1 /* 2 * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved. 3 * Copyright 2012, 2013 SAP AG. All rights reserved. 4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 5 * 6 * This code is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License version 2 only, as 8 * published by the Free Software Foundation. 9 * 10 * This code is distributed in the hope that it will be useful, but WITHOUT 11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 13 * version 2 for more details (a copy is included in the LICENSE file that 14 * accompanied this code). 15 * 16 * You should have received a copy of the GNU General Public License version 17 * 2 along with this work; if not, write to the Free Software Foundation, 18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 19 * 20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 21 * or visit www.oracle.com if you need additional information or have any 22 * questions. 23 * 24 */ 25 26 #include "precompiled.hpp" 27 28 #if !defined(_WINDOWS) && !defined(__APPLE__) 29 30 #include "memory/allocation.inline.hpp" 31 #include "utilities/elfFuncDescTable.hpp" 32 33 ElfFuncDescTable::ElfFuncDescTable(FILE* file, Elf_Shdr shdr, int index) { 34 assert(file, "null file handle"); 35 // The actual function address (i.e. function entry point) is always the 36 // first value in the function descriptor (on IA64 and PPC64 they look as follows): 37 // PPC64: [function entry point, TOC pointer, environment pointer] 38 // IA64 : [function entry point, GP (global pointer) value] 39 // Unfortunately 'shdr.sh_entsize' doesn't always seem to contain this size (it's zero on PPC64) so we can't assert 40 // assert(IA64_ONLY(2) PPC64_ONLY(3) * sizeof(address) == shdr.sh_entsize, "Size mismatch for '.opd' section entries"); 41 42 m_funcDescs = NULL; 43 m_file = file; 44 m_index = index; 45 m_status = NullDecoder::no_error; 46 47 // try to load the function descriptor table 48 long cur_offset = ftell(file); 49 if (cur_offset != -1) { 50 // call malloc so we can back up if memory allocation fails. 51 m_funcDescs = (address*)os::malloc(shdr.sh_size, mtInternal); 52 if (m_funcDescs) { 53 if (fseek(file, shdr.sh_offset, SEEK_SET) || 54 fread((void*)m_funcDescs, shdr.sh_size, 1, file) != 1 || 55 fseek(file, cur_offset, SEEK_SET)) { 56 m_status = NullDecoder::file_invalid; 57 os::free(m_funcDescs); 58 m_funcDescs = NULL; 59 } 60 } 61 if (!NullDecoder::is_error(m_status)) { 62 memcpy(&m_shdr, &shdr, sizeof(Elf_Shdr)); 63 } 64 } else { 65 m_status = NullDecoder::file_invalid; 66 } 67 } 68 69 ElfFuncDescTable::~ElfFuncDescTable() { 70 if (m_funcDescs != NULL) { 71 os::free(m_funcDescs); 72 } 73 } 74 75 address ElfFuncDescTable::lookup(Elf_Word index) { 76 if (NullDecoder::is_error(m_status)) { 77 return NULL; 78 } 79 80 if (m_funcDescs != NULL) { 81 if (m_shdr.sh_size > 0 && m_shdr.sh_addr <= index && index <= m_shdr.sh_addr + m_shdr.sh_size) { 82 // Notice that 'index' is a byte-offset into the function descriptor table. 83 return m_funcDescs[(index - m_shdr.sh_addr) / sizeof(address)]; 84 } 85 return NULL; 86 } else { 87 long cur_pos; 88 address addr; 89 if (!(m_shdr.sh_size > 0 && m_shdr.sh_addr <= index && index <= m_shdr.sh_addr + m_shdr.sh_size)) { 90 // don't put the whole decoder in error mode if we just tried a wrong index 91 return NULL; 92 } 93 if ((cur_pos = ftell(m_file)) == -1 || 94 fseek(m_file, m_shdr.sh_offset + index - m_shdr.sh_addr, SEEK_SET) || 95 fread(&addr, sizeof(addr), 1, m_file) != 1 || 96 fseek(m_file, cur_pos, SEEK_SET)) { 97 m_status = NullDecoder::file_invalid; 98 return NULL; 99 } 100 return addr; 101 } 102 } 103 104 #endif // !_WINDOWS && !__APPLE__