elf_object.hh revision 14017:815c925b777d 
1/*
2 * Copyright (c) 2013 ARM Limited
3 * All rights reserved
4 *
5 * The license below extends only to copyright in the software and shall
6 * not be construed as granting a license to any other intellectual
7 * property including but not limited to intellectual property relating
8 * to a hardware implementation of the functionality of the software
9 * licensed hereunder.  You may use the software subject to the license
10 * terms below provided that you ensure that this notice is replicated
11 * unmodified and in its entirety in all distributions of the software,
12 * modified or unmodified, in source code or in binary form.
13 *
14 * Copyright (c) 2003-2005 The Regents of The University of Michigan
15 * All rights reserved.
16 *
17 * Redistribution and use in source and binary forms, with or without
18 * modification, are permitted provided that the following conditions are
19 * met: redistributions of source code must retain the above copyright
20 * notice, this list of conditions and the following disclaimer;
21 * redistributions in binary form must reproduce the above copyright
22 * notice, this list of conditions and the following disclaimer in the
23 * documentation and/or other materials provided with the distribution;
24 * neither the name of the copyright holders nor the names of its
25 * contributors may be used to endorse or promote products derived from
26 * this software without specific prior written permission.
27 *
28 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
29 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
30 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
31 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
32 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
33 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
34 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
35 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
36 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
37 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
38 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
39 *
40 * Authors: Steve Reinhardt
41 */
42
43#ifndef __ELF_OBJECT_HH__
44#define __ELF_OBJECT_HH__
45
46#include <set>
47#include <vector>
48
49#include "base/loader/object_file.hh"
50
51class ElfObject : public ObjectFile
52{
53  protected:
54    // The global definition of a gem5 "Section" is closest to ELF's segments.
55    typedef ObjectFile::Section Segment;
56
57    // These values are provided to a linux process by the kernel, so we
58    // need to keep them around.
59    Addr _programHeaderTable;
60    uint16_t _programHeaderSize;
61    uint16_t _programHeaderCount;
62    std::set<std::string> sectionNames;
63
64    ElfObject *interpreter;
65
66    // An interpreter load bias is the location in the process address space
67    // where the interpreter is chosen to reside. Typically, this is carved
68    // out of the top of the mmap reserve section.
69    Addr ldBias;
70
71    // The interpreter is typically a relocatable shared library and will
72    // have a default value of zero which means that it does not care where
73    // it is placed. However, the loader can be compiled and linked so that
74    // it does care and needs a specific entry point.
75    bool relocate;
76
77    // The ldMin and ldMax fields are required to know how large of an
78    // area is required to map the interpreter.
79    Addr ldMin;
80    Addr ldMax;
81
82    /// Helper functions for loadGlobalSymbols() and loadLocalSymbols().
83    bool loadSomeSymbols(SymbolTable *symtab, int binding, Addr mask,
84                         Addr base, Addr offset);
85
86    ElfObject(const std::string &_filename, size_t _len, uint8_t *_data,
87              Arch _arch, OpSys _opSys);
88
89    void getSections();
90    bool sectionExists(std::string sec);
91
92    std::vector<Segment> extraSegments;
93
94  public:
95    virtual ~ElfObject() {}
96
97    bool loadSections(const PortProxy& mem_proxy, Addr addr_mask = maxAddr,
98                      Addr offset = 0) override;
99
100    virtual bool loadAllSymbols(SymbolTable *symtab, Addr base = 0,
101                                Addr offset = 0, Addr addr_mask = maxAddr)
102                                override;
103
104    virtual bool loadGlobalSymbols(SymbolTable *symtab, Addr base = 0,
105                                   Addr offset = 0, Addr addr_mask = maxAddr)
106                                   override;
107
108    virtual bool loadLocalSymbols(SymbolTable *symtab, Addr base = 0,
109                                  Addr offset = 0, Addr addr_mask = maxAddr)
110                                  override;
111
112    virtual bool loadWeakSymbols(SymbolTable *symtab, Addr base = 0,
113                                 Addr offset = 0, Addr addr_mask = maxAddr)
114                                 override;
115
116
117    virtual ObjectFile *getInterpreter() const override
118    { return interpreter; }
119    virtual Addr bias() const override { return ldBias; }
120    virtual bool relocatable() const override { return relocate; }
121    virtual Addr mapSize() const override { return ldMax - ldMin; }
122    virtual void updateBias(Addr bias_addr) override;
123
124    virtual bool hasTLS() override { return sectionExists(".tbss"); }
125
126    static ObjectFile *tryFile(const std::string &fname,
127                               size_t len, uint8_t *data,
128                               bool skip_interp_check = false);
129    Addr programHeaderTable() {return _programHeaderTable;}
130    uint16_t programHeaderSize() {return _programHeaderSize;}
131    uint16_t programHeaderCount() {return _programHeaderCount;}
132};
133
134#endif // __ELF_OBJECT_HH__
135