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/*
* Copyright (c) 2013, 2019 ARM Limited
* All rights reserved
*
* The license below extends only to copyright in the software and shall
* not be construed as granting a license to any other intellectual
* property including but not limited to intellectual property relating
* to a hardware implementation of the functionality of the software
* licensed hereunder. You may use the software subject to the license
* terms below provided that you ensure that this notice is replicated
* unmodified and in its entirety in all distributions of the software,
* modified or unmodified, in source code or in binary form.
*
* Copyright (c) 2003-2005 The Regents of The University of Michigan
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met: redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer;
* redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution;
* neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Authors: Steve Reinhardt
*/
#ifndef __BASE_LOADER_ELF_OBJECT_HH__
#define __BASE_LOADER_ELF_OBJECT_HH__
#include <set>
#include <vector>
#include "base/loader/object_file.hh"
#include "gelf.h"
class ElfObjectFormat : public ObjectFileFormat
{
public:
ObjectFile *load(ImageFileDataPtr data) override;
};
class ElfObject : public ObjectFile
{
protected:
Elf *elf;
GElf_Ehdr ehdr;
void determineArch();
void determineOpSys();
void handleLoadableSegment(GElf_Phdr phdr, int seg_num);
// These values are provided to a linux process by the kernel, so we
// need to keep them around.
Addr _programHeaderTable = 0;
uint16_t _programHeaderSize = 0;
uint16_t _programHeaderCount = 0;
std::set<std::string> sectionNames;
ElfObject *interpreter = nullptr;
// An interpreter load bias is the location in the process address space
// where the interpreter is chosen to reside. Typically, this is carved
// out of the top of the mmap reserve section.
Addr ldBias = 0;
// The interpreter is typically a relocatable shared library and will
// have a default value of zero which means that it does not care where
// it is placed. However, the loader can be compiled and linked so that
// it does care and needs a specific entry point.
bool relocate = true;
// The ldMin and ldMax fields are required to know how large of an
// area is required to map the interpreter.
Addr ldMin = MaxAddr;
Addr ldMax = MaxAddr;
/// Helper functions for loadGlobalSymbols() and loadLocalSymbols().
bool loadSomeSymbols(SymbolTable *symtab, int binding, Addr mask,
Addr base, Addr offset);
void getSections();
bool sectionExists(std::string sec);
MemoryImage image;
public:
ElfObject(ImageFileDataPtr ifd);
~ElfObject();
MemoryImage buildImage() const override { return image; }
bool loadAllSymbols(SymbolTable *symtab, Addr base=0,
Addr offset=0, Addr addr_mask=MaxAddr) override;
bool loadGlobalSymbols(SymbolTable *symtab, Addr base=0,
Addr offset=0, Addr addr_mask=MaxAddr) override;
bool loadLocalSymbols(SymbolTable *symtab, Addr base=0,
Addr offset=0, Addr addr_mask=MaxAddr) override;
bool loadWeakSymbols(SymbolTable *symtab, Addr base=0,
Addr offset=0, Addr addr_mask=MaxAddr) override;
ObjectFile *getInterpreter() const override { return interpreter; }
std::string getInterpPath(const GElf_Phdr &phdr) const;
Addr bias() const override { return ldBias; }
bool relocatable() const override { return relocate; }
Addr mapSize() const override { return ldMax - ldMin; }
void updateBias(Addr bias_addr) override;
bool hasTLS() override { return sectionExists(".tbss"); }
Addr programHeaderTable() {return _programHeaderTable;}
uint16_t programHeaderSize() {return _programHeaderSize;}
uint16_t programHeaderCount() {return _programHeaderCount;}
};
/**
* This is the interface for setting up a base path for the
* elf interpreter. This is needed when loading a
* cross-compiled (guest ISA != host ISA) dynamically
* linked application.
* @param dirname base path for the interpreter
*/
void setInterpDir(const std::string &dirname);
#endif // __BASE_LOADER_ELF_OBJECT_HH__
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