| /* |
| * Copyright (c) 2016, Google Inc. |
| * All rights reserved. |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #include <cstring> |
| #include <iomanip> |
| #include <memory> |
| #include <sstream> |
| #include <unordered_map> |
| #include <vector> |
| |
| #include "int_compat.h" |
| #include "intervalmap.h" |
| #include "path_matching.h" |
| #include "perf_data_handler.h" |
| #include "string_compat.h" |
| #include "quipper/perf_reader.h" |
| |
| using quipper::PerfDataProto; |
| using quipper::PerfDataProto_MMapEvent; |
| using quipper::PerfDataProto_CommEvent; |
| |
| namespace perftools { |
| namespace { |
| |
| // Normalizer processes a PerfDataProto and maintains tables to the |
| // current metadata for each process. It drives callbacks to |
| // PerfDataHandler with samples in a fully normalized form. |
| class Normalizer { |
| public: |
| Normalizer(const PerfDataProto& perf_proto, PerfDataHandler* handler) |
| : perf_proto_(perf_proto), handler_(handler) { |
| for (const auto& build_id : perf_proto_.build_ids()) { |
| const string& bytes = build_id.build_id_hash(); |
| std::stringstream hex; |
| for (size_t i = 0; i < bytes.size(); ++i) { |
| // The char must be turned into an int to be used by stringstream; |
| // however, if the byte's value -8 it should be turned to 0x00f8 as an |
| // int, not 0xfff8. This cast solves this problem. |
| const auto& byte = static_cast<unsigned char>(bytes[i]); |
| hex << std::hex << std::setfill('0') << std::setw(2) |
| << static_cast<int>(byte); |
| } |
| if (build_id.filename() != "") { |
| filename_to_build_id_[build_id.filename()] = hex.str(); |
| } else { |
| std::stringstream filename; |
| filename << std::hex << build_id.filename_md5_prefix(); |
| filename_to_build_id_[filename.str().c_str()] = hex.str(); |
| } |
| } |
| |
| uint64 current_event_index = 0; |
| for (const auto& attr : perf_proto_.file_attrs()) { |
| for (uint64 id : attr.ids()) { |
| id_to_event_index_[id] = current_event_index; |
| } |
| current_event_index++; |
| } |
| } |
| |
| Normalizer(const Normalizer&) = delete; |
| Normalizer& operator=(const Normalizer&) = delete; |
| |
| ~Normalizer() {} |
| |
| // Convert to a protobuf using quipper and then aggregate the results. |
| void Normalize(); |
| |
| private: |
| // Using a 32-bit type for the PID values as the max PID value on 64-bit |
| // systems is 2^22, see http://man7.org/linux/man-pages/man5/proc.5.html. |
| typedef std::unordered_map<uint32, PerfDataHandler::Mapping*> PidToMMapMap; |
| typedef std::unordered_map<uint32, const PerfDataProto_CommEvent*> |
| PidToCommMap; |
| |
| typedef IntervalMap<const PerfDataHandler::Mapping*> MMapIntervalMap; |
| |
| // Copy the parent's mmaps/comm if they exist. Otherwise, items |
| // will be lazily populated. |
| void UpdateMapsWithMMapEvent(const quipper::PerfDataProto_MMapEvent* mmap); |
| |
| void UpdateMapsWithForkEvent(const quipper::PerfDataProto_ForkEvent& fork); |
| void LogStats(); |
| |
| // Normalize the sample_event in event_proto and call handler_->Sample |
| void InvokeHandleSample(const quipper::PerfDataProto::PerfEvent& perf_event); |
| |
| // Find the MMAP event which has ip in its address range from pid. If no |
| // mapping is found, returns nullptr. |
| const PerfDataHandler::Mapping* TryLookupInPid(uint32 pid, uint64 ip) const; |
| |
| // Find the mapping for a given ip given a pid context (in user or kernel |
