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1 /*
2  * Copyright (C) 2015 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include "thread_tree.h"
18 
19 #include <limits>
20 
21 #include <android-base/logging.h>
22 
23 #include "environment.h"
24 #include "perf_event.h"
25 #include "record.h"
26 
27 namespace simpleperf {
28 
operator ()(const MapEntry * map1,const MapEntry * map2) const29 bool MapComparator::operator()(const MapEntry* map1, const MapEntry* map2) const {
30   if (map1->start_addr != map2->start_addr) {
31     return map1->start_addr < map2->start_addr;
32   }
33   // Compare map->len instead of map->get_end_addr() here. Because we set map's len
34   // to std::numeric_limits<uint64_t>::max() in FindMapByAddr(), which makes
35   // map->get_end_addr() overflow.
36   if (map1->len != map2->len) {
37     return map1->len < map2->len;
38   }
39   if (map1->time != map2->time) {
40     return map1->time < map2->time;
41   }
42   return false;
43 }
44 
AddThread(int pid,int tid,const std::string & comm)45 void ThreadTree::AddThread(int pid, int tid, const std::string& comm) {
46   auto it = thread_tree_.find(tid);
47   if (it == thread_tree_.end()) {
48     ThreadEntry* thread = new ThreadEntry{
49         pid, tid,
50         "unknown",                             // comm
51         std::set<MapEntry*, MapComparator>(),  // maps
52     };
53     auto pair = thread_tree_.insert(std::make_pair(tid, std::unique_ptr<ThreadEntry>(thread)));
54     CHECK(pair.second);
55     it = pair.first;
56   }
57   thread_comm_storage_.push_back(std::unique_ptr<std::string>(new std::string(comm)));
58   it->second->comm = thread_comm_storage_.back()->c_str();
59 }
60 
ForkThread(int pid,int tid,int ppid,int ptid)61 void ThreadTree::ForkThread(int pid, int tid, int ppid, int ptid) {
62   ThreadEntry* parent = FindThreadOrNew(ppid, ptid);
63   ThreadEntry* child = FindThreadOrNew(pid, tid);
64   child->comm = parent->comm;
65   child->maps = parent->maps;
66 }
67 
FindThreadOrNew(int pid,int tid)68 ThreadEntry* ThreadTree::FindThreadOrNew(int pid, int tid) {
69   auto it = thread_tree_.find(tid);
70   if (it == thread_tree_.end()) {
71     AddThread(pid, tid, "unknown");
72     it = thread_tree_.find(tid);
73   } else {
74     if (pid != it->second.get()->pid) {
75       // TODO: b/22185053.
76       LOG(DEBUG) << "unexpected (pid, tid) pair: expected (" << it->second.get()->pid << ", " << tid
77                  << "), actual (" << pid << ", " << tid << ")";
78     }
79   }
80   return it->second.get();
81 }
82 
AddKernelMap(uint64_t start_addr,uint64_t len,uint64_t pgoff,uint64_t time,const std::string & filename)83 void ThreadTree::AddKernelMap(uint64_t start_addr, uint64_t len, uint64_t pgoff, uint64_t time,
84                               const std::string& filename) {
85   // kernel map len can be 0 when record command is not run in supervisor mode.
