1 /*
2 * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26
27 #if !defined(_WINDOWS) && !defined(__APPLE__)
28
29 #include "memory/allocation.inline.hpp"
30 #include "utilities/elfFuncDescTable.hpp"
31 #include "utilities/elfSymbolTable.hpp"
32
33 ElfSymbolTable::ElfSymbolTable(FILE* file, Elf_Shdr shdr) {
34 assert(file, "null file handle");
35 m_symbols = NULL;
36 m_next = NULL;
37 m_file = file;
38 m_status = NullDecoder::no_error;
39
40 // try to load the string table
41 long cur_offset = ftell(file);
42 if (cur_offset != -1) {
43 // call malloc so we can back up if memory allocation fails.
44 m_symbols = (Elf_Sym*)os::malloc(shdr.sh_size, mtInternal);
45 if (m_symbols) {
46 if (fseek(file, shdr.sh_offset, SEEK_SET) ||
47 fread((void*)m_symbols, shdr.sh_size, 1, file) != 1 ||
48 fseek(file, cur_offset, SEEK_SET)) {
49 m_status = NullDecoder::file_invalid;
50 os::free(m_symbols);
51 m_symbols = NULL;
52 }
53 }
54 if (!NullDecoder::is_error(m_status)) {
55 memcpy(&m_shdr, &shdr, sizeof(Elf_Shdr));
56 }
57 } else {
58 m_status = NullDecoder::file_invalid;
59 }
60 }
61
62 ElfSymbolTable::~ElfSymbolTable() {
63 if (m_symbols != NULL) {
64 os::free(m_symbols);
65 }
66
67 if (m_next != NULL) {
68 delete m_next;
69 }
70 }
71
72 bool ElfSymbolTable::lookup(address addr, int* stringtableIndex, int* posIndex, int* offset, ElfFuncDescTable* funcDescTable) {
73 assert(stringtableIndex, "null string table index pointer");
74 assert(posIndex, "null string table offset pointer");
75 assert(offset, "null offset pointer");
76
77 if (NullDecoder::is_error(m_status)) {
78 return false;
79 }
80
81 size_t sym_size = sizeof(Elf_Sym);
82 assert((m_shdr.sh_size % sym_size) == 0, "check size");
83 int count = m_shdr.sh_size / sym_size;
84 if (m_symbols != NULL) {
85 for (int index = 0; index < count; index ++) {
86 if (STT_FUNC == ELF_ST_TYPE(m_symbols[index].st_info)) {
87 Elf_Word st_size = m_symbols[index].st_size;
88 address sym_addr;
89 if (funcDescTable != NULL && funcDescTable->get_index() == m_symbols[index].st_shndx) {
90 // We need to go another step trough the function descriptor table (currently PPC64 only)
91 sym_addr = funcDescTable->lookup(m_symbols[index].st_value);
92 } else {
93 sym_addr = (address)m_symbols[index].st_value;
94 }
95 if (sym_addr <= addr && (Elf_Word)(addr - sym_addr) < st_size) {
96 *offset = (int)(addr - sym_addr);
97 *posIndex = m_symbols[index].st_name;
98 *stringtableIndex = m_shdr.sh_link;
99 return true;
100 }
101 }
102 }
103 } else {
104 long cur_pos;
105 if ((cur_pos = ftell(m_file)) == -1 ||
106 fseek(m_file, m_shdr.sh_offset, SEEK_SET)) {
107 m_status = NullDecoder::file_invalid;
108 return false;
109 }
110
111 Elf_Sym sym;
112 for (int index = 0; index < count; index ++) {
113 if (fread(&sym, sym_size, 1, m_file) == 1) {
114 if (STT_FUNC == ELF_ST_TYPE(sym.st_info)) {
115 Elf_Word st_size = sym.st_size;
116 address sym_addr;
117 if (funcDescTable != NULL && funcDescTable->get_index() == sym.st_shndx) {
118 // We need to go another step trough the function descriptor table (currently PPC64 only)
119 sym_addr = funcDescTable->lookup(sym.st_value);
120 } else {
121 sym_addr = (address)sym.st_value;
122 }
123 if (sym_addr <= addr && (Elf_Word)(addr - sym_addr) < st_size) {
124 *offset = (int)(addr - sym_addr);
125 *posIndex = sym.st_name;
126 *stringtableIndex = m_shdr.sh_link;
127 return true;
128 }
129 }
130 } else {
131 m_status = NullDecoder::file_invalid;
132 return false;
133 }
134 }
135 fseek(m_file, cur_pos, SEEK_SET);
136 }
137 return true;
138 }
139
140 #endif // !_WINDOWS && !__APPLE__