1//===-- sanitizer_procmaps_linux.cpp --------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// Information about the process mappings (Linux-specific parts).
10//===----------------------------------------------------------------------===//
11
12#include "sanitizer_platform.h"
13#if SANITIZER_LINUX
14#include "sanitizer_common.h"
15#include "sanitizer_procmaps.h"
16
17namespace __sanitizer {
18
19void ReadProcMaps(ProcSelfMapsBuff *proc_maps) {
20  if (!ReadFileToBuffer("/proc/self/maps", &proc_maps->data,
21                        &proc_maps->mmaped_size, &proc_maps->len)) {
22    proc_maps->data = nullptr;
23    proc_maps->mmaped_size = 0;
24    proc_maps->len = 0;
25  }
26}
27
28static bool IsOneOf(char c, char c1, char c2) {
29  return c == c1 || c == c2;
30}
31
32bool MemoryMappingLayout::Next(MemoryMappedSegment *segment) {
33  if (Error()) return false; // simulate empty maps
34  char *last = data_.proc_self_maps.data + data_.proc_self_maps.len;
35  if (data_.current >= last) return false;
36  char *next_line =
37      (char *)internal_memchr(data_.current, '\n', last - data_.current);
38  if (next_line == 0)
39    next_line = last;
40  // Example: 08048000-08056000 r-xp 00000000 03:0c 64593   /foo/bar
41  segment->start = ParseHex(&data_.current);
42  CHECK_EQ(*data_.current++, '-');
43  segment->end = ParseHex(&data_.current);
44  CHECK_EQ(*data_.current++, ' ');
45  CHECK(IsOneOf(*data_.current, '-', 'r'));
46  segment->protection = 0;
47  if (*data_.current++ == 'r') segment->protection |= kProtectionRead;
48  CHECK(IsOneOf(*data_.current, '-', 'w'));
49  if (*data_.current++ == 'w') segment->protection |= kProtectionWrite;
50  CHECK(IsOneOf(*data_.current, '-', 'x'));
51  if (*data_.current++ == 'x') segment->protection |= kProtectionExecute;
52  CHECK(IsOneOf(*data_.current, 's', 'p'));
53  if (*data_.current++ == 's') segment->protection |= kProtectionShared;
54  CHECK_EQ(*data_.current++, ' ');
55  segment->offset = ParseHex(&data_.current);
56  CHECK_EQ(*data_.current++, ' ');
57  ParseHex(&data_.current);
58  CHECK_EQ(*data_.current++, ':');
59  ParseHex(&data_.current);
60  CHECK_EQ(*data_.current++, ' ');
61  while (IsDecimal(*data_.current)) data_.current++;
62  // Qemu may lack the trailing space.
63  // https://github.com/google/sanitizers/issues/160
64  // CHECK_EQ(*data_.current++, ' ');
65  // Skip spaces.
66  while (data_.current < next_line && *data_.current == ' ') data_.current++;
67  // Fill in the filename.
68  if (segment->filename) {
69    uptr len =
70        Min((uptr)(next_line - data_.current), segment->filename_size - 1);
71    internal_strncpy(segment->filename, data_.current, len);
72    segment->filename[len] = 0;
73  }
74
75  data_.current = next_line + 1;
76  return true;
77}
78
79}  // namespace __sanitizer
80
81#endif  // SANITIZER_LINUX
82