86   if (len == 0) {
87     return;
88   }
89   Dso* dso = FindKernelDsoOrNew(filename);
90   MapEntry* map = AllocateMap(MapEntry(start_addr, len, pgoff, time, dso));
91   FixOverlappedMap(&kernel_map_tree_, map);
92   auto pair = kernel_map_tree_.insert(map);
93   CHECK(pair.second);
94 }
95 
FindKernelDsoOrNew(const std::string & filename)96 Dso* ThreadTree::FindKernelDsoOrNew(const std::string& filename) {
97   if (filename == DEFAULT_KERNEL_MMAP_NAME) {
98     if (kernel_dso_ == nullptr) {
99       kernel_dso_ = Dso::CreateDso(DSO_KERNEL);
100     }
101     return kernel_dso_.get();
102   }
103   auto it = module_dso_tree_.find(filename);
104   if (it == module_dso_tree_.end()) {
105     module_dso_tree_[filename] = Dso::CreateDso(DSO_KERNEL_MODULE, filename);
106     it = module_dso_tree_.find(filename);
107   }
108   return it->second.get();
109 }
110 
AddThreadMap(int pid,int tid,uint64_t start_addr,uint64_t len,uint64_t pgoff,uint64_t time,const std::string & filename)111 void ThreadTree::AddThreadMap(int pid, int tid, uint64_t start_addr, uint64_t len, uint64_t pgoff,
112                               uint64_t time, const std::string& filename) {
113   ThreadEntry* thread = FindThreadOrNew(pid, tid);
114   Dso* dso = FindUserDsoOrNew(filename);
115   MapEntry* map = AllocateMap(MapEntry(start_addr, len, pgoff, time, dso));
116   FixOverlappedMap(&thread->maps, map);
117   auto pair = thread->maps.insert(map);
118   CHECK(pair.second);
119 }
120 
FindUserDsoOrNew(const std::string & filename)121 Dso* ThreadTree::FindUserDsoOrNew(const std::string& filename) {
122   auto it = user_dso_tree_.find(filename);
123   if (it == user_dso_tree_.end()) {
124     user_dso_tree_[filename] = Dso::CreateDso(DSO_ELF_FILE, filename);
125     it = user_dso_tree_.find(filename);
126   }
127   return it->second.get();
128 }
129 
AllocateMap(const MapEntry & value)130 MapEntry* ThreadTree::AllocateMap(const MapEntry& value) {
131   MapEntry* map = new MapEntry(value);
132   map_storage_.push_back(std::unique_ptr<MapEntry>(map));
133   return map;
134 }
135 
FixOverlappedMap(std::set<MapEntry *,MapComparator> * map_set,const MapEntry * map)136 void ThreadTree::FixOverlappedMap(std::set<MapEntry*, MapComparator>* map_set, const MapEntry* map) {
137   for (auto it = map_set->begin(); it != map_set->end();) {
138     if ((*it)->start_addr >= map->get_end_addr()) {
139       // No more overlapped maps.
140       break;
141     }
142     if ((*it)->get_end_addr() <= map->start_addr) {
143       ++it;
144     } else {
145       MapEntry* old = *it;
146       if (old->start_addr < map->start_addr) {
147         MapEntry* before = AllocateMap(MapEntry(old->start_addr, map->start_addr - old->start_addr,
148                                                 old->pgoff, old->time, old->dso));
149         map_set->insert(before);
150       }
151       if (old->get_end_addr() > map->get_end_addr()) {
152         MapEntry* after = AllocateMap(
153             MapEntry(map->get_end_addr(), old->get_end_addr() - map->get_end_addr(),
154                      map->get_end_addr() - old->start_addr + old->pgoff, old->time, old->dso));
155         map_set->insert(after);
156       }
157 
158       it = map_set->erase(it);
159     }
160   }
161 }
162 
IsAddrInMap(uint64_t addr,const MapEntry * map)163 static bool IsAddrInMap(uint64_t addr, const MapEntry* map) {
164   return (addr >= map->start_addr && addr < map->get_end_addr());
165 }
166 
FindMapByAddr(const std::set<MapEntry *,MapComparator> & maps,uint64_t addr)167 static MapEntry* FindMapByAddr(const std::set<MapEntry*, MapComparator>& maps, uint64_t addr) {
168   // Construct a map_entry which is strictly after the searched map_entry, based on MapComparator.
