1//===-- DynamicLoaderPOSIXDYLD.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// Main header include
10#include "DynamicLoaderPOSIXDYLD.h"
11
12#include "lldb/Breakpoint/BreakpointLocation.h"
13#include "lldb/Core/Module.h"
14#include "lldb/Core/ModuleSpec.h"
15#include "lldb/Core/PluginManager.h"
16#include "lldb/Core/Section.h"
17#include "lldb/Symbol/Function.h"
18#include "lldb/Symbol/ObjectFile.h"
19#include "lldb/Target/MemoryRegionInfo.h"
20#include "lldb/Target/Platform.h"
21#include "lldb/Target/Target.h"
22#include "lldb/Target/Thread.h"
23#include "lldb/Target/ThreadPlanRunToAddress.h"
24#include "lldb/Utility/LLDBLog.h"
25#include "lldb/Utility/Log.h"
26#include "lldb/Utility/ProcessInfo.h"
27
28#include <memory>
29#include <optional>
30
31using namespace lldb;
32using namespace lldb_private;
33
34LLDB_PLUGIN_DEFINE_ADV(DynamicLoaderPOSIXDYLD, DynamicLoaderPosixDYLD)
35
36void DynamicLoaderPOSIXDYLD::Initialize() {
37  PluginManager::RegisterPlugin(GetPluginNameStatic(),
38                                GetPluginDescriptionStatic(), CreateInstance);
39}
40
41void DynamicLoaderPOSIXDYLD::Terminate() {}
42
43llvm::StringRef DynamicLoaderPOSIXDYLD::GetPluginDescriptionStatic() {
44  return "Dynamic loader plug-in that watches for shared library "
45         "loads/unloads in POSIX processes.";
46}
47
48DynamicLoader *DynamicLoaderPOSIXDYLD::CreateInstance(Process *process,
49                                                      bool force) {
50  bool create = force;
51  if (!create) {
52    const llvm::Triple &triple_ref =
53        process->GetTarget().GetArchitecture().GetTriple();
54    if (triple_ref.getOS() == llvm::Triple::FreeBSD ||
55        triple_ref.getOS() == llvm::Triple::Linux ||
56        triple_ref.getOS() == llvm::Triple::NetBSD ||
57        triple_ref.getOS() == llvm::Triple::OpenBSD)
58      create = true;
59  }
60
61  if (create)
62    return new DynamicLoaderPOSIXDYLD(process);
63  return nullptr;
64}
65
66DynamicLoaderPOSIXDYLD::DynamicLoaderPOSIXDYLD(Process *process)
67    : DynamicLoader(process), m_rendezvous(process),
68      m_load_offset(LLDB_INVALID_ADDRESS), m_entry_point(LLDB_INVALID_ADDRESS),
69      m_auxv(), m_dyld_bid(LLDB_INVALID_BREAK_ID),
70      m_vdso_base(LLDB_INVALID_ADDRESS),
71      m_interpreter_base(LLDB_INVALID_ADDRESS), m_initial_modules_added(false) {
72}
73
74DynamicLoaderPOSIXDYLD::~DynamicLoaderPOSIXDYLD() {
75  if (m_dyld_bid != LLDB_INVALID_BREAK_ID) {
76    m_process->GetTarget().RemoveBreakpointByID(m_dyld_bid);
77    m_dyld_bid = LLDB_INVALID_BREAK_ID;
78  }
79}
80
81void DynamicLoaderPOSIXDYLD::DidAttach() {
82  Log *log = GetLog(LLDBLog::DynamicLoader);
83  LLDB_LOGF(log, "DynamicLoaderPOSIXDYLD::%s() pid %" PRIu64, __FUNCTION__,
84            m_process ? m_process->GetID() : LLDB_INVALID_PROCESS_ID);
85  m_auxv = std::make_unique<AuxVector>(m_process->GetAuxvData());
86
87  LLDB_LOGF(
88      log, "DynamicLoaderPOSIXDYLD::%s pid %" PRIu64 " reloaded auxv data",
89      __FUNCTION__, m_process ? m_process->GetID() : LLDB_INVALID_PROCESS_ID);
90
91  ModuleSP executable_sp = GetTargetExecutable();
92  ResolveExecutableModule(executable_sp);
93  m_rendezvous.UpdateExecutablePath();
94
95  // find the main process load offset
96  addr_t load_offset = ComputeLoadOffset();
97  LLDB_LOGF(log,
98            "DynamicLoaderPOSIXDYLD::%s pid %" PRIu64
99            " executable '%s', load_offset 0x%" PRIx64,
100            __FUNCTION__,
101            m_process ? m_process->GetID() : LLDB_INVALID_PROCESS_ID,
102            executable_sp ? executable_sp->GetFileSpec().GetPath().c_str()
103                          : "<null executable>",
104            load_offset);
105
106  EvalSpecialModulesStatus();
107
108  // if we dont have a load address we cant re-base
109  bool rebase_exec = load_offset != LLDB_INVALID_ADDRESS;
