1/*
2 * Copyright (c) 1997, 2018, 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
33ElfSymbolTable::ElfSymbolTable(FILE* const file, Elf_Shdr& shdr) :
34 _next(NULL), _fd(file), _section(file, shdr) {
35 assert(file != NULL, "null file handle");
36 _status = _section.status();
37
38 if (_section.section_header()->sh_size % sizeof(Elf_Sym) != 0) {
39 _status = NullDecoder::file_invalid;
40 }
41}
42
43ElfSymbolTable::~ElfSymbolTable() {
44 if (_next != NULL) {
45 delete _next;
46 }
47}
48
49bool ElfSymbolTable::compare(const Elf_Sym* sym, address addr, int* stringtableIndex, int* posIndex, int* offset, ElfFuncDescTable* funcDescTable) {
50 if (STT_FUNC == ELF_ST_TYPE(sym->st_info)) {
51 Elf_Word st_size = sym->st_size;
52 const Elf_Shdr* shdr = _section.section_header();
53 address sym_addr;
54 if (funcDescTable != NULL && funcDescTable->get_index() == sym->st_shndx) {
55 // We need to go another step trough the function descriptor table (currently PPC64 only)
56 sym_addr = funcDescTable->lookup(sym->st_value);
57 } else {
58 sym_addr = (address)sym->st_value;
59 }
60 if (sym_addr <= addr && (Elf_Word)(addr - sym_addr) < st_size) {
61 *offset = (int)(addr - sym_addr);
62 *posIndex = sym->st_name;
63 *stringtableIndex = shdr->sh_link;
64 return true;
65 }
66 }
67 return false;
68}
69
70bool ElfSymbolTable::lookup(address addr, int* stringtableIndex, int* posIndex, int* offset, ElfFuncDescTable* funcDescTable) {
71 assert(stringtableIndex, "null string table index pointer");
72 assert(posIndex, "null string table offset pointer");
73 assert(offset, "null offset pointer");
74
75 if (NullDecoder::is_error(get_status())) {
76 return false;
77 }
78
79 size_t sym_size = sizeof(Elf_Sym);
80 int count = _section.section_header()->sh_size / sym_size;
81 Elf_Sym* symbols = (Elf_Sym*)_section.section_data();
82
83 if (symbols != NULL) {
84 for (int index = 0; index < count; index ++) {
85 if (compare(&symbols[index], addr, stringtableIndex, posIndex, offset, funcDescTable)) {
86 return true;
87 }
88 }
89 } else {
90 MarkedFileReader mfd(_fd);
91
92 if (!mfd.has_mark() || !mfd.set_position(_section.section_header()->sh_offset)) {
93 _status = NullDecoder::file_invalid;
94 return false;
95 }
96
97 Elf_Sym sym;
98 for (int index = 0; index < count; index ++) {
99 if (!mfd.read((void*)&sym, sizeof(sym))) {
100 _status = NullDecoder::file_invalid;
101 return false;
102 }
103
104 if (compare(&sym, addr, stringtableIndex, posIndex, offset, funcDescTable)) {
105 return true;
106 }
107 }
108 }
109 return false;
110}
111
112#endif // !_WINDOWS && !__APPLE__
113