elf_object.hh revision 11389:1e55f16160cb
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
55    //The global definition of a "Section" is closest to elf's segments.
56    typedef ObjectFile::Section Segment;
57
58    //These values are provided to a linux process by the kernel, so we
59    //need to keep them around.
60    Addr _programHeaderTable;
61    uint16_t _programHeaderSize;
62    uint16_t _programHeaderCount;
63    std::set<std::string> sectionNames;
64
65    ElfObject *interpreter;
66
67    // An interpreter load bias is the location in the process address space
68    // where the interpreter is chosen to reside. Typically, this is carved
69    // out of the top of the mmap reserve section.
70    Addr ldBias;
71
72    // The interpreter is typically a relocatable shared library and will
73    // have a default value of zero which means that it does not care where
74    // it is placed. However, the loader can be compiled and linked so that
75    // it does care and needs a specific entry point.
76    bool relocate;
77
78    // The ldMin and ldMax fields are required to know how large of an
79    // area is required to map the interpreter.
80    Addr ldMin;
81    Addr ldMax;
82
83    /// Helper functions for loadGlobalSymbols() and loadLocalSymbols().
84    bool loadSomeSymbols(SymbolTable *symtab, int binding, Addr mask);
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(PortProxy& memProxy,
98            Addr addrMask = std::numeric_limits<Addr>::max(),
99            Addr offset = 0) override;
100    virtual bool loadGlobalSymbols(SymbolTable *symtab, Addr addrMask =
101            std::numeric_limits<Addr>::max()) override;
102    virtual bool loadLocalSymbols(SymbolTable *symtab, Addr addrMask =
103            std::numeric_limits<Addr>::max()) override;
104    virtual bool loadWeakSymbols(SymbolTable *symtab, Addr addrMask =
105            std::numeric_limits<Addr>::max()) override;
106
107    virtual ObjectFile *getInterpreter() const override
108    { return interpreter; }
109    virtual Addr bias() const override { return ldBias; }
110    virtual bool relocatable() const override { return relocate; }
111    virtual Addr mapSize() const override { return ldMax - ldMin; }
112    virtual void updateBias(Addr bias_addr) override;
113
114    virtual bool hasTLS() override { return sectionExists(".tbss"); }
115
116    static ObjectFile *tryFile(const std::string &fname,
117                               size_t len, uint8_t *data,
118                               bool skip_interp_check = false);
119    Addr programHeaderTable() {return _programHeaderTable;}
120    uint16_t programHeaderSize() {return _programHeaderSize;}
121    uint16_t programHeaderCount() {return _programHeaderCount;}
122};
123
124#endif // __ELF_OBJECT_HH__
125