 0 || strcmp(shell_name, "tcsh") == 0 ||
 185       strcmp(shell_name, "zsh") == 0 || strcmp(shell_name, "sh") == 0) {
 186     // These shells seem to re-exec themselves.  Add another resume.
 187     ++resume_count;
 188   }
 189
 190   return resume_count;
 191 }
 192
 193 bool PlatformLinux::CanDebugProcess() {
 194   if (IsHost()) {
 195     return true;
 196   } else {
 197     // If we're connected, we can debug.
 198     return IsConnected();
 199   }
 200 }
 201
 202 void PlatformLinux::CalculateTrapHandlerSymbolNames() {
 203   m_trap_handlers.push_back(ConstString("_sigtramp"));
 204   m_trap_handlers.push_back(ConstString("__kernel_rt_sigreturn"));
 205   m_trap_handlers.push_back(ConstString("__restore_rt"));
 206 }
 207
 208 static lldb::UnwindPlanSP GetAArch64TrapHandlerUnwindPlan(ConstString name) {
 209   UnwindPlanSP unwind_plan_sp;
 210   if (name != "__kernel_rt_sigreturn")
 211     return unwind_plan_sp;
 212
 213   UnwindPlan::RowSP row = std::make_shared<UnwindPlan::Row>();
 214   row->SetOffset(0);
 215
 216   // In the signal trampoline frame, sp points to an rt_sigframe[1], which is:
 217   //  - 128-byte siginfo struct
 218   //  - ucontext struct:
 219   //     - 8-byte long (uc_flags)
 220   //     - 8-byte pointer (uc_link)
 221   //     - 24-byte stack_t
 222   //     - 128-byte signal set
 223   //     - 8 bytes of padding because sigcontext has 16-byte alignment
 224   //     - sigcontext/mcontext_t
 225   // [1]
 226   // https://github.com/torvalds/linux/blob/master/arch/arm64/kernel/signal.c
 227   int32_t offset = 128 + 8 + 8 + 24 + 128 + 8;
 228   // Then sigcontext[2] is:
 229   // - 8 byte fault address
 230   // - 31 8 byte registers
 231   // - 8 byte sp
 232   // - 8 byte pc
 233   // [2]
 234   // https://github.com/torvalds/linux/blob/master/arch/arm64/include/uapi/asm/sigcontext.h
 235
 236   // Skip fault address
 237   offset += 8;
 238   row->GetCFAValue().SetIsRegisterPlusOffset(arm64_dwarf::sp, offset);
 239
 240   row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x0, 0 * 8, false);
 241   row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x1, 1 * 8, false);
 242   row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x2, 2 * 8, false);
 243   row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x3, 3 * 8, false);
 244   row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x4, 4 * 8, false);
 245   row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x5, 5 * 8, false);
 246   row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x6, 6 * 8, false);
 247   row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x7, 7 * 8, false);
 248   row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x8, 8 * 8, false);
 249   row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x9, 9 * 8, false);
 250   row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x10, 10 * 8, false);
 251   row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x11, 11 * 8, false);
 252   row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x12, 12 * 8, false);
 253   row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x13, 13 * 8, false);
 254   row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x14, 14 * 8, false);
 255   row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x15, 15 * 8, false);
 256   row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x16, 16 * 8, false);
 257   row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x17, 17 * 8, false);
 258   row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x18, 18 * 8, false);
 259   row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x19, 19 * 8, false);
 260   row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x20, 20 * 8, false);
 261   row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x21, 21 * 8, false);
 262   row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x22, 22 * 8, false);
 263   row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x23, 23 * 8, false);
 264   row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x24, 24 * 8, false);
 265   row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x25, 25 * 8, false);
 266   row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x26, 26 * 8, false);
 267   row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x27, 27 * 8, false);
 268   row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x28, 28 * 8, false);
 269   row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::fp, 29 * 8, false);
 270   row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::x30, 30 * 8, false);
 271   row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::sp, 31 * 8, false);
 272   row->SetRegisterLocationToAtCFAPlusOffset(arm64_dwarf::pc, 32 * 8, false);
 273
 274   // The sigcontext may also contain floating point and SVE registers.
 275   // However this would require a dynamic unwind plan so they are not included
 276   // here.
