DynamicLoaderPOSIXDYLD.cpp 26 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766
//===-- DynamicLoaderPOSIXDYLD.cpp ------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

// Main header include
#include "DynamicLoaderPOSIXDYLD.h"

#include "lldb/Breakpoint/BreakpointLocation.h"
#include "lldb/Core/Module.h"
#include "lldb/Core/ModuleSpec.h"
#include "lldb/Core/PluginManager.h"
#include "lldb/Core/Section.h"
#include "lldb/Symbol/Function.h"
#include "lldb/Symbol/ObjectFile.h"
#include "lldb/Target/MemoryRegionInfo.h"
#include "lldb/Target/Platform.h"
#include "lldb/Target/Target.h"
#include "lldb/Target/Thread.h"
#include "lldb/Target/ThreadPlanRunToAddress.h"
#include "lldb/Utility/Log.h"
#include "lldb/Utility/ProcessInfo.h"

#include <memory>

using namespace lldb;
using namespace lldb_private;

void DynamicLoaderPOSIXDYLD::Initialize() {
  PluginManager::RegisterPlugin(GetPluginNameStatic(),
                                GetPluginDescriptionStatic(), CreateInstance);
}

void DynamicLoaderPOSIXDYLD::Terminate() {}

lldb_private::ConstString DynamicLoaderPOSIXDYLD::GetPluginName() {
  return GetPluginNameStatic();
}

lldb_private::ConstString DynamicLoaderPOSIXDYLD::GetPluginNameStatic() {
  static ConstString g_name("linux-dyld");
  return g_name;
}

const char *DynamicLoaderPOSIXDYLD::GetPluginDescriptionStatic() {
  return "Dynamic loader plug-in that watches for shared library "
         "loads/unloads in POSIX processes.";
}

uint32_t DynamicLoaderPOSIXDYLD::GetPluginVersion() { return 1; }

DynamicLoader *DynamicLoaderPOSIXDYLD::CreateInstance(Process *process,
                                                      bool force) {
  bool create = force;
  if (!create) {
    const llvm::Triple &triple_ref =
        process->GetTarget().GetArchitecture().GetTriple();
    if (triple_ref.getOS() == llvm::Triple::FreeBSD ||
        triple_ref.getOS() == llvm::Triple::Linux ||
        triple_ref.getOS() == llvm::Triple::NetBSD)
      create = true;
  }

  if (create)
    return new DynamicLoaderPOSIXDYLD(process);
  return nullptr;
}

DynamicLoaderPOSIXDYLD::DynamicLoaderPOSIXDYLD(Process *process)
    : DynamicLoader(process), m_rendezvous(process),
      m_load_offset(LLDB_INVALID_ADDRESS), m_entry_point(LLDB_INVALID_ADDRESS),
      m_auxv(), m_dyld_bid(LLDB_INVALID_BREAK_ID),
      m_vdso_base(LLDB_INVALID_ADDRESS),
      m_interpreter_base(LLDB_INVALID_ADDRESS) {}

DynamicLoaderPOSIXDYLD::~DynamicLoaderPOSIXDYLD() {
  if (m_dyld_bid != LLDB_INVALID_BREAK_ID) {
    m_process->GetTarget().RemoveBreakpointByID(m_dyld_bid);
    m_dyld_bid = LLDB_INVALID_BREAK_ID;
  }
}

void DynamicLoaderPOSIXDYLD::DidAttach() {
  Log *log(GetLogIfAnyCategoriesSet(LIBLLDB_LOG_DYNAMIC_LOADER));
  LLDB_LOGF(log, "DynamicLoaderPOSIXDYLD::%s() pid %" PRIu64, __FUNCTION__,
            m_process ? m_process->GetID() : LLDB_INVALID_PROCESS_ID);
  m_auxv = std::make_unique<AuxVector>(m_process->GetAuxvData());

  LLDB_LOGF(
      log, "DynamicLoaderPOSIXDYLD::%s pid %" PRIu64 " reloaded auxv data",
      __FUNCTION__, m_process ? m_process->GetID() : LLDB_INVALID_PROCESS_ID);