| // mappings); returns nullptr if none can be found. |
| const PerfDataHandler::Mapping* GetMappingFromPidAndIP(uint32 pid, |
| uint64 ip) const; |
| |
| // Find the main MMAP event for this pid. If no mapping is found, |
| // nullptr is returned. |
| const PerfDataHandler::Mapping* GetMainMMapFromPid(uint32 pid) const; |
| |
| // For profiles with a single event, perf doesn't bother sending the |
| // id. So, if there is only one event, the event index must be 0. |
| // Returns the event index corresponding to the id for this sample, or |
| // -1 for an error. |
| int64 GetEventIndexForSample( |
| const quipper::PerfDataProto_SampleEvent& sample) const; |
| |
| const quipper::PerfDataProto& perf_proto_; |
| PerfDataHandler* handler_; // unowned. |
| |
| // Mapping we have allocated. |
| std::vector<std::unique_ptr<PerfDataHandler::Mapping>> owned_mappings_; |
| std::vector<std::unique_ptr<quipper::PerfDataProto_MMapEvent>> |
| owned_quipper_mappings_; |
| |
| // The event for a given sample is determined by the id. |
| // Map each id to an index in the event_profiles_ vector. |
| std::unordered_map<uint64, uint64> id_to_event_index_; |
| |
| // pid_to_comm_event maps a pid to the corresponding comm event. |
| PidToCommMap pid_to_comm_event_; |
| |
| // pid_to_mmaps maps a pid to all mmap events that correspond to that pid. |
| std::unordered_map<uint32, std::unique_ptr<MMapIntervalMap>> pid_to_mmaps_; |
| |
| // pid_to_executable_mmap maps a pid to mmap that most likely contains the |
| // filename of the main executable for that pid. |
| PidToMMapMap pid_to_executable_mmap_; |
| |
| // map filenames to build-ids. |
| std::unordered_map<string, string> filename_to_build_id_; |
| |
| struct { |
| int64 samples = 0; |
| int64 missing_main_mmap = 0; |
| int64 missing_sample_mmap = 0; |
| |
| int64 callchain_ips = 0; |
| int64 missing_callchain_mmap = 0; |
| |
| int64 branch_stack_ips = 0; |
| int64 missing_branch_stack_mmap = 0; |
| |
| int64 no_event_errors = 0; |
| } stat_; |
| }; |
| |
| void Normalizer::UpdateMapsWithForkEvent( |
| const quipper::PerfDataProto_ForkEvent& fork) { |
| if (fork.pid() == fork.ppid()) { |
| // Don't care about threads. |
| return; |
| } |
| const auto& it = pid_to_mmaps_.find(fork.ppid()); |
| if (it != pid_to_mmaps_.end()) { |
| pid_to_mmaps_[fork.pid()] = std::unique_ptr<MMapIntervalMap>( |
| new MMapIntervalMap(*it->second.get())); |
| } |
| auto comm_it = pid_to_comm_event_.find(fork.ppid()); |
| if (comm_it != pid_to_comm_event_.end()) { |
| pid_to_comm_event_[fork.pid()] = comm_it->second; |
| } |
| auto exec_mmap_it = pid_to_executable_mmap_.find(fork.ppid()); |
| if (exec_mmap_it != pid_to_executable_mmap_.end()) { |
| pid_to_executable_mmap_[fork.pid()] = exec_mmap_it->second; |
| } |
| } |
| |
| inline bool HasPrefixString(const string& haystack, const char* needle) { |
| const size_t needle_len = strlen(needle); |
| const size_t haystack_len = haystack.length(); |
| return haystack_len >= needle_len && |
| haystack.compare(0, needle_len, needle) == 0; |
| } |
| |
| inline bool HasSuffixString(const string& haystack, const char* needle) { |
| const size_t needle_len = strlen(needle); |
| const size_t haystack_len = haystack.length(); |
| return haystack_len >= needle_len && |
| haystack.compare(haystack_len - needle_len, needle_len, needle) == 0; |
| } |
| |
| void Normalizer::Normalize() { |
