Mercurial > hg > graal-compiler
view src/share/vm/utilities/elfFile.cpp @ 21642:57912478d94d
fixed pylint issue
author | Doug Simon <doug.simon@oracle.com> |
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date | Mon, 01 Jun 2015 18:13:48 +0200 |
parents | 52b4284cb496 |
children |
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/* * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #include "precompiled.hpp" #if !defined(_WINDOWS) && !defined(__APPLE__) #include <string.h> #include <stdio.h> #include <limits.h> #include <new> #include "memory/allocation.inline.hpp" #include "utilities/decoder.hpp" #include "utilities/elfFile.hpp" #include "utilities/elfFuncDescTable.hpp" #include "utilities/elfStringTable.hpp" #include "utilities/elfSymbolTable.hpp" ElfFile::ElfFile(const char* filepath) { assert(filepath, "null file path"); memset(&m_elfHdr, 0, sizeof(m_elfHdr)); m_string_tables = NULL; m_symbol_tables = NULL; m_funcDesc_table = NULL; m_next = NULL; m_status = NullDecoder::no_error; int len = strlen(filepath) + 1; m_filepath = (const char*)os::malloc(len * sizeof(char), mtInternal); if (m_filepath != NULL) { strcpy((char*)m_filepath, filepath); m_file = fopen(filepath, "r"); if (m_file != NULL) { load_tables(); } else { m_status = NullDecoder::file_not_found; } } else { m_status = NullDecoder::out_of_memory; } } ElfFile::~ElfFile() { if (m_string_tables != NULL) { delete m_string_tables; } if (m_symbol_tables != NULL) { delete m_symbol_tables; } if (m_file != NULL) { fclose(m_file); } if (m_filepath != NULL) { os::free((void*)m_filepath); } if (m_next != NULL) { delete m_next; } }; //Check elf header to ensure the file is valid. bool ElfFile::is_elf_file(Elf_Ehdr& hdr) { return (ELFMAG0 == hdr.e_ident[EI_MAG0] && ELFMAG1 == hdr.e_ident[EI_MAG1] && ELFMAG2 == hdr.e_ident[EI_MAG2] && ELFMAG3 == hdr.e_ident[EI_MAG3] && ELFCLASSNONE != hdr.e_ident[EI_CLASS] && ELFDATANONE != hdr.e_ident[EI_DATA]); } bool ElfFile::load_tables() { assert(m_file, "file not open"); assert(!NullDecoder::is_error(m_status), "already in error"); // read elf file header if (fread(&m_elfHdr, sizeof(m_elfHdr), 1, m_file) != 1) { m_status = NullDecoder::file_invalid; return false; } if (!is_elf_file(m_elfHdr)) { m_status = NullDecoder::file_invalid; return false; } // walk elf file's section headers, and load string tables Elf_Shdr shdr; if (!fseek(m_file, m_elfHdr.e_shoff, SEEK_SET)) { if (NullDecoder::is_error(m_status)) return false; for (int index = 0; index < m_elfHdr.e_shnum; index ++) { if (fread((void*)&shdr, sizeof(Elf_Shdr), 1, m_file) != 1) { m_status = NullDecoder::file_invalid; return false; } if (shdr.sh_type == SHT_STRTAB) { // string tables ElfStringTable* table = new (std::nothrow) ElfStringTable(m_file, shdr, index); if (table == NULL) { m_status = NullDecoder::out_of_memory; return false; } add_string_table(table); } else if (shdr.sh_type == SHT_SYMTAB || shdr.sh_type == SHT_DYNSYM) { // symbol tables ElfSymbolTable* table = new (std::nothrow) ElfSymbolTable(m_file, shdr); if (table == NULL) { m_status = NullDecoder::out_of_memory; return false; } add_symbol_table(table); } } #if defined(PPC64) && !defined(ABI_ELFv2) // Now read the .opd section wich contains the PPC64 function descriptor table. // The .opd section is only available on PPC64 (see for example: // http://refspecs.linuxfoundation.org/LSB_3.1.1/LSB-Core-PPC64/LSB-Core-PPC64/specialsections.html) // so this code should do no harm on other platforms but because of performance reasons we only // execute it on PPC64 platforms. // Notice that we can only find the .opd section after we have successfully read in the string // tables in the previous loop, because we need to query the name of each section which is // contained in one of the string tables (i.e. the one with the index m_elfHdr.e_shstrndx). // Reset the file pointer if (fseek(m_file, m_elfHdr.e_shoff, SEEK_SET)) { m_status = NullDecoder::file_invalid; return false; } for (int index = 0; index < m_elfHdr.e_shnum; index ++) { if (fread((void*)&shdr, sizeof(Elf_Shdr), 1, m_file) != 1) { m_status = NullDecoder::file_invalid; return false; } if (m_elfHdr.e_shstrndx != SHN_UNDEF && shdr.sh_type == SHT_PROGBITS) { ElfStringTable* string_table = get_string_table(m_elfHdr.e_shstrndx); if (string_table == NULL) { m_status = NullDecoder::file_invalid; return false; } char buf[8]; // '8' is enough because we only want to read ".opd" if (string_table->string_at(shdr.sh_name, buf, sizeof(buf)) && !strncmp(".opd", buf, 4)) { m_funcDesc_table = new (std::nothrow) ElfFuncDescTable(m_file, shdr, index); if (m_funcDesc_table == NULL) { m_status = NullDecoder::out_of_memory; return false; } break; } } } #endif } return true; } bool ElfFile::decode(address addr, char* buf, int buflen, int* offset) { // something already went wrong, just give up if (NullDecoder::is_error(m_status)) { return false; } ElfSymbolTable* symbol_table = m_symbol_tables; int string_table_index; int pos_in_string_table; int off = INT_MAX; bool found_symbol = false; while (symbol_table != NULL) { if (symbol_table->lookup(addr, &string_table_index, &pos_in_string_table, &off, m_funcDesc_table)) { found_symbol = true; break; } symbol_table = symbol_table->m_next; } if (!found_symbol) return false; ElfStringTable* string_table = get_string_table(string_table_index); if (string_table == NULL) { m_status = NullDecoder::file_invalid; return false; } if (offset) *offset = off; return string_table->string_at(pos_in_string_table, buf, buflen); } void ElfFile::add_symbol_table(ElfSymbolTable* table) { if (m_symbol_tables == NULL) { m_symbol_tables = table; } else { table->m_next = m_symbol_tables; m_symbol_tables = table; } } void ElfFile::add_string_table(ElfStringTable* table) { if (m_string_tables == NULL) { m_string_tables = table; } else { table->m_next = m_string_tables; m_string_tables = table; } } ElfStringTable* ElfFile::get_string_table(int index) { ElfStringTable* p = m_string_tables; while (p != NULL) { if (p->index() == index) return p; p = p->m_next; } return NULL; } #ifdef LINUX bool ElfFile::specifies_noexecstack() { Elf_Phdr phdr; if (!m_file) return true; if (!fseek(m_file, m_elfHdr.e_phoff, SEEK_SET)) { for (int index = 0; index < m_elfHdr.e_phnum; index ++) { if (fread((void*)&phdr, sizeof(Elf_Phdr), 1, m_file) != 1) { m_status = NullDecoder::file_invalid; return false; } if (phdr.p_type == PT_GNU_STACK) { if (phdr.p_flags == (PF_R | PF_W)) { return true; } else { return false; } } } } return false; } #endif #endif // !_WINDOWS && !__APPLE__