jdk

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/*
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 * Copyright (c) 1997, 2023, Oracle and/or its affiliates. All rights reserved.
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 * Copyright (c) 2012, 2013 SAP SE. All rights reserved.
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 *
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 * This code is free software; you can redistribute it and/or modify it
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 * under the terms of the GNU General Public License version 2 only, as
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 * published by the Free Software Foundation.
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 *
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 * This code is distributed in the hope that it will be useful, but WITHOUT
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 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
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 * version 2 for more details (a copy is included in the LICENSE file that
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 * accompanied this code).
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 *
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 * You should have received a copy of the GNU General Public License version
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 * 2 along with this work; if not, write to the Free Software Foundation,
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 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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 *
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 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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 * or visit www.oracle.com if you need additional information or have any
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 * questions.
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 *
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 */
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#include "precompiled.hpp"
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#if !defined(_WINDOWS) && !defined(__APPLE__)
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#include "memory/allocation.inline.hpp"
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#include "utilities/elfFuncDescTable.hpp"
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ElfFuncDescTable::ElfFuncDescTable(FILE* file, Elf_Shdr shdr, int index) :
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  _section(file, shdr), _file(file), _index(index) {
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  assert(file, "null file handle");
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  // The actual function address (i.e. function entry point) is always the
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  // first value in the function descriptor (on IA64 and PPC64 they look as follows):
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  // PPC64: [function entry point, TOC pointer, environment pointer]
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  // IA64 : [function entry point, GP (global pointer) value]
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  // Unfortunately 'shdr.sh_entsize' doesn't always seem to contain this size (it's zero on PPC64) so we can't assert
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  // assert(IA64_ONLY(2) PPC64_ONLY(3) * sizeof(address) == shdr.sh_entsize, "Size mismatch for '.opd' section entries");
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  _status = _section.status();
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}
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ElfFuncDescTable::~ElfFuncDescTable() {
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}
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address ElfFuncDescTable::lookup(Elf_Addr index) {
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  if (NullDecoder::is_error(_status)) {
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    return nullptr;
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  }
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  address*  func_descs = cached_func_descs();
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  const Elf_Shdr* shdr = _section.section_header();
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  if (!(shdr->sh_size > 0 && shdr->sh_addr <= index && index <= shdr->sh_addr + shdr->sh_size)) {
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    // don't put the whole decoder in error mode if we just tried a wrong index
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    return nullptr;
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  }
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  if (func_descs != nullptr) {
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    return func_descs[(index - shdr->sh_addr) / sizeof(address)];
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  } else {
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    MarkedFileReader mfd(_file);
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    address addr;
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    if (!mfd.has_mark() ||
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        !mfd.set_position(shdr->sh_offset + index - shdr->sh_addr) ||
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        !mfd.read((void*)&addr, sizeof(addr))) {
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      _status = NullDecoder::file_invalid;
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      return nullptr;
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    }
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    return addr;
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  }
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}
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#endif // !_WINDOWS && !__APPLE__
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