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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 <inttypes.h>
     20 
     21 #include <limits>
     22 
     23 #include <android-base/logging.h>
     24 #include <android-base/stringprintf.h>
     25 
     26 #include "perf_event.h"
     27 #include "record.h"
     28 
     29 namespace simpleperf {
     30 
     31 bool MapComparator::operator()(const MapEntry* map1,
     32                                const MapEntry* map2) const {
     33   if (map1->start_addr != map2->start_addr) {
     34     return map1->start_addr < map2->start_addr;
     35   }
     36   // Compare map->len instead of map->get_end_addr() here. Because we set map's
     37   // len to std::numeric_limits<uint64_t>::max() in FindMapByAddr(), which makes
     38   // map->get_end_addr() overflow.
     39   if (map1->len != map2->len) {
     40     return map1->len < map2->len;
     41   }
     42   if (map1->time != map2->time) {
     43     return map1->time < map2->time;
     44   }
     45   return false;
     46 }
     47 
     48 void ThreadTree::SetThreadName(int pid, int tid, const std::string& comm) {
     49   ThreadEntry* thread = FindThreadOrNew(pid, tid);
     50   if (comm != thread->comm) {
     51     thread_comm_storage_.push_back(
     52         std::unique_ptr<std::string>(new std::string(comm)));
     53     thread->comm = thread_comm_storage_.back()->c_str();
     54   }
     55 }
     56 
     57 void ThreadTree::ForkThread(int pid, int tid, int ppid, int ptid) {
     58   ThreadEntry* parent = FindThreadOrNew(ppid, ptid);
     59   ThreadEntry* child = FindThreadOrNew(pid, tid);
     60   child->comm = parent->comm;
     61   if (pid != ppid) {
     62     // Copy maps from parent process.
     63     *child->maps = *parent->maps;
     64   }
     65 }
     66 
     67 ThreadEntry* ThreadTree::FindThreadOrNew(int pid, int tid) {
     68   auto it = thread_tree_.find(tid);
     69   if (it == thread_tree_.end()) {
     70     return CreateThread(pid, tid);
     71   } else {
     72     if (pid != it->second.get()->pid) {
     73       // TODO: b/22185053.
     74       LOG(DEBUG) << "unexpected (pid, tid) pair: expected ("
     75                  << it->second.get()->pid << ", " << tid << "), actual (" << pid
     76                  << ", " << tid << ")";
     77     }
     78   }
     79   return it->second.get();
     80 }
     81 
     82 ThreadEntry* ThreadTree::CreateThread(int pid, int tid) {
     83   MapSet* maps = nullptr;
     84   if (pid == tid) {
     85     maps = new MapSet;
     86     map_set_storage_.push_back(std::unique_ptr<MapSet>(maps));
     87   } else {
     88     // Share maps among threads in the same thread group.
     89     ThreadEntry* process = FindThreadOrNew(pid, pid);
     90     maps = process->maps;
     91   }
     92   ThreadEntry* thread = new ThreadEntry{
     93     pid, tid,
     94     "unknown",
     95     maps,
     96   };
     97   auto pair = thread_tree_.insert(std::make_pair(tid, std::unique_ptr<ThreadEntry>(thread)));
     98   CHECK(pair.second);
     99   return thread;
    100 }
    101 
    102 void ThreadTree::AddKernelMap(uint64_t start_addr, uint64_t len, uint64_t pgoff,
    103                               uint64_t time, const std::string& filename) {
    104   // kernel map len can be 0 when record command is not run in supervisor mode.
    105   if (len == 0) {
    106     return;
    107   }
    108   Dso* dso = FindKernelDsoOrNew(filename);
    109   MapEntry* map =
    110       AllocateMap(MapEntry(start_addr, len, pgoff, time, dso, true));
    111   FixOverlappedMap(&kernel_maps_, map);
    112   auto pair = kernel_maps_.maps.insert(map);
    113   CHECK(pair.second);
    114 }
    115 
    116 Dso* ThreadTree::FindKernelDsoOrNew(const std::string& filename) {
    117   if (filename == DEFAULT_KERNEL_MMAP_NAME ||
    118       filename == DEFAULT_KERNEL_MMAP_NAME_PERF) {
    119     return kernel_dso_.get();
    120   }
    121   auto it = module_dso_tree_.find(filename);
    122   if (it == module_dso_tree_.end()) {
    123     module_dso_tree_[filename] = Dso::CreateDso(DSO_KERNEL_MODULE, filename);
    124     it = module_dso_tree_.find(filename);
    125   }
    126   return it->second.get();
    127 }
    128 
    129 void ThreadTree::AddThreadMap(int pid, int tid, uint64_t start_addr,
    130                               uint64_t len, uint64_t pgoff, uint64_t time,
    131                               const std::string& filename) {
    132   ThreadEntry* thread = FindThreadOrNew(pid, tid);
    133   Dso* dso = FindUserDsoOrNew(filename, start_addr);
    134   MapEntry* map =
    135       AllocateMap(MapEntry(start_addr, len, pgoff, time, dso, false));
    136   FixOverlappedMap(thread->maps, map);
    137   auto pair = thread->maps->maps.insert(map);
    138   CHECK(pair.second);
    139   thread->maps->version++;
    140 }
    141 
    142 Dso* ThreadTree::FindUserDsoOrNew(const std::string& filename, uint64_t start_addr) {
    143   auto it = user_dso_tree_.find(filename);
    144   if (it == user_dso_tree_.end()) {
    145     bool force_64bit = start_addr > UINT_MAX;
    146     user_dso_tree_[filename] = Dso::CreateDso(DSO_ELF_FILE, filename, force_64bit);
    147     it = user_dso_tree_.find(filename);
    148   }
    149   return it->second.get();
    150 }
    151 
    152 MapEntry* ThreadTree::AllocateMap(const MapEntry& value) {
    153   MapEntry* map = new MapEntry(value);
    154   map_storage_.push_back(std::unique_ptr<MapEntry>(map));
    155   return map;
    156 }
    157 
    158 void ThreadTree::FixOverlappedMap(MapSet* maps, const MapEntry* map) {
    159   for (auto it = maps->maps.begin(); it != maps->maps.end();) {
    160     if ((*it)->start_addr >= map->get_end_addr()) {
    161       // No more overlapped maps.
