1 //===-- FuncUnwinders.cpp ----------------------------------*- 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 #include "lldb/Core/AddressRange.h"
11 #include "lldb/Core/Address.h"
12 #include "lldb/Symbol/FuncUnwinders.h"
13 #include "lldb/Symbol/DWARFCallFrameInfo.h"
14 #include "lldb/Symbol/CompactUnwindInfo.h"
15 #include "lldb/Symbol/ObjectFile.h"
16 #include "lldb/Symbol/UnwindPlan.h"
17 #include "lldb/Symbol/UnwindTable.h"
18 #include "lldb/Target/ABI.h"
19 #include "lldb/Target/ExecutionContext.h"
20 #include "lldb/Target/Process.h"
21 #include "lldb/Target/Thread.h"
22 #include "lldb/Target/Target.h"
23 #include "lldb/Target/UnwindAssembly.h"
24
25 using namespace lldb;
26 using namespace lldb_private;
27
28 //------------------------------------------------
29 /// constructor
30 //------------------------------------------------
31
FuncUnwinders(UnwindTable & unwind_table,AddressRange range)32 FuncUnwinders::FuncUnwinders (UnwindTable& unwind_table, AddressRange range) :
33 m_unwind_table (unwind_table),
34 m_range (range),
35 m_mutex (Mutex::eMutexTypeRecursive),
36 m_unwind_plan_assembly_sp (),
37 m_unwind_plan_eh_frame_sp (),
38 m_unwind_plan_eh_frame_augmented_sp (),
39 m_unwind_plan_compact_unwind (),
40 m_unwind_plan_fast_sp (),
41 m_unwind_plan_arch_default_sp (),
42 m_unwind_plan_arch_default_at_func_entry_sp (),
43 m_tried_unwind_plan_assembly (false),
44 m_tried_unwind_plan_eh_frame (false),
45 m_tried_unwind_plan_eh_frame_augmented (false),
46 m_tried_unwind_plan_compact_unwind (false),
47 m_tried_unwind_fast (false),
48 m_tried_unwind_arch_default (false),
49 m_tried_unwind_arch_default_at_func_entry (false),
50 m_first_non_prologue_insn ()
51 {
52 }
53
54 //------------------------------------------------
55 /// destructor
56 //------------------------------------------------
57
~FuncUnwinders()58 FuncUnwinders::~FuncUnwinders ()
59 {
60 }
61
62 UnwindPlanSP
GetUnwindPlanAtCallSite(Target & target,int current_offset)63 FuncUnwinders::GetUnwindPlanAtCallSite (Target &target, int current_offset)
64 {
65 Mutex::Locker locker (m_mutex);
66
67 UnwindPlanSP unwind_plan_sp = GetEHFrameUnwindPlan (target, current_offset);
68 if (unwind_plan_sp.get() == nullptr)
69 {
70 unwind_plan_sp = GetCompactUnwindUnwindPlan (target, current_offset);
71 }
72
73 return unwind_plan_sp;
74 }
75
76 UnwindPlanSP
GetCompactUnwindUnwindPlan(Target & target,int current_offset)77 FuncUnwinders::GetCompactUnwindUnwindPlan (Target &target, int current_offset)
78 {
79 if (m_unwind_plan_compact_unwind.size() > 0)
80 return m_unwind_plan_compact_unwind[0]; // FIXME support multiple compact unwind plans for one func
81 if (m_tried_unwind_plan_compact_unwind)
82 return UnwindPlanSP();
83
84 Mutex::Locker lock (m_mutex);
85 m_tried_unwind_plan_compact_unwind = true;
86 if (m_range.GetBaseAddress().IsValid())
87 {
