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 #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 

    39 typedef Elf64_Half      Elf_Half;

    40 typedef Elf64_Word      Elf_Word;

    41 typedef Elf64_Off       Elf_Off;

    42 typedef Elf64_Addr      Elf_Addr;

    43 

    44 typedef Elf64_Ehdr      Elf_Ehdr;

    45 typedef Elf64_Shdr      Elf_Shdr;

    46 typedef Elf64_Phdr      Elf_Phdr;

    47 typedef 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 

    55 typedef Elf32_Half      Elf_Half;

    56 typedef Elf32_Word      Elf_Word;

    57 typedef Elf32_Off       Elf_Off;

    58 typedef Elf32_Addr      Elf_Addr;

    59 

    60 

    61 typedef Elf32_Ehdr      Elf_Ehdr;

    62 typedef Elf32_Shdr      Elf_Shdr;

    63 typedef Elf32_Phdr      Elf_Phdr;

    64 typedef 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 

    76 class ElfStringTable;

    77 class ElfSymbolTable;

    78 class ElfFuncDescTable;

    79 

    80 

    81 // On Solaris/Linux platforms, libjvm.so does contain all private symbols.

    82 // ElfFile is basically an elf file parser, which can lookup the symbol

    83 // that is the nearest to the given address.

    84 // Beware, this code is called from vm error reporting code, when vm is already

    85 // in "error" state, so there are scenarios, lookup will fail. We want this

    86 // part of code to be very defensive, and bait out if anything went wrong.

    87 

    88 class ElfFile: public CHeapObj<mtInternal> {

    89   friend class ElfDecoder;

    90  public:

    91   ElfFile(const char* filepath);

    92   ~ElfFile();

    93 

    94   bool decode(address addr, char* buf, int buflen, int* offset);

    95   const char* filepath() {

    96     return m_filepath;

    97   }

    98 

    99   bool same_elf_file(const char* filepath) {

   100     assert(filepath, "null file path");

   101     assert(m_filepath, "already out of memory");

   102     return (m_filepath && !strcmp(filepath, m_filepath));

   103   }

   104 

   105   NullDecoder::decoder_status get_status() {

   106     return m_status;

   107   }

   108 

   109  private:

   110   // sanity check, if the file is a real elf file

   111   static bool is_elf_file(Elf_Ehdr&);

   112 

   113   // load string tables from the elf file

   114   bool load_tables();

   115 

   116   // string tables are stored in a linked list

   117   void add_string_table(ElfStringTable* table);

   118 

   119   // symbol tables are stored in a linked list

   120   void add_symbol_table(ElfSymbolTable* table);

   121 

   122   // return a string table at specified section index

   123   ElfStringTable* get_string_table(int index);

   124 

   125 protected:

   126    ElfFile*  next() const { return m_next; }

   127    void set_next(ElfFile* file) { m_next = file; }

   128 

   129  public:

   130   // Returns true if the elf file is marked NOT to require an executable stack,

   131   // or if the file could not be opened.

   132   // Returns false if the elf file requires an executable stack, the stack flag

   133   // is not set at all, or if the file can not be read.

   134   // On systems other than linux it always returns false.

   135   static bool specifies_noexecstack(const char* filepath) NOT_LINUX({ return false; });

   136 

   137  protected:

   138     ElfFile*         m_next;

   139 

   140  private:

   141   // file

   142   const char* m_filepath;

   143   FILE* m_file;

   144 

   145   // Elf header

   146   Elf_Ehdr                     m_elfHdr;

   147 

   148   // symbol tables

   149   ElfSymbolTable*              m_symbol_tables;

   150 

   151   // string tables

   152   ElfStringTable*              m_string_tables;

   153 

   154   // function descriptors table

   155   ElfFuncDescTable*            m_funcDesc_table;

   156 

   157   NullDecoder::decoder_status  m_status;

   158 };

   159 

   160 #endif // !_WINDOWS && !__APPLE__

   161 

   162 #endif // SHARE_VM_UTILITIES_ELF_FILE_HPP