1 /*
2 * Copyright (C) 2015 The Android Open Source Project
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * * Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in
12 * the documentation and/or other materials provided with the
13 * distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include "linker_mapped_file_fragment.h"
30 #include "linker_debug.h"
31 #include "linker_utils.h"
32
33 #include <inttypes.h>
34 #include <stdlib.h>
35 #include <sys/mman.h>
36 #include <unistd.h>
37
MappedFileFragment()38 MappedFileFragment::MappedFileFragment() : map_start_(nullptr), map_size_(0),
39 data_(nullptr), size_ (0)
40 { }
41
~MappedFileFragment()42 MappedFileFragment::~MappedFileFragment() {
43 if (map_start_ != nullptr) {
44 munmap(map_start_, map_size_);
45 }
46 }
47
Map(int fd,off64_t base_offset,size_t elf_offset,size_t size)48 bool MappedFileFragment::Map(int fd, off64_t base_offset, size_t elf_offset, size_t size) {
49 off64_t offset;
50 CHECK(safe_add(&offset, base_offset, elf_offset));
51
52 off64_t page_min = page_start(offset);
53 off64_t end_offset;
54
55 CHECK(safe_add(&end_offset, offset, size));
56 CHECK(safe_add(&end_offset, end_offset, page_offset(offset)));
57
58 size_t map_size = static_cast<size_t>(end_offset - page_min);
59 CHECK(map_size >= size);
60
61 uint8_t* map_start = static_cast<uint8_t*>(
62 mmap64(nullptr, map_size, PROT_READ, MAP_PRIVATE, fd, page_min));
63
64 if (map_start == MAP_FAILED) {
65 return false;
66 }
67
68 map_start_ = map_start;
69 map_size_ = map_size;
70
71 data_ = map_start + page_offset(offset);
72 size_ = size;
73
74 return true;
75 }
76