    162       break;
    163     }
    164     if ((*it)->get_end_addr() <= map->start_addr) {
    165       ++it;
    166     } else {
    167       MapEntry* old = *it;
    168       if (old->start_addr < map->start_addr) {
    169         MapEntry* before = AllocateMap(
    170             MapEntry(old->start_addr, map->start_addr - old->start_addr,
    171                      old->pgoff, old->time, old->dso, old->in_kernel));
    172         maps->maps.insert(before);
    173       }
    174       if (old->get_end_addr() > map->get_end_addr()) {
    175         MapEntry* after = AllocateMap(MapEntry(
    176             map->get_end_addr(), old->get_end_addr() - map->get_end_addr(),
    177             map->get_end_addr() - old->start_addr + old->pgoff, old->time,
    178             old->dso, old->in_kernel));
    179         maps->maps.insert(after);
    180       }
    181 
    182       it = maps->maps.erase(it);
    183     }
    184   }
    185 }
    186 
    187 static bool IsAddrInMap(uint64_t addr, const MapEntry* map) {
    188   return (addr >= map->start_addr && addr < map->get_end_addr());
    189 }
    190 
    191 static MapEntry* FindMapByAddr(const MapSet& maps, uint64_t addr) {
    192   // Construct a map_entry which is strictly after the searched map_entry, based
    193   // on MapComparator.
    194   MapEntry find_map(addr, std::numeric_limits<uint64_t>::max(), 0,
    195                     std::numeric_limits<uint64_t>::max(), nullptr, false);
    196   auto it = maps.maps.upper_bound(&find_map);
    197   if (it != maps.maps.begin() && IsAddrInMap(addr, *--it)) {
    198     return *it;
    199   }
    200   return nullptr;
    201 }
    202 
    203 const MapEntry* ThreadTree::FindMap(const ThreadEntry* thread, uint64_t ip,
    204                                     bool in_kernel) {
    205   MapEntry* result = nullptr;
    206   if (!in_kernel) {
    207     result = FindMapByAddr(*thread->maps, ip);
    208   } else {
    209     result = FindMapByAddr(kernel_maps_, ip);
    210   }
    211   return result != nullptr ? result : &unknown_map_;
    212 }
    213 
    214 const MapEntry* ThreadTree::FindMap(const ThreadEntry* thread, uint64_t ip) {
    215   MapEntry* result = FindMapByAddr(*thread->maps, ip);
    216   if (result != nullptr) {
    217     return result;
    218   }
    219   result = FindMapByAddr(kernel_maps_, ip);
    220   return result != nullptr ? result : &unknown_map_;
    221 }
    222 
    223 const Symbol* ThreadTree::FindSymbol(const MapEntry* map, uint64_t ip,
    224                                      uint64_t* pvaddr_in_file, Dso** pdso) {
    225   uint64_t vaddr_in_file;
    226   const Symbol* symbol = nullptr;
    227   Dso* dso = map->dso;
    228   if (!map->in_kernel) {
    229     // Find symbol in user space shared libraries.
    230     vaddr_in_file = ip - map->start_addr + map->dso->MinVirtualAddress();
    231     symbol = dso->FindSymbol(vaddr_in_file);
    232   } else {
    233     if (dso != kernel_dso_.get()) {
    234       // Find symbol in kernel modules.
    235       vaddr_in_file = ip - map->start_addr + map->dso->MinVirtualAddress();
    236       symbol = dso->FindSymbol(vaddr_in_file);
    237     }
    238     if (symbol == nullptr) {
    239       // If the ip address hits the vmlinux, or hits a kernel module, but we can't find its symbol
    240       // in the kernel module file, then find its symbol in /proc/kallsyms or vmlinux.
