1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
|
// Copyright 2020 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifdef UNSAFE_BUFFERS_BUILD
// TODO(crbug.com/40285824): Remove this and convert code to safer constructs.
#pragma allow_unsafe_buffers
#endif
#include "chromeos/ash/components/memory/pagemap.h"
#include <fcntl.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include <chrono>
#include <random>
#include "base/files/scoped_file.h"
#include "base/memory/page_size.h"
#include "base/posix/eintr_wrapper.h"
#include "testing/gtest/include/gtest/gtest.h"
namespace ash {
namespace memory {
namespace {
template <typename T, size_t N>
constexpr size_t countof(T (&array)[N]) {
return N;
}
} // namespace
class PagemapTest : public testing::Test {
public:
void SetUp() override {
// Use a memfd so we can truncate it to arbitrary lengths to simulate a real
// pagemap file in procfs.
pagemap_.fd_.reset(memfd_create("pagemap_test", MFD_CLOEXEC));
ASSERT_TRUE(pagemap_.fd_.is_valid());
}
void TearDown() override {}
protected:
// Set the size of the pagemap appropriate for this many pages.
void CreateStorageForPages(uint64_t pages,
void** start_address,
void** end_address) {
ASSERT_NE(
ftruncate(pagemap_.fd_.get(), pages * sizeof(Pagemap::PagemapEntry)),
-1);
*start_address = 0x0;
*end_address =
reinterpret_cast<char*>(*start_address) + base::GetPageSize() * pages;
}
void PutEntries(void* address, uint64_t* entries, size_t size) {
ASSERT_EQ(HANDLE_EINTR(pwrite(
pagemap_.fd_.get(), entries, sizeof(entries[0]) * size,
reinterpret_cast<off_t>(address) / base::GetPageSize())),
static_cast<ssize_t>(sizeof(entries[0]) * size));
}
Pagemap pagemap_{0};
};
// See: https://www.kernel.org/doc/Documentation/vm/pagemap.txt for more
// information.
//
// We make sure that we only have 55 bits set of the PFN which is why we and it
// with 2^55 - 1.
#define PFN(VALUE) \
((reinterpret_cast<uint64_t>(reinterpret_cast<void*>(VALUE))) & \
((static_cast<uint64_t>(1) << 55) - 1))
#define SOFT_DIRTY static_cast<uint64_t>(1) << 55
#define EXCLUSIVELY_MAPPED static_cast<uint64_t>(1) << 56
#define FILE_PAGE static_cast<uint64_t>(1) << 61
#define SWAPPED static_cast<uint64_t>(1) << 62
#define PRESENT static_cast<uint64_t>(1) << 63
#define PFN_FROM_TYPE_AND_OFFSET(SWAP_TYPE, OFFSET) \
((SWAP_TYPE & 0x1F) | (OFFSET << 5))
TEST_F(PagemapTest, Basic) {
void* start_address;
void* end_address;
CreateStorageForPages(4, &start_address, &end_address);
uint64_t page_map_entries[] = {PFN(8675309) | SOFT_DIRTY | PRESENT,
PFN(1234) | SWAPPED,
PFN(5551212) | SOFT_DIRTY | FILE_PAGE,
PFN(0xF00) | PRESENT | EXCLUSIVELY_MAPPED};
PutEntries(start_address, page_map_entries, countof(page_map_entries));
// We now have 4 pages populated in the page map from start address to 4 *
// pagesize();
// Validate that the Pagemap class can interpret them correctly.
std::vector<Pagemap::PagemapEntry> entries;
entries.resize(countof(page_map_entries));
ASSERT_TRUE(pagemap_.GetEntries(
reinterpret_cast<uint64_t>(start_address),
countof(page_map_entries) * base::GetPageSize(), &entries));
ASSERT_EQ(
PFN_FROM_TYPE_AND_OFFSET(entries[0].swap_type, entries[0].swap_offset),
8675309u);
ASSERT_EQ(entries[0].pte_soft_dirty, true);
ASSERT_EQ(entries[0].page_present, true);
ASSERT_EQ(entries[0].page_swapped, false);
ASSERT_EQ(entries[0].page_exclusively_mapped, false);
ASSERT_EQ(entries[0].page_file_or_shared_anon, false);
ASSERT_EQ(
PFN_FROM_TYPE_AND_OFFSET(entries[1].swap_type, entries[1].swap_offset),
1234u);
ASSERT_EQ(entries[1].pte_soft_dirty, false);
ASSERT_EQ(entries[1].page_present, false);
ASSERT_EQ(entries[1].page_swapped, true);
ASSERT_EQ(entries[1].page_exclusively_mapped, false);
ASSERT_EQ(entries[1].page_file_or_shared_anon, false);
ASSERT_EQ(
PFN_FROM_TYPE_AND_OFFSET(entries[2].swap_type, entries[2].swap_offset),
5551212u);
ASSERT_EQ(entries[2].pte_soft_dirty, true);
ASSERT_EQ(entries[2].page_present, false);
ASSERT_EQ(entries[2].page_swapped, false);
ASSERT_EQ(entries[2].page_exclusively_mapped, false);
ASSERT_EQ(entries[2].page_file_or_shared_anon, true);
ASSERT_EQ(
PFN_FROM_TYPE_AND_OFFSET(entries[3].swap_type, entries[3].swap_offset),
0xF00u);
ASSERT_EQ(entries[3].pte_soft_dirty, false);
ASSERT_EQ(entries[3].page_present, true);
ASSERT_EQ(entries[3].page_swapped, false);
ASSERT_EQ(entries[3].page_exclusively_mapped, true);
ASSERT_EQ(entries[3].page_file_or_shared_anon, false);
}
TEST_F(PagemapTest, MidRangeRead) {
// This test will validate that we can read only a portion of the pages.