| for (const auto& event_proto : perf_proto_.events()) { |
| if (event_proto.has_mmap_event()) { |
| UpdateMapsWithMMapEvent(&event_proto.mmap_event()); |
| } else if (event_proto.has_comm_event()) { |
| if (event_proto.comm_event().pid() == event_proto.comm_event().tid()) { |
| // pid==tid happens on exec() |
| pid_to_executable_mmap_.erase(event_proto.comm_event().pid()); |
| pid_to_comm_event_[event_proto.comm_event().pid()] = |
| &event_proto.comm_event(); |
| } |
| PerfDataHandler::CommContext comm_context; |
| comm_context.comm = &event_proto.comm_event(); |
| handler_->Comm(comm_context); |
| } else if (event_proto.has_fork_event()) { |
| UpdateMapsWithForkEvent(event_proto.fork_event()); |
| } else if (event_proto.has_lost_event()) { |
| stat_.samples += event_proto.lost_event().lost(); |
| stat_.missing_main_mmap += event_proto.lost_event().lost(); |
| stat_.missing_sample_mmap += event_proto.lost_event().lost(); |
| quipper::PerfDataProto::SampleEvent sample; |
| quipper::PerfDataProto::EventHeader header; |
| sample.set_id(event_proto.lost_event().id()); |
| sample.set_pid(event_proto.lost_event().sample_info().pid()); |
| sample.set_tid(event_proto.lost_event().sample_info().tid()); |
| PerfDataHandler::SampleContext context(header, sample); |
| context.file_attrs_index = GetEventIndexForSample(sample); |
| if (context.file_attrs_index == -1) { |
| ++stat_.no_event_errors; |
| continue; |
| } |
| for (uint64 i = 0; i < event_proto.lost_event().lost(); ++i) { |
| handler_->Sample(context); |
| } |
| } else if (event_proto.has_sample_event()) { |
| InvokeHandleSample(event_proto); |
| } |
| } |
| |
| LogStats(); |
| } |
| |
| void Normalizer::InvokeHandleSample( |
| const quipper::PerfDataProto::PerfEvent& event_proto) { |
| if (!event_proto.has_sample_event()) { |
| std::cerr << "Expected sample event." << std::endl; |
| abort(); |
| } |
| const auto& sample = event_proto.sample_event(); |
| PerfDataHandler::SampleContext context(event_proto.header(), |
| event_proto.sample_event()); |
| context.file_attrs_index = GetEventIndexForSample(context.sample); |
| if (context.file_attrs_index == -1) { |
| ++stat_.no_event_errors; |
| return; |
| } |
| ++stat_.samples; |
| |
| uint32 pid = sample.pid(); |
| |
| context.sample_mapping = GetMappingFromPidAndIP(pid, sample.ip()); |
| stat_.missing_sample_mmap += context.sample_mapping == nullptr; |
| |
| context.main_mapping = GetMainMMapFromPid(pid); |
| std::unique_ptr<PerfDataHandler::Mapping> fake; |
| // Kernel samples might take some extra work. |
| if (context.main_mapping == nullptr && |
| (event_proto.header().misc() & PERF_RECORD_MISC_CPUMODE_MASK) == |
| PERF_RECORD_MISC_KERNEL) { |
| auto comm_it = pid_to_comm_event_.find(pid); |
| auto kernel_it = pid_to_executable_mmap_.find(-1); |
| if (comm_it != pid_to_comm_event_.end()) { |
| const string* build_id = nullptr; |
| if (kernel_it != pid_to_executable_mmap_.end()) { |
| build_id = kernel_it->second->build_id; |
| } |
| fake.reset(new PerfDataHandler::Mapping(&comm_it->second->comm(), |
| build_id, 0, 1, 0, 0)); |
| context.main_mapping = fake.get(); |
| } else if (pid == 0 && kernel_it != pid_to_executable_mmap_.end()) { |
| context.main_mapping = kernel_it->second; |
| } |
| } |
| |
| stat_.missing_main_mmap += context.main_mapping == nullptr; |
| |
| // Normalize the callchain. |
| context.callchain.resize(sample.callchain_size()); |
