1 //===-- DynamicLoaderPOSIXDYLD.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 #ifndef liblldb_DynamicLoaderPOSIXDYLD_h_
11 #define liblldb_DynamicLoaderPOSIXDYLD_h_
12 
13 // C Includes
14 // C++ Includes
15 #include <map>
16 #include <memory>
17 
18 // Other libraries and framework includes
19 // Project includes
20 #include "DYLDRendezvous.h"
21 #include "lldb/Breakpoint/StoppointCallbackContext.h"
22 #include "lldb/Core/ModuleList.h"
23 #include "lldb/Target/DynamicLoader.h"
24 
25 class AuxVector;
26 
27 class DynamicLoaderPOSIXDYLD : public lldb_private::DynamicLoader {
28 public:
29   DynamicLoaderPOSIXDYLD(lldb_private::Process *process);
30 
31   ~DynamicLoaderPOSIXDYLD() override;
32 
33   static void Initialize();
34 
35   static void Terminate();
36 
37   static lldb_private::ConstString GetPluginNameStatic();
38 
39   static const char *GetPluginDescriptionStatic();
40 
41   static lldb_private::DynamicLoader *
42   CreateInstance(lldb_private::Process *process, bool force);
43 
44   //------------------------------------------------------------------
45   // DynamicLoader protocol
46   //------------------------------------------------------------------
47 
48   void DidAttach() override;
49 
50   void DidLaunch() override;
51 
52   lldb::ThreadPlanSP GetStepThroughTrampolinePlan(lldb_private::Thread &thread,
53                                                   bool stop_others) override;
54 
55   lldb_private::Status CanLoadImage() override;
56 
57   lldb::addr_t GetThreadLocalData(const lldb::ModuleSP module,
58                                   const lldb::ThreadSP thread,
59                                   lldb::addr_t tls_file_addr) override;
60 
61   //------------------------------------------------------------------
62   // PluginInterface protocol
63   //------------------------------------------------------------------
64   lldb_private::ConstString GetPluginName() override;
65 
66   uint32_t GetPluginVersion() override;
67 
68 protected:
69   /// Runtime linker rendezvous structure.
70   DYLDRendezvous m_rendezvous;
71 
72   /// Virtual load address of the inferior process.
73   lldb::addr_t m_load_offset;
74 
75   /// Virtual entry address of the inferior process.
76   lldb::addr_t m_entry_point;
77 
78   /// Auxiliary vector of the inferior process.
79   std::unique_ptr<AuxVector> m_auxv;
80 
81   /// Rendezvous breakpoint.
82   lldb::break_id_t m_dyld_bid;
83 
84   /// Contains AT_SYSINFO_EHDR, which means a vDSO has been
85   /// mapped to the address space
86   lldb::addr_t m_vdso_base;
87 
88   /// Contains AT_BASE, which means a dynamic loader has been
89   /// mapped to the address space
90   lldb::addr_t m_interpreter_base;
91 
92   /// Loaded module list. (link map for each module)
93   std::map<lldb::ModuleWP, lldb::addr_t, std::owner_less<lldb::ModuleWP>>
94       m_loaded_modules;
95 
96   /// If possible sets a breakpoint on a function called by the runtime
97   /// linker each time a module is loaded or unloaded.
98   bool SetRendezvousBreakpoint();
99 
100   /// Callback routine which updates the current list of loaded modules based
101   /// on the information supplied by the runtime linker.
102   static bool RendezvousBreakpointHit(
103       void *baton, lldb_private::StoppointCallbackContext *context,
104       lldb::user_id_t break_id, lldb::user_id_t break_loc_id);
105 
106   /// Helper method for RendezvousBreakpointHit.  Updates LLDB's current set
107   /// of loaded modules.
108   void RefreshModules();
109 
110   /// Updates the load address of every allocatable section in @p module.
111   ///
112   /// @param module The module to traverse.
113   ///
114   /// @param link_map_addr The virtual address of the link map for the @p
115   /// module.
116   ///
117   /// @param base_addr The virtual base address @p module is loaded at.
118   void UpdateLoadedSections(lldb::ModuleSP module, lldb::addr_t link_map_addr,
119                             lldb::addr_t base_addr,
120                             bool base_addr_is_offset) override;
121 
122   /// Removes the loaded sections from the target in @p module.
123   ///
124   /// @param module The module to traverse.
125   void UnloadSections(const lldb::ModuleSP module) override;
126 
127   /// Resolves the entry point for the current inferior process and sets a
128   /// breakpoint at that address.
129   void ProbeEntry();
130 
131   /// Callback routine invoked when we hit the breakpoint on process entry.
132   ///
133   /// This routine is responsible for resolving the load addresses of all
134   /// dependent modules required by the inferior and setting up the rendezvous
135   /// breakpoint.
136   static bool
137   EntryBreakpointHit(void *baton,
138                      lldb_private::StoppointCallbackContext *context,
139                      lldb::user_id_t break_id, lldb::user_id_t break_loc_id);
140 
141   /// Helper for the entry breakpoint callback.  Resolves the load addresses
142   /// of all dependent modules.
143   virtual void LoadAllCurrentModules();
144 
145   void LoadVDSO();
146 
147   // Loading an interpreter module (if present) assumming m_interpreter_base
148   // already points to its base address.
149   lldb::ModuleSP LoadInterpreterModule();
150 
151   /// Computes a value for m_load_offset returning the computed address on
152   /// success and LLDB_INVALID_ADDRESS on failure.
153   lldb::addr_t ComputeLoadOffset();
154 
155   /// Computes a value for m_entry_point returning the computed address on
156   /// success and LLDB_INVALID_ADDRESS on failure.
157   lldb::addr_t GetEntryPoint();
158 
159   /// Evaluate if Aux vectors contain vDSO and LD information
160   /// in case they do, read and assign the address to m_vdso_base
161   /// and m_interpreter_base.
162   void EvalSpecialModulesStatus();
163 
164   /// Loads Module from inferior process.
165   void ResolveExecutableModule(lldb::ModuleSP &module_sp);
166 
167   bool AlwaysRelyOnEHUnwindInfo(lldb_private::SymbolContext &sym_ctx) override;
168 
169 private:
170   DISALLOW_COPY_AND_ASSIGN(DynamicLoaderPOSIXDYLD);
171 };
172 
173 #endif // liblldb_DynamicLoaderPOSIXDYLD_h_
174