libsanitizer/sanitizer_common/sanitizer_procmaps_linux.cpp

   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