1 /* 2 * Copyright (c) 2020, Oracle and/or its affiliates. All rights reserved. 3 * Copyright (c) 2020, NTT DATA. 4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 5 * 6 * This code is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License version 2 only, as 8 * published by the Free Software Foundation. 9 * 10 * This code is distributed in the hope that it will be useful, but WITHOUT 11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 13 * version 2 for more details (a copy is included in the LICENSE file that 14 * accompanied this code). 15 * 16 * You should have received a copy of the GNU General Public License version 17 * 2 along with this work; if not, write to the Free Software Foundation, 18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 19 * 20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 21 * or visit www.oracle.com if you need additional information or have any 22 * questions. 23 * 24 */ 25 26 #ifndef _DWARF_HPP_ 27 #define _DWARF_HPP_ 28 29 #include "libproc_impl.h" 30 31 /* 32 * from System V Application Binary Interface 33 * AMD64 Architecture Processor Supplement 34 * Figure 3.38: DWARF Register Number Mapping 35 * https://software.intel.com/sites/default/files/article/402129/mpx-linux64-abi.pdf 36 */ 37 enum DWARF_Register { 38 RAX, 39 RDX, 40 RCX, 41 RBX, 42 RSI, 43 RDI, 44 RBP, 45 RSP, 46 R8, 47 R9, 48 R10, 49 R11, 50 R12, 51 R13, 52 R14, 53 R15, 54 RA, 55 MAX_VALUE 56 }; 57 58 /* 59 * DwarfParser finds out CFA (Canonical Frame Address) from DWARF in ELF binary. 60 * Also Return Address (RA) and Base Pointer (BP) are calculated from CFA. 61 */ 62 class DwarfParser { 63 private: 64 const lib_info *_lib; 65 unsigned char *_buf; 66 unsigned char _encoding; 67 enum DWARF_Register _cfa_reg; 68 enum DWARF_Register _return_address_reg; 69 unsigned int _code_factor; 70 int _data_factor; 71 72 uintptr_t _current_pc; 73 int _cfa_offset; 74 int _ra_cfa_offset; 75 int _bp_cfa_offset; 76 bool _bp_offset_available; 77 78 uintptr_t read_leb(bool sign); 79 uint64_t get_entry_length(); 80 void process_cie(unsigned char *start_of_entry, uint32_t id); 81 void parse_dwarf_instructions(uintptr_t begin, uintptr_t pc, const unsigned char *end); 82 uint32_t get_decoded_value(); 83 unsigned int get_pc_range(); 84 85 public: 86 DwarfParser(lib_info *lib) : _lib(lib), 87 _buf(NULL), 88 _encoding(0), 89 _cfa_reg(RSP), 90 _return_address_reg(RA), 91 _code_factor(0), 92 _data_factor(0), 93 _current_pc(0L), 94 _cfa_offset(0), 95 _ra_cfa_offset(0), 96 _bp_cfa_offset(0), 97 _bp_offset_available(false) {}; 98 99 ~DwarfParser() {} 100 uintptr_t process_dwarf(const uintptr_t pc); 101 enum DWARF_Register get_cfa_register() { return _cfa_reg; } 102 int get_cfa_offset() { return _cfa_offset; } 103 int get_ra_cfa_offset() { return _ra_cfa_offset; } 104 int get_bp_cfa_offset() { return _bp_cfa_offset; } 105 bool is_bp_offset_available() { return _bp_offset_available; } 106 107 bool is_in(long pc) { 108 return (_lib->exec_start <= pc) && (pc < _lib->exec_end); 109 } 110 111 bool is_parseable() { 112 return _lib->eh_frame.data != NULL; 113 } 114 }; 115 116 #endif //_DWARF_HPP_