1 //===-- HexagonDYLDRendezvous.h ---------------------------------*- C++ -*-===// 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 #ifndef LLDB_SOURCE_PLUGINS_DYNAMICLOADER_HEXAGON_DYLD_HEXAGONDYLDRENDEZVOUS_H 10 #define LLDB_SOURCE_PLUGINS_DYNAMICLOADER_HEXAGON_DYLD_HEXAGONDYLDRENDEZVOUS_H 11 12 #include <limits.h> 13 #include <list> 14 #include <map> 15 #include <string> 16 17 #include "lldb/lldb-defines.h" 18 #include "lldb/lldb-types.h" 19 20 namespace lldb_private { 21 class Process; 22 } 23 24 /// \class HexagonDYLDRendezvous 25 /// Interface to the runtime linker. 26 /// 27 /// A structure is present in a processes memory space which is updated by the 28 /// runtime liker each time a module is loaded or unloaded. This class 29 /// provides an interface to this structure and maintains a consistent 30 /// snapshot of the currently loaded modules. 31 class HexagonDYLDRendezvous { 32 33 // This structure is used to hold the contents of the debug rendezvous 34 // information (struct r_debug) as found in the inferiors memory. Note that 35 // the layout of this struct is not binary compatible, it is simply large 36 // enough to hold the information on both 32 and 64 bit platforms. 37 struct Rendezvous { 38 uint64_t version = 0; 39 lldb::addr_t map_addr = LLDB_INVALID_ADDRESS; 40 lldb::addr_t brk = LLDB_INVALID_ADDRESS; 41 uint64_t state = 0; 42 lldb::addr_t ldbase = 0; 43 44 Rendezvous() = default; 45 }; 46 47 public: 48 // Various metadata supplied by the inferior's threading library to describe 49 // the per-thread state. 50 struct ThreadInfo { 51 bool valid; // whether we read valid metadata 52 uint32_t dtv_offset; // offset of DTV pointer within pthread 53 uint32_t dtv_slot_size; // size of one DTV slot 54 uint32_t modid_offset; // offset of module ID within link_map 55 uint32_t tls_offset; // offset of TLS pointer within DTV slot 56 }; 57 58 HexagonDYLDRendezvous(lldb_private::Process *process); 59 60 /// Update the internal snapshot of runtime linker rendezvous and recompute 61 /// the currently loaded modules. 62 /// 63 /// This method should be called once one start up, then once each time the 64 /// runtime linker enters the function given by GetBreakAddress(). 65 /// 66 /// \returns true on success and false on failure. 67 /// 68 /// \see GetBreakAddress(). 69 bool Resolve(); 70 71 /// \returns true if this rendezvous has been located in the inferiors 72 /// address space and false otherwise. 73 bool IsValid(); 74 75 /// \returns the address of the rendezvous structure in the inferiors 76 /// address space. 77 lldb::addr_t GetRendezvousAddress() const { return m_rendezvous_addr; } 78 79 /// Provide the dyld structure address 80 void SetRendezvousAddress(lldb::addr_t); 81 82 /// \returns the version of the rendezvous protocol being used. 83 uint64_t GetVersion() const { return m_current.version; } 84 85 /// \returns address in the inferiors address space containing the linked 86 /// list of shared object descriptors. 87 lldb::addr_t GetLinkMapAddress() const { return m_current.map_addr; } 88 89 /// A breakpoint should be set at this address and Resolve called on each 90 /// hit. 91 /// 92 /// \returns the address of a function called by the runtime linker each 93 /// time a module is loaded/unloaded, or about to be loaded/unloaded. 94 /// 95 /// \see Resolve() 96 lldb::addr_t GetBreakAddress() const { return m_current.brk; } 97 98 /// In hexagon it is possible that we can know the dyld breakpoint without 99 /// having to find it from the rendezvous structure 100 /// 101 void SetBreakAddress(lldb::addr_t addr) { m_current.brk = addr; } 102 103 /// Returns the current state of the rendezvous structure. 104 uint64_t GetState() const { return m_current.state; } 105 106 /// \returns the base address of the runtime linker in the inferiors address 107 /// space. 108 lldb::addr_t GetLDBase() const { return m_current.ldbase; } 109 110 /// \returns the thread layout metadata from the inferiors thread library. 111 const ThreadInfo &GetThreadInfo(); 112 113 /// \returns true if modules have been loaded into the inferior since the 114 /// last call to Resolve(). 115 bool ModulesDidLoad() const { return !m_added_soentries.empty(); } 116 117 /// \returns true if modules have been unloaded from the inferior since the 118 /// last call to Resolve(). 