268 lines · cpp
1//===-- OProfileWrapper.cpp - OProfile JIT API Wrapper implementation -----===//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-exception6//7//===----------------------------------------------------------------------===//8//9// This file implements the interface in OProfileWrapper.h. It is responsible10// for loading the opagent dynamic library when the first call to an op_11// function occurs.12//13//===----------------------------------------------------------------------===//14 15#include "llvm/ExecutionEngine/OProfileWrapper.h"16#include "llvm/ADT/SmallString.h"17#include "llvm/Support/Debug.h"18#include "llvm/Support/DynamicLibrary.h"19#include "llvm/Support/Mutex.h"20#include "llvm/Support/raw_ostream.h"21#include <cstring>22#include <dirent.h>23#include <fcntl.h>24#include <mutex>25#include <stddef.h>26#include <sys/stat.h>27#include <unistd.h>28 29#define DEBUG_TYPE "oprofile-wrapper"30 31namespace {32 33// Global mutex to ensure a single thread initializes oprofile agent.34llvm::sys::Mutex OProfileInitializationMutex;35 36} // anonymous namespace37 38namespace llvm {39 40OProfileWrapper::OProfileWrapper()41: Agent(0),42 OpenAgentFunc(0),43 CloseAgentFunc(0),44 WriteNativeCodeFunc(0),45 WriteDebugLineInfoFunc(0),46 UnloadNativeCodeFunc(0),47 MajorVersionFunc(0),48 MinorVersionFunc(0),49 IsOProfileRunningFunc(0),50 Initialized(false) {51}52 53bool OProfileWrapper::initialize() {54 using namespace llvm;55 using namespace llvm::sys;56 57 std::lock_guard<sys::Mutex> Guard(OProfileInitializationMutex);58 59 if (Initialized)60 return OpenAgentFunc != 0;61 62 Initialized = true;63 64 // If the oprofile daemon is not running, don't load the opagent library65 if (!isOProfileRunning()) {66 LLVM_DEBUG(dbgs() << "OProfile daemon is not detected.\n");67 return false;68 }69 70 std::string error;71 if(!DynamicLibrary::LoadLibraryPermanently("libopagent.so", &error)) {72 LLVM_DEBUG(73 dbgs()74 << "OProfile connector library libopagent.so could not be loaded: "75 << error << "\n");76 }77 78 // Get the addresses of the opagent functions79 OpenAgentFunc = (op_open_agent_ptr_t)(intptr_t)80 DynamicLibrary::SearchForAddressOfSymbol("op_open_agent");81 CloseAgentFunc = (op_close_agent_ptr_t)(intptr_t)82 DynamicLibrary::SearchForAddressOfSymbol("op_close_agent");83 WriteNativeCodeFunc = (op_write_native_code_ptr_t)(intptr_t)84 DynamicLibrary::SearchForAddressOfSymbol("op_write_native_code");85 WriteDebugLineInfoFunc = (op_write_debug_line_info_ptr_t)(intptr_t)86 DynamicLibrary::SearchForAddressOfSymbol("op_write_debug_line_info");87 UnloadNativeCodeFunc = (op_unload_native_code_ptr_t)(intptr_t)88 DynamicLibrary::SearchForAddressOfSymbol("op_unload_native_code");89 MajorVersionFunc = (op_major_version_ptr_t)(intptr_t)90 DynamicLibrary::SearchForAddressOfSymbol("op_major_version");91 MinorVersionFunc = (op_major_version_ptr_t)(intptr_t)92 DynamicLibrary::SearchForAddressOfSymbol("op_minor_version");93 94 // With missing functions, we can do nothing95 if (!OpenAgentFunc96 || !CloseAgentFunc97 || !WriteNativeCodeFunc98 || !WriteDebugLineInfoFunc99 || !UnloadNativeCodeFunc) {100 OpenAgentFunc = 0;101 CloseAgentFunc = 0;102 WriteNativeCodeFunc = 0;103 WriteDebugLineInfoFunc = 0;104 UnloadNativeCodeFunc = 0;105 return false;106 }107 108 return true;109}110 111bool OProfileWrapper::isOProfileRunning() {112 