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29
30// elf_core_dump.h: Define the google_breakpad::ElfCoreDump class, which
31// encapsulates an ELF core dump file mapped into memory.
32
33#ifndef COMMON_LINUX_ELF_CORE_DUMP_H_
34#define COMMON_LINUX_ELF_CORE_DUMP_H_
35
36#include <elf.h>
37#include <link.h>
38#include <stddef.h>
39
40#include "common/memory_range.h"
41
42namespace google_breakpad {
43
44// A class encapsulating an ELF core dump file mapped into memory, which
45// provides methods for accessing program headers and the note section.
46class ElfCoreDump {
47 public:
48  // ELF types based on the value of __WORDSIZE.
49  typedef ElfW(Ehdr) Ehdr;
50  typedef ElfW(Nhdr) Nhdr;
51  typedef ElfW(Phdr) Phdr;
52  typedef ElfW(Word) Word;
53  typedef ElfW(Addr) Addr;
54#if __WORDSIZE == 32
55  static const int kClass = ELFCLASS32;
56#elif __WORDSIZE == 64
57  static const int kClass = ELFCLASS64;
58#else
59#error "Unsupported __WORDSIZE for ElfCoreDump."
60#endif
61
62  // A class encapsulating the note content in a core dump, which provides
63  // methods for accessing the name and description of a note.
64  class Note {
65   public:
66    Note();
67
68    // Constructor that takes the note content from |content|.
69    explicit Note(const MemoryRange& content);
70
71    // Returns true if this note is valid, i,e. a note header is found in
72    // |content_|, or false otherwise.
73    bool IsValid() const;
74
75    // Returns the note header, or NULL if no note header is found in
76    // |content_|.
77    const Nhdr* GetHeader() const;
78
79    // Returns the note type, or 0 if no note header is found in |content_|.
80    Word GetType() const;
81
82    // Returns a memory range covering the note name, or an empty range
83    // if no valid note name is found in |content_|.
84    MemoryRange GetName() const;
85
86    // Returns a memory range covering the note description, or an empty
87    // range if no valid note description is found in |content_|.
88    MemoryRange GetDescription() const;
89
90    // Returns the note following this note, or an empty note if no valid
91    // note is found after this note.
92    Note GetNextNote() const;
93
94   private:
95    // Returns the size in bytes round up to the word alignment, specified
96    // for the note section, of a given size in bytes.
97    static size_t AlignedSize(size_t size);
98
99    // Note content.
100    MemoryRange content_;
101  };
102
103  ElfCoreDump();
104
105  // Constructor that takes the core dump content from |content|.
106  explicit ElfCoreDump(const MemoryRange& content);
107
108  // Sets the core dump content to |content|.
109  void SetContent(const MemoryRange& content);
110
111  // Returns true if a valid ELF header in the core dump, or false otherwise.
112  bool IsValid() const;
113
114  // Returns the ELF header in the core dump, or NULL if no ELF header
115  // is found in |content_|.
116  const Ehdr* GetHeader() const;
117
118  // Returns the |index|-th program header in the core dump, or NULL if no
119  // ELF header is found in |content_| or |index| is out of bounds.
120  const Phdr* GetProgramHeader(unsigned index) const;
121
122  // Returns the first program header of |type| in the core dump, or NULL if
123  // no ELF header is found in |content_| or no program header of |type| is
124  // found.
125  const Phdr* GetFirstProgramHeaderOfType(Word type) const;
126
127  // Returns the number of program headers in the core dump, or 0 if no
128  // ELF header is found in |content_|.
129  unsigned GetProgramHeaderCount() const;
130
131  // Copies |length| bytes of data starting at |virtual_address| in the core
132  // dump to |buffer|. |buffer| should be a valid pointer to a buffer of at
133  // least |length| bytes. Returns true if the data to be copied is found in
134  // the core dump, or false otherwise.
135  bool CopyData(void* buffer, Addr virtual_address, size_t length);
136
137  // Returns the first note found in the note section of the core dump, or
138  // an empty note if no note is found.
139  Note GetFirstNote() const;
140
141 private:
142  // Core dump content.
143  MemoryRange content_;
144};
145
146}  // namespace google_breakpad
147
148#endif  // COMMON_LINUX_ELF_CORE_DUMP_H_
149