contrib/llvm/tools/lldb/source/Plugins/DynamicLoader/POSIX-DYLD/DynamicLoaderPOSIXDYLD.cpp

   1 //===-- DynamicLoaderPOSIX.h ------------------------------------*- C++ -*-===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 // C Includes
  11 // C++ Includes
  12 // Other libraries and framework includes
  13 #include "lldb/Core/PluginManager.h"
  14 #include "lldb/Core/Log.h"
  15 #include "lldb/Core/Module.h"
  16 #include "lldb/Core/ModuleSpec.h"
  17 #include "lldb/Core/Section.h"
  18 #include "lldb/Symbol/ObjectFile.h"
  19 #include "lldb/Target/Process.h"
  20 #include "lldb/Target/Target.h"
  21 #include "lldb/Target/Thread.h"
  22 #include "lldb/Target/ThreadPlanRunToAddress.h"
  23 #include "lldb/Breakpoint/BreakpointLocation.h"
  24
  25 #include "AuxVector.h"
  26 #include "DynamicLoaderPOSIXDYLD.h"
  27
  28 using namespace lldb;
  29 using namespace lldb_private;
  30
  31 void
  32 DynamicLoaderPOSIXDYLD::Initialize()
  33 {
  34     PluginManager::RegisterPlugin(GetPluginNameStatic(),
  35                                   GetPluginDescriptionStatic(),
  36                                   CreateInstance);
  37 }
  38
  39 void
  40 DynamicLoaderPOSIXDYLD::Terminate()
  41 {
  42 }
  43
  44 lldb_private::ConstString
  45 DynamicLoaderPOSIXDYLD::GetPluginName()
  46 {
  47     return GetPluginNameStatic();
  48 }
  49
  50 lldb_private::ConstString
  51 DynamicLoaderPOSIXDYLD::GetPluginNameStatic()
  52 {
  53     static ConstString g_name("linux-dyld");
  54     return g_name;
  55 }
  56
  57 const char *
  58 DynamicLoaderPOSIXDYLD::GetPluginDescriptionStatic()
  59 {
  60     return "Dynamic loader plug-in that watches for shared library "
  61            "loads/unloads in POSIX processes.";
  62 }
  63
  64 void
  65 DynamicLoaderPOSIXDYLD::GetPluginCommandHelp(const char *command, Stream *strm)
  66 {
  67 }
  68
  69 uint32_t
  70 DynamicLoaderPOSIXDYLD::GetPluginVersion()
  71 {
  72     return 1;
  73 }
  74
  75 DynamicLoader *
  76 DynamicLoaderPOSIXDYLD::CreateInstance(Process *process, bool force)
  77 {
  78     bool create = force;
  79     if (!create)
  80     {
  81         const llvm::Triple &triple_ref = process->GetTarget().GetArchitecture().GetTriple();
  82         if (triple_ref.getOS() == llvm::Triple::Linux ||
  83             triple_ref.getOS() == llvm::Triple::FreeBSD)
  84             create = true;
  85     }
  86
  87     if (create)
  88         return new DynamicLoaderPOSIXDYLD (process);
  89     return NULL;
  90 }
  91
  92 DynamicLoaderPOSIXDYLD::DynamicLoaderPOSIXDYLD(Process *process)
  93     : DynamicLoader(process),
  94       m_rendezvous(process),
  95       m_load_offset(LLDB_INVALID_ADDRESS),
  96       m_entry_point(LLDB_INVALID_ADDRESS),
  97       m_auxv(),
  98       m_dyld_bid(LLDB_INVALID_BREAK_ID)
  99 {
 100 }
 101
 102 DynamicLoaderPOSIXDYLD::~DynamicLoaderPOSIXDYLD()
 103 {
 104     if (m_dyld_bid != LLDB_INVALID_BREAK_ID)
 105     {
 106         m_process->GetTarget().RemoveBreakpointByID (m_dyld_bid);
 107         m_dyld_bid = LLDB_INVALID_BREAK_ID;
 108     }
 109 }
 110
 111 void
 112 DynamicLoaderPOSIXDYLD::DidAttach()
 113 {
 114     ModuleSP executable;
 115     addr_t load_offset;
 116
 117     m_auxv.reset(new AuxVector(m_process));
 118
 119     executable = GetTargetExecutable();
 120     load_offset = ComputeLoadOffset();
 121
 122     if (executable.get() && load_offset != LLDB_INVALID_ADDRESS)
 123     {
 124         ModuleList module_list;
 125         module_list.Append(executable);
 126         UpdateLoadedSections(executable, load_offset);
 127         LoadAllCurrentModules();
 128         m_process->GetTarget().ModulesDidLoad(module_list);
 129     }
 130 }
 131
 132 void
 133 DynamicLoaderPOSIXDYLD::DidLaunch()
 134 {
 135     ModuleSP executable;
 136     addr_t load_offset;
 137
 138     m_auxv.reset(new AuxVector(m_process));
 139
 140     executable = GetTargetExecutable();
 141     load_offset = ComputeLoadOffset();
 142