 277
 278   unwind_plan_sp = std::make_shared<UnwindPlan>(eRegisterKindDWARF);
 279   unwind_plan_sp->AppendRow(row);
 280   unwind_plan_sp->SetSourceName("AArch64 Linux sigcontext");
 281   unwind_plan_sp->SetSourcedFromCompiler(eLazyBoolYes);
 282   // Because sp is the same throughout the function
 283   unwind_plan_sp->SetUnwindPlanValidAtAllInstructions(eLazyBoolYes);
 284   unwind_plan_sp->SetUnwindPlanForSignalTrap(eLazyBoolYes);
 285
 286   return unwind_plan_sp;
 287 }
 288
 289 lldb::UnwindPlanSP
 290 PlatformLinux::GetTrapHandlerUnwindPlan(const llvm::Triple &triple,
 291                                         ConstString name) {
 292   if (triple.isAArch64())
 293     return GetAArch64TrapHandlerUnwindPlan(name);
 294
 295   return {};
 296 }
 297
 298 MmapArgList PlatformLinux::GetMmapArgumentList(const ArchSpec &arch,
 299                                                addr_t addr, addr_t length,
 300                                                unsigned prot, unsigned flags,
 301                                                addr_t fd, addr_t offset) {
 302   uint64_t flags_platform = 0;
 303   uint64_t map_anon = arch.IsMIPS() ? 0x800 : MAP_ANON;
 304
 305   if (flags & eMmapFlagsPrivate)
 306     flags_platform |= MAP_PRIVATE;
 307   if (flags & eMmapFlagsAnon)
 308     flags_platform |= map_anon;
 309
 310   MmapArgList args({addr, length, prot, flags_platform, fd, offset});
 311   return args;
 312 }
 313
 314 CompilerType PlatformLinux::GetSiginfoType(const llvm::Triple &triple) {
 315   {
 316     std::lock_guard<std::mutex> guard(m_mutex);
 317     if (!m_type_system)
 318       m_type_system = std::make_shared<TypeSystemClang>("siginfo", triple);
 319   }
 320   TypeSystemClang *ast = m_type_system.get();
 321
 322   bool si_errno_then_code = true;
 323
 324   switch (triple.getArch()) {
 325   case llvm::Triple::mips:
 326   case llvm::Triple::mipsel:
 327   case llvm::Triple::mips64:
 328   case llvm::Triple::mips64el:
 329     // mips has si_code and si_errno swapped
 330     si_errno_then_code = false;
 331     break;
 332   default:
 333     break;
 334   }
 335
 336   // generic types
 337   CompilerType int_type = ast->GetBasicType(eBasicTypeInt);
 338   CompilerType uint_type = ast->GetBasicType(eBasicTypeUnsignedInt);
 339   CompilerType short_type = ast->GetBasicType(eBasicTypeShort);
 340   CompilerType long_type = ast->GetBasicType(eBasicTypeLong);
 341   CompilerType voidp_type = ast->GetBasicType(eBasicTypeVoid).GetPointerType();
 342
 343   // platform-specific types
 344   CompilerType &pid_type = int_type;
 345   CompilerType &uid_type = uint_type;
 346   CompilerType &clock_type = long_type;
 347   CompilerType &band_type = long_type;
 348
 349   CompilerType sigval_type = ast->CreateRecordType(
 350       nullptr, OptionalClangModuleID(), lldb::eAccessPublic, "__lldb_sigval_t",
 351       llvm::to_underlying(clang::TagTypeKind::Union), lldb::eLanguageTypeC);
 352   ast->StartTagDeclarationDefinition(sigval_type);
 353   ast->AddFieldToRecordType(sigval_type, "sival_int", int_type,
 354                             lldb::eAccessPublic, 0);
 355   ast->AddFieldToRecordType(sigval_type, "sival_ptr", voidp_type,
 356                             lldb::eAccessPublic, 0);
 357   ast->CompleteTagDeclarationDefinition(sigval_type);
 358
 359   CompilerType sigfault_bounds_type = ast->CreateRecordType(
 360       nullptr, OptionalClangModuleID(), lldb::eAccessPublic, "",
 361       llvm::to_underlying(clang::TagTypeKind::Union), lldb::eLanguageTypeC);
 362   ast->StartTagDeclarationDefinition(sigfault_bounds_type);
 363   ast->AddFieldToRecordType(
 364       sigfault_bounds_type, "_addr_bnd",
 365       ast->CreateStructForIdentifier(llvm::StringRef(),
 366                                      {
 367                                          {"_lower", voidp_type},
 368                                          {"_upper", voidp_type},
 369                                      }),
 370       lldb::eAccessPublic, 0);
 371   ast->AddFieldToRecordType(sigfault_bounds_type, "_pkey", uint_type,
 372                             lldb::eAccessPublic, 0);
 373   ast->CompleteTagDeclarationDefinition(sigfault_bounds_type);
 374
 375   // siginfo_t
 376   CompilerType siginfo_type = ast->CreateRecordType(
 377       nullptr, OptionalClangModuleID(), lldb::eAccessPublic, "__lldb_siginfo_t",
 378       llvm::to_underlying(clang::TagTypeKind::Struct), lldb::eLanguageTypeC);
 379   ast->StartTagDeclarationDefinition(siginfo_type);
 380   ast->AddFieldToRecordType(siginfo_type, "si_signo", int_type,
 381                             lldb::eAccessPublic, 0);
 382
 383   if (si_errno_then_code) {
