1 /*
2 * Copyright (C) 2016 The Android Open Source Project
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * * Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in
12 * the documentation and/or other materials provided with the
13 * distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include <errno.h>
30 #include <fcntl.h>
31 #include <inttypes.h>
32 #include <pthread.h>
33 #include <stdatomic.h>
34 #include <stdint.h>
35 #include <stdio.h>
36 #include <stdlib.h>
37 #include <sys/types.h>
38
39 #include <mutex>
40
41 #include <memory_trace/MemoryTrace.h>
42
43 #include "Config.h"
44 #include "DebugData.h"
45 #include "Nanotime.h"
46 #include "RecordData.h"
47 #include "debug_disable.h"
48 #include "debug_log.h"
49
50 struct ThreadData {
ThreadDataThreadData51 ThreadData(RecordData* record_data) : record_data(record_data) {}
52
53 RecordData* record_data = nullptr;
54 size_t count = 0;
55 };
56
ThreadKeyDelete(void * data)57 void RecordData::ThreadKeyDelete(void* data) {
58 ThreadData* thread_data = reinterpret_cast<ThreadData*>(data);
59
60 thread_data->count++;
61
62 // This should be the last time we are called.
63 if (thread_data->count == 4) {
64 ScopedDisableDebugCalls disable;
65
66 memory_trace::Entry* entry = thread_data->record_data->InternalReserveEntry();
67 if (entry != nullptr) {
68 *entry = memory_trace::Entry{
69 .tid = gettid(), .type = memory_trace::THREAD_DONE, .end_ns = Nanotime()};
70 }
71 delete thread_data;
72 } else {
73 pthread_setspecific(thread_data->record_data->key(), data);
74 }
75 }
76
77 RecordData* RecordData::record_obj_ = nullptr;
78
WriteData(int,siginfo_t *,void *)79 void RecordData::WriteData(int, siginfo_t*, void*) {
80 // Dump from here, the function must not allocate so this is safe.
81 record_obj_->WriteEntries();
82 }
83
WriteEntriesOnExit()84 void RecordData::WriteEntriesOnExit() {
85 if (record_obj_ == nullptr) return;
86
87 // Append the current pid to the file name to avoid multiple processes
88 // writing to the same file.
89 std::string file(record_obj_->file());
90 file += "." + std::to_string(getpid());
91 record_obj_->WriteEntries(file);
92 }
93
WriteEntries()94 void RecordData::WriteEntries() {
95 WriteEntries(file_);
96 }
97
WriteEntries(const std::string & file)98 void RecordData::WriteEntries(const std::string& file) {
99 std::lock_guard<std::mutex> entries_lock(entries_lock_);
100 if (cur_index_ == 0) {
101 info_log("No alloc entries to write.");
102 return;
103 }
104
105 int dump_fd = open(file.c_str(), O_WRONLY | O_CREAT | O_TRUNC | O_CLOEXEC | O_NOFOLLOW, 0755);
106 if (dump_fd == -1) {
107 error_log("Cannot create record alloc file %s: %s", file.c_str(), strerror(errno));
108 return;
109 }
110
111 for (size_t i = 0; i < cur_index_; i++) {
112 if (entries_[i].type == memory_trace::UNKNOWN) {
113 // This can happen if an entry was reserved but not filled in due to some
114 // type of error during the operation.
115 continue;
116 }
117 if (!memory_trace::WriteEntryToFd(dump_fd, entries_[i])) {
118 error_log("Failed to write record alloc information: %s", strerror(errno));
119 break;
120 }
121 }
122 close(dump_fd);
123
124 // Mark the entries dumped.