  // ask the process if it can load any of its own modules
  auto error = m_process->LoadModules();
  LLDB_LOG_ERROR(log, std::move(error), "Couldn't load modules: {0}");

  ModuleSP executable_sp = GetTargetExecutable();
  ResolveExecutableModule(executable_sp);

  // find the main process load offset
  addr_t load_offset = ComputeLoadOffset();
  LLDB_LOGF(log,
            "DynamicLoaderPOSIXDYLD::%s pid %" PRIu64
            " executable '%s', load_offset 0x%" PRIx64,
            __FUNCTION__,
            m_process ? m_process->GetID() : LLDB_INVALID_PROCESS_ID,
            executable_sp ? executable_sp->GetFileSpec().GetPath().c_str()
                          : "<null executable>",
            load_offset);

  EvalSpecialModulesStatus();

  // if we dont have a load address we cant re-base
  bool rebase_exec = load_offset != LLDB_INVALID_ADDRESS;

  // if we have a valid executable
  if (executable_sp.get()) {
    lldb_private::ObjectFile *obj = executable_sp->GetObjectFile();
    if (obj) {
      // don't rebase if the module already has a load address
      Target &target = m_process->GetTarget();
      Address addr = obj->GetImageInfoAddress(&target);
      if (addr.GetLoadAddress(&target) != LLDB_INVALID_ADDRESS)
        rebase_exec = false;
    }
  } else {
    // no executable, nothing to re-base
    rebase_exec = false;
  }

  // if the target executable should be re-based
  if (rebase_exec) {
    ModuleList module_list;

    module_list.Append(executable_sp);
    LLDB_LOGF(log,
              "DynamicLoaderPOSIXDYLD::%s pid %" PRIu64
              " added executable '%s' to module load list",
              __FUNCTION__,
              m_process ? m_process->GetID() : LLDB_INVALID_PROCESS_ID,
              executable_sp->GetFileSpec().GetPath().c_str());

    UpdateLoadedSections(executable_sp, LLDB_INVALID_ADDRESS, load_offset,
                         true);

    LoadAllCurrentModules();

    m_process->GetTarget().ModulesDidLoad(module_list);
    if (log) {
      LLDB_LOGF(log,
                "DynamicLoaderPOSIXDYLD::%s told the target about the "
                "modules that loaded:",
                __FUNCTION__);
      for (auto module_sp : module_list.Modules()) {
        LLDB_LOGF(log, "-- [module] %s (pid %" PRIu64 ")",
                  module_sp ? module_sp->GetFileSpec().GetPath().c_str()
                            : "<null>",
                  m_process ? m_process->GetID() : LLDB_INVALID_PROCESS_ID);
      }
    }
  }

  if (executable_sp.get()) {
    if (!SetRendezvousBreakpoint()) {
      // If we cannot establish rendezvous breakpoint right now we'll try again
      // at entry point.
      ProbeEntry();
    }
  }
}

void DynamicLoaderPOSIXDYLD::DidLaunch() {
  Log *log(GetLogIfAnyCategoriesSet(LIBLLDB_LOG_DYNAMIC_LOADER));
  LLDB_LOGF(log, "DynamicLoaderPOSIXDYLD::%s()", __FUNCTION__);

  ModuleSP executable;
  addr_t load_offset;

  m_auxv = std::make_unique<AuxVector>(m_process->GetAuxvData());

  executable = GetTargetExecutable();
  load_offset = ComputeLoadOffset();
  EvalSpecialModulesStatus();

  if (executable.get() && load_offset != LLDB_INVALID_ADDRESS) {
    ModuleList module_list;
    module_list.Append(executable);
    UpdateLoadedSections(executable, LLDB_INVALID_ADDRESS, load_offset, true);

    LLDB_LOGF(log, "DynamicLoaderPOSIXDYLD::%s about to call ProbeEntry()",
              __FUNCTION__);

    if (!SetRendezvousBreakpoint()) {
      // If we cannot establish rendezvous breakpoint right now we'll try again
      // at entry point.
      ProbeEntry();
    }