110
111  // if we have a valid executable
112  if (executable_sp.get()) {
113    lldb_private::ObjectFile *obj = executable_sp->GetObjectFile();
114    if (obj) {
115      // don't rebase if the module already has a load address
116      Target &target = m_process->GetTarget();
117      Address addr = obj->GetImageInfoAddress(&target);
118      if (addr.GetLoadAddress(&target) != LLDB_INVALID_ADDRESS)
119        rebase_exec = false;
120    }
121  } else {
122    // no executable, nothing to re-base
123    rebase_exec = false;
124  }
125
126  // if the target executable should be re-based
127  if (rebase_exec) {
128    ModuleList module_list;
129
130    module_list.Append(executable_sp);
131    LLDB_LOGF(log,
132              "DynamicLoaderPOSIXDYLD::%s pid %" PRIu64
133              " added executable '%s' to module load list",
134              __FUNCTION__,
135              m_process ? m_process->GetID() : LLDB_INVALID_PROCESS_ID,
136              executable_sp->GetFileSpec().GetPath().c_str());
137
138    UpdateLoadedSections(executable_sp, LLDB_INVALID_ADDRESS, load_offset,
139                         true);
140
141    LoadAllCurrentModules();
142
143    m_process->GetTarget().ModulesDidLoad(module_list);
144    if (log) {
145      LLDB_LOGF(log,
146                "DynamicLoaderPOSIXDYLD::%s told the target about the "
147                "modules that loaded:",
148                __FUNCTION__);
149      for (auto module_sp : module_list.Modules()) {
150        LLDB_LOGF(log, "-- [module] %s (pid %" PRIu64 ")",
151                  module_sp ? module_sp->GetFileSpec().GetPath().c_str()
152                            : "<null>",
153                  m_process ? m_process->GetID() : LLDB_INVALID_PROCESS_ID);
154      }
155    }
156  }
157
158  if (executable_sp.get()) {
159    if (!SetRendezvousBreakpoint()) {
160      // If we cannot establish rendezvous breakpoint right now we'll try again
161      // at entry point.
162      ProbeEntry();
163    }
164  }
165}
166
167void DynamicLoaderPOSIXDYLD::DidLaunch() {
168  Log *log = GetLog(LLDBLog::DynamicLoader);
169  LLDB_LOGF(log, "DynamicLoaderPOSIXDYLD::%s()", __FUNCTION__);
170
171  ModuleSP executable;
172  addr_t load_offset;
173
174  m_auxv = std::make_unique<AuxVector>(m_process->GetAuxvData());
175
176  executable = GetTargetExecutable();
177  load_offset = ComputeLoadOffset();
178  EvalSpecialModulesStatus();
179
180  if (executable.get() && load_offset != LLDB_INVALID_ADDRESS) {
181    ModuleList module_list;
182    module_list.Append(executable);
183    UpdateLoadedSections(executable, LLDB_INVALID_ADDRESS, load_offset, true);
184
185    LLDB_LOGF(log, "DynamicLoaderPOSIXDYLD::%s about to call ProbeEntry()",
186              __FUNCTION__);
187
188    if (!SetRendezvousBreakpoint()) {
189      // If we cannot establish rendezvous breakpoint right now we'll try again
190      // at entry point.
191      ProbeEntry();
192    }
193
194    LoadVDSO();
195    m_process->GetTarget().ModulesDidLoad(module_list);
196  }
197}
198
199Status DynamicLoaderPOSIXDYLD::CanLoadImage() { return Status(); }
200
201void DynamicLoaderPOSIXDYLD::UpdateLoadedSections(ModuleSP module,
202                                                  addr_t link_map_addr,
203                                                  addr_t base_addr,
204                                                  bool base_addr_is_offset) {
205  m_loaded_modules[module] = link_map_addr;
206  UpdateLoadedSectionsCommon(module, base_addr, base_addr_is_offset);
207}
208
209void DynamicLoaderPOSIXDYLD::UnloadSections(const ModuleSP module) {
210  m_loaded_modules.erase(module);
211
212  UnloadSectionsCommon(module);
213}
214
215void DynamicLoaderPOSIXDYLD::ProbeEntry() {
216  Log *log = GetLog(LLDBLog::DynamicLoader);
217
218  // If we have a core file, we don't need any breakpoints.