    241       vaddr_in_file = ip;
    242       dso = kernel_dso_.get();
    243       symbol = dso->FindSymbol(vaddr_in_file);
    244     }
    245   }
    246 
    247   if (symbol == nullptr) {
    248     if (show_ip_for_unknown_symbol_) {
    249       std::string name = android::base::StringPrintf(
    250           "%s%s[+%" PRIx64 "]", (show_mark_for_unknown_symbol_ ? "*" : ""),
    251           dso->FileName().c_str(), vaddr_in_file);
    252       dso->AddUnknownSymbol(vaddr_in_file, name);
    253       symbol = dso->FindSymbol(vaddr_in_file);
    254       CHECK(symbol != nullptr);
    255     } else {
    256       symbol = &unknown_symbol_;
    257     }
    258   }
    259   if (pvaddr_in_file != nullptr) {
    260     *pvaddr_in_file = vaddr_in_file;
    261   }
    262   if (pdso != nullptr) {
    263     *pdso = dso;
    264   }
    265   return symbol;
    266 }
    267 
    268 const Symbol* ThreadTree::FindKernelSymbol(uint64_t ip) {
    269   const MapEntry* map = FindMap(nullptr, ip, true);
    270   return FindSymbol(map, ip, nullptr);
    271 }
    272 
    273 void ThreadTree::ClearThreadAndMap() {
    274   thread_tree_.clear();
    275   thread_comm_storage_.clear();
    276   map_set_storage_.clear();
    277   kernel_maps_.maps.clear();
    278   map_storage_.clear();
    279 }
    280 
    281 void ThreadTree::AddDsoInfo(const std::string& file_path, uint32_t file_type,
    282                             uint64_t min_vaddr, std::vector<Symbol>* symbols) {
    283   DsoType dso_type = static_cast<DsoType>(file_type);
    284   Dso* dso = nullptr;
    285   if (dso_type == DSO_KERNEL || dso_type == DSO_KERNEL_MODULE) {
    286     dso = FindKernelDsoOrNew(file_path);
    287   } else {
    288     dso = FindUserDsoOrNew(file_path);
    289   }
    290   dso->SetMinVirtualAddress(min_vaddr);
    291   dso->SetSymbols(symbols);
    292 }
    293 
    294 void ThreadTree::Update(const Record& record) {
    295   if (record.type() == PERF_RECORD_MMAP) {
    296     const MmapRecord& r = *static_cast<const MmapRecord*>(&record);
    297     if (r.InKernel()) {
    298       AddKernelMap(r.data->addr, r.data->len, r.data->pgoff,
    299                    r.sample_id.time_data.time, r.filename);
    300     } else {
    301       AddThreadMap(r.data->pid, r.data->tid, r.data->addr, r.data->len,
    302                    r.data->pgoff, r.sample_id.time_data.time, r.filename);
    303     }
    304   } else if (record.type() == PERF_RECORD_MMAP2) {
    305     const Mmap2Record& r = *static_cast<const Mmap2Record*>(&record);
    306     if (r.InKernel()) {
    307       AddKernelMap(r.data->addr, r.data->len, r.data->pgoff,
    308                    r.sample_id.time_data.time, r.filename);
    309     } else {
    310       std::string filename = (r.filename == DEFAULT_EXECNAME_FOR_THREAD_MMAP)
    311                                  ? "[unknown]"
    312                                  : r.filename;
    313       AddThreadMap(r.data->pid, r.data->tid, r.data->addr, r.data->len,
    314                    r.data->pgoff, r.sample_id.time_data.time, filename);
    315     }
    316   } else if (record.type() == PERF_RECORD_COMM) {
    317     const CommRecord& r = *static_cast<const CommRecord*>(&record);
    318     SetThreadName(r.data->pid, r.data->tid, r.comm);
    319   } else if (record.type() == PERF_RECORD_FORK) {
    320     const ForkRecord& r = *static_cast<const ForkRecord*>(&record);
    321     ForkThread(r.data->pid, r.data->tid, r.data->ppid, r.data->ptid);
    322   } else if (record.type() == SIMPLE_PERF_RECORD_KERNEL_SYMBOL) {
    323     const auto& r = *static_cast<const KernelSymbolRecord*>(&record);
    324     Dso::SetKallsyms(std::move(r.kallsyms));
    325   }
    326 }
    327 
    328 std::vector<Dso*> ThreadTree::GetAllDsos() const {
    329   std::vector<Dso*> result;
    330   result.push_back(kernel_dso_.get());
    331   for (auto& p : module_dso_tree_) {
    332     result.push_back(p.second.get());
    333   }
    334   for (auto& p : user_dso_tree_) {
    335     result.push_back(p.second.get());
    336   }
    337   result.push_back(unknown_dso_.get());
    338   return result;
    339 }
    340 
    341 std::vector<const ThreadEntry*> ThreadTree::GetAllThreads() const {
    342   std::vector<const ThreadEntry*> threads;
    343   for (auto& pair : thread_tree_) {
    344     threads.push_back(pair.second.get());
    345   }
    346   return threads;
    347 }
    348 
    349 }  // namespace simpleperf
    350