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
BitsToString(const std::string & name,uint64_t bits,const std::vector<std::pair<int,std::string>> & bit_names)29 static 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
SampleTypeToString(uint64_t sample_type)47 static 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
ReadFormatToString(uint64_t read_format)67 static 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
CreateDefaultPerfEventAttr(const EventType & event_type)77 perf_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
DumpPerfEventAttr(const perf_event_attr & attr,size_t indent)100 void 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
GetCommonEventIdPositionsForAttrs(std::vector<perf_event_attr> & attrs,size_t * event_id_pos_in_sample_records,size_t * event_id_reverse_pos_in_non_sample_records)142 bool 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
IsTimestampSupported(const perf_event_attr & attr)221 bool IsTimestampSupported(const perf_event_attr& attr) {
222 return attr.sample_id_all && (attr.sample_type & PERF_SAMPLE_TIME);
223 }
224
IsCpuSupported(const perf_event_attr & attr)225 bool IsCpuSupported(const perf_event_attr& attr) {
226 return attr.sample_id_all && (attr.sample_type & PERF_SAMPLE_CPU);
227 }
228
GetEventNameByAttr(const perf_event_attr & attr)229 std::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