libsanitizer/sanitizer_common/sanitizer_procmaps.h

   1 //===-- sanitizer_procmaps.h ------------------------------------*- C++ -*-===//
   2 //
   3 // This file is distributed under the University of Illinois Open Source
   4 // License. See LICENSE.TXT for details.
   5 //
   6 //===----------------------------------------------------------------------===//
   7 //
   8 // This file is shared between AddressSanitizer and ThreadSanitizer.
   9 //
  10 // Information about the process mappings.
  11 //===----------------------------------------------------------------------===//
  12 #ifndef SANITIZER_PROCMAPS_H
  13 #define SANITIZER_PROCMAPS_H
  14
  15 #include "sanitizer_internal_defs.h"
  16
  17 namespace __sanitizer {
  18
  19 #ifdef _WIN32
  20 class MemoryMappingLayout {
  21  public:
  22   MemoryMappingLayout() {}
  23   bool GetObjectNameAndOffset(uptr addr, uptr *offset,
  24                               char filename[], uptr filename_size) {
  25     UNIMPLEMENTED();
  26     return false;
  27   }
  28 };
  29
  30 #else  // _WIN32
  31 class MemoryMappingLayout {
  32  public:
  33   MemoryMappingLayout();
  34   bool Next(uptr *start, uptr *end, uptr *offset,
  35             char filename[], uptr filename_size);
  36   void Reset();
  37   // Gets the object file name and the offset in that object for a given
  38   // address 'addr'. Returns true on success.
  39   bool GetObjectNameAndOffset(uptr addr, uptr *offset,
  40                               char filename[], uptr filename_size);
  41   ~MemoryMappingLayout();
  42
  43  private:
  44   // Default implementation of GetObjectNameAndOffset.
  45   // Quite slow, because it iterates through the whole process map for each
  46   // lookup.
  47   bool IterateForObjectNameAndOffset(uptr addr, uptr *offset,
  48                                      char filename[], uptr filename_size) {
  49     Reset();
  50     uptr start, end, file_offset;
  51     for (int i = 0; Next(&start, &end, &file_offset, filename, filename_size);
  52          i++) {
  53       if (addr >= start && addr < end) {
  54         // Don't subtract 'start' for the first entry:
  55         // * If a binary is compiled w/o -pie, then the first entry in
  56         //   process maps is likely the binary itself (all dynamic libs
  57         //   are mapped higher in address space). For such a binary,
  58         //   instruction offset in binary coincides with the actual
  59         //   instruction address in virtual memory (as code section
  60         //   is mapped to a fixed memory range).
  61         // * If a binary is compiled with -pie, all the modules are
  62         //   mapped high at address space (in particular, higher than
  63         //   shadow memory of the tool), so the module can't be the
  64         //   first entry.
  65         *offset = (addr - (i ? start : 0)) + file_offset;
  66         return true;
  67       }
  68     }
  69     if (filename_size)
  70       filename[0] = '\0';
  71     return false;
  72   }
  73
  74 # if defined __linux__
  75   char *proc_self_maps_buff_;
  76   uptr proc_self_maps_buff_mmaped_size_;
  77   uptr proc_self_maps_buff_len_;
  78   char *current_;
  79 # elif defined __APPLE__
  80   template<u32 kLCSegment, typename SegmentCommand>
  81   bool NextSegmentLoad(uptr *start, uptr *end, uptr *offset,
  82                        char filename[], uptr filename_size);
  83   int current_image_;
  84   u32 current_magic_;
  85   u32 current_filetype_;
  86   int current_load_cmd_count_;
  87   char *current_load_cmd_addr_;
  88 # endif
  89 };
  90
  91 #endif  // _WIN32
  92
  93 }  // namespace __sanitizer
  94
  95 #endif  // SANITIZER_PROCMAPS_H