1 /* 2 * Copyright (c) 1997, 2017, 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 "prims/jvm.h" 31 #include "runtime/os.hpp" 32 #include "utilities/elfStringTable.hpp" 33 34 // We will try to load whole string table into memory if we can. 35 // Otherwise, fallback to more expensive file operation. 36 ElfStringTable::ElfStringTable(FILE* file, Elf_Shdr shdr, int index) { 37 assert(file, "null file handle"); 38 m_table = NULL; 39 m_index = index; 40 m_next = NULL; 41 m_file = file; 42 m_status = NullDecoder::no_error; 43 44 // try to load the string table 45 long cur_offset = ftell(file); 46 m_table = (char*)os::malloc(sizeof(char) * shdr.sh_size, mtInternal); 47 if (m_table != NULL) { 48 // if there is an error, mark the error 49 if (fseek(file, shdr.sh_offset, SEEK_SET) || 50 fread((void*)m_table, shdr.sh_size, 1, file) != 1 || 51 fseek(file, cur_offset, SEEK_SET)) { 52 m_status = NullDecoder::file_invalid; 53 os::free((void*)m_table); 54 m_table = NULL; 55 } 56 } else { 57 memcpy(&m_shdr, &shdr, sizeof(Elf_Shdr)); 58 } 59 } 60 61 ElfStringTable::~ElfStringTable() { 62 if (m_table != NULL) { 63 os::free((void*)m_table); 64 } 65 66 if (m_next != NULL) { 67 delete m_next; 68 } 69 } 70 71 bool ElfStringTable::string_at(int pos, char* buf, int buflen) { 72 if (NullDecoder::is_error(m_status)) { 73 return false; 74 } 75 if (m_table != NULL) { 76 jio_snprintf(buf, buflen, "%s", (const char*)(m_table + pos)); 77 return true; 78 } else { 79 long cur_pos = ftell(m_file); 80 if (cur_pos == -1 || 81 fseek(m_file, m_shdr.sh_offset + pos, SEEK_SET) || 82 fread(buf, 1, buflen, m_file) <= 0 || 83 fseek(m_file, cur_pos, SEEK_SET)) { 84 m_status = NullDecoder::file_invalid; 85 return false; 86 } 87 return true; 88 } 89 } 90 91 #endif // !_WINDOWS && !__APPLE__