1 //===-- ObjectFileJIT.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 "llvm/ADT/StringRef.h"
10 
11 #include "ObjectFileJIT.h"
12 #include "lldb/Core/Debugger.h"
13 #include "lldb/Core/FileSpecList.h"
14 #include "lldb/Core/Module.h"
15 #include "lldb/Core/ModuleSpec.h"
16 #include "lldb/Core/PluginManager.h"
17 #include "lldb/Core/Section.h"
18 #include "lldb/Core/StreamFile.h"
19 #include "lldb/Host/Host.h"
20 #include "lldb/Symbol/ObjectFile.h"
21 #include "lldb/Target/Platform.h"
22 #include "lldb/Target/Process.h"
23 #include "lldb/Target/SectionLoadList.h"
24 #include "lldb/Target/Target.h"
25 #include "lldb/Utility/ArchSpec.h"
26 #include "lldb/Utility/DataBuffer.h"
27 #include "lldb/Utility/DataBufferHeap.h"
28 #include "lldb/Utility/FileSpec.h"
29 #include "lldb/Utility/Log.h"
30 #include "lldb/Utility/RangeMap.h"
31 #include "lldb/Utility/StreamString.h"
32 #include "lldb/Utility/Timer.h"
33 #include "lldb/Utility/UUID.h"
34 
35 #ifndef __APPLE__
36 #include "Utility/UuidCompatibility.h"
37 #endif
38 
39 using namespace lldb;
40 using namespace lldb_private;
41 
42 LLDB_PLUGIN_DEFINE(ObjectFileJIT)
43 
44 char ObjectFileJIT::ID;
45 
46 void ObjectFileJIT::Initialize() {
47   PluginManager::RegisterPlugin(GetPluginNameStatic(),
48                                 GetPluginDescriptionStatic(), CreateInstance,
49                                 CreateMemoryInstance, GetModuleSpecifications);
50 }
51 
52 void ObjectFileJIT::Terminate() {
53   PluginManager::UnregisterPlugin(CreateInstance);
54 }
55 
56 lldb_private::ConstString ObjectFileJIT::GetPluginNameStatic() {
57   static ConstString g_name("jit");
58   return g_name;
59 }
60 
61 const char *ObjectFileJIT::GetPluginDescriptionStatic() {
62   return "JIT code object file";
63 }
64 
65 ObjectFile *ObjectFileJIT::CreateInstance(const lldb::ModuleSP &module_sp,
66                                           DataBufferSP &data_sp,
67                                           lldb::offset_t data_offset,
68                                           const FileSpec *file,
69                                           lldb::offset_t file_offset,
70                                           lldb::offset_t length) {
71   // JIT'ed object file is backed by the ObjectFileJITDelegate, never read from
72   // a file
73   return nullptr;
74 }
75 
76 ObjectFile *ObjectFileJIT::CreateMemoryInstance(const lldb::ModuleSP &module_sp,
77                                                 DataBufferSP &data_sp,
78                                                 const ProcessSP &process_sp,
79                                                 lldb::addr_t header_addr) {
80   // JIT'ed object file is backed by the ObjectFileJITDelegate, never read from
81   // memory
82   return nullptr;
83 }
84 
85 size_t ObjectFileJIT::GetModuleSpecifications(
86     const lldb_private::FileSpec &file, lldb::DataBufferSP &data_sp,
87     lldb::offset_t data_offset, lldb::offset_t file_offset,
88     lldb::offset_t length, lldb_private::ModuleSpecList &specs) {
89   // JIT'ed object file can't be read from a file on disk
90   return 0;
91 }
92 
93 ObjectFileJIT::ObjectFileJIT(const lldb::ModuleSP &module_sp,
94                              const ObjectFileJITDelegateSP &delegate_sp)
95     : ObjectFile(module_sp, nullptr, 0, 0, DataBufferSP(), 0), m_delegate_wp() {
96   if (delegate_sp) {
97     m_delegate_wp = delegate_sp;
98     m_data.SetByteOrder(delegate_sp->GetByteOrder());
99     m_data.SetAddressByteSize(delegate_sp->GetAddressByteSize());
100   }
101 }
102 
103 ObjectFileJIT::~ObjectFileJIT() = default;
104 
105 bool ObjectFileJIT::ParseHeader() {
106   // JIT code is never in a file, nor is it required to have any header
107   return false;
108 }
109 
110 ByteOrder ObjectFileJIT::GetByteOrder() const { return m_data.GetByteOrder(); }
111 
112 bool ObjectFileJIT::IsExecutable() const { return false; }
113 
114 uint32_t ObjectFileJIT::GetAddressByteSize() const {
115   return m_data.GetAddressByteSize();
116 }
117 
118 Symtab *ObjectFileJIT::GetSymtab() {
119   ModuleSP module_sp(GetModule());
120   if (module_sp) {
121     std::lock_guard<std::recursive_mutex> guard(module_sp->GetMutex());
122     if (m_symtab_up == nullptr) {
123       m_symtab_up = std::make_unique<Symtab>(this);
124       std::lock_guard<std::recursive_mutex> symtab_guard(
125           m_symtab_up->GetMutex());
126       ObjectFileJITDelegateSP delegate_sp(m_delegate_wp.lock());
127       if (delegate_sp)
128         delegate_sp->PopulateSymtab(this, *m_symtab_up);
129       // TODO: get symbols from delegate
130       m_symtab_up->Finalize();
131     }
132   }
133   return m_symtab_up.get();
134 }
135 
