1 /*
2 * Copyright (C) 2020 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 "src/traced/probes/ftrace/vendor_tracepoints.h"
18
19 #include <errno.h>
20 #include <string.h>
21
22 #include <map>
23 #include <string>
24 #include <vector>
25
26 #include "perfetto/base/status.h"
27 #include "perfetto/ext/base/file_utils.h"
28 #include "perfetto/ext/base/string_splitter.h"
29 #include "src/traced/probes/ftrace/atrace_hal_wrapper.h"
30 #include "src/traced/probes/ftrace/ftrace_procfs.h"
31 #include "src/traced/probes/ftrace/proto_translation_table.h"
32
33 namespace perfetto {
34 namespace vendor_tracepoints {
35 namespace {
36
37 using EmptyTokenMode = ::perfetto::base::StringSplitter::EmptyTokenMode;
38
DiscoverTracepoints(AtraceHalWrapper * hal,FtraceProcfs * ftrace,const std::string & category)39 std::vector<GroupAndName> DiscoverTracepoints(AtraceHalWrapper* hal,
40 FtraceProcfs* ftrace,
41 const std::string& category) {
42 ftrace->DisableAllEvents();
43 hal->EnableCategories({category});
44
45 std::vector<GroupAndName> events;
46 for (const std::string& group_name : ftrace->ReadEnabledEvents()) {
47 size_t pos = group_name.find('/');
48 PERFETTO_CHECK(pos != std::string::npos);
49 events.push_back(
50 GroupAndName(group_name.substr(0, pos), group_name.substr(pos + 1)));
51 }
52
53 hal->DisableAllCategories();
54 ftrace->DisableAllEvents();
55 return events;
56 }
57
ParseEventLine(base::StringView line,std::vector<GroupAndName> * category)58 base::Status ParseEventLine(base::StringView line,
59 std::vector<GroupAndName>* category) {
60 // `line` is a line in the vendor file that starts with one or more whitespace
61 // and is expected to contain the path to an ftrace event like:
62 // ```
63 // cma/cma_alloc_start
64 // ```
65 while (!line.empty() && (line.at(0) == ' ' || line.at(0) == '\t')) {
66 line = line.substr(1);
67 }
68 if (line.empty()) {
69 return base::OkStatus();
70 }
71 size_t pos = line.find('/');
72 if (pos == line.npos) {
73 return base::ErrStatus("Ftrace event path not in group/event format");
74 }
75 base::StringView group = line.substr(0, pos);
76 if (group.empty()) {
77 return base::ErrStatus("Ftrace event path group is empty");
78 }
79 base::StringView name = line.substr(pos + 1);
80 if (name.find('/') != name.npos) {
81 return base::ErrStatus("Ftrace event path has extra / in event name");
82 }
83 if (name.empty()) {
84 return base::ErrStatus("Ftrace event name empty");
85 }
86 category->push_back(GroupAndName(group.ToStdString(), name.ToStdString()));
87 return base::OkStatus();
88 }
89
90 } // namespace
91
92 std::map<std::string, std::vector<GroupAndName>>
DiscoverVendorTracepointsWithHal(AtraceHalWrapper * hal,FtraceProcfs * ftrace)93 DiscoverVendorTracepointsWithHal(AtraceHalWrapper* hal, FtraceProcfs* ftrace) {
94 std::map<std::string, std::vector<GroupAndName>> results;
95 for (const auto& category : hal->ListCategories()) {
96 results.emplace(category, DiscoverTracepoints(hal, ftrace, category));
97 }
98 return results;
99 }
100
DiscoverVendorTracepointsWithFile(const std::string & vendor_atrace_categories_path,std::map<std::string,std::vector<GroupAndName>> * categories_map)101 base::Status DiscoverVendorTracepointsWithFile(
102 const std::string& vendor_atrace_categories_path,
103 std::map<std::string, std::vector<GroupAndName>>* categories_map) {
104 std::string content;
105 if (!base::ReadFile(vendor_atrace_categories_path, &content)) {
106 return base::ErrStatus("Cannot read vendor atrace file: %s (errno: %d, %s)",
107 vendor_atrace_categories_path.c_str(), errno,
108 strerror(errno));
109 }
110 // The file should contain a list of categories (one per line) and, for each
111 // category, a list of ftrace events (one per line, nested):
112 // ```
113 // gfx
114 // mali/gpu_power_state
115 // mali/mali_pm_status
116 // thermal_tj
117 // thermal_exynos/thermal_cpu_pressure
118 // thermal_exynos/thermal_exynos_arm_update
119 // ```
120 std::vector<GroupAndName>* category = nullptr;
121 for (base::StringSplitter lines(std::move(content), '\n',
122 EmptyTokenMode::DISALLOW_EMPTY_TOKENS);
123 lines.Next();) {
124 base::StringView line(lines.cur_token());
125 if (line.empty()) {
126 continue;
127 }
128 char firstchar = line.at(0);
129 if (firstchar == '\t' || firstchar == ' ') {
130 // The line begins with a whitespace. It should contain an ftrace event
131 // path, part of a previously defined category.
132 if (category == nullptr) {
133 return base::ErrStatus(
134 "Ftrace event path before category. Malformed vendor atrace file");
135 }
136 base::Status status = ParseEventLine(line, category);
137 if (!status.ok()) {
138 return status;
139 }
140 } else {
141 // The line doesn't begin with a whitespace. Start a new category.
142 category = &(*categories_map)[line.ToStdString()];
143 }
144 }
145 return base::OkStatus();
146 }
147
DiscoverAccessibleVendorTracepointsWithFile(const std::string & vendor_atrace_categories_path,std::map<std::string,std::vector<GroupAndName>> * categories_map,FtraceProcfs * ftrace)148 base::Status DiscoverAccessibleVendorTracepointsWithFile(
149 const std::string& vendor_atrace_categories_path,
150 std::map<std::string, std::vector<GroupAndName>>* categories_map,
151 FtraceProcfs* ftrace) {
152 categories_map->clear();
153 base::Status status = DiscoverVendorTracepointsWithFile(
154 vendor_atrace_categories_path, categories_map);
155 if (!status.ok()) {
156 return status;
157 }
158
159 for (auto& it : *categories_map) {
160 std::vector<GroupAndName>& events = it.second;
161 events.erase(std::remove_if(events.begin(), events.end(),
162 [ftrace](const GroupAndName& event) {
163 return !ftrace->IsEventAccessible(
164 event.group(), event.name());
165 }),
166 events.end());
167 }
168
169 return base::OkStatus();
170 }
171
172 } // namespace vendor_tracepoints
173 } // namespace perfetto
174