zgu@2364: /*
zgu@2364:  * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved.
zgu@2364:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
zgu@2364:  *
zgu@2364:  * This code is free software; you can redistribute it and/or modify it
zgu@2364:  * under the terms of the GNU General Public License version 2 only, as
zgu@2364:  * published by the Free Software Foundation.
zgu@2364:  *
zgu@2364:  * This code is distributed in the hope that it will be useful, but WITHOUT
zgu@2364:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
zgu@2364:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
zgu@2364:  * version 2 for more details (a copy is included in the LICENSE file that
zgu@2364:  * accompanied this code).
zgu@2364:  *
zgu@2364:  * You should have received a copy of the GNU General Public License version
zgu@2364:  * 2 along with this work; if not, write to the Free Software Foundation,
zgu@2364:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
zgu@2364:  *
zgu@2364:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
zgu@2364:  * or visit www.oracle.com if you need additional information or have any
zgu@2364:  * questions.
zgu@2364:  *
zgu@2364:  */
zgu@2364: 
zgu@2364: #include "precompiled.hpp"
zgu@2364: 
never@3156: #if !defined(_WINDOWS) && !defined(__APPLE__)
zgu@2364: 
zgu@2364: #include <string.h>
zgu@2364: #include <stdio.h>
zgu@2364: #include <limits.h>
zgu@2834: #include <new>
zgu@2364: 
zgu@2364: #include "memory/allocation.inline.hpp"
zgu@2364: #include "utilities/decoder.hpp"
zgu@2364: #include "utilities/elfFile.hpp"
zgu@2364: #include "utilities/elfStringTable.hpp"
zgu@2364: #include "utilities/elfSymbolTable.hpp"
zgu@2364: 
zgu@2364: 
zgu@2364: ElfFile::ElfFile(const char* filepath) {
zgu@2364:   assert(filepath, "null file path");
zgu@2364:   memset(&m_elfHdr, 0, sizeof(m_elfHdr));
zgu@2364:   m_string_tables = NULL;
zgu@2364:   m_symbol_tables = NULL;
zgu@2364:   m_next = NULL;
zgu@3430:   m_status = NullDecoder::no_error;
zgu@2364: 
zgu@2364:   int len = strlen(filepath) + 1;
zgu@2834:   m_filepath = (const char*)os::malloc(len * sizeof(char));
zgu@2364:   if (m_filepath != NULL) {
zgu@2364:     strcpy((char*)m_filepath, filepath);
zgu@2364:     m_file = fopen(filepath, "r");
zgu@2364:     if (m_file != NULL) {
zgu@2364:       load_tables();
zgu@2364:     } else {
zgu@3430:       m_status = NullDecoder::file_not_found;
zgu@2364:     }
zgu@2364:   } else {
zgu@3430:     m_status = NullDecoder::out_of_memory;
zgu@2364:   }
zgu@2364: }
zgu@2364: 
zgu@2364: ElfFile::~ElfFile() {
zgu@2364:   if (m_string_tables != NULL) {
zgu@2364:     delete m_string_tables;
zgu@2364:   }
zgu@2364: 
zgu@2364:   if (m_symbol_tables != NULL) {
zgu@2364:     delete m_symbol_tables;
zgu@2364:   }
zgu@2364: 
zgu@2364:   if (m_file != NULL) {
zgu@2364:     fclose(m_file);
zgu@2364:   }
zgu@2364: 
zgu@2364:   if (m_filepath != NULL) {
zgu@2834:     os::free((void*)m_filepath);
zgu@2364:   }
zgu@2364: 
zgu@2364:   if (m_next != NULL) {
zgu@2364:     delete m_next;
zgu@2364:   }
zgu@2364: };
zgu@2364: 
zgu@2364: 
zgu@2364: //Check elf header to ensure the file is valid.