125 cur_index_ = 0U;
126 }
127
RecordData()128 RecordData::RecordData() {
129 pthread_key_create(&key_, ThreadKeyDelete);
130 }
131
Initialize(const Config & config)132 bool RecordData::Initialize(const Config& config) {
133 record_obj_ = this;
134 struct sigaction64 dump_act = {};
135 dump_act.sa_sigaction = RecordData::WriteData;
136 dump_act.sa_flags = SA_RESTART | SA_SIGINFO | SA_ONSTACK;
137 if (sigaction64(config.record_allocs_signal(), &dump_act, nullptr) != 0) {
138 error_log("Unable to set up record dump signal function: %s", strerror(errno));
139 return false;
140 }
141 pthread_setspecific(key_, nullptr);
142
143 if (config.options() & VERBOSE) {
144 info_log("%s: Run: 'kill -%d %d' to dump the allocation records.", getprogname(),
145 config.record_allocs_signal(), getpid());
146 }
147
148 entries_.resize(config.record_allocs_num_entries());
149 cur_index_ = 0U;
150 file_ = config.record_allocs_file();
151
152 pagemap_fd_ = TEMP_FAILURE_RETRY(open("/proc/self/pagemap", O_RDONLY | O_CLOEXEC));
153 if (pagemap_fd_ == -1) {
154 error_log("Unable to open /proc/self/pagemap: %s", strerror(errno));
155 return false;
156 }
157
158 return true;
159 }
160
~RecordData()161 RecordData::~RecordData() {
162 if (pagemap_fd_ != -1) {
163 close(pagemap_fd_);
164 }
165
166 pthread_key_delete(key_);
167 }
168
InternalReserveEntry()169 memory_trace::Entry* RecordData::InternalReserveEntry() {
170 std::lock_guard<std::mutex> entries_lock(entries_lock_);
171 if (cur_index_ == entries_.size()) {
172 return nullptr;
173 }
174
175 memory_trace::Entry* entry = &entries_[cur_index_];
176 entry->type = memory_trace::UNKNOWN;
177 if (++cur_index_ == entries_.size()) {
178 info_log("Maximum number of records added, all new operations will be dropped.");
179 }
180 return entry;
181 }
182
ReserveEntry()183 memory_trace::Entry* RecordData::ReserveEntry() {
184 void* data = pthread_getspecific(key_);
185 if (data == nullptr) {
186 ThreadData* thread_data = new ThreadData(this);
187 pthread_setspecific(key_, thread_data);
188 }
189
190 return InternalReserveEntry();
191 }
192
IsPagePresent(uint64_t page_data)193 static inline bool IsPagePresent(uint64_t page_data) {
194 // Page Present is bit 63
195 return (page_data & (1ULL << 63)) != 0;
196 }
197
GetPresentBytes(void * ptr,size_t alloc_size)198 int64_t RecordData::GetPresentBytes(void* ptr, size_t alloc_size) {
199 uintptr_t addr = reinterpret_cast<uintptr_t>(ptr);
200 if (addr == 0 || alloc_size == 0) {
201 return -1;
202 }
203
204 uintptr_t page_size = getpagesize();
205 uintptr_t page_size_mask = page_size - 1;
206
207 size_t start_page = (addr & ~page_size_mask) / page_size;
208 size_t last_page = ((addr + alloc_size - 1) & ~page_size_mask) / page_size;
209
210 constexpr size_t kMaxReadPages = 1024;
211 uint64_t page_data[kMaxReadPages];
212
213 int64_t present_bytes = 0;
214 size_t cur_page = start_page;
215 while (cur_page <= last_page) {
216 size_t num_pages = last_page - cur_page + 1;
217 size_t last_page_index;
218 if (num_pages > kMaxReadPages) {
219 num_pages = kMaxReadPages;
220 last_page_index = num_pages;
221 } else {
222 // Handle the last page differently, so do not handle it in the loop.
223 last_page_index = num_pages - 1;
224 }
225 ssize_t bytes_read =
226 pread64(pagemap_fd_, page_data, num_pages * sizeof(uint64_t), cur_page * sizeof(uint64_t));
227 if (bytes_read <= 0) {
228 error_log("Failed to read page data: %s", strerror(errno));
229 return -1;
230 }
231
232 size_t page_index = 0;
233 // Handling the first page is special, handle it separately.
234 if (cur_page == start_page) {
235 if (IsPagePresent(page_data[0])) {
236 present_bytes = page_size - (addr & page_size_mask);
237 if (present_bytes >= alloc_size) {
238 // The allocation fits on a single page and that page is present.
239 return alloc_size;
240 }
241 } else if (start_page == last_page) {
242 // Only one page that isn't present.
243 return 0;
244 }
245 page_index = 1;
246 }
247
248 for (; page_index < last_page_index; page_index++) {
249 if (IsPagePresent(page_data[page_index])) {
250 present_bytes += page_size;
251 }
252 }
253
254 cur_page += last_page_index;
255
256 // Check the last page in the allocation.
257 if (cur_page == last_page) {
258 if (IsPagePresent(page_data[num_pages - 1])) {
259 present_bytes += ((addr + alloc_size - 1) & page_size_mask) + 1;
260 }
261 return present_bytes;
262 }
263 }
264
265 return present_bytes;
266 }
267