219  if (IsCoreFile())
220    return;
221
222  const addr_t entry = GetEntryPoint();
223  if (entry == LLDB_INVALID_ADDRESS) {
224    LLDB_LOGF(
225        log,
226        "DynamicLoaderPOSIXDYLD::%s pid %" PRIu64
227        " GetEntryPoint() returned no address, not setting entry breakpoint",
228        __FUNCTION__, m_process ? m_process->GetID() : LLDB_INVALID_PROCESS_ID);
229    return;
230  }
231
232  LLDB_LOGF(log,
233            "DynamicLoaderPOSIXDYLD::%s pid %" PRIu64
234            " GetEntryPoint() returned address 0x%" PRIx64
235            ", setting entry breakpoint",
236            __FUNCTION__,
237            m_process ? m_process->GetID() : LLDB_INVALID_PROCESS_ID, entry);
238
239  if (m_process) {
240    Breakpoint *const entry_break =
241        m_process->GetTarget().CreateBreakpoint(entry, true, false).get();
242    entry_break->SetCallback(EntryBreakpointHit, this, true);
243    entry_break->SetBreakpointKind("shared-library-event");
244
245    // Shoudn't hit this more than once.
246    entry_break->SetOneShot(true);
247  }
248}
249
250// The runtime linker has run and initialized the rendezvous structure once the
251// process has hit its entry point.  When we hit the corresponding breakpoint
252// we interrogate the rendezvous structure to get the load addresses of all
253// dependent modules for the process.  Similarly, we can discover the runtime
254// linker function and setup a breakpoint to notify us of any dynamically
255// loaded modules (via dlopen).
256bool DynamicLoaderPOSIXDYLD::EntryBreakpointHit(
257    void *baton, StoppointCallbackContext *context, user_id_t break_id,
258    user_id_t break_loc_id) {
259  assert(baton && "null baton");
260  if (!baton)
261    return false;
262
263  Log *log = GetLog(LLDBLog::DynamicLoader);
264  DynamicLoaderPOSIXDYLD *const dyld_instance =
265      static_cast<DynamicLoaderPOSIXDYLD *>(baton);
266  LLDB_LOGF(log, "DynamicLoaderPOSIXDYLD::%s called for pid %" PRIu64,
267            __FUNCTION__,
268            dyld_instance->m_process ? dyld_instance->m_process->GetID()
269                                     : LLDB_INVALID_PROCESS_ID);
270
271  // Disable the breakpoint --- if a stop happens right after this, which we've
272  // seen on occasion, we don't want the breakpoint stepping thread-plan logic
273  // to show a breakpoint instruction at the disassembled entry point to the
274  // program.  Disabling it prevents it.  (One-shot is not enough - one-shot
275  // removal logic only happens after the breakpoint goes public, which wasn't
276  // happening in our scenario).
277  if (dyld_instance->m_process) {
278    BreakpointSP breakpoint_sp =
279        dyld_instance->m_process->GetTarget().GetBreakpointByID(break_id);
280    if (breakpoint_sp) {
281      LLDB_LOGF(log,
282                "DynamicLoaderPOSIXDYLD::%s pid %" PRIu64
283                " disabling breakpoint id %" PRIu64,
284                __FUNCTION__, dyld_instance->m_process->GetID(), break_id);
285      breakpoint_sp->SetEnabled(false);
286    } else {
287      LLDB_LOGF(log,
288                "DynamicLoaderPOSIXDYLD::%s pid %" PRIu64
289                " failed to find breakpoint for breakpoint id %" PRIu64,
290                __FUNCTION__, dyld_instance->m_process->GetID(), break_id);
291    }
292  } else {
293    LLDB_LOGF(log,
294              "DynamicLoaderPOSIXDYLD::%s breakpoint id %" PRIu64
295              " no Process instance!  Cannot disable breakpoint",
296              __FUNCTION__, break_id);
297  }
298
299  dyld_instance->LoadAllCurrentModules();
300  dyld_instance->SetRendezvousBreakpoint();
301  return false; // Continue running.
302}
303
304bool DynamicLoaderPOSIXDYLD::SetRendezvousBreakpoint() {
305  Log *log = GetLog(LLDBLog::DynamicLoader);
306
307  // If we have a core file, we don't need any breakpoints.
308  if (IsCoreFile())
309    return false;
310
311  if (m_dyld_bid != LLDB_INVALID_BREAK_ID) {
312    LLDB_LOG(log,
313             "Rendezvous breakpoint breakpoint id {0} for pid {1}"
314             "is already set.",
315             m_dyld_bid,
316             m_process ? m_process->GetID() : LLDB_INVALID_PROCESS_ID);
317    return true;
318  }
319
320  addr_t break_addr;
321  Target &target = m_process->GetTarget();
322  BreakpointSP dyld_break;
323  if (m_rendezvous.IsValid() && m_rendezvous.GetBreakAddress() != 0) {
324    break_addr = m_rendezvous.GetBreakAddress();
325    LLDB_LOG(log, "Setting rendezvous break address for pid {0} at {1:x}",
326             m_process ? m_process->GetID() : LLDB_INVALID_PROCESS_ID,
327             break_addr);
328    dyld_break = target.CreateBreakpoint(break_addr, true, false);
329  } else {
330    LLDB_LOG(log, "Rendezvous structure is not set up yet. "
331                  "Trying to locate rendezvous breakpoint in the interpreter "
332                  "by symbol name.");
333    // Function names from different dynamic loaders that are known to be
334    // used as rendezvous between the loader and debuggers.
