1 //===-- ABISysV_x86_64.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 liblldb_ABISysV_x86_64_h_ 10 #define liblldb_ABISysV_x86_64_h_ 11 12 #include "lldb/Target/ABI.h" 13 #include "lldb/lldb-private.h" 14 15 class ABISysV_x86_64 : public lldb_private::ABI { 16 public: 17 ~ABISysV_x86_64() override = default; 18 19 size_t GetRedZoneSize() const override; 20 21 bool PrepareTrivialCall(lldb_private::Thread &thread, lldb::addr_t sp, 22 lldb::addr_t functionAddress, 23 lldb::addr_t returnAddress, 24 llvm::ArrayRef<lldb::addr_t> args) const override; 25 26 bool GetArgumentValues(lldb_private::Thread &thread, 27 lldb_private::ValueList &values) const override; 28 29 lldb_private::Status 30 SetReturnValueObject(lldb::StackFrameSP &frame_sp, 31 lldb::ValueObjectSP &new_value) override; 32 33 lldb::ValueObjectSP 34 GetReturnValueObjectImpl(lldb_private::Thread &thread, 35 lldb_private::CompilerType &type) const override; 36 37 bool 38 CreateFunctionEntryUnwindPlan(lldb_private::UnwindPlan &unwind_plan) override; 39 40 bool CreateDefaultUnwindPlan(lldb_private::UnwindPlan &unwind_plan) override; 41 42 bool RegisterIsVolatile(const lldb_private::RegisterInfo *reg_info) override; 43 44 // The SysV x86_64 ABI requires that stack frames be 16 byte aligned. 45 // When there is a trap handler on the stack, e.g. _sigtramp in userland 46 // code, we've seen that the stack pointer is often not aligned properly 47 // before the handler is invoked. This means that lldb will stop the unwind 48 // early -- before the function which caused the trap. 49 // 50 // To work around this, we relax that alignment to be just word-size 51 // (8-bytes). 52 // Whitelisting the trap handlers for user space would be easy (_sigtramp) but 53 // in other environments there can be a large number of different functions 54 // involved in async traps. CallFrameAddressIsValid(lldb::addr_t cfa)55 bool CallFrameAddressIsValid(lldb::addr_t cfa) override { 56 // Make sure the stack call frame addresses are 8 byte aligned 57 if (cfa & (8ull - 1ull)) 58 return false; // Not 8 byte aligned 59 if (cfa == 0) 60 return false; // Zero is not a valid stack address 61 return true; 62 } 63 CodeAddressIsValid(lldb::addr_t pc)64 bool CodeAddressIsValid(lldb::addr_t pc) override { 65 // We have a 64 bit address space, so anything is valid as opcodes 66 // aren't fixed width... 67 return true; 68 } 69 70 const lldb_private::RegisterInfo * 71 GetRegisterInfoArray(uint32_t &count) override; 72 73 bool GetPointerReturnRegister(const char *&name) override; 74 75 // Static Functions 76 77 static void Initialize(); 78 79 static void Terminate(); 80 81 static lldb::ABISP CreateInstance(lldb::ProcessSP process_sp, const lldb_private::ArchSpec &arch); 82 83 static lldb_private::ConstString GetPluginNameStatic(); 84 85 // PluginInterface protocol 86 87 lldb_private::ConstString GetPluginName() override; 88 89 uint32_t GetPluginVersion() override; 90 91 protected: 92 void CreateRegisterMapIfNeeded(); 93 94 lldb::ValueObjectSP 95 GetReturnValueObjectSimple(lldb_private::Thread &thread, 96 lldb_private::CompilerType &ast_type) const; 97 98 bool RegisterIsCalleeSaved(const lldb_private::RegisterInfo *reg_info); 99 100 private: ABISysV_x86_64(lldb::ProcessSP process_sp,std::unique_ptr<llvm::MCRegisterInfo> info_up)101 ABISysV_x86_64(lldb::ProcessSP process_sp, 102 std::unique_ptr<llvm::MCRegisterInfo> info_up) 103 : lldb_private::ABI(std::move(process_sp), std::move(info_up)) { 104 // Call CreateInstance instead. 105 } 106 }; 107 108 #endif // liblldb_ABISysV_x86_64_h_ 109