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
Initialize()32 DynamicLoaderPOSIXDYLD::Initialize()
33 {
34 PluginManager::RegisterPlugin(GetPluginNameStatic(),
35 GetPluginDescriptionStatic(),
36 CreateInstance);
37 }
38
39 void
Terminate()40 DynamicLoaderPOSIXDYLD::Terminate()
41 {
42 }
43
44 lldb_private::ConstString
GetPluginName()45 DynamicLoaderPOSIXDYLD::GetPluginName()
46 {
47 return GetPluginNameStatic();
48 }
49
50 lldb_private::ConstString
GetPluginNameStatic()51 DynamicLoaderPOSIXDYLD::GetPluginNameStatic()
52 {
53 static ConstString g_name("linux-dyld");
54 return g_name;
55 }
56
57 const char *
GetPluginDescriptionStatic()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
GetPluginCommandHelp(const char * command,Stream * strm)65 DynamicLoaderPOSIXDYLD::GetPluginCommandHelp(const char *command, Stream *strm)
66 {
67 }
68
69 uint32_t
GetPluginVersion()70 DynamicLoaderPOSIXDYLD::GetPluginVersion()
71 {
72 return 1;
73 }
74
75 DynamicLoader *
CreateInstance(Process * process,bool force)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
DynamicLoaderPOSIXDYLD(Process * process)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
~DynamicLoaderPOSIXDYLD()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
DidAttach()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
DidLaunch()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
GetTargetExecutable()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
ExecutePluginCommand(Args & command,Stream * strm)194 DynamicLoaderPOSIXDYLD::ExecutePluginCommand(Args &command, Stream *strm)
195 {
196 return Error();
197 }
198
199 Log *
EnablePluginLogging(Stream * strm,Args & command)200 DynamicLoaderPOSIXDYLD::EnablePluginLogging(Stream *strm, Args &command)
201 {
202 return NULL;
203 }
204
205 Error
CanLoadImage()206 DynamicLoaderPOSIXDYLD::CanLoadImage()
207 {
208 return Error();
209 }
210
211 void
UpdateLoadedSections(ModuleSP module,addr_t base_addr)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
ProbeEntry()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
EntryBreakpointHit(void * baton,StoppointCallbackContext * context,user_id_t break_id,user_id_t break_loc_id)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
SetRendezvousBreakpoint()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
RendezvousBreakpointHit(void * baton,StoppointCallbackContext * context,user_id_t break_id,user_id_t break_loc_id)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
RefreshModules()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
GetStepThroughTrampolinePlan(Thread & thread,bool stop)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
LoadAllCurrentModules()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
LoadModuleAtAddress(const FileSpec & file,addr_t base_addr)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
ComputeLoadOffset()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 ObjectFile *exe = module->GetObjectFile();
453 Address file_entry = exe->GetEntryPointAddress();
454
455 if (!file_entry.IsValid())
456 return LLDB_INVALID_ADDRESS;
457
458 m_load_offset = virt_entry - file_entry.GetFileAddress();
459 return m_load_offset;
460 }
461
462 addr_t
GetEntryPoint()463 DynamicLoaderPOSIXDYLD::GetEntryPoint()
464 {
465 if (m_entry_point != LLDB_INVALID_ADDRESS)
466 return m_entry_point;
467
468 if (m_auxv.get() == NULL)
469 return LLDB_INVALID_ADDRESS;
470
471 AuxVector::iterator I = m_auxv->FindEntry(AuxVector::AT_ENTRY);
472
473 if (I == m_auxv->end())
474 return LLDB_INVALID_ADDRESS;
475
476 m_entry_point = static_cast<addr_t>(I->value);
477 return m_entry_point;
478 }
479