elfFile.hpp revision 4275:9058789475af 
1/*
2 * Copyright (c) 1997, 2012, 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.
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23 */
24
25#ifndef SHARE_VM_UTILITIES_ELF_FILE_HPP
26#define SHARE_VM_UTILITIES_ELF_FILE_HPP
27
28#if !defined(_WINDOWS) && !defined(__APPLE__)
29
30#if defined(__OpenBSD__)
31#include <sys/exec_elf.h>
32#else
33#include <elf.h>
34#endif
35#include <stdio.h>
36
37#ifdef _LP64
38
39typedef Elf64_Half      Elf_Half;
40typedef Elf64_Word      Elf_Word;
41typedef Elf64_Off       Elf_Off;
42typedef Elf64_Addr      Elf_Addr;
43
44typedef Elf64_Ehdr      Elf_Ehdr;
45typedef Elf64_Shdr      Elf_Shdr;
46typedef Elf64_Phdr      Elf_Phdr;
47typedef Elf64_Sym       Elf_Sym;
48
49#if !defined(_ALLBSD_SOURCE) || defined(__APPLE__)
50#define ELF_ST_TYPE ELF64_ST_TYPE
51#endif
52
53#else
54
55typedef Elf32_Half      Elf_Half;
56typedef Elf32_Word      Elf_Word;
57typedef Elf32_Off       Elf_Off;
58typedef Elf32_Addr      Elf_Addr;
59
60
61typedef Elf32_Ehdr      Elf_Ehdr;
62typedef Elf32_Shdr      Elf_Shdr;
63typedef Elf32_Phdr      Elf_Phdr;
64typedef Elf32_Sym       Elf_Sym;
65
66#if !defined(_ALLBSD_SOURCE) || defined(__APPLE__)
67#define ELF_ST_TYPE ELF32_ST_TYPE
68#endif
69#endif
70
71#include "globalDefinitions.hpp"
72#include "memory/allocation.hpp"
73#include "utilities/decoder.hpp"
74
75
76class ElfStringTable;
77class ElfSymbolTable;
78
79
80// On Solaris/Linux platforms, libjvm.so does contain all private symbols.
81// ElfFile is basically an elf file parser, which can lookup the symbol
82// that is the nearest to the given address.
83// Beware, this code is called from vm error reporting code, when vm is already
84// in "error" state, so there are scenarios, lookup will fail. We want this
85// part of code to be very defensive, and bait out if anything went wrong.
86
87class ElfFile: public CHeapObj<mtInternal> {
88  friend class ElfDecoder;
89 public:
90  ElfFile(const char* filepath);
91  ~ElfFile();
92
93  bool decode(address addr, char* buf, int buflen, int* offset);
94  const char* filepath() {
95    return m_filepath;
96  }
97
98  bool same_elf_file(const char* filepath) {
99    assert(filepath, "null file path");
100    assert(m_filepath, "already out of memory");
101    return (m_filepath && !strcmp(filepath, m_filepath));
102  }
103
104  NullDecoder::decoder_status get_status() {
105    return m_status;
106  }
107
108 private:
109  // sanity check, if the file is a real elf file
110  bool is_elf_file(Elf_Ehdr&);
111
112  // load string tables from the elf file
113  bool load_tables();
114
115  // string tables are stored in a linked list
116  void add_string_table(ElfStringTable* table);
117
118  // symbol tables are stored in a linked list
119  void add_symbol_table(ElfSymbolTable* table);
120
121  // return a string table at specified section index
122  ElfStringTable* get_string_table(int index);
123
124protected:
125   ElfFile*  next() const { return m_next; }
126   void set_next(ElfFile* file) { m_next = file; }
127
128 public:
129  // Returns true if the elf file is marked NOT to require an executable stack,
130  // or if the file could not be opened.
131  // Returns false if the elf file requires an executable stack, the stack flag
132  // is not set at all, or if the file can not be read.
133  // On systems other than linux it always returns false.
134  bool specifies_noexecstack() NOT_LINUX({ return false; });
135
136 protected:
137    ElfFile*         m_next;
138
139 private:
140  // file
141  const char* m_filepath;
142  FILE* m_file;
143
144  // Elf header
145  Elf_Ehdr                     m_elfHdr;
146
147  // symbol tables
148  ElfSymbolTable*              m_symbol_tables;
149
150  // string tables
151  ElfStringTable*              m_string_tables;
152
153  NullDecoder::decoder_status  m_status;
154};
155
156#endif // _WINDOWS
157
158#endif // SHARE_VM_UTILITIES_ELF_FILE_HPP
159