aboutsummaryrefslogtreecommitdiff
path: root/src/common/linux/elf_core_dump.cc
blob: 0e7db7b1fa3cdf3c57c9a25f87c0644320051c55 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
// Copyright (c) 2011, Google Inc.
// 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 Google Inc. 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.

// elf_core_dump.cc: Implement google_breakpad::ElfCoreDump.
// See elf_core_dump.h for details.

#include "common/linux/elf_core_dump.h"

#include <stddef.h>
#include <string.h>

namespace google_breakpad {

// Implementation of ElfCoreDump::Note.

ElfCoreDump::Note::Note() {}

ElfCoreDump::Note::Note(const MemoryRange& content) : content_(content) {}

bool ElfCoreDump::Note::IsValid() const {
  return GetHeader() != NULL;
}

const ElfCoreDump::Nhdr* ElfCoreDump::Note::GetHeader() const {
  return content_.GetData<Nhdr>(0);
}

ElfCoreDump::Word ElfCoreDump::Note::GetType() const {
  const Nhdr* header = GetHeader();
  // 0 is not being used as a NOTE type.
  return header ? header->n_type : 0;
}

MemoryRange ElfCoreDump::Note::GetName() const {
  const Nhdr* header = GetHeader();
  if (header) {
      return content_.Subrange(sizeof(Nhdr), header->n_namesz);
  }
  return MemoryRange();
}

MemoryRange ElfCoreDump::Note::GetDescription() const {
  const Nhdr* header = GetHeader();
  if (header) {
    return content_.Subrange(AlignedSize(sizeof(Nhdr) + header->n_namesz),
                             header->n_descsz);
  }
  return MemoryRange();
}

ElfCoreDump::Note ElfCoreDump::Note::GetNextNote() const {
  MemoryRange next_content;
  const Nhdr* header = GetHeader();
  if (header) {
    size_t next_offset = AlignedSize(sizeof(Nhdr) + header->n_namesz);
    next_offset = AlignedSize(next_offset + header->n_descsz);
    next_content =
        content_.Subrange(next_offset, content_.length() - next_offset);
  }
  return Note(next_content);
}

// static
size_t ElfCoreDump::Note::AlignedSize(size_t size) {
  size_t mask = sizeof(Word) - 1;
  return (size + mask) & ~mask;
}


// Implementation of ElfCoreDump.

ElfCoreDump::ElfCoreDump() {}

ElfCoreDump::ElfCoreDump(const MemoryRange& content)
    : content_(content) {
}

void ElfCoreDump::SetContent(const MemoryRange& content) {
  content_ = content;
}

bool ElfCoreDump::IsValid() const {
  const Ehdr* header = GetHeader();
  return (header &&
          header->e_ident[0] == ELFMAG0 &&
          header->e_ident[1] == ELFMAG1 &&
          header->e_ident[2] == ELFMAG2 &&
          header->e_ident[3] == ELFMAG3 &&
          header->e_ident[4] == kClass &&
          header->e_version == EV_CURRENT &&
          header->e_type == ET_CORE);
}

const ElfCoreDump::Ehdr* ElfCoreDump::GetHeader() const {
  return content_.GetData<Ehdr>(0);
}

const ElfCoreDump::Phdr* ElfCoreDump::GetProgramHeader(unsigned index) const {
  const Ehdr* header = GetHeader();
  if (header) {
    return reinterpret_cast<const Phdr*>(content_.GetArrayElement(
        header->e_phoff, header->e_phentsize, index));
  }
  return NULL;
}

const ElfCoreDump::Phdr* ElfCoreDump::GetFirstProgramHeaderOfType(
    Word type) const {
  for (unsigned i = 0, n = GetProgramHeaderCount(); i < n; ++i) {
    const Phdr* program = GetProgramHeader(i);
    if (program->p_type == type) {
      return program;
    }
  }
  return NULL;
}

unsigned ElfCoreDump::GetProgramHeaderCount() const {
  const Ehdr* header = GetHeader();
  return header ? header->e_phnum : 0;
}

bool ElfCoreDump::CopyData(void* buffer, Addr virtual_address, size_t length) {
  for (unsigned i = 0, n = GetProgramHeaderCount(); i < n; ++i) {
    const Phdr* program = GetProgramHeader(i);
    if (program->p_type != PT_LOAD)
      continue;

    size_t offset_in_segment = virtual_address - program->p_vaddr;
    if (virtual_address >= program->p_vaddr &&
        offset_in_segment < program->p_filesz) {
      const void* data =
          content_.GetData(program->p_offset + offset_in_segment, length);
      if (data) {
        memcpy(buffer, data, length);
        return true;
      }
    }
  }
  return false;
}

ElfCoreDump::Note ElfCoreDump::GetFirstNote() const {
  MemoryRange note_content;
  const Phdr* program_header = GetFirstProgramHeaderOfType(PT_NOTE);
  if (program_header) {
    note_content = content_.Subrange(program_header->p_offset,
                                     program_header->p_filesz);
  }
  return Note(note_content);
}

}  // namespace google_breakpad