88 Address current_pc (m_range.GetBaseAddress ());
89 if (current_offset != -1)
90 current_pc.SetOffset (current_pc.GetOffset() + current_offset);
91 CompactUnwindInfo *compact_unwind = m_unwind_table.GetCompactUnwindInfo();
92 if (compact_unwind)
93 {
94 UnwindPlanSP unwind_plan_sp (new UnwindPlan (lldb::eRegisterKindGeneric));
95 if (compact_unwind->GetUnwindPlan (target, current_pc, *unwind_plan_sp))
96 {
97 m_unwind_plan_compact_unwind.push_back (unwind_plan_sp);
98 return m_unwind_plan_compact_unwind[0]; // FIXME support multiple compact unwind plans for one func
99 }
100 }
101 }
102 return UnwindPlanSP();
103 }
104
105 UnwindPlanSP
GetEHFrameUnwindPlan(Target & target,int current_offset)106 FuncUnwinders::GetEHFrameUnwindPlan (Target &target, int current_offset)
107 {
108 if (m_unwind_plan_eh_frame_sp.get() || m_tried_unwind_plan_eh_frame)
109 return m_unwind_plan_eh_frame_sp;
110
111 Mutex::Locker lock (m_mutex);
112 m_tried_unwind_plan_eh_frame = true;
113 if (m_range.GetBaseAddress().IsValid())
114 {
115 Address current_pc (m_range.GetBaseAddress ());
116 if (current_offset != -1)
117 current_pc.SetOffset (current_pc.GetOffset() + current_offset);
118 DWARFCallFrameInfo *eh_frame = m_unwind_table.GetEHFrameInfo();
119 if (eh_frame)
120 {
121 m_unwind_plan_eh_frame_sp.reset (new UnwindPlan (lldb::eRegisterKindGeneric));
122 if (!eh_frame->GetUnwindPlan (current_pc, *m_unwind_plan_eh_frame_sp))
123 m_unwind_plan_eh_frame_sp.reset();
124 }
125 }
126 return m_unwind_plan_eh_frame_sp;
127 }
128
129 UnwindPlanSP
GetEHFrameAugmentedUnwindPlan(Target & target,Thread & thread,int current_offset)130 FuncUnwinders::GetEHFrameAugmentedUnwindPlan (Target &target, Thread &thread, int current_offset)
131 {
132 if (m_unwind_plan_eh_frame_augmented_sp.get() || m_tried_unwind_plan_eh_frame_augmented)
133 return m_unwind_plan_eh_frame_augmented_sp;
134
135 // Only supported on x86 architectures where we get eh_frame from the compiler that describes
136 // the prologue instructions perfectly, and sometimes the epilogue instructions too.
137 if (target.GetArchitecture().GetCore() != ArchSpec::eCore_x86_32_i386
138 && target.GetArchitecture().GetCore() != ArchSpec::eCore_x86_64_x86_64
139 && target.GetArchitecture().GetCore() != ArchSpec::eCore_x86_64_x86_64h)
140 {
141 m_tried_unwind_plan_eh_frame_augmented = true;
142 return m_unwind_plan_eh_frame_augmented_sp;
143 }
144
145 Mutex::Locker lock (m_mutex);
146 m_tried_unwind_plan_eh_frame_augmented = true;
147
148 UnwindPlanSP eh_frame_plan = GetEHFrameUnwindPlan (target, current_offset);
149 if (!eh_frame_plan)
150 return m_unwind_plan_eh_frame_augmented_sp;
151
152 m_unwind_plan_eh_frame_augmented_sp.reset(new UnwindPlan(*eh_frame_plan));
153
154 // Augment the eh_frame instructions with epilogue descriptions if necessary so the
155 // UnwindPlan can be used at any instruction in the function.