| for (int i = 0; i < sample.callchain_size(); ++i) { |
| ++stat_.callchain_ips; |
| context.callchain[i].ip = sample.callchain(i); |
| context.callchain[i].mapping = |
| GetMappingFromPidAndIP(pid, sample.callchain(i)); |
| stat_.missing_callchain_mmap += context.callchain[i].mapping == nullptr; |
| } |
| |
| // Normalize the branch_stack. |
| context.branch_stack.resize(sample.branch_stack_size()); |
| for (int i = 0; i < sample.branch_stack_size(); ++i) { |
| stat_.branch_stack_ips += 2; |
| auto bse = sample.branch_stack(i); |
| // from |
| context.branch_stack[i].from.ip = bse.from_ip(); |
| context.branch_stack[i].from.mapping = |
| GetMappingFromPidAndIP(pid, bse.from_ip()); |
| stat_.missing_branch_stack_mmap += |
| context.branch_stack[i].from.mapping == nullptr; |
| // to |
| context.branch_stack[i].to.ip = bse.to_ip(); |
| context.branch_stack[i].to.mapping = |
| GetMappingFromPidAndIP(pid, bse.to_ip()); |
| stat_.missing_branch_stack_mmap += |
| context.branch_stack[i].to.mapping == nullptr; |
| // mispredicted |
| context.branch_stack[i].mispredicted = bse.mispredicted(); |
| } |
| |
| handler_->Sample(context); |
| } |
| |
| static void CheckStat(int64 num, int64 denom, const string& desc) { |
| const int max_missing_pct = 1; |
| if (denom > 0 && num * 100 / denom > max_missing_pct) { |
| LOG(ERROR) << "stat: " << desc << " " << num << "/" << denom; |
| } |
| } |
| |
| void Normalizer::LogStats() { |
| CheckStat(stat_.missing_main_mmap, stat_.samples, "missing_main_mmap"); |
| CheckStat(stat_.missing_sample_mmap, stat_.samples, "missing_sample_mmap"); |
| CheckStat(stat_.missing_callchain_mmap, stat_.callchain_ips, |
| "missing_callchain_mmap"); |
| CheckStat(stat_.missing_branch_stack_mmap, stat_.branch_stack_ips, |
| "missing_branch_stack_mmap"); |
| CheckStat(stat_.no_event_errors, 1, "unknown event id"); |
| } |
| |
| static bool IsVirtualMapping(const string& map_name) { |
| return HasPrefixString(map_name, "//") || |
| (HasPrefixString(map_name, "[") && HasSuffixString(map_name, "]")); |
| } |
| |
| void Normalizer::UpdateMapsWithMMapEvent( |
| const quipper::PerfDataProto_MMapEvent* mmap) { |
| if (mmap->len() == 0) { |
| LOG(WARNING) << "bogus mapping: " << mmap->filename(); |
| return; |
| } |
| uint32 pid = mmap->pid(); |
| MMapIntervalMap* interval_map = nullptr; |
| const auto& it = pid_to_mmaps_.find(pid); |
| if (it == pid_to_mmaps_.end()) { |
| interval_map = new MMapIntervalMap; |
| pid_to_mmaps_[pid] = std::unique_ptr<MMapIntervalMap>(interval_map); |
| } else { |
| interval_map = it->second.get(); |
| } |
| std::unordered_map<string, string>::const_iterator build_id_it; |
| if (mmap->filename() != "") { |
| build_id_it = filename_to_build_id_.find(mmap->filename()); |
| } else { |
| std::stringstream filename; |
| filename << std::hex << mmap->filename_md5_prefix(); |
| build_id_it = filename_to_build_id_.find(filename.str()); |
| } |
| |
| const string* build_id = build_id_it == filename_to_build_id_.end() |
| ? nullptr |
| : &build_id_it->second; |
| PerfDataHandler::Mapping* mapping = new PerfDataHandler::Mapping( |
| &mmap->filename(), build_id, mmap->start(), mmap->start() + mmap->len(), |
| mmap->pgoff(), mmap->filename_md5_prefix()); |
| owned_mappings_.emplace_back(mapping); |
| if (mapping->file_offset > (static_cast<uint64>(1) << 63) && |
| mapping->limit > (static_cast<uint64>(1) << 63)) { |