    LoadVDSO();
    m_process->GetTarget().ModulesDidLoad(module_list);
  }
}

Status DynamicLoaderPOSIXDYLD::CanLoadImage() { return Status(); }

void DynamicLoaderPOSIXDYLD::UpdateLoadedSections(ModuleSP module,
                                                  addr_t link_map_addr,
                                                  addr_t base_addr,
                                                  bool base_addr_is_offset) {
  m_loaded_modules[module] = link_map_addr;
  UpdateLoadedSectionsCommon(module, base_addr, base_addr_is_offset);
}

void DynamicLoaderPOSIXDYLD::UnloadSections(const ModuleSP module) {
  m_loaded_modules.erase(module);

  UnloadSectionsCommon(module);
}

void DynamicLoaderPOSIXDYLD::ProbeEntry() {
  Log *log(GetLogIfAnyCategoriesSet(LIBLLDB_LOG_DYNAMIC_LOADER));

  const addr_t entry = GetEntryPoint();
  if (entry == LLDB_INVALID_ADDRESS) {
    LLDB_LOGF(
        log,
        "DynamicLoaderPOSIXDYLD::%s pid %" PRIu64
        " GetEntryPoint() returned no address, not setting entry breakpoint",
        __FUNCTION__, m_process ? m_process->GetID() : LLDB_INVALID_PROCESS_ID);
    return;
  }

  LLDB_LOGF(log,
            "DynamicLoaderPOSIXDYLD::%s pid %" PRIu64
            " GetEntryPoint() returned address 0x%" PRIx64
            ", setting entry breakpoint",
            __FUNCTION__,
            m_process ? m_process->GetID() : LLDB_INVALID_PROCESS_ID, entry);

  if (m_process) {
    Breakpoint *const entry_break =
        m_process->GetTarget().CreateBreakpoint(entry, true, false).get();
    entry_break->SetCallback(EntryBreakpointHit, this, true);
    entry_break->SetBreakpointKind("shared-library-event");

    // Shoudn't hit this more than once.
    entry_break->SetOneShot(true);
  }
}

// The runtime linker has run and initialized the rendezvous structure once the
// process has hit its entry point.  When we hit the corresponding breakpoint
// we interrogate the rendezvous structure to get the load addresses of all
// dependent modules for the process.  Similarly, we can discover the runtime
// linker function and setup a breakpoint to notify us of any dynamically
// loaded modules (via dlopen).
bool DynamicLoaderPOSIXDYLD::EntryBreakpointHit(
    void *baton, StoppointCallbackContext *context, user_id_t break_id,
    user_id_t break_loc_id) {
  assert(baton && "null baton");
  if (!baton)
    return false;

  Log *log(GetLogIfAnyCategoriesSet(LIBLLDB_LOG_DYNAMIC_LOADER));
  DynamicLoaderPOSIXDYLD *const dyld_instance =
      static_cast<DynamicLoaderPOSIXDYLD *>(baton);
  LLDB_LOGF(log, "DynamicLoaderPOSIXDYLD::%s called for pid %" PRIu64,
            __FUNCTION__,
            dyld_instance->m_process ? dyld_instance->m_process->GetID()
                                     : LLDB_INVALID_PROCESS_ID);