136 bool ObjectFileJIT::IsStripped() {
137   return false; // JIT code that is in a module is never stripped
138 }
139 
140 void ObjectFileJIT::CreateSections(SectionList &unified_section_list) {
141   if (!m_sections_up) {
142     m_sections_up = std::make_unique<SectionList>();
143     ObjectFileJITDelegateSP delegate_sp(m_delegate_wp.lock());
144     if (delegate_sp) {
145       delegate_sp->PopulateSectionList(this, *m_sections_up);
146       unified_section_list = *m_sections_up;
147     }
148   }
149 }
150 
151 void ObjectFileJIT::Dump(Stream *s) {
152   ModuleSP module_sp(GetModule());
153   if (module_sp) {
154     std::lock_guard<std::recursive_mutex> guard(module_sp->GetMutex());
155     s->Printf("%p: ", static_cast<void *>(this));
156     s->Indent();
157     s->PutCString("ObjectFileJIT");
158 
159     if (ArchSpec arch = GetArchitecture())
160       *s << ", arch = " << arch.GetArchitectureName();
161 
162     s->EOL();
163 
164     SectionList *sections = GetSectionList();
165     if (sections)
166       sections->Dump(s->AsRawOstream(), s->GetIndentLevel(), nullptr, true,
167                      UINT32_MAX);
168 
169     if (m_symtab_up)
170       m_symtab_up->Dump(s, nullptr, eSortOrderNone);
171   }
172 }
173 
174 UUID ObjectFileJIT::GetUUID() {
175   // TODO: maybe get from delegate, not needed for first pass
176   return UUID();
177 }
178 
179 uint32_t ObjectFileJIT::GetDependentModules(FileSpecList &files) {
180   // JIT modules don't have dependencies, but they could
181   // if external functions are called and we know where they are
182   files.Clear();
183   return 0;
184 }
185 
186 lldb_private::Address ObjectFileJIT::GetEntryPointAddress() {
187   return Address();
188 }
189 
190 lldb_private::Address ObjectFileJIT::GetBaseAddress() { return Address(); }
191 
192 ObjectFile::Type ObjectFileJIT::CalculateType() { return eTypeJIT; }
193 
194 ObjectFile::Strata ObjectFileJIT::CalculateStrata() { return eStrataJIT; }
195 
196 ArchSpec ObjectFileJIT::GetArchitecture() {
197   if (ObjectFileJITDelegateSP delegate_sp = m_delegate_wp.lock())
198     return delegate_sp->GetArchitecture();
199   return ArchSpec();
200 }
201 
202 // PluginInterface protocol
203 lldb_private::ConstString ObjectFileJIT::GetPluginName() {
204   return GetPluginNameStatic();
205 }
206 
207 uint32_t ObjectFileJIT::GetPluginVersion() { return 1; }
208 
209 bool ObjectFileJIT::SetLoadAddress(Target &target, lldb::addr_t value,
210                                    bool value_is_offset) {
211   size_t num_loaded_sections = 0;
212   SectionList *section_list = GetSectionList();
213   if (section_list) {
214     const size_t num_sections = section_list->GetSize();
215     // "value" is an offset to apply to each top level segment
216     for (size_t sect_idx = 0; sect_idx < num_sections; ++sect_idx) {
217       // Iterate through the object file sections to find all of the sections
218       // that size on disk (to avoid __PAGEZERO) and load them
219       SectionSP section_sp(section_list->GetSectionAtIndex(sect_idx));
220       if (section_sp && section_sp->GetFileSize() > 0 &&
221           !section_sp->IsThreadSpecific()) {
222         if (target.GetSectionLoadList().SetSectionLoadAddress(
223                 section_sp, section_sp->GetFileAddress() + value))
224           ++num_loaded_sections;
225       }
226     }
227   }
228   return num_loaded_sections > 0;
229 }
230 
231 size_t ObjectFileJIT::ReadSectionData(lldb_private::Section *section,
232                                       lldb::offset_t section_offset, void *dst,
233                                       size_t dst_len) {
234   lldb::offset_t file_size = section->GetFileSize();
235   if (section_offset < file_size) {
236     size_t src_len = file_size - section_offset;
237     if (src_len > dst_len)
238       src_len = dst_len;
239     const uint8_t *src =
240         ((uint8_t *)(uintptr_t)section->GetFileOffset()) + section_offset;
241 
242     memcpy(dst, src, src_len);
243     return src_len;
244   }
245   return 0;
246 }
247 
248 size_t ObjectFileJIT::ReadSectionData(
249     lldb_private::Section *section,
250     lldb_private::DataExtractor &section_data) {
251   if (section->GetFileSize()) {
252     const void *src = (void *)(uintptr_t)section->GetFileOffset();
253 
254     DataBufferSP data_sp =
255         std::make_shared<DataBufferHeap>(src, section->GetFileSize());
256     section_data.SetData(data_sp, 0, data_sp->GetByteSize());
257     section_data.SetByteOrder(GetByteOrder());
258     section_data.SetAddressByteSize(GetAddressByteSize());
259     return section_data.GetByteSize();
260   }
261   section_data.Clear();
262   return 0;
263 }
264