169   MapEntry find_map(addr, std::numeric_limits<uint64_t>::max(), 0,
170                     std::numeric_limits<uint64_t>::max(), nullptr);
171   auto it = maps.upper_bound(&find_map);
172   if (it != maps.begin() && IsAddrInMap(addr, *--it)) {
173     return *it;
174   }
175   return nullptr;
176 }
177 
FindMap(const ThreadEntry * thread,uint64_t ip,bool in_kernel)178 const MapEntry* ThreadTree::FindMap(const ThreadEntry* thread, uint64_t ip, bool in_kernel) {
179   MapEntry* result = nullptr;
180   if (!in_kernel) {
181     result = FindMapByAddr(thread->maps, ip);
182   } else {
183     result = FindMapByAddr(kernel_map_tree_, ip);
184   }
185   return result != nullptr ? result : &unknown_map_;
186 }
187 
FindSymbol(const MapEntry * map,uint64_t ip)188 const Symbol* ThreadTree::FindSymbol(const MapEntry* map, uint64_t ip) {
189   uint64_t vaddr_in_file;
190   if (map->dso == kernel_dso_.get()) {
191     vaddr_in_file = ip;
192   } else {
193     vaddr_in_file = ip - map->start_addr + map->dso->MinVirtualAddress();
194   }
195   const Symbol* symbol = map->dso->FindSymbol(vaddr_in_file);
196   if (symbol == nullptr) {
197     symbol = &unknown_symbol_;
198   }
199   return symbol;
200 }
201 
Clear()202 void ThreadTree::Clear() {
203   thread_tree_.clear();
204   thread_comm_storage_.clear();
205   kernel_map_tree_.clear();
206   map_storage_.clear();
207   kernel_dso_.reset();
208   module_dso_tree_.clear();
209   user_dso_tree_.clear();
210 }
211 
212 }  // namespace simpleperf
213 
BuildThreadTree(const Record & record,ThreadTree * thread_tree)214 void BuildThreadTree(const Record& record, ThreadTree* thread_tree) {
215   if (record.header.type == PERF_RECORD_MMAP) {
216     const MmapRecord& r = *static_cast<const MmapRecord*>(&record);
217     if ((r.header.misc & PERF_RECORD_MISC_CPUMODE_MASK) == PERF_RECORD_MISC_KERNEL) {
218       thread_tree->AddKernelMap(r.data.addr, r.data.len, r.data.pgoff, r.sample_id.time_data.time,
219                                 r.filename);
220     } else {
221       thread_tree->AddThreadMap(r.data.pid, r.data.tid, r.data.addr, r.data.len, r.data.pgoff,
222                                 r.sample_id.time_data.time, r.filename);
223     }
224   } else if (record.header.type == PERF_RECORD_MMAP2) {
225     const Mmap2Record& r = *static_cast<const Mmap2Record*>(&record);
226     if ((r.header.misc & PERF_RECORD_MISC_CPUMODE_MASK) == PERF_RECORD_MISC_KERNEL) {
227       thread_tree->AddKernelMap(r.data.addr, r.data.len, r.data.pgoff, r.sample_id.time_data.time,
228                                 r.filename);
229     } else {
230       std::string filename =
231           (r.filename == DEFAULT_EXECNAME_FOR_THREAD_MMAP) ? "[unknown]" : r.filename;
232       thread_tree->AddThreadMap(r.data.pid, r.data.tid, r.data.addr, r.data.len, r.data.pgoff,
233                                 r.sample_id.time_data.time, filename);
234     }
235   } else if (record.header.type == PERF_RECORD_COMM) {
236     const CommRecord& r = *static_cast<const CommRecord*>(&record);
237     thread_tree->AddThread(r.data.pid, r.data.tid, r.comm);
238   } else if (record.header.type == PERF_RECORD_FORK) {
239     const ForkRecord& r = *static_cast<const ForkRecord*>(&record);
240     thread_tree->ForkThread(r.data.pid, r.data.tid, r.data.ppid, r.data.ptid);
241   }
242 }
243