  // Disable the breakpoint --- if a stop happens right after this, which we've
  // seen on occasion, we don't want the breakpoint stepping thread-plan logic
  // to show a breakpoint instruction at the disassembled entry point to the
  // program.  Disabling it prevents it.  (One-shot is not enough - one-shot
  // removal logic only happens after the breakpoint goes public, which wasn't
  // happening in our scenario).
  if (dyld_instance->m_process) {
    BreakpointSP breakpoint_sp =
        dyld_instance->m_process->GetTarget().GetBreakpointByID(break_id);
    if (breakpoint_sp) {
      LLDB_LOGF(log,
                "DynamicLoaderPOSIXDYLD::%s pid %" PRIu64
                " disabling breakpoint id %" PRIu64,
                __FUNCTION__, dyld_instance->m_process->GetID(), break_id);
      breakpoint_sp->SetEnabled(false);
    } else {
      LLDB_LOGF(log,
                "DynamicLoaderPOSIXDYLD::%s pid %" PRIu64
                " failed to find breakpoint for breakpoint id %" PRIu64,
                __FUNCTION__, dyld_instance->m_process->GetID(), break_id);
    }
  } else {
    LLDB_LOGF(log,
              "DynamicLoaderPOSIXDYLD::%s breakpoint id %" PRIu64
              " no Process instance!  Cannot disable breakpoint",
              __FUNCTION__, break_id);
  }

  dyld_instance->LoadAllCurrentModules();
  dyld_instance->SetRendezvousBreakpoint();
  return false; // Continue running.
}

bool DynamicLoaderPOSIXDYLD::SetRendezvousBreakpoint() {
  Log *log(GetLogIfAnyCategoriesSet(LIBLLDB_LOG_DYNAMIC_LOADER));
  if (m_dyld_bid != LLDB_INVALID_BREAK_ID) {
    LLDB_LOG(log,
             "Rendezvous breakpoint breakpoint id {0} for pid {1}"
             "is already set.",
             m_dyld_bid,
             m_process ? m_process->GetID() : LLDB_INVALID_PROCESS_ID);
    return true;
  }

  addr_t break_addr;
  Target &target = m_process->GetTarget();
  BreakpointSP dyld_break;
  if (m_rendezvous.IsValid()) {
    break_addr = m_rendezvous.GetBreakAddress();
    LLDB_LOG(log, "Setting rendezvous break address for pid {0} at {1:x}",
             m_process ? m_process->GetID() : LLDB_INVALID_PROCESS_ID,
             break_addr);
    dyld_break = target.CreateBreakpoint(break_addr, true, false);
  } else {
    LLDB_LOG(log, "Rendezvous structure is not set up yet. "
                  "Trying to locate rendezvous breakpoint in the interpreter "
                  "by symbol name.");
    ModuleSP interpreter = LoadInterpreterModule();
    if (!interpreter) {
      LLDB_LOG(log, "Can't find interpreter, rendezvous breakpoint isn't set.");
      return false;
    }

    // Function names from different dynamic loaders that are known to be used
    // as rendezvous between the loader and debuggers.
    static std::vector<std::string> DebugStateCandidates{
        "_dl_debug_state", "rtld_db_dlactivity", "__dl_rtld_db_dlactivity",
        "r_debug_state",   "_r_debug_state",     "_rtld_debug_state",
    };

    FileSpecList containingModules;
    containingModules.Append(interpreter->GetFileSpec());
    dyld_break = target.CreateBreakpoint(
        &containingModules, nullptr /* containingSourceFiles */,
        DebugStateCandidates, eFunctionNameTypeFull, eLanguageTypeC,
        0,           /* offset */
        eLazyBoolNo, /* skip_prologue */
        true,        /* internal */
        false /* request_hardware */);
  }

  if (dyld_break->GetNumResolvedLocations() != 1) {
    LLDB_LOG(
        log,
        "Rendezvous breakpoint has abnormal number of"
        " resolved locations ({0}) in pid {1}. It's supposed to be exactly 1.",
        dyld_break->GetNumResolvedLocations(),
        m_process ? m_process->GetID() : LLDB_INVALID_PROCESS_ID);

    target.RemoveBreakpointByID(dyld_break->GetID());
    return false;
  }

  BreakpointLocationSP location = dyld_break->GetLocationAtIndex(0);
  LLDB_LOG(log,
           "Successfully set rendezvous breakpoint at address {0:x} "
           "for pid {1}",
           location->GetLoadAddress(),
           m_process ? m_process->GetID() : LLDB_INVALID_PROCESS_ID);

  dyld_break->SetCallback(RendezvousBreakpointHit, this, true);
  dyld_break->SetBreakpointKind("shared-library-event");
  m_dyld_bid = dyld_break->GetID();
  return true;
}

bool DynamicLoaderPOSIXDYLD::RendezvousBreakpointHit(
    void *baton, StoppointCallbackContext *context, user_id_t break_id,
    user_id_t break_loc_id) {
  assert(baton && "null baton");
  if (!baton)
    return false;