void* start_address;
void* end_address;
CreateStorageForPages(4, &start_address, &end_address);
uint64_t page_map_entries[] = {PFN(8675309) | SOFT_DIRTY | PRESENT,
PFN(1234) | SWAPPED,
PFN(5551212) | SOFT_DIRTY | FILE_PAGE,
PFN(0xF00) | PRESENT | EXCLUSIVELY_MAPPED};
PutEntries(start_address, page_map_entries, countof(page_map_entries));
// We will read the two middle pages.
std::vector<Pagemap::PagemapEntry> entries;
ASSERT_TRUE(pagemap_.GetEntries(
reinterpret_cast<uint64_t>(start_address) + base::GetPageSize(),
2 * base::GetPageSize(), &entries));
ASSERT_EQ(entries.size(), 2u);
ASSERT_EQ(
PFN_FROM_TYPE_AND_OFFSET(entries[0].swap_type, entries[0].swap_offset),
1234u);
ASSERT_EQ(entries[0].pte_soft_dirty, false);
ASSERT_EQ(entries[0].page_present, false);
ASSERT_EQ(entries[0].page_swapped, true);
ASSERT_EQ(entries[0].page_exclusively_mapped, false);
ASSERT_EQ(entries[0].page_file_or_shared_anon, false);
ASSERT_EQ(
PFN_FROM_TYPE_AND_OFFSET(entries[1].swap_type, entries[1].swap_offset),
5551212u);
ASSERT_EQ(entries[1].pte_soft_dirty, true);
ASSERT_EQ(entries[1].page_present, false);
ASSERT_EQ(entries[1].page_swapped, false);
ASSERT_EQ(entries[1].page_exclusively_mapped, false);
ASSERT_EQ(entries[1].page_file_or_shared_anon, true);
}
TEST_F(PagemapTest, VectorResizedWhenIncorrectlySized) {
// This test validates that passing in an incorrectly sized vector is handled
// automatically.
void* start_address;
void* end_address;
CreateStorageForPages(4, &start_address, &end_address);
uint64_t page_map_entries[] = {PFN(8675309) | SOFT_DIRTY | PRESENT,
PFN(1234) | SWAPPED,
PFN(5551212) | SOFT_DIRTY | FILE_PAGE,
PFN(0xF00) | PRESENT | EXCLUSIVELY_MAPPED};
PutEntries(start_address, page_map_entries, countof(page_map_entries));
// We will read the two middle pages.
std::vector<Pagemap::PagemapEntry> entries;
entries.resize(1); // This is too short, it will be automatically resized.
ASSERT_TRUE(pagemap_.GetEntries(
reinterpret_cast<uint64_t>(start_address) + base::GetPageSize(),
2 * base::GetPageSize(), &entries));
ASSERT_EQ(entries.size(), 2u);
ASSERT_EQ(
PFN_FROM_TYPE_AND_OFFSET(entries[0].swap_type, entries[0].swap_offset),
1234u);
ASSERT_EQ(entries[0].pte_soft_dirty, false);
ASSERT_EQ(entries[0].page_present, false);
ASSERT_EQ(entries[0].page_swapped, true);
ASSERT_EQ(entries[0].page_exclusively_mapped, false);
ASSERT_EQ(entries[0].page_file_or_shared_anon, false);
ASSERT_EQ(
PFN_FROM_TYPE_AND_OFFSET(entries[1].swap_type, entries[1].swap_offset),
5551212u);
ASSERT_EQ(entries[1].pte_soft_dirty, true);
ASSERT_EQ(entries[1].page_present, false);
ASSERT_EQ(entries[1].page_swapped, false);
ASSERT_EQ(entries[1].page_exclusively_mapped, false);
ASSERT_EQ(entries[1].page_file_or_shared_anon, true);
}
} // namespace memory
} // namespace ash
|
