1//===-- DynamicLoader.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#include "lldb/Target/DynamicLoader.h"
10
11#include "lldb/Core/Module.h"
12#include "lldb/Core/ModuleList.h"
13#include "lldb/Core/ModuleSpec.h"
14#include "lldb/Core/PluginManager.h"
15#include "lldb/Core/Section.h"
16#include "lldb/Symbol/LocateSymbolFile.h"
17#include "lldb/Symbol/ObjectFile.h"
18#include "lldb/Target/MemoryRegionInfo.h"
19#include "lldb/Target/Platform.h"
20#include "lldb/Target/Process.h"
21#include "lldb/Target/Target.h"
22#include "lldb/Utility/ConstString.h"
23#include "lldb/Utility/LLDBLog.h"
24#include "lldb/Utility/Log.h"
25#include "lldb/lldb-private-interfaces.h"
26
27#include "llvm/ADT/StringRef.h"
28
29#include <memory>
30
31#include <cassert>
32
33using namespace lldb;
34using namespace lldb_private;
35
36DynamicLoader *DynamicLoader::FindPlugin(Process *process,
37 llvm::StringRef plugin_name) {
38 DynamicLoaderCreateInstance create_callback = nullptr;
39 if (!plugin_name.empty()) {
40 create_callback =
41 PluginManager::GetDynamicLoaderCreateCallbackForPluginName(plugin_name);
42 if (create_callback) {
43 std::unique_ptr<DynamicLoader> instance_up(
44 create_callback(process, true));
45 if (instance_up)
46 return instance_up.release();
47 }
48 } else {
49 for (uint32_t idx = 0;
50 (create_callback =
51 PluginManager::GetDynamicLoaderCreateCallbackAtIndex(idx)) !=
52 nullptr;
53 ++idx) {
54 std::unique_ptr<DynamicLoader> instance_up(
55 create_callback(process, false));
56 if (instance_up)
57 return instance_up.release();
58 }
59 }
60 return nullptr;
61}
62
63DynamicLoader::DynamicLoader(Process *process) : m_process(process) {}
64
65// Accessosors to the global setting as to whether to stop at image (shared
66// library) loading/unloading.
67
68bool DynamicLoader::GetStopWhenImagesChange() const {
69 return m_process->GetStopOnSharedLibraryEvents();
70}
71
72void DynamicLoader::SetStopWhenImagesChange(bool stop) {
73 m_process->SetStopOnSharedLibraryEvents(stop);
74}
75
76ModuleSP DynamicLoader::GetTargetExecutable() {
77 Target &target = m_process->GetTarget();
78 ModuleSP executable = target.GetExecutableModule();
79
80 if (executable) {
81 if (FileSystem::Instance().Exists(executable->GetFileSpec())) {
82 ModuleSpec module_spec(executable->GetFileSpec(),
83 executable->GetArchitecture());
84 auto module_sp = std::make_shared<Module>(module_spec);
85
86 // Check if the executable has changed and set it to the target
87 // executable if they differ.
88 if (module_sp && module_sp->GetUUID().IsValid() &&
89 executable->GetUUID().IsValid()) {
90 if (module_sp->GetUUID() != executable->GetUUID())
91 executable.reset();
92 } else if (executable->FileHasChanged()) {
93 executable.reset();
94 }
95
96 if (!executable) {
97 executable = target.GetOrCreateModule(module_spec, true /* notify */);
98 if (executable.get() != target.GetExecutableModulePointer()) {
99 // Don't load dependent images since we are in dyld where we will
100 // know and find out about all images that are loaded
101 target.SetExecutableModule(executable, eLoadDependentsNo);
102 }
103 }
104 }
105 }
106 return executable;
107}
108
109void DynamicLoader::UpdateLoadedSections(ModuleSP module, addr_t link_map_addr,
110 addr_t base_addr,
111 bool base_addr_is_offset) {
112 UpdateLoadedSectionsCommon(module, base_addr, base_addr_is_offset);
113}
114
115void DynamicLoader::UpdateLoadedSectionsCommon(ModuleSP module,
116 addr_t base_addr,
117 bool base_addr_is_offset) {
118 bool changed;
119 module->SetLoadAddress(m_process->GetTarget(), base_addr, base_addr_is_offset,
120 changed);
121}
122
123void DynamicLoader::UnloadSections(const ModuleSP module) {
124 UnloadSectionsCommon(module);
125}
126
127void DynamicLoader::UnloadSectionsCommon(const ModuleSP module) {
128 Target &target = m_process->GetTarget();
129 const SectionList *sections = GetSectionListFromModule(module);
130
131 assert(sections && "SectionList missing from unloaded module.");
132
133 const size_t num_sections = sections->GetSize();
134 for (size_t i = 0; i < num_sections; ++i) {
135 SectionSP section_sp(sections->GetSectionAtIndex(i));
136 target.SetSectionUnloaded(section_sp);
137 }
138}
139
140const SectionList *
141DynamicLoader::GetSectionListFromModule(const ModuleSP module) const {
142 SectionList *sections = nullptr;
143 if (module) {
144 ObjectFile *obj_file = module->GetObjectFile();
145 if (obj_file != nullptr) {
146 sections = obj_file->GetSectionList();
147 }
148 }
149 return sections;
150}
151
152ModuleSP DynamicLoader::FindModuleViaTarget(const FileSpec &file) {
