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 "event_attr.h" 18 19#include <inttypes.h> 20#include <stdio.h> 21#include <string> 22#include <unordered_map> 23 24#include <android-base/logging.h> 25 26#include "event_type.h" 27#include "utils.h" 28 29static std::string BitsToString(const std::string& name, uint64_t bits, 30 const std::vector<std::pair<int, std::string>>& bit_names) { 31 std::string result; 32 for (auto& p : bit_names) { 33 if (bits & p.first) { 34 bits &= ~p.first; 35 if (!result.empty()) { 36 result += ", "; 37 } 38 result += p.second; 39 } 40 } 41 if (bits != 0) { 42 LOG(DEBUG) << "unknown " << name << " bits: " << std::hex << bits; 43 } 44 return result; 45} 46 47static std::string SampleTypeToString(uint64_t sample_type) { 48 static std::vector<std::pair<int, std::string>> sample_type_names = { 49 {PERF_SAMPLE_ADDR, "addr"}, 50 {PERF_SAMPLE_BRANCH_STACK, "branch_stack"}, 51 {PERF_SAMPLE_CALLCHAIN, "callchain"}, 52 {PERF_SAMPLE_CPU, "cpu"}, 53 {PERF_SAMPLE_ID, "id"}, 54 {PERF_SAMPLE_IP, "ip"}, 55 {PERF_SAMPLE_PERIOD, "period"}, 56 {PERF_SAMPLE_RAW, "raw"}, 57 {PERF_SAMPLE_READ, "read"}, 58 {PERF_SAMPLE_REGS_USER, "regs_user"}, 59 {PERF_SAMPLE_STACK_USER, "stack_user"}, 60 {PERF_SAMPLE_STREAM_ID, "stream_id"}, 61 {PERF_SAMPLE_TID, "tid"}, 62 {PERF_SAMPLE_TIME, "time"}, 63 }; 64 return BitsToString("sample_type", sample_type, sample_type_names); 65} 66 67static std::string ReadFormatToString(uint64_t read_format) { 68 static std::vector<std::pair<int, std::string>> read_format_names = { 69 {PERF_FORMAT_TOTAL_TIME_ENABLED, "total_time_enabled"}, 70 {PERF_FORMAT_TOTAL_TIME_RUNNING, "total_time_running"}, 71 {PERF_FORMAT_ID, "id"}, 72 {PERF_FORMAT_GROUP, "group"}, 73 }; 74 return BitsToString("read_format", read_format, read_format_names); 75} 76 77perf_event_attr CreateDefaultPerfEventAttr(const EventType& event_type) { 78 perf_event_attr attr; 79 memset(&attr, 0, sizeof(attr)); 80 attr.size = sizeof(perf_event_attr); 81 attr.type = event_type.type; 82 attr.config = event_type.config; 83 attr.mmap = 1; 84 attr.comm = 1; 85 attr.disabled = 0; 86 // Changing read_format affects the layout of the data read from perf_event_file, namely 87 // PerfCounter in event_fd.h. 88 attr.read_format = 89 PERF_FORMAT_TOTAL_TIME_ENABLED | PERF_FORMAT_TOTAL_TIME_RUNNING | PERF_FORMAT_ID; 90 attr.sample_type |= PERF_SAMPLE_IP | PERF_SAMPLE_TID | PERF_SAMPLE_TIME | PERF_SAMPLE_PERIOD | 91 PERF_SAMPLE_CPU | PERF_SAMPLE_ID; 92 93 if (attr.type == PERF_TYPE_TRACEPOINT) { 94 // Tracepoint information are stored in raw data in sample records. 95 attr.sample_type |= PERF_SAMPLE_RAW; 96 } 97 return attr; 98} 99 100void DumpPerfEventAttr(const perf_event_attr& attr, size_t indent) { 101 std::string event_name = GetEventNameByAttr(attr); 102 PrintIndented(indent, "event_attr: for event type %s\n", event_name.c_str()); 103 104 PrintIndented(indent + 1, "type %u, size %u, config %llu\n", attr.type, attr.size, attr.config); 105 106 if (attr.freq != 0) { 107 PrintIndented(indent + 1, "sample_freq %llu\n", attr.sample_freq); 108 } else { 109 PrintIndented(indent + 1, "sample_period %llu\n", attr.sample_period); 110 } 111 112 PrintIndented(indent + 1, "sample_type (0x%llx) %s\n", attr.sample_type, 113 SampleTypeToString(attr.sample_type).c_str()); 114 115 PrintIndented(indent + 1, "read_format (0x%llx) %s\n", attr.read_format, 116 ReadFormatToString(attr.read_format).c_str()); 117 118 PrintIndented(indent + 1, "disabled %u, inherit %u, pinned %u, exclusive %u\n", attr.disabled, 119 attr.inherit, attr.pinned, attr.exclusive); 120 121 PrintIndented(indent + 1, "exclude_user %u, exclude_kernel %u, exclude_hv %u\n", 122 attr.exclude_user, attr.exclude_kernel, attr.exclude_hv); 123 124 PrintIndented(indent + 1, "exclude_idle %u, mmap %u, comm %u, freq %u\n", attr.exclude_idle, 125 attr.mmap, attr.comm, attr.freq); 126 127 PrintIndented(indent + 1, "inherit_stat %u, enable_on_exec %u, task %u\n", attr.inherit_stat, 128 attr.enable_on_exec, attr.task); 129 130 PrintIndented(indent + 1, "watermark %u, precise_ip %u, mmap_data %u\n", attr.watermark, 131 attr.precise_ip, attr.mmap_data); 132 133 PrintIndented(indent + 1, "sample_id_all %u, exclude_host %u, exclude_guest %u\n", 134 attr.sample_id_all, attr.exclude_host, attr.exclude_guest); 135 PrintIndented(indent + 1, "branch_sample_type 0x%" PRIx64 "\n", attr.branch_sample_type); 136 PrintIndented(indent + 1, "exclude_callchain_kernel %u, exclude_callchain_user %u\n", 137 attr.exclude_callchain_kernel, attr.exclude_callchain_user); 138 PrintIndented(indent + 1, "sample_regs_user 0x%" PRIx64 "\n", attr.sample_regs_user); 139 PrintIndented(indent + 1, "sample_stack_user 0x%" PRIx64 "\n", attr.sample_stack_user); 140} 141 142bool GetCommonEventIdPositionsForAttrs(std::vector<perf_event_attr>& attrs, 143 size_t* event_id_pos_in_sample_records, 144 size_t* event_id_reverse_pos_in_non_sample_records) { 145 // When there are more than one perf_event_attrs, we need to read event id 146 // in each record to decide current record should use which attr. So 147 // we need to determine the event id position in a record here. 148 std::vector<uint64_t> sample_types; 149 for (const auto& attr : attrs) { 150 sample_types.push_back(attr.sample_type); 151 } 152 // First determine event_id_pos_in_sample_records. 153 // If PERF_SAMPLE_IDENTIFIER is enabled, it is just after perf_event_header. 154 // If PERF_SAMPLE_ID is enabled, then PERF_SAMPLE_IDENTIFIER | IP | TID | TIME | ADDR 155 // should also be the same. 156 bool identifier_enabled = true; 157 bool id_enabled = true; 158 uint64_t flags_before_id_mask = PERF_SAMPLE_IDENTIFIER | PERF_SAMPLE_IP | PERF_SAMPLE_TID | 159 PERF_SAMPLE_TIME | PERF_SAMPLE_ADDR; 160 uint64_t flags_before_id = sample_types[0] & flags_before_id_mask; 161 bool flags_before_id_are_the_same = true; 162 for (auto type : sample_types) { 163 identifier_enabled &= (type & PERF_SAMPLE_IDENTIFIER) != 0; 164 id_enabled &= (type & PERF_SAMPLE_ID) != 0; 165 flags_before_id_are_the_same &= (type & flags_before_id_mask) == flags_before_id; 166 } 167 if (identifier_enabled) { 168 *event_id_pos_in_sample_records = sizeof(perf_event_header); 169 } else if (id_enabled && flags_before_id_are_the_same) { 170 uint64_t pos = sizeof(perf_event_header); 171 while (flags_before_id != 0) { 172 // Each flags takes 8 bytes in sample records. 173 flags_before_id &= flags_before_id - 1; 174 pos += 8; 175 } 176 *event_id_pos_in_sample_records = pos; 177 } else { 178 LOG(ERROR) << "perf_event_attrs don't have a common event id position in sample records"; 179 return false; 180 } 181 182 // Secondly determine event_id_reverse_pos_in_non_sample_record. 183 // If sample_id_all is not enabled, there is no event id in non sample records. 184 // If PERF_SAMPLE_IDENTIFIER is enabled, it is at the last 8 bytes of the record. 185 // If PERF_SAMPLE_ID is enabled, then PERF_SAMPLE_IDENTIFIER | CPU | STREAM_ID should 186 // also be the same. 187 bool sample_id_all_enabled = true; 188 for (const auto& attr : attrs) { 189 if (attr.sample_id_all == 0) { 190 sample_id_all_enabled = false; 191 } 192 } 193 if (!sample_id_all_enabled) { 194 LOG(ERROR) << "there are perf_event_attrs not enabling sample_id_all, so can't determine " 195 << "perf_event_attr for non sample records"; 196 return false; 197 } 198 uint64_t flags_after_id_mask = PERF_SAMPLE_IDENTIFIER | PERF_SAMPLE_CPU | PERF_SAMPLE_STREAM_ID; 199 uint64_t flags_after_id = sample_types[0] & flags_after_id_mask; 200 bool flags_after_id_are_the_same = true; 201 for (auto type : sample_types) { 202 flags_after_id_are_the_same &= (type & flags_after_id_mask) == flags_after_id; 203 } 204 if (identifier_enabled) { 205 *event_id_reverse_pos_in_non_sample_records = 8; 206 } else if (id_enabled && flags_after_id_are_the_same) { 207 uint64_t pos = 8; 208 while (flags_after_id != 0) { 209 // Each flag takes 8 bytes in sample_id of non sample records. 210 flags_after_id &= flags_after_id - 1; 211 pos += 8; 212 } 213 *event_id_reverse_pos_in_non_sample_records = pos; 214 } else { 215 LOG(ERROR) << "perf_event_attrs don't have a common event id reverse position in non sample records"; 216 return false; 217 } 218 return true; 219} 220 221bool IsTimestampSupported(const perf_event_attr& attr) { 222 return attr.sample_id_all && (attr.sample_type & PERF_SAMPLE_TIME); 223} 224 225bool IsCpuSupported(const perf_event_attr& attr) { 226 return attr.sample_id_all && (attr.sample_type & PERF_SAMPLE_CPU); 227} 228 229std::string GetEventNameByAttr(const perf_event_attr& attr) { 230 for (const auto& event_type : GetAllEventTypes()) { 231 if (event_type.type == attr.type && event_type.config == attr.config) { 232 std::string name = event_type.name; 233 if (attr.exclude_user && !attr.exclude_kernel) { 234 name += ":k"; 235 } else if (attr.exclude_kernel && !attr.exclude_user) { 236 name += ":u"; 237 } 238 return name; 239 } 240 } 241 return "unknown"; 242} 243