if (IsOProfileRunningFunc != 0)113 return IsOProfileRunningFunc();114 return checkForOProfileProcEntry();115}116 117bool OProfileWrapper::checkForOProfileProcEntry() {118 DIR* ProcDir;119 120 ProcDir = opendir("/proc");121 if (!ProcDir)122 return false;123 124 // Walk the /proc tree looking for the oprofile daemon125 struct dirent* Entry;126 while (0 != (Entry = readdir(ProcDir))) {127 if (Entry->d_type == DT_DIR) {128 // Build a path from the current entry name129 SmallString<256> CmdLineFName;130 raw_svector_ostream(CmdLineFName) << "/proc/" << Entry->d_name131 << "/cmdline";132 133 // Open the cmdline file134 int CmdLineFD = open(CmdLineFName.c_str(), S_IRUSR);135 if (CmdLineFD != -1) {136 char ExeName[PATH_MAX+1];137 char* BaseName = 0;138 139 // Read the cmdline file140 ssize_t NumRead = read(CmdLineFD, ExeName, PATH_MAX+1);141 close(CmdLineFD);142 ssize_t Idx = 0;143 144 if (ExeName[0] != '/') {145 BaseName = ExeName;146 }147 148 // Find the terminator for the first string149 while (Idx < NumRead-1 && ExeName[Idx] != 0) {150 Idx++;151 }152 153 // Go back to the last non-null character154 Idx--;155 156 // Find the last path separator in the first string157 while (Idx > 0) {158 if (ExeName[Idx] == '/') {159 BaseName = ExeName + Idx + 1;160 break;161 }162 Idx--;163 }164 165 // Test this to see if it is the oprofile daemon166 if (BaseName != 0 && (!strcmp("oprofiled", BaseName) ||167 !strcmp("operf", BaseName))) {168 // If it is, we're done169 closedir(ProcDir);170 return true;171 }172 }173 }174 }175 176 // We've looked through all the files and didn't find the daemon177 closedir(ProcDir);178 return false;179}180 181bool OProfileWrapper::op_open_agent() {182 if (!Initialized)183 initialize();184 185 if (OpenAgentFunc != 0) {186 Agent = OpenAgentFunc();187 return Agent != 0;188 }189 190 return false;191}192 193int OProfileWrapper::op_close_agent() {194 if (!Initialized)195 initialize();196 197 int ret = -1;198 if (Agent && CloseAgentFunc) {199 ret = CloseAgentFunc(Agent);200 if (ret == 0) {201 Agent = 0;202 }203 }204 return ret;205}206 207bool OProfileWrapper::isAgentAvailable() {208 return Agent != 0;209}210 211int OProfileWrapper::op_write_native_code(const char* Name,212 uint64_t Addr,213 void const* Code,214 const unsigned int Size) {215 if (!Initialized)216 initialize();217 218 if (Agent && WriteNativeCodeFunc)219 return WriteNativeCodeFunc(Agent, Name, Addr, Code, Size);220 221 return -1;222}223 224int OProfileWrapper::op_write_debug_line_info(225 void const* Code,226 size_t NumEntries,227 struct debug_line_info const* Info) {228 if (!Initialized)229 initialize();230 231 if (Agent && WriteDebugLineInfoFunc)232 return WriteDebugLineInfoFunc(Agent, Code, NumEntries, Info);233 234 return -1;235}236 237int OProfileWrapper::op_major_version() {238 if (!Initialized)239 initialize();240 241 if (Agent && MajorVersionFunc)242 return MajorVersionFunc();243 244 return -1;245}246 247int OProfileWrapper::op_minor_version() {248 if (!Initialized)249 initialize();250 251 if (Agent && MinorVersionFunc)252 return MinorVersionFunc();253 254 return -1;255}256 257int OProfileWrapper::op_unload_native_code(uint64_t Addr) {258 if (!Initialized)259 initialize();260 261 if (Agent && UnloadNativeCodeFunc)262 return UnloadNativeCodeFunc(Agent, Addr);263 264 return -1;265}266 267} // namespace llvm268