335    static std::vector<std::string> DebugStateCandidates{
336        "_dl_debug_state", "rtld_db_dlactivity", "__dl_rtld_db_dlactivity",
337        "r_debug_state",   "_r_debug_state",     "_rtld_debug_state",
338    };
339
340    ModuleSP interpreter = LoadInterpreterModule();
341    FileSpecList containingModules;
342    if (interpreter)
343      containingModules.Append(interpreter->GetFileSpec());
344    else
345      containingModules.Append(
346          m_process->GetTarget().GetExecutableModulePointer()->GetFileSpec());
347
348    dyld_break = target.CreateBreakpoint(
349        &containingModules, /*containingSourceFiles=*/nullptr,
350        DebugStateCandidates, eFunctionNameTypeFull, eLanguageTypeC,
351        /*m_offset=*/0,
352        /*skip_prologue=*/eLazyBoolNo,
353        /*internal=*/true,
354        /*request_hardware=*/false);
355  }
356
357  if (dyld_break->GetNumResolvedLocations() != 1) {
358    LLDB_LOG(
359        log,
360        "Rendezvous breakpoint has abnormal number of"
361        " resolved locations ({0}) in pid {1}. It's supposed to be exactly 1.",
362        dyld_break->GetNumResolvedLocations(),
363        m_process ? m_process->GetID() : LLDB_INVALID_PROCESS_ID);
364
365    target.RemoveBreakpointByID(dyld_break->GetID());
366    return false;
367  }
368
369  BreakpointLocationSP location = dyld_break->GetLocationAtIndex(0);
370  LLDB_LOG(log,
371           "Successfully set rendezvous breakpoint at address {0:x} "
372           "for pid {1}",
373           location->GetLoadAddress(),
374           m_process ? m_process->GetID() : LLDB_INVALID_PROCESS_ID);
375
376  dyld_break->SetCallback(RendezvousBreakpointHit, this, true);
377  dyld_break->SetBreakpointKind("shared-library-event");
378  m_dyld_bid = dyld_break->GetID();
379  return true;
380}
381
382bool DynamicLoaderPOSIXDYLD::RendezvousBreakpointHit(
383    void *baton, StoppointCallbackContext *context, user_id_t break_id,
384    user_id_t break_loc_id) {
385  assert(baton && "null baton");
386  if (!baton)
387    return false;
388
389  Log *log = GetLog(LLDBLog::DynamicLoader);
390  DynamicLoaderPOSIXDYLD *const dyld_instance =
391      static_cast<DynamicLoaderPOSIXDYLD *>(baton);
392  LLDB_LOGF(log, "DynamicLoaderPOSIXDYLD::%s called for pid %" PRIu64,
393            __FUNCTION__,
394            dyld_instance->m_process ? dyld_instance->m_process->GetID()
395                                     : LLDB_INVALID_PROCESS_ID);
396
397  dyld_instance->RefreshModules();
398
399  // Return true to stop the target, false to just let the target run.
400  const bool stop_when_images_change = dyld_instance->GetStopWhenImagesChange();
401  LLDB_LOGF(log,
402            "DynamicLoaderPOSIXDYLD::%s pid %" PRIu64
403            " stop_when_images_change=%s",
404            __FUNCTION__,
405            dyld_instance->m_process ? dyld_instance->m_process->GetID()
406                                     : LLDB_INVALID_PROCESS_ID,
407            stop_when_images_change ? "true" : "false");
408  return stop_when_images_change;
409}
410
411void DynamicLoaderPOSIXDYLD::RefreshModules() {
412  if (!m_rendezvous.Resolve())
413    return;
414
415  // The rendezvous class doesn't enumerate the main module, so track that
416  // ourselves here.
417  ModuleSP executable = GetTargetExecutable();
418  m_loaded_modules[executable] = m_rendezvous.GetLinkMapAddress();
419
420  DYLDRendezvous::iterator I;
421  DYLDRendezvous::iterator E;
422
423  ModuleList &loaded_modules = m_process->GetTarget().GetImages();
424
425  if (m_rendezvous.ModulesDidLoad() || !m_initial_modules_added) {
426    ModuleList new_modules;
427
428    // If this is the first time rendezvous breakpoint fires, we need
429    // to take care of adding all the initial modules reported by
430    // the loader.  This is necessary to list ld-linux.so on Linux,
431    // and all DT_NEEDED entries on *BSD.
