1 /*
2  * Copyright (c) 2024 Huawei Device Co., Ltd.
3  * Licensed under the Apache License, Version 2.0 (the "License");
4  * you may not use this file except in compliance with the License.
5  * You may obtain a copy of the License at
6  *
7  * http://www.apache.org/licenses/LICENSE-2.0
8  *
9  * Unless required by applicable law or agreed to in writing, software
10  * distributed under the License is distributed on an "AS IS" BASIS,
11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12  * See the License for the specific language governing permissions and
13  * limitations under the License.
14  */
15 #ifndef UNIQUE_STACK_TABLE_H
16 #define UNIQUE_STACK_TABLE_H
17 
18 #include <cinttypes>
19 #include <mutex>
20 #include <memory>
21 #include <string>
22 #include <vector>
23 
24 #include <sys/mman.h>
25 
26 namespace OHOS {
27 namespace HiviewDFX {
28 #define ADDR_BIT_LENGTH        40
29 #define IDX_BIT_LENGTH         23
30 #define KERNEL_FLAG_BIT_LENGTH 1
31 #define DECONFLICT_INCREASE_STEP  3
32 #define RESIZE_MULTIPLE          2
33 #define NR_BIT_LENGTH          41
34 constexpr uint32_t INITIAL_TABLE_SIZE = 1 * 1024 * 1024;
35 constexpr uint32_t MAX_NODES_CNT = 1 << IDX_BIT_LENGTH ;
36 constexpr uint64_t PC_IN_KERNEL = 1ull << 63;
37 constexpr uint64_t HEAD_NODE_INDEX = 0;
38 // FFFFFF0000000000
39 constexpr uint64_t KERNEL_PREFIX = 0xFFFFFFull << 40;
40 constexpr uint8_t INIT_DECONFLICT_ALLOWED = 22;
41 
42 // align
43 #pragma pack(push, 4)
44 
45 union Node {
46     uint64_t value;
47     struct {
48         uint64_t pc : ADDR_BIT_LENGTH;
49         uint64_t prevIdx : IDX_BIT_LENGTH;
50         uint64_t inKernel : KERNEL_FLAG_BIT_LENGTH;
51     } section;
52 };
53 
54 struct UniStackNode {
55     uint32_t index;
56     Node node;
57 };
58 
59 struct UniStackTableInfo {
60     uint32_t pid;
61     uint32_t tableSize;
62     uint32_t numNodes;
63     std::vector<UniStackNode> nodes;
64 };
65 
66 union StackId {
67     uint64_t value;
68     struct {
69         uint64_t id : IDX_BIT_LENGTH;
70         uint64_t nr : NR_BIT_LENGTH;
71     } section;
72 };
73 
74 #pragma pack(pop)
75 static_assert(sizeof(Node) == 8, "Node size must be 8 byte");
76 
77 class UniqueStackTable {
78 public:
79     bool Init();
80     static UniqueStackTable* Instance();
81 
UniqueStackTable()82     UniqueStackTable()
83     {
84     }
85 
UniqueStackTable(pid_t pid)86     explicit UniqueStackTable(pid_t pid) : pid_(pid)
87     {
88     }
89 
UniqueStackTable(pid_t pid,uint32_t size)90     UniqueStackTable(pid_t pid, uint32_t size) : pid_(pid), tableSize_(size)
91     {
92     }
93 
94     UniqueStackTable(void* buf, uint32_t size, bool releaseBuffer = true)
95         :tableBufMMap_(buf), tableSize_(size), releaseBuffer_(releaseBuffer)
96     {
97         totalNodes_ = ((tableSize_ / sizeof(Node)) >> 1) << 1;
98     }
99 
~UniqueStackTable()100     ~UniqueStackTable()
101     {
102         if (tableBufMMap_ != nullptr && releaseBuffer_) {
103             munmap(tableBufMMap_, tableSize_);
104             tableBufMMap_ = nullptr;
105         }
106     }
107 
108     uint64_t PutPcsInTable(StackId *stackId, uintptr_t *pcs, size_t nr);
109     bool GetPcsByStackId(const StackId stackId, std::vector<uintptr_t>& pcs);
110     bool ImportNode(uint32_t index, const Node& node);
111     size_t GetWriteSize();
112 
113     bool Resize();
114 
GetPid()115     uint32_t GetPid()
116     {
117         return pid_;
118     }
119 
GetTabelSize()120     uint32_t GetTabelSize()
121     {
122         return tableSize_;
123     }
124 
GetUsedIndexes()125     std::vector<uint32_t>& GetUsedIndexes()
126     {
127         return usedSlots_;
128     }
129 
GetHeadNode()130     Node* GetHeadNode()
131     {
132         return reinterpret_cast<Node *>(tableBufMMap_);
133     }
134 
135 private:
136     Node* GetFrame(uint64_t stackId);
137     uint64_t PutPcInSlot(uint64_t thisPc, uint64_t prevIdx);
138     int32_t pid_ = 0;
139     void* tableBufMMap_ = nullptr;
140     uint32_t tableSize_ = INITIAL_TABLE_SIZE;
141     std::vector<uint32_t> usedSlots_;
142     uint32_t totalNodes_ = 0;
143     // current available node count, include index 0
144     uint32_t availableNodes_ = 0;
145     uint32_t hashModulus_ = 0;
146     // 0 for reserved, start from 1
147     uint32_t availableIndex_ = 1;
148     // for de-conflict
149     uint64_t hashStep_ = 0;
150     uint8_t deconflictTimes_ = INIT_DECONFLICT_ALLOWED;
151     std::mutex stackTableMutex_;
152     bool releaseBuffer_ = true;
153 };
154 }
155 }
156 #endif // HIEPRF_UNIQUE_STACK_TABLE_H