  Log *log(GetLogIfAnyCategoriesSet(LIBLLDB_LOG_DYNAMIC_LOADER));
  DynamicLoaderPOSIXDYLD *const dyld_instance =
      static_cast<DynamicLoaderPOSIXDYLD *>(baton);
  LLDB_LOGF(log, "DynamicLoaderPOSIXDYLD::%s called for pid %" PRIu64,
            __FUNCTION__,
            dyld_instance->m_process ? dyld_instance->m_process->GetID()
                                     : LLDB_INVALID_PROCESS_ID);

  dyld_instance->RefreshModules();

  // Return true to stop the target, false to just let the target run.
  const bool stop_when_images_change = dyld_instance->GetStopWhenImagesChange();
  LLDB_LOGF(log,
            "DynamicLoaderPOSIXDYLD::%s pid %" PRIu64
            " stop_when_images_change=%s",
            __FUNCTION__,
            dyld_instance->m_process ? dyld_instance->m_process->GetID()
                                     : LLDB_INVALID_PROCESS_ID,
            stop_when_images_change ? "true" : "false");
  return stop_when_images_change;
}

void DynamicLoaderPOSIXDYLD::RefreshModules() {
  if (!m_rendezvous.Resolve())
    return;

  DYLDRendezvous::iterator I;
  DYLDRendezvous::iterator E;

  ModuleList &loaded_modules = m_process->GetTarget().GetImages();

  if (m_rendezvous.ModulesDidLoad()) {
    ModuleList new_modules;

    E = m_rendezvous.loaded_end();
    for (I = m_rendezvous.loaded_begin(); I != E; ++I) {
      ModuleSP module_sp =
          LoadModuleAtAddress(I->file_spec, I->link_addr, I->base_addr, true);
      if (module_sp.get()) {
        loaded_modules.AppendIfNeeded(module_sp);
        new_modules.Append(module_sp);
      }
    }
    m_process->GetTarget().ModulesDidLoad(new_modules);
  }

  if (m_rendezvous.ModulesDidUnload()) {
    ModuleList old_modules;

    E = m_rendezvous.unloaded_end();
    for (I = m_rendezvous.unloaded_begin(); I != E; ++I) {
      ModuleSpec module_spec{I->file_spec};
      ModuleSP module_sp = loaded_modules.FindFirstModule(module_spec);

      if (module_sp.get()) {
        old_modules.Append(module_sp);
        UnloadSections(module_sp);
      }
    }
    loaded_modules.Remove(old_modules);
    m_process->GetTarget().ModulesDidUnload(old_modules, false);
  }
}

ThreadPlanSP
DynamicLoaderPOSIXDYLD::GetStepThroughTrampolinePlan(Thread &thread,
                                                     bool stop) {
  ThreadPlanSP thread_plan_sp;

  StackFrame *frame = thread.GetStackFrameAtIndex(0).get();
  const SymbolContext &context = frame->GetSymbolContext(eSymbolContextSymbol);
  Symbol *sym = context.symbol;

  if (sym == nullptr || !sym->IsTrampoline())
    return thread_plan_sp;

  ConstString sym_name = sym->GetName();
  if (!sym_name)
    return thread_plan_sp;