432    if (m_initial_modules_added) {
433      I = m_rendezvous.loaded_begin();
434      E = m_rendezvous.loaded_end();
435    } else {
436      I = m_rendezvous.begin();
437      E = m_rendezvous.end();
438      m_initial_modules_added = true;
439    }
440    for (; I != E; ++I) {
441      // Don't load a duplicate copy of ld.so if we have already loaded it
442      // earlier in LoadInterpreterModule. If we instead loaded then unloaded it
443      // later, the section information for ld.so would be removed. That
444      // information is required for placing breakpoints on Arm/Thumb systems.
445      if ((m_interpreter_module.lock() != nullptr) &&
446          (I->base_addr == m_interpreter_base))
447        continue;
448
449      ModuleSP module_sp =
450          LoadModuleAtAddress(I->file_spec, I->link_addr, I->base_addr, true);
451      if (!module_sp.get())
452        continue;
453
454      if (module_sp->GetObjectFile()->GetBaseAddress().GetLoadAddress(
455              &m_process->GetTarget()) == m_interpreter_base) {
456        ModuleSP interpreter_sp = m_interpreter_module.lock();
457        if (m_interpreter_module.lock() == nullptr) {
458          m_interpreter_module = module_sp;
459        } else if (module_sp == interpreter_sp) {
460          // Module already loaded.
461          continue;
462        }
463      }
464
465      loaded_modules.AppendIfNeeded(module_sp);
466      new_modules.Append(module_sp);
467    }
468    m_process->GetTarget().ModulesDidLoad(new_modules);
469  }
470
471  if (m_rendezvous.ModulesDidUnload()) {
472    ModuleList old_modules;
473
474    E = m_rendezvous.unloaded_end();
475    for (I = m_rendezvous.unloaded_begin(); I != E; ++I) {
476      ModuleSpec module_spec{I->file_spec};
477      ModuleSP module_sp = loaded_modules.FindFirstModule(module_spec);
478
479      if (module_sp.get()) {
480        old_modules.Append(module_sp);
481        UnloadSections(module_sp);
482      }
483    }
484    loaded_modules.Remove(old_modules);
485    m_process->GetTarget().ModulesDidUnload(old_modules, false);
486  }
487}
488
489ThreadPlanSP
490DynamicLoaderPOSIXDYLD::GetStepThroughTrampolinePlan(Thread &thread,
491                                                     bool stop) {
492  ThreadPlanSP thread_plan_sp;
493
494  StackFrame *frame = thread.GetStackFrameAtIndex(0).get();
495  const SymbolContext &context = frame->GetSymbolContext(eSymbolContextSymbol);
496  Symbol *sym = context.symbol;
497
498  if (sym == nullptr || !sym->IsTrampoline())
499    return thread_plan_sp;
500
501  ConstString sym_name = sym->GetMangled().GetName(Mangled::ePreferMangled);
502  if (!sym_name)
503    return thread_plan_sp;
504
505  SymbolContextList target_symbols;
506  Target &target = thread.GetProcess()->GetTarget();
507  const ModuleList &images = target.GetImages();
508
509  images.FindSymbolsWithNameAndType(sym_name, eSymbolTypeCode, target_symbols);
510  if (!target_symbols.GetSize())
511    return thread_plan_sp;
512
513  typedef std::vector<lldb::addr_t> AddressVector;
514  AddressVector addrs;
515  for (const SymbolContext &context : target_symbols) {
516    AddressRange range;
517    context.GetAddressRange(eSymbolContextEverything, 0, false, range);
518    lldb::addr_t addr = range.GetBaseAddress().GetLoadAddress(&target);
519    if (addr != LLDB_INVALID_ADDRESS)
520      addrs.push_back(addr);
521  }
522
523  if (addrs.size() > 0) {
524    AddressVector::iterator start = addrs.begin();
525    AddressVector::iterator end = addrs.end();
526
527    llvm::sort(start, end);
528    addrs.erase(std::unique(start, end), end);
529    thread_plan_sp =
530        std::make_shared<ThreadPlanRunToAddress>(thread, addrs, stop);
531  }
532
533  return thread_plan_sp;
534}
535
536void DynamicLoaderPOSIXDYLD::LoadVDSO() {
537  if (m_vdso_base == LLDB_INVALID_ADDRESS)
538    return;