153 Target &target = m_process->GetTarget();
154 ModuleSpec module_spec(file, target.GetArchitecture());
155
156 if (ModuleSP module_sp = target.GetImages().FindFirstModule(module_spec))
157 return module_sp;
158
159 if (ModuleSP module_sp = target.GetOrCreateModule(module_spec, false))
160 return module_sp;
161
162 return nullptr;
163}
164
165ModuleSP DynamicLoader::LoadModuleAtAddress(const FileSpec &file,
166 addr_t link_map_addr,
167 addr_t base_addr,
168 bool base_addr_is_offset) {
169 if (ModuleSP module_sp = FindModuleViaTarget(file)) {
170 UpdateLoadedSections(module_sp, link_map_addr, base_addr,
171 base_addr_is_offset);
172 return module_sp;
173 }
174
175 return nullptr;
176}
177
178static ModuleSP ReadUnnamedMemoryModule(Process *process, addr_t addr) {
179 char namebuf[80];
180 snprintf(namebuf, sizeof(namebuf), "memory-image-0x%" PRIx64, addr);
181 return process->ReadModuleFromMemory(FileSpec(namebuf), addr);
182}
183
184ModuleSP DynamicLoader::LoadBinaryWithUUIDAndAddress(Process *process,
185 UUID uuid, addr_t value,
186 bool value_is_offset,
187 bool force_symbol_search,
188 bool notify) {
189 ModuleSP memory_module_sp;
190 ModuleSP module_sp;
191 PlatformSP platform_sp = process->GetTarget().GetPlatform();
192 Target &target = process->GetTarget();
193 Status error;
194 ModuleSpec module_spec;
195 module_spec.GetUUID() = uuid;
196
197 if (!uuid.IsValid() && !value_is_offset) {
198 memory_module_sp = ReadUnnamedMemoryModule(process, value);
199
200 if (memory_module_sp)
201 uuid = memory_module_sp->GetUUID();
202 }
203
204 if (uuid.IsValid()) {
205 ModuleSpec module_spec;
206 module_spec.GetUUID() = uuid;
207
208 if (!module_sp)
209 module_sp = target.GetOrCreateModule(module_spec, false, &error);
210
211 // If we haven't found a binary, or we don't have a SymbolFile, see
212 // if there is an external search tool that can find it.
213 if (force_symbol_search &&
214 (!module_sp || !module_sp->GetSymbolFileFileSpec())) {
215 Symbols::DownloadObjectAndSymbolFile(module_spec, error, true);
216 if (FileSystem::Instance().Exists(module_spec.GetFileSpec())) {
217 module_sp = std::make_shared<Module>(module_spec);
218 }
219 }
220 }
221
222 // If we couldn't find the binary anywhere else, as a last resort,
223 // read it out of memory.
224 if (!module_sp.get() && value != LLDB_INVALID_ADDRESS && !value_is_offset) {
225 if (!memory_module_sp)
226 memory_module_sp = ReadUnnamedMemoryModule(process, value);
227 if (memory_module_sp)
228 module_sp = memory_module_sp;
229 }
230
231 Log *log = GetLog(LLDBLog::DynamicLoader);
232 if (module_sp.get()) {
233 target.GetImages().AppendIfNeeded(module_sp, false);
234
235 bool changed = false;
236 if (module_sp->GetObjectFile()) {
237 if (value != LLDB_INVALID_ADDRESS) {
238 LLDB_LOGF(log, "Loading binary UUID %s at %s 0x%" PRIx64,
239 uuid.GetAsString().c_str(),
240 value_is_offset ? "offset" : "address", value);
241 module_sp->SetLoadAddress(target, value, value_is_offset, changed);
242 } else {
243 // No address/offset/slide, load the binary at file address,
244 // offset 0.
245 LLDB_LOGF(log, "Loading binary UUID %s at file address",
246 uuid.GetAsString().c_str());
247 module_sp->SetLoadAddress(target, 0, true /* value_is_slide */,
248 changed);
249 }
250 } else {
251 // In-memory image, load at its true address, offset 0.
252 LLDB_LOGF(log, "Loading binary UUID %s from memory at address 0x%" PRIx64,
253 uuid.GetAsString().c_str(), value);
254 module_sp->SetLoadAddress(target, 0, true /* value_is_slide */, changed);
255 }
256
257 if (notify) {
258 ModuleList added_module;
259 added_module.Append(module_sp, false);
260 target.ModulesDidLoad(added_module);
261 }
262 } else {
263 LLDB_LOGF(log, "Unable to find binary with UUID %s and load it at "
264 "%s 0x%" PRIx64,
265 uuid.GetAsString().c_str(),
266 value_is_offset ? "offset" : "address", value);
267 }
268
269 return module_sp;
270}
271
272int64_t DynamicLoader::ReadUnsignedIntWithSizeInBytes(addr_t addr,
273 int size_in_bytes) {
274 Status error;
275 uint64_t value =
276 m_process->ReadUnsignedIntegerFromMemory(addr, size_in_bytes, 0, error);
277 if (error.Fail())
278 return -1;
279 else
280 return (int64_t)value;
281}
282
283addr_t DynamicLoader::ReadPointer(addr_t addr) {
284 Status error;
285 addr_t value = m_process->ReadPointerFromMemory(addr, error);
286 if (error.Fail())
287 return LLDB_INVALID_ADDRESS;
288 else
289 return value;
290}
291
292void DynamicLoader::LoadOperatingSystemPlugin(bool flush)
293{
294 if (m_process)
295 m_process->LoadOperatingSystemPlugin(flush);
296}
297
298

source code of lldb/source/Core/DynamicLoader.cpp