  SymbolContextList target_symbols;
  Target &target = thread.GetProcess()->GetTarget();
  const ModuleList &images = target.GetImages();

  images.FindSymbolsWithNameAndType(sym_name, eSymbolTypeCode, target_symbols);
  size_t num_targets = target_symbols.GetSize();
  if (!num_targets)
    return thread_plan_sp;

  typedef std::vector<lldb::addr_t> AddressVector;
  AddressVector addrs;
  for (size_t i = 0; i < num_targets; ++i) {
    SymbolContext context;
    AddressRange range;
    if (target_symbols.GetContextAtIndex(i, context)) {
      context.GetAddressRange(eSymbolContextEverything, 0, false, range);
      lldb::addr_t addr = range.GetBaseAddress().GetLoadAddress(&target);
      if (addr != LLDB_INVALID_ADDRESS)
        addrs.push_back(addr);
    }
  }

  if (addrs.size() > 0) {
    AddressVector::iterator start = addrs.begin();
    AddressVector::iterator end = addrs.end();

    llvm::sort(start, end);
    addrs.erase(std::unique(start, end), end);
    thread_plan_sp =
        std::make_shared<ThreadPlanRunToAddress>(thread, addrs, stop);
  }

  return thread_plan_sp;
}

void DynamicLoaderPOSIXDYLD::LoadVDSO() {
  if (m_vdso_base == LLDB_INVALID_ADDRESS)
    return;

  FileSpec file("[vdso]");

  MemoryRegionInfo info;
  Status status = m_process->GetMemoryRegionInfo(m_vdso_base, info);
  if (status.Fail()) {
    Log *log(GetLogIfAnyCategoriesSet(LIBLLDB_LOG_DYNAMIC_LOADER));
    LLDB_LOG(log, "Failed to get vdso region info: {0}", status);
    return;
  }

  if (ModuleSP module_sp = m_process->ReadModuleFromMemory(
          file, m_vdso_base, info.GetRange().GetByteSize())) {
    UpdateLoadedSections(module_sp, LLDB_INVALID_ADDRESS, m_vdso_base, false);
    m_process->GetTarget().GetImages().AppendIfNeeded(module_sp);
  }
}

ModuleSP DynamicLoaderPOSIXDYLD::LoadInterpreterModule() {
  if (m_interpreter_base == LLDB_INVALID_ADDRESS)
    return nullptr;

  MemoryRegionInfo info;
  Target &target = m_process->GetTarget();
  Status status = m_process->GetMemoryRegionInfo(m_interpreter_base, info);
  if (status.Fail() || info.GetMapped() != MemoryRegionInfo::eYes ||
      info.GetName().IsEmpty()) {
    Log *log(GetLogIfAnyCategoriesSet(LIBLLDB_LOG_DYNAMIC_LOADER));
    LLDB_LOG(log, "Failed to get interpreter region info: {0}", status);
    return nullptr;
  }

  FileSpec file(info.GetName().GetCString());
  ModuleSpec module_spec(file, target.GetArchitecture());

  if (ModuleSP module_sp = target.GetOrCreateModule(module_spec, 
                                                    true /* notify */)) {
    UpdateLoadedSections(module_sp, LLDB_INVALID_ADDRESS, m_interpreter_base,
                         false);
    return module_sp;
  }
  return nullptr;
}

void DynamicLoaderPOSIXDYLD::LoadAllCurrentModules() {
  DYLDRendezvous::iterator I;
  DYLDRendezvous::iterator E;
  ModuleList module_list;
  Log *log(GetLogIfAnyCategoriesSet(LIBLLDB_LOG_DYNAMIC_LOADER));

  LoadVDSO();

  if (!m_rendezvous.Resolve()) {
    LLDB_LOGF(log,
              "DynamicLoaderPOSIXDYLD::%s unable to resolve POSIX DYLD "
              "rendezvous address",
              __FUNCTION__);
    return;
  }