539
540  FileSpec file("[vdso]");
541
542  MemoryRegionInfo info;
543  Status status = m_process->GetMemoryRegionInfo(m_vdso_base, info);
544  if (status.Fail()) {
545    Log *log = GetLog(LLDBLog::DynamicLoader);
546    LLDB_LOG(log, "Failed to get vdso region info: {0}", status);
547    return;
548  }
549
550  if (ModuleSP module_sp = m_process->ReadModuleFromMemory(
551          file, m_vdso_base, info.GetRange().GetByteSize())) {
552    UpdateLoadedSections(module_sp, LLDB_INVALID_ADDRESS, m_vdso_base, false);
553    m_process->GetTarget().GetImages().AppendIfNeeded(module_sp);
554  }
555}
556
557ModuleSP DynamicLoaderPOSIXDYLD::LoadInterpreterModule() {
558  if (m_interpreter_base == LLDB_INVALID_ADDRESS)
559    return nullptr;
560
561  MemoryRegionInfo info;
562  Target &target = m_process->GetTarget();
563  Status status = m_process->GetMemoryRegionInfo(m_interpreter_base, info);
564  if (status.Fail() || info.GetMapped() != MemoryRegionInfo::eYes ||
565      info.GetName().IsEmpty()) {
566    Log *log = GetLog(LLDBLog::DynamicLoader);
567    LLDB_LOG(log, "Failed to get interpreter region info: {0}", status);
568    return nullptr;
569  }
570
571  FileSpec file(info.GetName().GetCString());
572  ModuleSpec module_spec(file, target.GetArchitecture());
573
574  if (ModuleSP module_sp = target.GetOrCreateModule(module_spec,
575                                                    true /* notify */)) {
576    UpdateLoadedSections(module_sp, LLDB_INVALID_ADDRESS, m_interpreter_base,
577                         false);
578    m_interpreter_module = module_sp;
579    return module_sp;
580  }
581  return nullptr;
582}
583
584ModuleSP DynamicLoaderPOSIXDYLD::LoadModuleAtAddress(const FileSpec &file,
585                                                     addr_t link_map_addr,
586                                                     addr_t base_addr,
587                                                     bool base_addr_is_offset) {
588  if (ModuleSP module_sp = DynamicLoader::LoadModuleAtAddress(
589          file, link_map_addr, base_addr, base_addr_is_offset))
590    return module_sp;
591
592  // This works around an dynamic linker "bug" on android <= 23, where the
593  // dynamic linker would report the application name
594  // (e.g. com.example.myapplication) instead of the main process binary
595  // (/system/bin/app_process(32)). The logic is not sound in general (it
596  // assumes base_addr is the real address, even though it actually is a load
597  // bias), but it happens to work on android because app_process has a file
598  // address of zero.
599  // This should be removed after we drop support for android-23.
600  if (m_process->GetTarget().GetArchitecture().GetTriple().isAndroid()) {
601    MemoryRegionInfo memory_info;
602    Status error = m_process->GetMemoryRegionInfo(base_addr, memory_info);
603    if (error.Success() && memory_info.GetMapped() &&
604        memory_info.GetRange().GetRangeBase() == base_addr &&
605        !(memory_info.GetName().IsEmpty())) {
606      if (ModuleSP module_sp = DynamicLoader::LoadModuleAtAddress(
607              FileSpec(memory_info.GetName().GetStringRef()), link_map_addr,
608              base_addr, base_addr_is_offset))
609        return module_sp;
610    }
611  }
612
613  return nullptr;
614}
615
616void DynamicLoaderPOSIXDYLD::LoadAllCurrentModules() {
617  DYLDRendezvous::iterator I;
618  DYLDRendezvous::iterator E;
619  ModuleList module_list;
620  Log *log = GetLog(LLDBLog::DynamicLoader);
621
622  LoadVDSO();
623
624  if (!m_rendezvous.Resolve()) {
625    LLDB_LOGF(log,
626              "DynamicLoaderPOSIXDYLD::%s unable to resolve POSIX DYLD "
627              "rendezvous address",
628              __FUNCTION__);
629    return;
630  }
631
632  // The rendezvous class doesn't enumerate the main module, so track that
633  // ourselves here.