156
157 UnwindAssemblySP assembly_profiler_sp (GetUnwindAssemblyProfiler(target));
158 if (assembly_profiler_sp)
159 {
160 if (!assembly_profiler_sp->AugmentUnwindPlanFromCallSite (m_range, thread, *m_unwind_plan_eh_frame_augmented_sp))
161 {
162 m_unwind_plan_eh_frame_augmented_sp.reset();
163 }
164 }
165 else
166 {
167 m_unwind_plan_eh_frame_augmented_sp.reset();
168 }
169 return m_unwind_plan_eh_frame_augmented_sp;
170 }
171
172
173 UnwindPlanSP
GetAssemblyUnwindPlan(Target & target,Thread & thread,int current_offset)174 FuncUnwinders::GetAssemblyUnwindPlan (Target &target, Thread &thread, int current_offset)
175 {
176 if (m_unwind_plan_assembly_sp.get() || m_tried_unwind_plan_assembly)
177 return m_unwind_plan_assembly_sp;
178
179 Mutex::Locker lock (m_mutex);
180 m_tried_unwind_plan_assembly = true;
181
182 UnwindAssemblySP assembly_profiler_sp (GetUnwindAssemblyProfiler(target));
183 if (assembly_profiler_sp)
184 {
185 m_unwind_plan_assembly_sp.reset (new UnwindPlan (lldb::eRegisterKindGeneric));
186 if (!assembly_profiler_sp->GetNonCallSiteUnwindPlanFromAssembly (m_range, thread, *m_unwind_plan_assembly_sp))
187 {
188 m_unwind_plan_assembly_sp.reset();
189 }
190 }
191 return m_unwind_plan_assembly_sp;
192 }
193
194
195 UnwindPlanSP
GetUnwindPlanAtNonCallSite(Target & target,Thread & thread,int current_offset)196 FuncUnwinders::GetUnwindPlanAtNonCallSite (Target& target, Thread& thread, int current_offset)
197 {
198 UnwindPlanSP non_call_site_unwindplan_sp = GetEHFrameAugmentedUnwindPlan (target, thread, current_offset);
199 if (non_call_site_unwindplan_sp.get() == nullptr)
200 {
201 non_call_site_unwindplan_sp = GetAssemblyUnwindPlan (target, thread, current_offset);
202 }
203 return non_call_site_unwindplan_sp;
204 }
205
206 UnwindPlanSP
GetUnwindPlanFastUnwind(Target & target,Thread & thread)207 FuncUnwinders::GetUnwindPlanFastUnwind (Target& target, Thread& thread)
208 {
209 if (m_unwind_plan_fast_sp.get() || m_tried_unwind_fast)
210 return m_unwind_plan_fast_sp;
211
212 Mutex::Locker locker (m_mutex);
213 m_tried_unwind_fast = true;
214
215 UnwindAssemblySP assembly_profiler_sp (GetUnwindAssemblyProfiler(target));
216 if (assembly_profiler_sp)
217 {
218 m_unwind_plan_fast_sp.reset (new UnwindPlan (lldb::eRegisterKindGeneric));
219 if (!assembly_profiler_sp->GetFastUnwindPlan (m_range, thread, *m_unwind_plan_fast_sp))
220 {
221 m_unwind_plan_fast_sp.reset();
222 }
223 }
224 return m_unwind_plan_fast_sp;
225 }
226
227 UnwindPlanSP
GetUnwindPlanArchitectureDefault(Thread & thread)228 FuncUnwinders::GetUnwindPlanArchitectureDefault (Thread& thread)
229 {
230 if (m_unwind_plan_arch_default_sp.get() || m_tried_unwind_arch_default)
231 return m_unwind_plan_arch_default_sp;
232
233 Mutex::Locker locker (m_mutex);
234 m_tried_unwind_arch_default = true;
235
236 Address current_pc;
237 ProcessSP process_sp (thread.CalculateProcess());
238 if (process_sp)
239 {
240 ABI *abi = process_sp->GetABI().get();
241 if (abi)
242 {
243 m_unwind_plan_arch_default_sp.reset (new UnwindPlan (lldb::eRegisterKindGeneric));
244 if (!abi->CreateDefaultUnwindPlan(*m_unwind_plan_arch_default_sp))
245 {
246 m_unwind_plan_arch_default_sp.reset();