  // The rendezvous class doesn't enumerate the main module, so track that
  // ourselves here.
  ModuleSP executable = GetTargetExecutable();
  m_loaded_modules[executable] = m_rendezvous.GetLinkMapAddress();

  std::vector<FileSpec> module_names;
  for (I = m_rendezvous.begin(), E = m_rendezvous.end(); I != E; ++I)
    module_names.push_back(I->file_spec);
  m_process->PrefetchModuleSpecs(
      module_names, m_process->GetTarget().GetArchitecture().GetTriple());

  for (I = m_rendezvous.begin(), E = m_rendezvous.end(); I != E; ++I) {
    ModuleSP module_sp =
        LoadModuleAtAddress(I->file_spec, I->link_addr, I->base_addr, true);
    if (module_sp.get()) {
      LLDB_LOG(log, "LoadAllCurrentModules loading module: {0}",
               I->file_spec.GetFilename());
      module_list.Append(module_sp);
    } else {
      Log *log(GetLogIfAnyCategoriesSet(LIBLLDB_LOG_DYNAMIC_LOADER));
      LLDB_LOGF(
          log,
          "DynamicLoaderPOSIXDYLD::%s failed loading module %s at 0x%" PRIx64,
          __FUNCTION__, I->file_spec.GetCString(), I->base_addr);
    }
  }

  m_process->GetTarget().ModulesDidLoad(module_list);
}

addr_t DynamicLoaderPOSIXDYLD::ComputeLoadOffset() {
  addr_t virt_entry;

  if (m_load_offset != LLDB_INVALID_ADDRESS)
    return m_load_offset;

  if ((virt_entry = GetEntryPoint()) == LLDB_INVALID_ADDRESS)
    return LLDB_INVALID_ADDRESS;

  ModuleSP module = m_process->GetTarget().GetExecutableModule();
  if (!module)
    return LLDB_INVALID_ADDRESS;

  ObjectFile *exe = module->GetObjectFile();
  if (!exe)
    return LLDB_INVALID_ADDRESS;

  Address file_entry = exe->GetEntryPointAddress();

  if (!file_entry.IsValid())
    return LLDB_INVALID_ADDRESS;

  m_load_offset = virt_entry - file_entry.GetFileAddress();
  return m_load_offset;
}

void DynamicLoaderPOSIXDYLD::EvalSpecialModulesStatus() {
  if (llvm::Optional<uint64_t> vdso_base =
          m_auxv->GetAuxValue(AuxVector::AUXV_AT_SYSINFO_EHDR))
    m_vdso_base = *vdso_base;

  if (llvm::Optional<uint64_t> interpreter_base =
          m_auxv->GetAuxValue(AuxVector::AUXV_AT_BASE))
    m_interpreter_base = *interpreter_base;
}

addr_t DynamicLoaderPOSIXDYLD::GetEntryPoint() {
  if (m_entry_point != LLDB_INVALID_ADDRESS)
    return m_entry_point;

  if (m_auxv == nullptr)
    return LLDB_INVALID_ADDRESS;

  llvm::Optional<uint64_t> entry_point =
      m_auxv->GetAuxValue(AuxVector::AUXV_AT_ENTRY);
  if (!entry_point)
    return LLDB_INVALID_ADDRESS;

  m_entry_point = static_cast<addr_t>(*entry_point);

  const ArchSpec &arch = m_process->GetTarget().GetArchitecture();

  // On ppc64, the entry point is actually a descriptor.  Dereference it.
  if (arch.GetMachine() == llvm::Triple::ppc64)
    m_entry_point = ReadUnsignedIntWithSizeInBytes(m_entry_point, 8);

  return m_entry_point;
}

lldb::addr_t
DynamicLoaderPOSIXDYLD::GetThreadLocalData(const lldb::ModuleSP module_sp,
                                           const lldb::ThreadSP thread,
                                           lldb::addr_t tls_file_addr) {
  auto it = m_loaded_modules.find(module_sp);
  if (it == m_loaded_modules.end())
    return LLDB_INVALID_ADDRESS;

  addr_t link_map = it->second;
  if (link_map == LLDB_INVALID_ADDRESS)
    return LLDB_INVALID_ADDRESS;

  const DYLDRendezvous::ThreadInfo &metadata = m_rendezvous.GetThreadInfo();
  if (!metadata.valid)
    return LLDB_INVALID_ADDRESS;