 143     if (executable.get() && load_offset != LLDB_INVALID_ADDRESS)
 144     {
 145         ModuleList module_list;
 146         module_list.Append(executable);
 147         UpdateLoadedSections(executable, load_offset);
 148         ProbeEntry();
 149         m_process->GetTarget().ModulesDidLoad(module_list);
 150     }
 151 }
 152
 153 ModuleSP
 154 DynamicLoaderPOSIXDYLD::GetTargetExecutable()
 155 {
 156     Target &target = m_process->GetTarget();
 157     ModuleSP executable = target.GetExecutableModule();
 158
 159     if (executable.get())
 160     {
 161         if (executable->GetFileSpec().Exists())
 162         {
 163             ModuleSpec module_spec (executable->GetFileSpec(), executable->GetArchitecture());
 164             ModuleSP module_sp (new Module (module_spec));
 165
 166             // Check if the executable has changed and set it to the target executable if they differ.
 167             if (module_sp.get() && module_sp->GetUUID().IsValid() && executable->GetUUID().IsValid())
 168             {
 169                 if (module_sp->GetUUID() != executable->GetUUID())
 170                     executable.reset();
 171             }
 172             else if (executable->FileHasChanged())
 173             {
 174                 executable.reset();
 175             }
 176
 177             if (!executable.get())
 178             {
 179                 executable = target.GetSharedModule(module_spec);
 180                 if (executable.get() != target.GetExecutableModulePointer())
 181                 {
 182                     // Don't load dependent images since we are in dyld where we will know
 183                     // and find out about all images that are loaded
 184                     const bool get_dependent_images = false;
 185                     target.SetExecutableModule(executable, get_dependent_images);
 186                 }
 187             }
 188         }
 189     }
 190     return executable;
 191 }
 192
 193 Error
 194 DynamicLoaderPOSIXDYLD::ExecutePluginCommand(Args &command, Stream *strm)
 195 {
 196     return Error();
 197 }
 198
 199 Log *
 200 DynamicLoaderPOSIXDYLD::EnablePluginLogging(Stream *strm, Args &command)
 201 {
 202     return NULL;
 203 }
 204
 205 Error
 206 DynamicLoaderPOSIXDYLD::CanLoadImage()
 207 {
 208     return Error();
 209 }
 210
 211 void
 212 DynamicLoaderPOSIXDYLD::UpdateLoadedSections(ModuleSP module, addr_t base_addr)
 213 {
 214     ObjectFile *obj_file = module->GetObjectFile();
 215     SectionList *sections = obj_file->GetSectionList();
 216     SectionLoadList &load_list = m_process->GetTarget().GetSectionLoadList();
 217     const size_t num_sections = sections->GetSize();
 218
 219     for (unsigned i = 0; i < num_sections; ++i)
 220     {
 221         SectionSP section_sp (sections->GetSectionAtIndex(i));
 222         lldb::addr_t new_load_addr = section_sp->GetFileAddress() + base_addr;
 223         lldb::addr_t old_load_addr = load_list.GetSectionLoadAddress(section_sp);
 224
 225         // If the file address of the section is zero then this is not an
 226         // allocatable/loadable section (property of ELF sh_addr).  Skip it.
 227         if (new_load_addr == base_addr)
 228             continue;
 229
 230         if (old_load_addr == LLDB_INVALID_ADDRESS ||
 231             old_load_addr != new_load_addr)
 232             load_list.SetSectionLoadAddress(section_sp, new_load_addr);
 233     }
 234 }
 235
 236 void
 237 DynamicLoaderPOSIXDYLD::ProbeEntry()
 238 {
 239     Breakpoint *entry_break;
 240     addr_t entry;
 241
 242     if ((entry = GetEntryPoint()) == LLDB_INVALID_ADDRESS)
 243         return;
 244
 245     entry_break = m_process->GetTarget().CreateBreakpoint(entry, true).get();
 246     entry_break->SetCallback(EntryBreakpointHit, this, true);
 247     entry_break->SetBreakpointKind("shared-library-event");
 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 we
 252 // 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 loaded
 255 // modules (via dlopen).