| // kernel is funky and basically swaps start and offset. Arrange |
| // them such that we can reasonably symbolize them later. |
| uint64 old_start = mapping->start; |
| // file_offset here actually refers to the address of the _stext |
| // kernel symbol, so we need to align it. |
| mapping->start = mapping->file_offset - mapping->file_offset % 4096; |
| mapping->file_offset = old_start; |
| } |
| |
| interval_map->Set(mapping->start, mapping->limit, mapping); |
| // Pass the final mapping through to the subclass also. |
| PerfDataHandler::MMapContext mmap_context; |
| mmap_context.pid = pid; |
| mmap_context.mapping = mapping; |
| handler_->MMap(mmap_context); |
| |
| // Main executables are usually loaded at 0x8048000 or 0x400000. |
| // If we ever see an MMAP starting at one of those locations, that should be |
| // our guess. |
| // This is true even if the old MMAP started at one of the locations, because |
| // the pid may have been recycled since then (so newer is better). |
| if (mapping->start == 0x8048000 || mapping->start == 0x400000) { |
| pid_to_executable_mmap_[pid] = mapping; |
| return; |
| } |
| // Figure out whether this MMAP is the main executable. |
| // If there have been no previous MMAPs for this pid, then this MMAP is our |
| // best guess. |
| auto old_mapping_it = pid_to_executable_mmap_.find(pid); |
| PerfDataHandler::Mapping* old_mapping = |
| old_mapping_it == pid_to_executable_mmap_.end() ? nullptr |
| : old_mapping_it->second; |
| |
| if (old_mapping != nullptr && old_mapping->start == 0x400000 && |
| (old_mapping->filename == nullptr || *old_mapping->filename == "") && |
| mapping->start - mapping->file_offset == 0x400000) { |
| // Hugepages remap the main binary, but the original mapping loses |
| // its name, so we have this hack. |
| old_mapping->filename = &mmap->filename(); |
| } |
| |
| static const char kKernelPrefix[] = "[kernel.kallsyms]"; |
| |
| if (old_mapping == nullptr && !HasSuffixString(mmap->filename(), ".ko") && |
| !HasSuffixString(mmap->filename(), ".so") && |
| !IsDeletedSharedObject(mmap->filename()) && |
| !IsVersionedSharedObject(mmap->filename()) && |
| !IsVirtualMapping(mmap->filename()) && |
| !HasPrefixString(mmap->filename(), kKernelPrefix)) { |
| if (!HasPrefixString(mmap->filename(), "/usr/bin") && |
| !HasPrefixString(mmap->filename(), "/usr/sbin") && |
| !HasSuffixString(mmap->filename(), "/sel_ldr")) { |
| LOG(INFO) << "guessing main for pid: " << pid << " " << mmap->filename(); |
| } |
| pid_to_executable_mmap_[pid] = mapping; |
| return; |
| } |
| |
| if (pid == std::numeric_limits<uint32>::max() && |
| HasPrefixString(mmap->filename(), kKernelPrefix)) { |
| pid_to_executable_mmap_[pid] = mapping; |
| } |
| } |
| |
| const PerfDataHandler::Mapping* Normalizer::TryLookupInPid(uint32 pid, |
| uint64 ip) const { |
| const auto& it = pid_to_mmaps_.find(pid); |
| if (it == pid_to_mmaps_.end()) { |
| VLOG(2) << "No mmaps for pid " << pid; |
| return nullptr; |
| } |
| MMapIntervalMap* mmaps = it->second.get(); |
| |
| const PerfDataHandler::Mapping* mapping = nullptr; |
| mmaps->Lookup(ip, &mapping); |
| return mapping; |
| } |
| |
| // Find the mapping for ip in the context of pid. We might be looking |
| // at a kernel IP, however (which can show up in any pid, and are |
| // stored in our map as pid = -1), so check there if the lookup fails |
| // in our process. |
| const PerfDataHandler::Mapping* Normalizer::GetMappingFromPidAndIP( |
