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| //===-- OProfileWrapper.cpp - OProfile JIT API Wrapper implementation -----===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file implements the interface in OProfileWrapper.h. It is responsible
// for loading the opagent dynamic library when the first call to an op_
// function occurs.
//
//===----------------------------------------------------------------------===//
#include "llvm/ExecutionEngine/OProfileWrapper.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/DynamicLibrary.h"
#include "llvm/Support/Mutex.h"
#include "llvm/Support/raw_ostream.h"
#include <cstring>
#include <dirent.h>
#include <fcntl.h>
#include <mutex>
#include <stddef.h>
#include <sys/stat.h>
#include <unistd.h>
#define DEBUG_TYPE "oprofile-wrapper"
namespace {
// Global mutex to ensure a single thread initializes oprofile agent.
llvm::sys::Mutex OProfileInitializationMutex;
} // anonymous namespace
namespace llvm {
OProfileWrapper::OProfileWrapper()
: Agent(0),
OpenAgentFunc(0),
CloseAgentFunc(0),
WriteNativeCodeFunc(0),
WriteDebugLineInfoFunc(0),
UnloadNativeCodeFunc(0),
MajorVersionFunc(0),
MinorVersionFunc(0),
IsOProfileRunningFunc(0),
Initialized(false) {
}
bool OProfileWrapper::initialize() {
using namespace llvm;
using namespace llvm::sys;
std::lock_guard<sys::Mutex> Guard(OProfileInitializationMutex);
if (Initialized)
return OpenAgentFunc != 0;
Initialized = true;
// If the oprofile daemon is not running, don't load the opagent library
if (!isOProfileRunning()) {
LLVM_DEBUG(dbgs() << "OProfile daemon is not detected.\n");
return false;
}
std::string error;
if(!DynamicLibrary::LoadLibraryPermanently("libopagent.so", &error)) {
LLVM_DEBUG(
dbgs()
<< "OProfile connector library libopagent.so could not be loaded: "
<< error << "\n");
}
// Get the addresses of the opagent functions
OpenAgentFunc = (op_open_agent_ptr_t)(intptr_t)
DynamicLibrary::SearchForAddressOfSymbol("op_open_agent");
CloseAgentFunc = (op_close_agent_ptr_t)(intptr_t)
DynamicLibrary::SearchForAddressOfSymbol("op_close_agent");
WriteNativeCodeFunc = (op_write_native_code_ptr_t)(intptr_t)
DynamicLibrary::SearchForAddressOfSymbol("op_write_native_code");
WriteDebugLineInfoFunc = (op_write_debug_line_info_ptr_t)(intptr_t)
DynamicLibrary::SearchForAddressOfSymbol("op_write_debug_line_info");
UnloadNativeCodeFunc = (op_unload_native_code_ptr_t)(intptr_t)
DynamicLibrary::SearchForAddressOfSymbol("op_unload_native_code");
MajorVersionFunc = (op_major_version_ptr_t)(intptr_t)
DynamicLibrary::SearchForAddressOfSymbol("op_major_version");
MinorVersionFunc = (op_major_version_ptr_t)(intptr_t)
DynamicLibrary::SearchForAddressOfSymbol("op_minor_version");
// With missing functions, we can do nothing
if (!OpenAgentFunc
|| !CloseAgentFunc
|| !WriteNativeCodeFunc
|| !WriteDebugLineInfoFunc
|| !UnloadNativeCodeFunc) {
OpenAgentFunc = 0;
CloseAgentFunc = 0;
WriteNativeCodeFunc = 0;
WriteDebugLineInfoFunc = 0;
UnloadNativeCodeFunc = 0;
return false;
}
return true;
}
bool OProfileWrapper::isOProfileRunning() {
if (IsOProfileRunningFunc != 0)
return IsOProfileRunningFunc();
return checkForOProfileProcEntry();
}
bool OProfileWrapper::checkForOProfileProcEntry() {
DIR* ProcDir;
ProcDir = opendir("/proc");
if (!ProcDir)
return false;
// Walk the /proc tree looking for the oprofile daemon
struct dirent* Entry;
while (0 != (Entry = readdir(ProcDir))) {
if (Entry->d_type == DT_DIR) {
// Build a path from the current entry name
SmallString<256> CmdLineFName;
raw_svector_ostream(CmdLineFName) << "/proc/" << Entry->d_name
<< "/cmdline";
// Open the cmdline file
int CmdLineFD = open(CmdLineFName.c_str(), S_IRUSR);
if (CmdLineFD != -1) {
char ExeName[PATH_MAX+1];
char* BaseName = 0;
// Read the cmdline file
ssize_t NumRead = read(CmdLineFD, ExeName, PATH_MAX+1);
close(CmdLineFD);
ssize_t Idx = 0;
if (ExeName[0] != '/') {
BaseName = ExeName;
}
// Find the terminator for the first string
while (Idx < NumRead-1 && ExeName[Idx] != 0) {
Idx++;
}
// Go back to the last non-null character
Idx--;
// Find the last path separator in the first string
while (Idx > 0) {
if (ExeName[Idx] == '/') {
BaseName = ExeName + Idx + 1;
break;
}
Idx--;
}
// Test this to see if it is the oprofile daemon
if (BaseName != 0 && (!strcmp("oprofiled", BaseName) ||
!strcmp("operf", BaseName))) {
// If it is, we're done
closedir(ProcDir);
return true;
}
}
}
}
// We've looked through all the files and didn't find the daemon
closedir(ProcDir);
return false;
}
bool OProfileWrapper::op_open_agent() {
if (!Initialized)
initialize();
if (OpenAgentFunc != 0) {
Agent = OpenAgentFunc();
return Agent != 0;
}
return false;
}
int OProfileWrapper::op_close_agent() {
if (!Initialized)
initialize();
int ret = -1;
if (Agent && CloseAgentFunc) {
ret = CloseAgentFunc(Agent);
if (ret == 0) {
Agent = 0;
}
}
return ret;
}
bool OProfileWrapper::isAgentAvailable() {
return Agent != 0;
}
int OProfileWrapper::op_write_native_code(const char* Name,
uint64_t Addr,
void const* Code,
const unsigned int Size) {
if (!Initialized)
initialize();
if (Agent && WriteNativeCodeFunc)
return WriteNativeCodeFunc(Agent, Name, Addr, Code, Size);
return -1;
}
int OProfileWrapper::op_write_debug_line_info(
void const* Code,
size_t NumEntries,
struct debug_line_info const* Info) {
if (!Initialized)
initialize();
if (Agent && WriteDebugLineInfoFunc)
return WriteDebugLineInfoFunc(Agent, Code, NumEntries, Info);
return -1;
}
int OProfileWrapper::op_major_version() {
if (!Initialized)
initialize();
if (Agent && MajorVersionFunc)
return MajorVersionFunc();
return -1;
}
int OProfileWrapper::op_minor_version() {
if (!Initialized)
initialize();
if (Agent && MinorVersionFunc)
return MinorVersionFunc();
return -1;
}
int OProfileWrapper::op_unload_native_code(uint64_t Addr) {
if (!Initialized)
initialize();
if (Agent && UnloadNativeCodeFunc)
return UnloadNativeCodeFunc(Agent, Addr);
return -1;
}
} // namespace llvm
|