634  ModuleSP executable = GetTargetExecutable();
635  m_loaded_modules[executable] = m_rendezvous.GetLinkMapAddress();
636
637  std::vector<FileSpec> module_names;
638  for (I = m_rendezvous.begin(), E = m_rendezvous.end(); I != E; ++I)
639    module_names.push_back(I->file_spec);
640  m_process->PrefetchModuleSpecs(
641      module_names, m_process->GetTarget().GetArchitecture().GetTriple());
642
643  for (I = m_rendezvous.begin(), E = m_rendezvous.end(); I != E; ++I) {
644    ModuleSP module_sp =
645        LoadModuleAtAddress(I->file_spec, I->link_addr, I->base_addr, true);
646    if (module_sp.get()) {
647      LLDB_LOG(log, "LoadAllCurrentModules loading module: {0}",
648               I->file_spec.GetFilename());
649      module_list.Append(module_sp);
650    } else {
651      Log *log = GetLog(LLDBLog::DynamicLoader);
652      LLDB_LOGF(
653          log,
654          "DynamicLoaderPOSIXDYLD::%s failed loading module %s at 0x%" PRIx64,
655          __FUNCTION__, I->file_spec.GetPath().c_str(), I->base_addr);
656    }
657  }
658
659  m_process->GetTarget().ModulesDidLoad(module_list);
660  m_initial_modules_added = true;
661}
662
663addr_t DynamicLoaderPOSIXDYLD::ComputeLoadOffset() {
664  addr_t virt_entry;
665
666  if (m_load_offset != LLDB_INVALID_ADDRESS)
667    return m_load_offset;
668
669  if ((virt_entry = GetEntryPoint()) == LLDB_INVALID_ADDRESS)
670    return LLDB_INVALID_ADDRESS;
671
672  ModuleSP module = m_process->GetTarget().GetExecutableModule();
673  if (!module)
674    return LLDB_INVALID_ADDRESS;
675
676  ObjectFile *exe = module->GetObjectFile();
677  if (!exe)
678    return LLDB_INVALID_ADDRESS;
679
680  Address file_entry = exe->GetEntryPointAddress();
681
682  if (!file_entry.IsValid())
683    return LLDB_INVALID_ADDRESS;
684
685  m_load_offset = virt_entry - file_entry.GetFileAddress();
686  return m_load_offset;
687}
688
689void DynamicLoaderPOSIXDYLD::EvalSpecialModulesStatus() {
690  if (std::optional<uint64_t> vdso_base =
691          m_auxv->GetAuxValue(AuxVector::AUXV_AT_SYSINFO_EHDR))
692    m_vdso_base = *vdso_base;
693
694  if (std::optional<uint64_t> interpreter_base =
695          m_auxv->GetAuxValue(AuxVector::AUXV_AT_BASE))
696    m_interpreter_base = *interpreter_base;
697}
698
699addr_t DynamicLoaderPOSIXDYLD::GetEntryPoint() {
700  if (m_entry_point != LLDB_INVALID_ADDRESS)
701    return m_entry_point;
702
703  if (m_auxv == nullptr)
704    return LLDB_INVALID_ADDRESS;
705
706  std::optional<uint64_t> entry_point =
707      m_auxv->GetAuxValue(AuxVector::AUXV_AT_ENTRY);
708  if (!entry_point)
709    return LLDB_INVALID_ADDRESS;
710
711  m_entry_point = static_cast<addr_t>(*entry_point);
712
713  const ArchSpec &arch = m_process->GetTarget().GetArchitecture();
714
715  // On ppc64, the entry point is actually a descriptor.  Dereference it.
716  if (arch.GetMachine() == llvm::Triple::ppc64)
717    m_entry_point = ReadUnsignedIntWithSizeInBytes(m_entry_point, 8);
718
719  return m_entry_point;
720}
721
722lldb::addr_t
723DynamicLoaderPOSIXDYLD::GetThreadLocalData(const lldb::ModuleSP module_sp,
724                                           const lldb::ThreadSP thread,
725                                           lldb::addr_t tls_file_addr) {
726  Log *log = GetLog(LLDBLog::DynamicLoader);
727  auto it = m_loaded_modules.find(module_sp);
728  if (it == m_loaded_modules.end()) {
729    LLDB_LOGF(
730        log, "GetThreadLocalData error: module(%s) not found in loaded modules",
731        module_sp->GetObjectName().AsCString());
732    return LLDB_INVALID_ADDRESS;
733  }
734
735  addr_t link_map = it->second;
736  if (link_map == LLDB_INVALID_ADDRESS || link_map == 0) {
737    LLDB_LOGF(log,
738              "GetThreadLocalData error: invalid link map address=0x%" PRIx64,
739              link_map);
740    return LLDB_INVALID_ADDRESS;
741  }
742
743  const DYLDRendezvous::ThreadInfo &metadata = m_rendezvous.GetThreadInfo();
744  if (!metadata.valid) {
745    LLDB_LOGF(log,
746              "GetThreadLocalData error: fail to read thread info metadata");
747    return LLDB_INVALID_ADDRESS;
748  }
749
750  LLDB_LOGF(log,
751            "GetThreadLocalData info: link_map=0x%" PRIx64
752            ", thread info metadata: "
753            "modid_offset=0x%" PRIx32 ", dtv_offset=0x%" PRIx32
754            ", tls_offset=0x%" PRIx32 ", dtv_slot_size=%" PRIx32 "\n",
755            link_map, metadata.modid_offset, metadata.dtv_offset,
756            metadata.tls_offset, metadata.dtv_slot_size);
757
758  // Get the thread pointer.
