1 /*
2 * Copyright (C) 2021 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 "libstatspull_lazy.h"
18
19 #include <mutex>
20
21 #include <dlfcn.h>
22 #include <stdatomic.h>
23
24 #include "log/log.h"
25
26 #include "stats_pull_atom_callback.h"
27
28 // This file provides a lazy interface to libstatspull.so to address early boot dependencies.
29 // Specifically bootanimation, surfaceflinger, and lmkd run before the statsd APEX is loaded and
30 // libstatspull.so is in the statsd APEX.
31
32 // Method pointers to libstatspull methods are held in an array which simplifies checking
33 // all pointers are initialized.
34 enum MethodIndex {
35 // PullAtomMetadata APIs in stats_pull_atom_callback.h.
36 k_AStatsManager_PullAtomMetadata_obtain,
37 k_AStatsManager_PullAtomMetadata_release,
38 k_AStatsManager_PullAtomMetadata_setCoolDownMillis,
39 k_AStatsManager_PullAtomMetadata_getCoolDownMillis,
40 k_AStatsManager_PullAtomMetadata_setTimeoutMillis,
41 k_AStatsManager_PullAtomMetadata_getTimeoutMillis,
42 k_AStatsManager_PullAtomMetadata_setAdditiveFields,
43 k_AStatsManager_PullAtomMetadata_getNumAdditiveFields,
44 k_AStatsManager_PullAtomMetadata_getAdditiveFields,
45
46 // AStatsEventList APIs in stats_pull_atom_callback.h
47 k_AStatsEventList_addStatsEvent,
48
49 // PullAtomCallback APIs in stats_pull_atom_callback.h
50 k_AStatsManager_setPullAtomCallback,
51 k_AStatsManager_clearPullAtomCallback,
52
53 // Marker for count of methods
54 k_MethodCount
55 };
56
57 // Table of methods pointers in libstatspull APIs.
58 static void* g_Methods[k_MethodCount];
59
60 //
61 // Libstatspull lazy loading.
62 //
63
64 static atomic_bool gPreventLibstatspullLoading = false; // Allows tests to block loading.
65
PreventLibstatspullLazyLoadingForTests()66 void PreventLibstatspullLazyLoadingForTests() {
67 gPreventLibstatspullLoading.store(true);
68 }
69
LoadLibstatspull(int dlopen_flags)70 static void* LoadLibstatspull(int dlopen_flags) {
71 if (gPreventLibstatspullLoading.load()) {
72 return nullptr;
73 }
74 return dlopen("libstatspull.so", dlopen_flags);
75 }
76
77 //
78 // Initialization and symbol binding.
79
BindSymbol(void * handle,const char * name,enum MethodIndex index)80 static void BindSymbol(void* handle, const char* name, enum MethodIndex index) {
81 void* symbol = dlsym(handle, name);
82 LOG_ALWAYS_FATAL_IF(symbol == nullptr, "Failed to find symbol '%s' in libstatspull.so: %s",
83 name, dlerror());
84 g_Methods[index] = symbol;
85 }
86
InitializeOnce()87 static void InitializeOnce() {
88 void* handle = LoadLibstatspull(RTLD_NOW);
89 LOG_ALWAYS_FATAL_IF(handle == nullptr, "Failed to load libstatspull.so: %s", dlerror());
90
91 #undef BIND_SYMBOL
92 #define BIND_SYMBOL(name) BindSymbol(handle, #name, k_##name);
93 // PullAtomMetadata APIs in stats_pull_atom_callback.h.
94 BIND_SYMBOL(AStatsManager_PullAtomMetadata_obtain);
95 BIND_SYMBOL(AStatsManager_PullAtomMetadata_release);
96 BIND_SYMBOL(AStatsManager_PullAtomMetadata_setCoolDownMillis);
97 BIND_SYMBOL(AStatsManager_PullAtomMetadata_getCoolDownMillis);
98 BIND_SYMBOL(AStatsManager_PullAtomMetadata_setTimeoutMillis);
99 BIND_SYMBOL(AStatsManager_PullAtomMetadata_getTimeoutMillis);
100 BIND_SYMBOL(AStatsManager_PullAtomMetadata_setAdditiveFields);
101 BIND_SYMBOL(AStatsManager_PullAtomMetadata_getNumAdditiveFields);
102 BIND_SYMBOL(AStatsManager_PullAtomMetadata_getAdditiveFields);
103
104 // AStatsEventList APIs in stats_pull_atom_callback.h
105 BIND_SYMBOL(AStatsEventList_addStatsEvent);
106
107 // PullAtomCallback APIs in stats_pull_atom_callback.h
108 BIND_SYMBOL(AStatsManager_setPullAtomCallback);
109 BIND_SYMBOL(AStatsManager_clearPullAtomCallback);
110
111 #undef BIND_SYMBOL
112
113 // Check every symbol is bound.