zgu@2364: bool ElfFile::is_elf_file(Elf_Ehdr& hdr) {
zgu@2364:   return (ELFMAG0 == hdr.e_ident[EI_MAG0] &&
zgu@2364:       ELFMAG1 == hdr.e_ident[EI_MAG1] &&
zgu@2364:       ELFMAG2 == hdr.e_ident[EI_MAG2] &&
zgu@2364:       ELFMAG3 == hdr.e_ident[EI_MAG3] &&
zgu@2364:       ELFCLASSNONE != hdr.e_ident[EI_CLASS] &&
zgu@2364:       ELFDATANONE != hdr.e_ident[EI_DATA]);
zgu@2364: }
zgu@2364: 
zgu@2364: bool ElfFile::load_tables() {
zgu@2364:   assert(m_file, "file not open");
zgu@3430:   assert(!NullDecoder::is_error(m_status), "already in error");
zgu@2364: 
zgu@2364:   // read elf file header
zgu@2364:   if (fread(&m_elfHdr, sizeof(m_elfHdr), 1, m_file) != 1) {
zgu@3430:     m_status = NullDecoder::file_invalid;
zgu@2364:     return false;
zgu@2364:   }
zgu@2364: 
zgu@2364:   if (!is_elf_file(m_elfHdr)) {
zgu@3430:     m_status = NullDecoder::file_invalid;
zgu@2364:     return false;
zgu@2364:   }
zgu@2364: 
zgu@2364:   // walk elf file's section headers, and load string tables
zgu@2364:   Elf_Shdr shdr;
zgu@2364:   if (!fseek(m_file, m_elfHdr.e_shoff, SEEK_SET)) {
zgu@3430:     if (NullDecoder::is_error(m_status)) return false;
zgu@2364: 
zgu@2364:     for (int index = 0; index < m_elfHdr.e_shnum; index ++) {
zgu@2364:       if (fread((void*)&shdr, sizeof(Elf_Shdr), 1, m_file) != 1) {
zgu@3430:         m_status = NullDecoder::file_invalid;
zgu@2364:         return false;
zgu@2364:       }
zgu@2364:       // string table
zgu@2364:       if (shdr.sh_type == SHT_STRTAB) {
zgu@2834:         ElfStringTable* table = new (std::nothrow) ElfStringTable(m_file, shdr, index);
zgu@2364:         if (table == NULL) {
zgu@3430:           m_status = NullDecoder::out_of_memory;
zgu@2364:           return false;
zgu@2364:         }
zgu@2364:         add_string_table(table);
zgu@2364:       } else if (shdr.sh_type == SHT_SYMTAB || shdr.sh_type == SHT_DYNSYM) {
zgu@2834:         ElfSymbolTable* table = new (std::nothrow) ElfSymbolTable(m_file, shdr);
zgu@2364:         if (table == NULL) {
zgu@3430:           m_status = NullDecoder::out_of_memory;
zgu@2364:           return false;
zgu@2364:         }
zgu@2364:         add_symbol_table(table);
zgu@2364:       }
zgu@2364:     }
zgu@2364:   }
zgu@2364:   return true;
zgu@2364: }
zgu@2364: 
zgu@3430: bool ElfFile::decode(address addr, char* buf, int buflen, int* offset) {
zgu@2364:   // something already went wrong, just give up
zgu@3430:   if (NullDecoder::is_error(m_status)) {
zgu@3430:     return false;
zgu@2364:   }
zgu@2364:   ElfSymbolTable* symbol_table = m_symbol_tables;
zgu@2364:   int string_table_index;
zgu@2364:   int pos_in_string_table;
zgu@2364:   int off = INT_MAX;
zgu@2364:   bool found_symbol = false;
zgu@2364:   while (symbol_table != NULL) {
zgu@3430:     if (symbol_table->lookup(addr, &string_table_index, &pos_in_string_table, &off)) {
zgu@2364:       found_symbol = true;
zgu@2364:     }
zgu@2364:     symbol_table = symbol_table->m_next;
zgu@2364:   }
zgu@3430:   if (!found_symbol) return false;
zgu@2364: 
zgu@2364:   ElfStringTable* string_table = get_string_table(string_table_index);
zgu@3430: 
zgu@2364:   if (string_table == NULL) {
zgu@3430:     m_status = NullDecoder::file_invalid;
zgu@3430:     return false;
zgu@2364:   }
zgu@2364:   if (offset) *offset = off;
zgu@3430: 
zgu@3430:   return string_table->string_at(pos_in_string_table, buf, buflen);
zgu@2364: }
zgu@2364: 
zgu@2364: 
zgu@2364: void ElfFile::add_symbol_table(ElfSymbolTable* table) {
zgu@2364:   if (m_symbol_tables == NULL) {
zgu@2364:     m_symbol_tables = table;
zgu@2364:   } else {
zgu@2364:     table->m_next = m_symbol_tables;
zgu@2364:     m_symbol_tables = table;
zgu@2364:   }
zgu@2364: }
zgu@2364: 
zgu@2364: void ElfFile::add_string_table(ElfStringTable* table) {
zgu@2364:   if (m_string_tables == NULL) {
zgu@2364:     m_string_tables = table;
zgu@2364:   } else {
zgu@2364:     table->m_next = m_string_tables;
zgu@2364:     m_string_tables = table;
zgu@2364:   }
zgu@2364: }
zgu@2364: 
zgu@2364: ElfStringTable* ElfFile::get_string_table(int index) {
zgu@2364:   ElfStringTable* p = m_string_tables;
zgu@2364:   while (p != NULL) {
zgu@2364:     if (p->index() == index) return p;
zgu@2364:     p = p->m_next;
zgu@2364:   }
zgu@2364:   return NULL;
zgu@2364: }
zgu@2364: 
zgu@2364: #endif // _WINDOWS