contrib/llvm-project/lldb/source/Plugins/Process/Utility/LinuxProcMaps.cpp

   1 //===-- LinuxProcMaps.cpp ---------------------------------------*- C++ -*-===//
   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 #include "LinuxProcMaps.h"
  10 #include "llvm/ADT/StringRef.h"
  11 #include "lldb/Target/MemoryRegionInfo.h"
  12 #include "lldb/Utility/Status.h"
  13 #include "lldb/Utility/StringExtractor.h"
  14
  15 using namespace lldb_private;
  16
  17 static Status
  18 ParseMemoryRegionInfoFromProcMapsLine(llvm::StringRef maps_line,
  19                                       MemoryRegionInfo &memory_region_info) {
  20   memory_region_info.Clear();
  21
  22   StringExtractor line_extractor(maps_line);
  23
  24   // Format: {address_start_hex}-{address_end_hex} perms offset  dev   inode
  25   // pathname perms: rwxp   (letter is present if set, '-' if not, final
  26   // character is p=private, s=shared).
  27
  28   // Parse out the starting address
  29   lldb::addr_t start_address = line_extractor.GetHexMaxU64(false, 0);
  30
  31   // Parse out hyphen separating start and end address from range.
  32   if (!line_extractor.GetBytesLeft() || (line_extractor.GetChar() != '-'))
  33     return Status(
  34         "malformed /proc/{pid}/maps entry, missing dash between address range");
  35
  36   // Parse out the ending address
  37   lldb::addr_t end_address = line_extractor.GetHexMaxU64(false, start_address);
  38
  39   // Parse out the space after the address.
  40   if (!line_extractor.GetBytesLeft() || (line_extractor.GetChar() != ' '))
  41     return Status(
  42         "malformed /proc/{pid}/maps entry, missing space after range");
  43
  44   // Save the range.
  45   memory_region_info.GetRange().SetRangeBase(start_address);
  46   memory_region_info.GetRange().SetRangeEnd(end_address);
  47
  48   // Any memory region in /proc/{pid}/maps is by definition mapped into the
  49   // process.
  50   memory_region_info.SetMapped(MemoryRegionInfo::OptionalBool::eYes);
  51
  52   // Parse out each permission entry.
  53   if (line_extractor.GetBytesLeft() < 4)
  54     return Status("malformed /proc/{pid}/maps entry, missing some portion of "
  55                   "permissions");
  56
  57   // Handle read permission.
  58   const char read_perm_char = line_extractor.GetChar();
  59   if (read_perm_char == 'r')
  60     memory_region_info.SetReadable(MemoryRegionInfo::OptionalBool::eYes);
  61   else if (read_perm_char == '-')
  62     memory_region_info.SetReadable(MemoryRegionInfo::OptionalBool::eNo);
  63   else
  64     return Status("unexpected /proc/{pid}/maps read permission char");
  65
  66   // Handle write permission.
  67   const char write_perm_char = line_extractor.GetChar();
  68   if (write_perm_char == 'w')
  69     memory_region_info.SetWritable(MemoryRegionInfo::OptionalBool::eYes);
  70   else if (write_perm_char == '-')
  71     memory_region_info.SetWritable(MemoryRegionInfo::OptionalBool::eNo);
  72   else
  73     return Status("unexpected /proc/{pid}/maps write permission char");
  74
  75   // Handle execute permission.
  76   const char exec_perm_char = line_extractor.GetChar();
  77   if (exec_perm_char == 'x')
  78     memory_region_info.SetExecutable(MemoryRegionInfo::OptionalBool::eYes);
  79   else if (exec_perm_char == '-')
  80     memory_region_info.SetExecutable(MemoryRegionInfo::OptionalBool::eNo);
  81   else
  82     return Status("unexpected /proc/{pid}/maps exec permission char");
  83
  84   line_extractor.GetChar();              // Read the private bit
  85   line_extractor.SkipSpaces();           // Skip the separator
  86   line_extractor.GetHexMaxU64(false, 0); // Read the offset
  87   line_extractor.GetHexMaxU64(false, 0); // Read the major device number
  88   line_extractor.GetChar();              // Read the device id separator
  89   line_extractor.GetHexMaxU64(false, 0); // Read the major device number
  90   line_extractor.SkipSpaces();           // Skip the separator
  91   line_extractor.GetU64(0, 10);          // Read the inode number
  92
  93   line_extractor.SkipSpaces();
  94   const char *name = line_extractor.Peek();
  95   if (name)
  96     memory_region_info.SetName(name);
  97
  98   return Status();
  99 }
 100
 101 void lldb_private::ParseLinuxMapRegions(llvm::StringRef linux_map,
 102                                         LinuxMapCallback const &callback) {
 103   llvm::StringRef lines(linux_map);
 104   llvm::StringRef line;
 105   while (!lines.empty()) {
 106     std::tie(line, lines) = lines.split('\n');
 107     MemoryRegionInfo region;
 108     Status error = ParseMemoryRegionInfoFromProcMapsLine(line, region);
 109     if (!callback(region, error))
 110       break;
 111   }
 112 }