 256 bool
 257 DynamicLoaderPOSIXDYLD::EntryBreakpointHit(void *baton,
 258                                            StoppointCallbackContext *context,
 259                                            user_id_t break_id,
 260                                            user_id_t break_loc_id)
 261 {
 262     DynamicLoaderPOSIXDYLD* dyld_instance;
 263
 264     dyld_instance = static_cast<DynamicLoaderPOSIXDYLD*>(baton);
 265     dyld_instance->LoadAllCurrentModules();
 266     dyld_instance->SetRendezvousBreakpoint();
 267     return false; // Continue running.
 268 }
 269
 270 void
 271 DynamicLoaderPOSIXDYLD::SetRendezvousBreakpoint()
 272 {
 273     addr_t break_addr = m_rendezvous.GetBreakAddress();
 274     Target &target = m_process->GetTarget();
 275
 276     if (m_dyld_bid == LLDB_INVALID_BREAK_ID)
 277     {
 278         Breakpoint *dyld_break = target.CreateBreakpoint (break_addr, true).get();
 279         dyld_break->SetCallback(RendezvousBreakpointHit, this, true);
 280         dyld_break->SetBreakpointKind ("shared-library-event");
 281         m_dyld_bid = dyld_break->GetID();
 282     }
 283
 284     // Make sure our breakpoint is at the right address.
 285     assert (target.GetBreakpointByID(m_dyld_bid)->FindLocationByAddress(break_addr)->GetBreakpoint().GetID() == m_dyld_bid);
 286 }
 287
 288 bool
 289 DynamicLoaderPOSIXDYLD::RendezvousBreakpointHit(void *baton,
 290                                                 StoppointCallbackContext *context,
 291                                                 user_id_t break_id,
 292                                                 user_id_t break_loc_id)
 293 {
 294     DynamicLoaderPOSIXDYLD* dyld_instance;
 295
 296     dyld_instance = static_cast<DynamicLoaderPOSIXDYLD*>(baton);
 297     dyld_instance->RefreshModules();
 298
 299     // Return true to stop the target, false to just let the target run.
 300     return dyld_instance->GetStopWhenImagesChange();
 301 }
 302
 303 void
 304 DynamicLoaderPOSIXDYLD::RefreshModules()
 305 {
 306     if (!m_rendezvous.Resolve())
 307         return;
 308
 309     DYLDRendezvous::iterator I;
 310     DYLDRendezvous::iterator E;
 311
 312     ModuleList &loaded_modules = m_process->GetTarget().GetImages();
 313
 314     if (m_rendezvous.ModulesDidLoad())
 315     {
 316         ModuleList new_modules;
 317
 318         E = m_rendezvous.loaded_end();
 319         for (I = m_rendezvous.loaded_begin(); I != E; ++I)
 320         {
 321             FileSpec file(I->path.c_str(), true);
 322             ModuleSP module_sp = LoadModuleAtAddress(file, I->base_addr);
 323             if (module_sp.get())
 324                 loaded_modules.AppendIfNeeded(module_sp);
 325         }
 326     }
 327
 328     if (m_rendezvous.ModulesDidUnload())
 329     {
 330         ModuleList old_modules;
 331
 332         E = m_rendezvous.unloaded_end();
 333         for (I = m_rendezvous.unloaded_begin(); I != E; ++I)
 334         {
 335             FileSpec file(I->path.c_str(), true);
 336             ModuleSpec module_spec (file);
 337             ModuleSP module_sp =
 338                 loaded_modules.FindFirstModule (module_spec);
 339             if (module_sp.get())
 340                 old_modules.Append(module_sp);
 341         }
 342         loaded_modules.Remove(old_modules);
 343     }
 344 }
 345
 346 ThreadPlanSP
 347 DynamicLoaderPOSIXDYLD::GetStepThroughTrampolinePlan(Thread &thread, bool stop)
 348 {
 349     ThreadPlanSP thread_plan_sp;
 350
 351     StackFrame *frame = thread.GetStackFrameAtIndex(0).get();
 352     const SymbolContext &context = frame->GetSymbolContext(eSymbolContextSymbol);
 353     Symbol *sym = context.symbol;
 354
 355     if (sym == NULL || !sym->IsTrampoline())
 356         return thread_plan_sp;
 357
 358     const ConstString &sym_name = sym->GetMangled().GetName(Mangled::ePreferMangled);
 359     if (!sym_name)
