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
15using namespace lldb_private;
16
17static Status
18ParseMemoryRegionInfoFromProcMapsLine(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
101void 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}
113