247 }
248 }
249 }
250
251 return m_unwind_plan_arch_default_sp;
252 }
253
254 UnwindPlanSP
GetUnwindPlanArchitectureDefaultAtFunctionEntry(Thread & thread)255 FuncUnwinders::GetUnwindPlanArchitectureDefaultAtFunctionEntry (Thread& thread)
256 {
257 if (m_unwind_plan_arch_default_at_func_entry_sp.get() || m_tried_unwind_arch_default_at_func_entry)
258 return m_unwind_plan_arch_default_at_func_entry_sp;
259
260 Mutex::Locker locker (m_mutex);
261 m_tried_unwind_arch_default_at_func_entry = true;
262
263 Address current_pc;
264 ProcessSP process_sp (thread.CalculateProcess());
265 if (process_sp)
266 {
267 ABI *abi = process_sp->GetABI().get();
268 if (abi)
269 {
270 m_unwind_plan_arch_default_at_func_entry_sp.reset (new UnwindPlan (lldb::eRegisterKindGeneric));
271 if (!abi->CreateFunctionEntryUnwindPlan(*m_unwind_plan_arch_default_at_func_entry_sp))
272 {
273 m_unwind_plan_arch_default_at_func_entry_sp.reset();
274 }
275 }
276 }
277
278 return m_unwind_plan_arch_default_at_func_entry_sp;
279 }
280
281
282 Address&
GetFirstNonPrologueInsn(Target & target)283 FuncUnwinders::GetFirstNonPrologueInsn (Target& target)
284 {
285 if (m_first_non_prologue_insn.IsValid())
286 return m_first_non_prologue_insn;
287
288 Mutex::Locker locker (m_mutex);
289 ExecutionContext exe_ctx (target.shared_from_this(), false);
290 UnwindAssemblySP assembly_profiler_sp (GetUnwindAssemblyProfiler(target));
291 if (assembly_profiler_sp)
292 assembly_profiler_sp->FirstNonPrologueInsn (m_range, exe_ctx, m_first_non_prologue_insn);
293 return m_first_non_prologue_insn;
294 }
295
296 const Address&
GetFunctionStartAddress() const297 FuncUnwinders::GetFunctionStartAddress () const
298 {
299 return m_range.GetBaseAddress();
300 }
301
302 lldb::UnwindAssemblySP
GetUnwindAssemblyProfiler(Target & target)303 FuncUnwinders::GetUnwindAssemblyProfiler (Target& target)
304 {
305 UnwindAssemblySP assembly_profiler_sp;
306 ArchSpec arch;
307 if (m_unwind_table.GetArchitecture (arch))
308 {
309 arch.MergeFrom (target.GetArchitecture ());
310 assembly_profiler_sp = UnwindAssembly::FindPlugin (arch);
311 }
312 return assembly_profiler_sp;
313 }
314
315 Address
GetLSDAAddress(Target & target)316 FuncUnwinders::GetLSDAAddress (Target &target)
317 {
318 Address lsda_addr;
319
320 UnwindPlanSP unwind_plan_sp = GetEHFrameUnwindPlan (target, -1);
321 if (unwind_plan_sp.get() == nullptr)
322 {
323 unwind_plan_sp = GetCompactUnwindUnwindPlan (target, -1);
324 }
325 if (unwind_plan_sp.get() && unwind_plan_sp->GetLSDAAddress().IsValid())
326 {
327 lsda_addr = unwind_plan_sp->GetLSDAAddress();
328 }
329 return lsda_addr;
330 }
331
332
333 Address
GetPersonalityRoutinePtrAddress(Target & target)334 FuncUnwinders::GetPersonalityRoutinePtrAddress (Target &target)
335 {
336 Address personality_addr;
337
338 UnwindPlanSP unwind_plan_sp = GetEHFrameUnwindPlan (target, -1);
339 if (unwind_plan_sp.get() == nullptr)
340 {
341 unwind_plan_sp = GetCompactUnwindUnwindPlan (target, -1);
342 }
343 if (unwind_plan_sp.get() && unwind_plan_sp->GetPersonalityFunctionPtr().IsValid())
344 {
345 personality_addr = unwind_plan_sp->GetPersonalityFunctionPtr();
346 }
347
348 return personality_addr;
349 }
350