 360         return thread_plan_sp;
 361
 362     SymbolContextList target_symbols;
 363     Target &target = thread.GetProcess()->GetTarget();
 364     const ModuleList &images = target.GetImages();
 365
 366     images.FindSymbolsWithNameAndType(sym_name, eSymbolTypeCode, target_symbols);
 367     size_t num_targets = target_symbols.GetSize();
 368     if (!num_targets)
 369         return thread_plan_sp;
 370
 371     typedef std::vector<lldb::addr_t> AddressVector;
 372     AddressVector addrs;
 373     for (size_t i = 0; i < num_targets; ++i)
 374     {
 375         SymbolContext context;
 376         AddressRange range;
 377         if (target_symbols.GetContextAtIndex(i, context))
 378         {
 379             context.GetAddressRange(eSymbolContextEverything, 0, false, range);
 380             lldb::addr_t addr = range.GetBaseAddress().GetLoadAddress(&target);
 381             if (addr != LLDB_INVALID_ADDRESS)
 382                 addrs.push_back(addr);
 383         }
 384     }
 385
 386     if (addrs.size() > 0)
 387     {
 388         AddressVector::iterator start = addrs.begin();
 389         AddressVector::iterator end = addrs.end();
 390
 391         std::sort(start, end);
 392         addrs.erase(std::unique(start, end), end);
 393         thread_plan_sp.reset(new ThreadPlanRunToAddress(thread, addrs, stop));
 394     }
 395
 396     return thread_plan_sp;
 397 }
 398
 399 void
 400 DynamicLoaderPOSIXDYLD::LoadAllCurrentModules()
 401 {
 402     DYLDRendezvous::iterator I;
 403     DYLDRendezvous::iterator E;
 404     ModuleList module_list;
 405
 406     if (!m_rendezvous.Resolve())
 407         return;
 408
 409     for (I = m_rendezvous.begin(), E = m_rendezvous.end(); I != E; ++I)
 410     {
 411         FileSpec file(I->path.c_str(), false);
 412         ModuleSP module_sp = LoadModuleAtAddress(file, I->base_addr);
 413         if (module_sp.get())
 414             module_list.Append(module_sp);
 415     }
 416
 417     m_process->GetTarget().ModulesDidLoad(module_list);
 418 }
 419
 420 ModuleSP
 421 DynamicLoaderPOSIXDYLD::LoadModuleAtAddress(const FileSpec &file, addr_t base_addr)
 422 {
 423     Target &target = m_process->GetTarget();
 424     ModuleList &modules = target.GetImages();
 425     ModuleSP module_sp;
 426
 427     ModuleSpec module_spec (file, target.GetArchitecture());
 428     if ((module_sp = modules.FindFirstModule (module_spec)))
 429     {
 430         UpdateLoadedSections(module_sp, base_addr);
 431     }
 432     else if ((module_sp = target.GetSharedModule(module_spec)))
 433     {
 434         UpdateLoadedSections(module_sp, base_addr);
 435     }
 436
 437     return module_sp;
 438 }
 439
 440 addr_t
 441 DynamicLoaderPOSIXDYLD::ComputeLoadOffset()
 442 {
 443     addr_t virt_entry;
 444
 445     if (m_load_offset != LLDB_INVALID_ADDRESS)
 446         return m_load_offset;
 447
 448     if ((virt_entry = GetEntryPoint()) == LLDB_INVALID_ADDRESS)
 449         return LLDB_INVALID_ADDRESS;
 450
 451     ModuleSP module = m_process->GetTarget().GetExecutableModule();
 452     if (!module)
 453         return LLDB_INVALID_ADDRESS;
 454
 455     ObjectFile *exe = module->GetObjectFile();
 456     Address file_entry = exe->GetEntryPointAddress();
 457
 458     if (!file_entry.IsValid())
 459         return LLDB_INVALID_ADDRESS;
 460
 461     m_load_offset = virt_entry - file_entry.GetFileAddress();
 462     return m_load_offset;
 463 }
 464
 465 addr_t
 466 DynamicLoaderPOSIXDYLD::GetEntryPoint()
 467 {
 468     if (m_entry_point != LLDB_INVALID_ADDRESS)
 469         return m_entry_point;
 470
 471     if (m_auxv.get() == NULL)
 472         return LLDB_INVALID_ADDRESS;
 473
 474     AuxVector::iterator I = m_auxv->FindEntry(AuxVector::AT_ENTRY);
 475
 476     if (I == m_auxv->end())
 477         return LLDB_INVALID_ADDRESS;
 478
 479     m_entry_point = static_cast<addr_t>(I->value);
 480     return m_entry_point;
 481 }