 384     ast->AddFieldToRecordType(siginfo_type, "si_errno", int_type,
 385                               lldb::eAccessPublic, 0);
 386     ast->AddFieldToRecordType(siginfo_type, "si_code", int_type,
 387                               lldb::eAccessPublic, 0);
 388   } else {
 389     ast->AddFieldToRecordType(siginfo_type, "si_code", int_type,
 390                               lldb::eAccessPublic, 0);
 391     ast->AddFieldToRecordType(siginfo_type, "si_errno", int_type,
 392                               lldb::eAccessPublic, 0);
 393   }
 394
 395   // the structure is padded on 64-bit arches to fix alignment
 396   if (triple.isArch64Bit())
 397     ast->AddFieldToRecordType(siginfo_type, "__pad0", int_type,
 398                               lldb::eAccessPublic, 0);
 399
 400   // union used to hold the signal data
 401   CompilerType union_type = ast->CreateRecordType(
 402       nullptr, OptionalClangModuleID(), lldb::eAccessPublic, "",
 403       llvm::to_underlying(clang::TagTypeKind::Union), lldb::eLanguageTypeC);
 404   ast->StartTagDeclarationDefinition(union_type);
 405
 406   ast->AddFieldToRecordType(
 407       union_type, "_kill",
 408       ast->CreateStructForIdentifier(llvm::StringRef(),
 409                                      {
 410                                          {"si_pid", pid_type},
 411                                          {"si_uid", uid_type},
 412                                      }),
 413       lldb::eAccessPublic, 0);
 414
 415   ast->AddFieldToRecordType(
 416       union_type, "_timer",
 417       ast->CreateStructForIdentifier(llvm::StringRef(),
 418                                      {
 419                                          {"si_tid", int_type},
 420                                          {"si_overrun", int_type},
 421                                          {"si_sigval", sigval_type},
 422                                      }),
 423       lldb::eAccessPublic, 0);
 424
 425   ast->AddFieldToRecordType(
 426       union_type, "_rt",
 427       ast->CreateStructForIdentifier(llvm::StringRef(),
 428                                      {
 429                                          {"si_pid", pid_type},
 430                                          {"si_uid", uid_type},
 431                                          {"si_sigval", sigval_type},
 432                                      }),
 433       lldb::eAccessPublic, 0);
 434
 435   ast->AddFieldToRecordType(
 436       union_type, "_sigchld",
 437       ast->CreateStructForIdentifier(llvm::StringRef(),
 438                                      {
 439                                          {"si_pid", pid_type},
 440                                          {"si_uid", uid_type},
 441                                          {"si_status", int_type},
 442                                          {"si_utime", clock_type},
 443                                          {"si_stime", clock_type},
 444                                      }),
 445       lldb::eAccessPublic, 0);
 446
 447   ast->AddFieldToRecordType(
 448       union_type, "_sigfault",
 449       ast->CreateStructForIdentifier(llvm::StringRef(),
 450                                      {
 451                                          {"si_addr", voidp_type},
 452                                          {"si_addr_lsb", short_type},
 453                                          {"_bounds", sigfault_bounds_type},
 454                                      }),
 455       lldb::eAccessPublic, 0);
 456
 457   ast->AddFieldToRecordType(
 458       union_type, "_sigpoll",
 459       ast->CreateStructForIdentifier(llvm::StringRef(),
 460                                      {
 461                                          {"si_band", band_type},
 462                                          {"si_fd", int_type},
 463                                      }),
 464       lldb::eAccessPublic, 0);
 465
 466   // NB: SIGSYS is not present on ia64 but we don't seem to support that
 467   ast->AddFieldToRecordType(
 468       union_type, "_sigsys",
 469       ast->CreateStructForIdentifier(llvm::StringRef(),
 470                                      {
 471                                          {"_call_addr", voidp_type},
 472                                          {"_syscall", int_type},
 473                                          {"_arch", uint_type},
 474                                      }),
 475       lldb::eAccessPublic, 0);
 476
 477   ast->CompleteTagDeclarationDefinition(union_type);
 478   ast->AddFieldToRecordType(siginfo_type, "_sifields", union_type,
 479                             lldb::eAccessPublic, 0);
 480
 481   ast->CompleteTagDeclarationDefinition(siginfo_type);
 482   return siginfo_type;
 483 }