1 //===-- ProcessorTrace.h -------------------------------------- -*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #ifndef liblldb_ProcessorTrace_H_ 10 #define liblldb_ProcessorTrace_H_ 11 12 #include "lldb/Utility/Status.h" 13 #include "lldb/Utility/TraceOptions.h" 14 #include "lldb/lldb-types.h" 15 #include "llvm/ADT/DenseMap.h" 16 #include "llvm/ADT/DenseSet.h" 17 18 #include <linux/perf_event.h> 19 #include <sys/mman.h> 20 #include <unistd.h> 21 22 namespace lldb_private { 23 24 namespace process_linux { 25 26 // This class keeps track of one tracing instance of 27 // Intel(R) Processor Trace on Linux OS. There is a map keeping track 28 // of different tracing instances on each thread, which enables trace 29 // gathering on a per thread level. 30 // 31 // The tracing instance is linked with a trace id. The trace id acts like 32 // a key to the tracing instance and trace manipulations could be 33 // performed using the trace id. 34 // 35 // The trace id could map to trace instances for a group of threads 36 // (spanning to all the threads in the process) or a single thread. 37 // The kernel interface for us is the perf_event_open. 38 39 class ProcessorTraceMonitor; 40 typedef std::unique_ptr<ProcessorTraceMonitor> ProcessorTraceMonitorUP; 41 42 class ProcessorTraceMonitor { 43 44 class munmap_delete { 45 size_t m_length; 46 47 public: munmap_delete(size_t length)48 munmap_delete(size_t length) : m_length(length) {} operator()49 void operator()(void *ptr) { 50 if (m_length) 51 munmap(ptr, m_length); 52 } 53 }; 54 55 class file_close { 56 57 public: 58 file_close() = default; operator()59 void operator()(int *ptr) { 60 if (ptr == nullptr) 61 return; 62 if (*ptr == -1) 63 return; 64 close(*ptr); 65 std::default_delete<int>()(ptr); 66 } 67 }; 68 69 std::unique_ptr<perf_event_mmap_page, munmap_delete> m_mmap_meta; 70 std::unique_ptr<uint8_t, munmap_delete> m_mmap_aux; 71 std::unique_ptr<int, file_close> m_fd; 72 73 // perf_event_mmap_page *m_mmap_base; 74 lldb::user_id_t m_traceid; 75 lldb::tid_t m_thread_id; 76 77 // Counter to track trace instances. 78 static lldb::user_id_t m_trace_num; 79 SetTraceID(lldb::user_id_t traceid)80 void SetTraceID(lldb::user_id_t traceid) { m_traceid = traceid; } 81 82 Status StartTrace(lldb::pid_t pid, lldb::tid_t tid, 83 const TraceOptions &config); 84 85 llvm::MutableArrayRef<uint8_t> GetAuxBuffer(); 86 llvm::MutableArrayRef<uint8_t> GetDataBuffer(); 87 ProcessorTraceMonitor()88 ProcessorTraceMonitor() 89 : m_mmap_meta(nullptr, munmap_delete(0)), 90 m_mmap_aux(nullptr, munmap_delete(0)), m_fd(nullptr, file_close()), 91 m_traceid(LLDB_INVALID_UID), m_thread_id(LLDB_INVALID_THREAD_ID){}; 92 SetThreadID(lldb::tid_t tid)93 void SetThreadID(lldb::tid_t tid) { m_thread_id = tid; } 94 95 public: 96 static Status GetCPUType(TraceOptions &config); 97 98 static llvm::Expected<ProcessorTraceMonitorUP> 99 Create(lldb::pid_t pid, lldb::tid_t tid, const TraceOptions &config, 100 bool useProcessSettings); 101 102 Status ReadPerfTraceAux(llvm::MutableArrayRef<uint8_t> &buffer, 103 size_t offset = 0); 104 105 Status ReadPerfTraceData(llvm::MutableArrayRef<uint8_t> &buffer, 106 size_t offset = 0); 107 108 ~ProcessorTraceMonitor() = default; 109 GetThreadID()110 lldb::tid_t GetThreadID() const { return m_thread_id; } 111 GetTraceID()112 lldb::user_id_t GetTraceID() const { return m_traceid; } 113 114 Status GetTraceConfig(TraceOptions &config) const; 115 116 /// Read data from a cyclic buffer 117 /// 118 /// \param[in] [out] buf 119 /// Destination buffer, the buffer will be truncated to written size. 120 /// 121 /// \param[in] src 122 /// Source buffer which must be a cyclic buffer. 123 /// 124 /// \param[in] src_cyc_index 125 /// The index pointer (start of the valid data in the cyclic 126 /// buffer). 127 /// 128 /// \param[in] offset 129 /// The offset to begin reading the data in the cyclic buffer. 130 static void ReadCyclicBuffer(llvm::MutableArrayRef<uint8_t> &dst, 131 llvm::MutableArrayRef<uint8_t> src, 132 size_t src_cyc_index, size_t offset); 133 }; 134 } // namespace process_linux 135 } // namespace lldb_private 136 #endif 137