114 for (int i = 0; i < k_MethodCount; ++i) {
115 LOG_ALWAYS_FATAL_IF(g_Methods[i] == nullptr,
116 "Uninitialized method in libstatspull_lazy at index: %d", i);
117 }
118 }
119
EnsureInitialized()120 static void EnsureInitialized() {
121 static std::once_flag initialize_flag;
122 std::call_once(initialize_flag, InitializeOnce);
123 }
124
125 #define INVOKE_METHOD(name, args...) \
126 do { \
127 EnsureInitialized(); \
128 void* method = g_Methods[k_##name]; \
129 return reinterpret_cast<decltype(&name)>(method)(args); \
130 } while (0)
131
132 //
133 // Forwarding for methods in stats_pull_atom_callback.h.
134 //
135
AStatsManager_PullAtomMetadata_obtain()136 AStatsManager_PullAtomMetadata* AStatsManager_PullAtomMetadata_obtain() {
137 INVOKE_METHOD(AStatsManager_PullAtomMetadata_obtain);
138 }
139
AStatsManager_PullAtomMetadata_release(AStatsManager_PullAtomMetadata * metadata)140 void AStatsManager_PullAtomMetadata_release(AStatsManager_PullAtomMetadata* metadata) {
141 INVOKE_METHOD(AStatsManager_PullAtomMetadata_release, metadata);
142 }
143
AStatsManager_PullAtomMetadata_setCoolDownMillis(AStatsManager_PullAtomMetadata * metadata,int64_t cool_down_millis)144 void AStatsManager_PullAtomMetadata_setCoolDownMillis(AStatsManager_PullAtomMetadata* metadata,
145 int64_t cool_down_millis) {
146 INVOKE_METHOD(AStatsManager_PullAtomMetadata_setCoolDownMillis, metadata, cool_down_millis);
147 }
148
AStatsManager_PullAtomMetadata_getCoolDownMillis(AStatsManager_PullAtomMetadata * metadata)149 int64_t AStatsManager_PullAtomMetadata_getCoolDownMillis(AStatsManager_PullAtomMetadata* metadata) {
150 INVOKE_METHOD(AStatsManager_PullAtomMetadata_getCoolDownMillis, metadata);
151 }
152
AStatsManager_PullAtomMetadata_setTimeoutMillis(AStatsManager_PullAtomMetadata * metadata,int64_t timeout_millis)153 void AStatsManager_PullAtomMetadata_setTimeoutMillis(AStatsManager_PullAtomMetadata* metadata,
154 int64_t timeout_millis) {
155 INVOKE_METHOD(AStatsManager_PullAtomMetadata_setTimeoutMillis, metadata, timeout_millis);
156 }
157
AStatsManager_PullAtomMetadata_getTimeoutMillis(AStatsManager_PullAtomMetadata * metadata)158 int64_t AStatsManager_PullAtomMetadata_getTimeoutMillis(AStatsManager_PullAtomMetadata* metadata) {
159 INVOKE_METHOD(AStatsManager_PullAtomMetadata_getTimeoutMillis, metadata);
160 }
161
AStatsManager_PullAtomMetadata_setAdditiveFields(AStatsManager_PullAtomMetadata * metadata,int32_t * additive_fields,int32_t num_fields)162 void AStatsManager_PullAtomMetadata_setAdditiveFields(AStatsManager_PullAtomMetadata* metadata,
163 int32_t* additive_fields,
164 int32_t num_fields) {
165 INVOKE_METHOD(AStatsManager_PullAtomMetadata_setAdditiveFields, metadata, additive_fields,
166 num_fields);
167 }
168
AStatsManager_PullAtomMetadata_getNumAdditiveFields(AStatsManager_PullAtomMetadata * metadata)169 int32_t AStatsManager_PullAtomMetadata_getNumAdditiveFields(
170 AStatsManager_PullAtomMetadata* metadata) {
171 INVOKE_METHOD(AStatsManager_PullAtomMetadata_getNumAdditiveFields, metadata);
172 }
173
AStatsManager_PullAtomMetadata_getAdditiveFields(AStatsManager_PullAtomMetadata * metadata,int32_t * fields)174 void AStatsManager_PullAtomMetadata_getAdditiveFields(AStatsManager_PullAtomMetadata* metadata,
175 int32_t* fields) {
176 INVOKE_METHOD(AStatsManager_PullAtomMetadata_getAdditiveFields, metadata, fields);
177 }
178
AStatsEventList_addStatsEvent(AStatsEventList * pull_data)179 AStatsEvent* AStatsEventList_addStatsEvent(AStatsEventList* pull_data) {
180 INVOKE_METHOD(AStatsEventList_addStatsEvent, pull_data);
181 }
182
AStatsManager_setPullAtomCallback(int32_t atom_tag,AStatsManager_PullAtomMetadata * metadata,AStatsManager_PullAtomCallback callback,void * cookie)183 void AStatsManager_setPullAtomCallback(int32_t atom_tag, AStatsManager_PullAtomMetadata* metadata,
184 AStatsManager_PullAtomCallback callback, void* cookie) {
185 INVOKE_METHOD(AStatsManager_setPullAtomCallback, atom_tag, metadata, callback, cookie);
186 }
187
AStatsManager_clearPullAtomCallback(int32_t atom_tag)188 void AStatsManager_clearPullAtomCallback(int32_t atom_tag) {
189 INVOKE_METHOD(AStatsManager_clearPullAtomCallback, atom_tag);
190 }
191