759  addr_t tp = thread->GetThreadPointer();
760  if (tp == LLDB_INVALID_ADDRESS) {
761    LLDB_LOGF(log, "GetThreadLocalData error: fail to read thread pointer");
762    return LLDB_INVALID_ADDRESS;
763  }
764
765  // Find the module's modid.
766  int modid_size = 4; // FIXME(spucci): This isn't right for big-endian 64-bit
767  int64_t modid = ReadUnsignedIntWithSizeInBytes(
768      link_map + metadata.modid_offset, modid_size);
769  if (modid == -1) {
770    LLDB_LOGF(log, "GetThreadLocalData error: fail to read modid");
771    return LLDB_INVALID_ADDRESS;
772  }
773
774  // Lookup the DTV structure for this thread.
775  addr_t dtv_ptr = tp + metadata.dtv_offset;
776  addr_t dtv = ReadPointer(dtv_ptr);
777  if (dtv == LLDB_INVALID_ADDRESS) {
778    LLDB_LOGF(log, "GetThreadLocalData error: fail to read dtv");
779    return LLDB_INVALID_ADDRESS;
780  }
781
782  // Find the TLS block for this module.
783  addr_t dtv_slot = dtv + metadata.dtv_slot_size * modid;
784  addr_t tls_block = ReadPointer(dtv_slot + metadata.tls_offset);
785
786  LLDB_LOGF(log,
787            "DynamicLoaderPOSIXDYLD::Performed TLS lookup: "
788            "module=%s, link_map=0x%" PRIx64 ", tp=0x%" PRIx64
789            ", modid=%" PRId64 ", tls_block=0x%" PRIx64 "\n",
790            module_sp->GetObjectName().AsCString(""), link_map, tp,
791            (int64_t)modid, tls_block);
792
793  if (tls_block == LLDB_INVALID_ADDRESS) {
794    LLDB_LOGF(log, "GetThreadLocalData error: fail to read tls_block");
795    return LLDB_INVALID_ADDRESS;
796  } else
797    return tls_block + tls_file_addr;
798}
799
800void DynamicLoaderPOSIXDYLD::ResolveExecutableModule(
801    lldb::ModuleSP &module_sp) {
802  Log *log = GetLog(LLDBLog::DynamicLoader);
803
804  if (m_process == nullptr)
805    return;
806
807  auto &target = m_process->GetTarget();
808  const auto platform_sp = target.GetPlatform();
809
810  ProcessInstanceInfo process_info;
811  if (!m_process->GetProcessInfo(process_info)) {
812    LLDB_LOGF(log,
813              "DynamicLoaderPOSIXDYLD::%s - failed to get process info for "
814              "pid %" PRIu64,
815              __FUNCTION__, m_process->GetID());
816    return;
817  }
818
819  LLDB_LOGF(
820      log, "DynamicLoaderPOSIXDYLD::%s - got executable by pid %" PRIu64 ": %s",
821      __FUNCTION__, m_process->GetID(),
822      process_info.GetExecutableFile().GetPath().c_str());
823
824  ModuleSpec module_spec(process_info.GetExecutableFile(),
825                         process_info.GetArchitecture());
826  if (module_sp && module_sp->MatchesModuleSpec(module_spec))
827    return;
828
829  const auto executable_search_paths(Target::GetDefaultExecutableSearchPaths());
830  auto error = platform_sp->ResolveExecutable(
831      module_spec, module_sp,
832      !executable_search_paths.IsEmpty() ? &executable_search_paths : nullptr);
833  if (error.Fail()) {
834    StreamString stream;
835    module_spec.Dump(stream);
836
837    LLDB_LOGF(log,
838              "DynamicLoaderPOSIXDYLD::%s - failed to resolve executable "
839              "with module spec \"%s\": %s",
840              __FUNCTION__, stream.GetData(), error.AsCString());
841    return;
842  }
843
844  target.SetExecutableModule(module_sp, eLoadDependentsNo);
845}
846
847bool DynamicLoaderPOSIXDYLD::AlwaysRelyOnEHUnwindInfo(
848    lldb_private::SymbolContext &sym_ctx) {
849  ModuleSP module_sp;
850  if (sym_ctx.symbol)
851    module_sp = sym_ctx.symbol->GetAddressRef().GetModule();
852  if (!module_sp && sym_ctx.function)
853    module_sp =
854        sym_ctx.function->GetAddressRange().GetBaseAddress().GetModule();
855  if (!module_sp)
856    return false;
857
858  return module_sp->GetFileSpec().GetPath() == "[vdso]";
859}
860
861bool DynamicLoaderPOSIXDYLD::IsCoreFile() const {
862  return !m_process->IsLiveDebugSession();
863}
864