xref: /freebsd/contrib/llvm-project/compiler-rt/lib/sanitizer_common/sanitizer_procmaps_linux.cpp (revision fe75646a0234a261c0013bf1840fdac4acaf0cec)
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 
17 namespace __sanitizer {
18 
19 void 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 
28 static bool IsOneOf(char c, char c1, char c2) {
29   return c == c1 || c == c2;
30 }
31 
32 bool 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