1  // Copyright 2013 Google LLC
  2  // Use of this source code is governed by a BSD-style license that can be
  3  // found in the LICENSE file.
  4  
  5  #ifndef __STDC_FORMAT_MACROS
  6  #define __STDC_FORMAT_MACROS
  7  #endif
  8  
  9  #ifdef HAVE_CONFIG_H
 10  #include <config.h>  // Must come first
 11  #endif
 12  
 13  #include "google_breakpad/processor/proc_maps_linux.h"
 14  
 15  #include <fcntl.h>
 16  #include <inttypes.h>
 17  #include <stdio.h>
 18  
 19  #include "common/using_std_string.h"
 20  #include "processor/logging.h"
 21  
 22  #if defined(OS_ANDROID) && !defined(__LP64__)
 23  // In 32-bit mode, Bionic's inttypes.h defines PRI/SCNxPTR as an
 24  // unsigned long int, which is incompatible with Bionic's stdint.h
 25  // defining uintptr_t as an unsigned int:
 26  // https://code.google.com/p/android/issues/detail?id=57218
 27  #undef SCNxPTR
 28  #define SCNxPTR "x"
 29  #endif
 30  
 31  namespace google_breakpad {
 32  
 33  bool ParseProcMaps(const string& input,
 34                     std::vector<MappedMemoryRegion>* regions_out) {
 35    std::vector<MappedMemoryRegion> regions;
 36  
 37    // This isn't async safe nor terribly efficient, but it doesn't need to be at
 38    // this point in time.
 39  
 40    // Split the string by newlines.
 41    std::vector<string> lines;
 42    string l = "";
 43    for (size_t i = 0; i < input.size(); i++) {
 44      if (input[i] != '\n' && input[i] != '\r') {
 45        l.push_back(input[i]);
 46      } else if (l.size() > 0) {
 47        lines.push_back(l);
 48        l.clear();
 49      }
 50    }
 51    if (l.size() > 0) {
 52      BPLOG(ERROR) << "Input doesn't end in newline";
 53      return false;
 54    }
 55  
 56    for (size_t i = 0; i < lines.size(); ++i) {
 57      MappedMemoryRegion region;
 58      const char* line = lines[i].c_str();
 59      char permissions[5] = {'\0'};  // Ensure NUL-terminated string.
 60      int path_index = 0;
 61  
 62      // Sample format from man 5 proc:
 63      //
 64      // address           perms offset  dev   inode   pathname
 65      // 08048000-08056000 r-xp 00000000 03:0c 64593   /usr/sbin/gpm
 66      //
 67      // The final %n term captures the offset in the input string, which is used
 68      // to determine the path name. It *does not* increment the return value.
 69      // Refer to man 3 sscanf for details.
 70      if (sscanf(line, "%" SCNx64 "-%" SCNx64 " %4c %" SCNx64" %hhx:%hhx %"
 71                 SCNd64 " %n", &region.start, &region.end, permissions,
 72                 &region.offset, &region.major_device, &region.minor_device,
 73                 &region.inode, &path_index) < 7) {
 74        BPLOG(ERROR) << "sscanf failed for line: " << line;
 75        return false;
 76      }
 77  
 78      region.permissions = 0;
 79  
 80      if (permissions[0] == 'r')
 81        region.permissions |= MappedMemoryRegion::READ;
 82      else if (permissions[0] != '-')
 83        return false;
 84  
 85      if (permissions[1] == 'w')
 86        region.permissions |= MappedMemoryRegion::WRITE;
 87      else if (permissions[1] != '-')
 88        return false;
 89  
 90      if (permissions[2] == 'x')
 91        region.permissions |= MappedMemoryRegion::EXECUTE;
 92      else if (permissions[2] != '-')
 93        return false;
 94  
 95      if (permissions[3] == 'p')
 96        region.permissions |= MappedMemoryRegion::PRIVATE;
 97      else if (permissions[3] != 's' && permissions[3] != 'S')  // Shared memory.
 98        return false;
 99  
100      // Pushing then assigning saves us a string copy.
101      regions.push_back(region);
102      regions.back().path.assign(line + path_index);
103      regions.back().line.assign(line);
104    }
105  
106    regions_out->swap(regions);
107    return true;
108  }
109  
110  }  // namespace google_breakpad