119 bool ModulesDidUnload() const { return !m_removed_soentries.empty(); } 120 121 void DumpToLog(lldb_private::Log *log) const; 122 123 /// Constants describing the state of the rendezvous. 124 /// 125 /// \see GetState(). 126 enum RendezvousState { 127 eConsistent = 0, 128 eAdd, 129 eDelete, 130 }; 131 132 /// Structure representing the shared objects currently loaded into the 133 /// inferior process. 134 /// 135 /// This object is a rough analogue to the struct link_map object which 136 /// actually lives in the inferiors memory. 137 struct SOEntry { 138 lldb::addr_t link_addr; ///< Address of this link_map. 139 lldb::addr_t base_addr; ///< Base address of the loaded object. 140 lldb::addr_t path_addr; ///< String naming the shared object. 141 lldb::addr_t dyn_addr; ///< Dynamic section of shared object. 142 lldb::addr_t next; ///< Address of next so_entry. 143 lldb::addr_t prev; ///< Address of previous so_entry. 144 std::string path; ///< File name of shared object. 145 146 SOEntry() { clear(); } 147 148 bool operator==(const SOEntry &entry) { return this->path == entry.path; } 149 150 void clear() { 151 link_addr = 0; 152 base_addr = 0; 153 path_addr = 0; 154 dyn_addr = 0; 155 next = 0; 156 prev = 0; 157 path.clear(); 158 } 159 }; 160 161 protected: 162 typedef std::list<SOEntry> SOEntryList; 163 164 public: 165 typedef SOEntryList::const_iterator iterator; 166 167 /// Iterators over all currently loaded modules. 168 iterator begin() const { return m_soentries.begin(); } 169 iterator end() const { return m_soentries.end(); } 170 171 /// Iterators over all modules loaded into the inferior since the last call 172 /// to Resolve(). 173 iterator loaded_begin() const { return m_added_soentries.begin(); } 174 iterator loaded_end() const { return m_added_soentries.end(); } 175 176 /// Iterators over all modules unloaded from the inferior since the last 177 /// call to Resolve(). 178 iterator unloaded_begin() const { return m_removed_soentries.begin(); } 179 iterator unloaded_end() const { return m_removed_soentries.end(); } 180 181 protected: 182 lldb_private::Process *m_process; 183 184 // Cached copy of executable pathname 185 char m_exe_path[PATH_MAX]; 186 187 /// Location of the r_debug structure in the inferiors address space. 188 lldb::addr_t m_rendezvous_addr; 189 190 /// Current and previous snapshots of the rendezvous structure. 191 Rendezvous m_current; 192 Rendezvous m_previous; 193 194 /// List of SOEntry objects corresponding to the current link map state. 195 SOEntryList m_soentries; 196 197 /// List of SOEntry's added to the link map since the last call to 198 /// Resolve(). 199 SOEntryList m_added_soentries; 200 201 /// List of SOEntry's removed from the link map since the last call to 202 /// Resolve(). 203 SOEntryList m_removed_soentries; 204 205 /// Threading metadata read from the inferior. 206 ThreadInfo m_thread_info; 207 208 /// Reads an unsigned integer of \p size bytes from the inferior's address 209 /// space starting at \p addr. 210 /// 211 /// \returns addr + size if the read was successful and false otherwise. 212 lldb::addr_t ReadWord(lldb::addr_t addr, uint64_t *dst, size_t size); 213 214 /// Reads an address from the inferior's address space starting at \p addr. 215 /// 216 /// \returns addr + target address size if the read was successful and 217 /// 0 otherwise. 218 lldb::addr_t ReadPointer(lldb::addr_t addr, lldb::addr_t *dst); 219 220 /// Reads a null-terminated C string from the memory location starting at @p 221 /// addr. 222 std::string ReadStringFromMemory(lldb::addr_t addr); 223 224 /// Reads an SOEntry starting at \p addr. 225 bool ReadSOEntryFromMemory(lldb::addr_t addr, SOEntry &entry); 226 227 /// Updates the current set of SOEntries, the set of added entries, and the 228 /// set of removed entries. 229 bool UpdateSOEntries(); 230 231 bool UpdateSOEntriesForAddition(); 232 233 bool UpdateSOEntriesForDeletion(); 234 235 /// Reads the current list of shared objects according to the link map 236 /// supplied by the runtime linker. 237 bool TakeSnapshot(SOEntryList &entry_list); 238 239 enum PThreadField { eSize, eNElem, eOffset }; 240 241 bool FindMetadata(const char *name, PThreadField field, uint32_t &value); 242 }; 243 244 #endif // LLDB_SOURCE_PLUGINS_DYNAMICLOADER_HEXAGON_DYLD_HEXAGONDYLDRENDEZVOUS_H 245