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