| uint32 pid, uint64 ip) const { |
| if (ip >= PERF_CONTEXT_MAX) { |
| // These aren't real IPs, they're context hints. Drop them. |
| return nullptr; |
| } |
| // One could try to decide if this is a kernel or user sample |
| // directly. ahh@ thinks there's a heuristic that should work on |
| // x86 (basically without any error): all kernel samples should have |
| // 16 high bits set, all user samples should have high 16 bits |
| // cleared. But that's not portable, and on any arch (...hopefully) |
| // the user/kernel mappings should be disjoint anyway, so just check |
| // both, starting with user. We could also use PERF_CONTEXT_KERNEL |
| // and friends (see for instance how perf handles this: |
| // https://goto.google.com/udgor) to know whether to check user or |
| // kernel, but this seems more robust. |
| const PerfDataHandler::Mapping* mapping = TryLookupInPid(pid, ip); |
| if (mapping == nullptr) { |
| // Might be a kernel sample. |
| mapping = TryLookupInPid(-1, ip); |
| } |
| if (mapping == nullptr) { |
| VLOG(2) << "no sample mmap found for pid " << pid << " and ip " << ip; |
| return nullptr; |
| } |
| if (ip < mapping->start || ip >= mapping->limit) { |
| std::cerr << "IP is not in mapping." << std::endl |
| << "IP: " << ip << std::endl |
| << "Start: " << mapping->start << std::endl |
| << "Limit: " << mapping->limit << std::endl; |
| abort(); |
| } |
| return mapping; |
| } |
| |
| const PerfDataHandler::Mapping* Normalizer::GetMainMMapFromPid( |
| uint32 pid) const { |
| auto mapping_it = pid_to_executable_mmap_.find(pid); |
| if (mapping_it != pid_to_executable_mmap_.end()) { |
| return mapping_it->second; |
| } |
| |
| VLOG(2) << "No argv0 name found for sample with pid: " << pid; |
| return nullptr; |
| } |
| |
| int64 Normalizer::GetEventIndexForSample( |
| const quipper::PerfDataProto_SampleEvent& sample) const { |
| if (perf_proto_.file_attrs().size() == 1) { |
| return 0; |
| } |
| |
| if (!sample.has_id()) { |
| LOG(ERROR) << "Perf sample did not have id"; |
| return -1; |
| } |
| |
| auto it = id_to_event_index_.find(sample.id()); |
| if (it == id_to_event_index_.end()) { |
| LOG(ERROR) << "Incorrect event id: " << sample.id(); |
| return -1; |
| } |
| return it->second; |
| } |
| } // namespace |
| |
| // Finds needle in haystack starting at cursor. It then returns the index |
| // directly after needle or string::npos if needle was not found. |
| size_t FindAfter(const string& haystack, const string& needle, size_t cursor) { |
| auto next_cursor = haystack.find(needle, cursor); |
| if (next_cursor != string::npos) { |
| next_cursor += needle.size(); |
| } |
| return next_cursor; |
| } |
| |
| bool IsDeletedSharedObject(const string& path) { |
| size_t cursor = 1; |
| while ((cursor = FindAfter(path, ".so", cursor)) != string::npos) { |
| const auto ch = path.at(cursor); |
| if (ch == '.' || ch == '_' || ch == ' ') { |
| return path.find("(deleted)", cursor) != string::npos; |
| } |
| } |
| return false; |
| } |
| |
| bool IsVersionedSharedObject(const string& path) { |
| return path.find(".so.", 1) != string::npos; |
| } |
| |
| PerfDataHandler::PerfDataHandler() {} |
| |
| void PerfDataHandler::Process(const quipper::PerfDataProto& perf_proto, |
| PerfDataHandler* handler) { |
| Normalizer Normalizer(perf_proto, handler); |
| return Normalizer.Normalize(); |
| } |
| |
| } // namespace perftools |