  // Get the thread pointer.
  addr_t tp = thread->GetThreadPointer();
  if (tp == LLDB_INVALID_ADDRESS)
    return LLDB_INVALID_ADDRESS;

  // Find the module's modid.
  int modid_size = 4; // FIXME(spucci): This isn't right for big-endian 64-bit
  int64_t modid = ReadUnsignedIntWithSizeInBytes(
      link_map + metadata.modid_offset, modid_size);
  if (modid == -1)
    return LLDB_INVALID_ADDRESS;

  // Lookup the DTV structure for this thread.
  addr_t dtv_ptr = tp + metadata.dtv_offset;
  addr_t dtv = ReadPointer(dtv_ptr);
  if (dtv == LLDB_INVALID_ADDRESS)
    return LLDB_INVALID_ADDRESS;

  // Find the TLS block for this module.
  addr_t dtv_slot = dtv + metadata.dtv_slot_size * modid;
  addr_t tls_block = ReadPointer(dtv_slot + metadata.tls_offset);

  Log *log(GetLogIfAnyCategoriesSet(LIBLLDB_LOG_DYNAMIC_LOADER));
  LLDB_LOGF(log,
            "DynamicLoaderPOSIXDYLD::Performed TLS lookup: "
            "module=%s, link_map=0x%" PRIx64 ", tp=0x%" PRIx64
            ", modid=%" PRId64 ", tls_block=0x%" PRIx64 "\n",
            module_sp->GetObjectName().AsCString(""), link_map, tp,
            (int64_t)modid, tls_block);

  if (tls_block == LLDB_INVALID_ADDRESS)
    return LLDB_INVALID_ADDRESS;
  else
    return tls_block + tls_file_addr;
}

void DynamicLoaderPOSIXDYLD::ResolveExecutableModule(
    lldb::ModuleSP &module_sp) {
  Log *log(GetLogIfAnyCategoriesSet(LIBLLDB_LOG_DYNAMIC_LOADER));

  if (m_process == nullptr)
    return;

  auto &target = m_process->GetTarget();
  const auto platform_sp = target.GetPlatform();

  ProcessInstanceInfo process_info;
  if (!m_process->GetProcessInfo(process_info)) {
    LLDB_LOGF(log,
              "DynamicLoaderPOSIXDYLD::%s - failed to get process info for "
              "pid %" PRIu64,
              __FUNCTION__, m_process->GetID());
    return;
  }

  LLDB_LOGF(
      log, "DynamicLoaderPOSIXDYLD::%s - got executable by pid %" PRIu64 ": %s",
      __FUNCTION__, m_process->GetID(),
      process_info.GetExecutableFile().GetPath().c_str());

  ModuleSpec module_spec(process_info.GetExecutableFile(),
                         process_info.GetArchitecture());
  if (module_sp && module_sp->MatchesModuleSpec(module_spec))
    return;

  const auto executable_search_paths(Target::GetDefaultExecutableSearchPaths());
  auto error = platform_sp->ResolveExecutable(
      module_spec, module_sp,
      !executable_search_paths.IsEmpty() ? &executable_search_paths : nullptr);
  if (error.Fail()) {
    StreamString stream;
    module_spec.Dump(stream);

    LLDB_LOGF(log,
              "DynamicLoaderPOSIXDYLD::%s - failed to resolve executable "
              "with module spec \"%s\": %s",
              __FUNCTION__, stream.GetData(), error.AsCString());
    return;
  }

  target.SetExecutableModule(module_sp, eLoadDependentsNo);
}

bool DynamicLoaderPOSIXDYLD::AlwaysRelyOnEHUnwindInfo(
    lldb_private::SymbolContext &sym_ctx) {
  ModuleSP module_sp;
  if (sym_ctx.symbol)
    module_sp = sym_ctx.symbol->GetAddressRef().GetModule();
  if (!module_sp && sym_ctx.function)
    module_sp =
        sym_ctx.function->GetAddressRange().GetBaseAddress().GetModule();
  if (!module_sp)
    return false;

  return module_sp->GetFileSpec().GetPath() == "[vdso]";
}