jdk8-mips64-public/hotspot: src/share/vm/utilities/elfFile.cpp@f90c822e73f8 (annotated)

src/share/vm/utilities/elfFile.cpp@f90c822e73f8 (annotated)

src/share/vm/utilities/elfFile.cpp

Wed, 27 Apr 2016 01:25:04 +0800

author: aoqi
date: Wed, 27 Apr 2016 01:25:04 +0800
changeset 0: f90c822e73f8
child 6876: 710a3c8b516e
permissions: -rw-r--r--

Initial load
http://hg.openjdk.java.net/jdk8u/jdk8u/hotspot/
changeset: 6782:28b50d07f6f8
tag: jdk8u25-b17

 /*
  * 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__

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/utilities/elfFile.cpp@f90c822e73f8 (annotated)

src/share/vm/utilities/elfFile.cpp