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(file_name: "/proc/self/maps", buff: &proc_maps->data,
21 buff_size: &proc_maps->mmaped_size, read_len: &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(s: data_.current, c: '\n', 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(p: &data_.current);
42 CHECK_EQ(*data_.current++, '-');
43 segment->end = ParseHex(p: &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(p: &data_.current);
56 CHECK_EQ(*data_.current++, ' ');
57 ParseHex(p: &data_.current);
58 CHECK_EQ(*data_.current++, ':');
59 ParseHex(p: &data_.current);
60 CHECK_EQ(*data_.current++, ' ');
61 while (IsDecimal(c: *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(a: (uptr)(next_line - data_.current), b: segment->filename_size - 1);
71 internal_strncpy(dst: segment->filename, src: data_.current, n: 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