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| //===-- MainThreadCheckerRuntime.cpp ----------------------------*- C++ -*-===//
//
// 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
//
//===----------------------------------------------------------------------===//
#include "MainThreadCheckerRuntime.h"
#include "lldb/Breakpoint/StoppointCallbackContext.h"
#include "lldb/Core/Module.h"
#include "lldb/Core/PluginManager.h"
#include "lldb/Symbol/Symbol.h"
#include "lldb/Symbol/SymbolContext.h"
#include "lldb/Symbol/Variable.h"
#include "lldb/Symbol/VariableList.h"
#include "lldb/Target/InstrumentationRuntimeStopInfo.h"
#include "lldb/Target/RegisterContext.h"
#include "lldb/Target/SectionLoadList.h"
#include "lldb/Target/StopInfo.h"
#include "lldb/Target/Target.h"
#include "lldb/Target/Thread.h"
#include "lldb/Utility/RegularExpression.h"
#include "Plugins/Process/Utility/HistoryThread.h"
#include <memory>
using namespace lldb;
using namespace lldb_private;
MainThreadCheckerRuntime::~MainThreadCheckerRuntime() {
Deactivate();
}
lldb::InstrumentationRuntimeSP
MainThreadCheckerRuntime::CreateInstance(const lldb::ProcessSP &process_sp) {
return InstrumentationRuntimeSP(new MainThreadCheckerRuntime(process_sp));
}
void MainThreadCheckerRuntime::Initialize() {
PluginManager::RegisterPlugin(
GetPluginNameStatic(), "MainThreadChecker instrumentation runtime plugin.",
CreateInstance, GetTypeStatic);
}
void MainThreadCheckerRuntime::Terminate() {
PluginManager::UnregisterPlugin(CreateInstance);
}
lldb_private::ConstString MainThreadCheckerRuntime::GetPluginNameStatic() {
return ConstString("MainThreadChecker");
}
lldb::InstrumentationRuntimeType MainThreadCheckerRuntime::GetTypeStatic() {
return eInstrumentationRuntimeTypeMainThreadChecker;
}
const RegularExpression &
MainThreadCheckerRuntime::GetPatternForRuntimeLibrary() {
static RegularExpression regex(llvm::StringRef("libMainThreadChecker.dylib"));
return regex;
}
bool MainThreadCheckerRuntime::CheckIfRuntimeIsValid(
const lldb::ModuleSP module_sp) {
static ConstString test_sym("__main_thread_checker_on_report");
const Symbol *symbol =
module_sp->FindFirstSymbolWithNameAndType(test_sym, lldb::eSymbolTypeAny);
return symbol != nullptr;
}
StructuredData::ObjectSP
MainThreadCheckerRuntime::RetrieveReportData(ExecutionContextRef exe_ctx_ref) {
ProcessSP process_sp = GetProcessSP();
if (!process_sp)
return StructuredData::ObjectSP();
ThreadSP thread_sp = exe_ctx_ref.GetThreadSP();
StackFrameSP frame_sp = thread_sp->GetSelectedFrame();
ModuleSP runtime_module_sp = GetRuntimeModuleSP();
Target &target = process_sp->GetTarget();
if (!frame_sp)
return StructuredData::ObjectSP();
RegisterContextSP regctx_sp = frame_sp->GetRegisterContext();
if (!regctx_sp)
return StructuredData::ObjectSP();
const RegisterInfo *reginfo = regctx_sp->GetRegisterInfoByName("arg1");
if (!reginfo)
return StructuredData::ObjectSP();
uint64_t apiname_ptr = regctx_sp->ReadRegisterAsUnsigned(reginfo, 0);
if (!apiname_ptr)
return StructuredData::ObjectSP();
std::string apiName = "";
Status read_error;
target.ReadCStringFromMemory(apiname_ptr, apiName, read_error);
if (read_error.Fail())
return StructuredData::ObjectSP();
std::string className = "";
std::string selector = "";
if (apiName.substr(0, 2) == "-[") {
size_t spacePos = apiName.find(" ");
if (spacePos != std::string::npos) {
className = apiName.substr(2, spacePos - 2);
selector = apiName.substr(spacePos + 1, apiName.length() - spacePos - 2);
}
}
// Gather the PCs of the user frames in the backtrace.
StructuredData::Array *trace = new StructuredData::Array();
auto trace_sp = StructuredData::ObjectSP(trace);
StackFrameSP responsible_frame;
for (unsigned I = 0; I < thread_sp->GetStackFrameCount(); ++I) {
StackFrameSP frame = thread_sp->GetStackFrameAtIndex(I);
Address addr = frame->GetFrameCodeAddress();
if (addr.GetModule() == runtime_module_sp) // Skip PCs from the runtime.
continue;
// The first non-runtime frame is responsible for the bug.
if (!responsible_frame)
responsible_frame = frame;
// First frame in stacktrace should point to a real PC, not return address.
if (I != 0 && trace->GetSize() == 0) {
addr.Slide(-1);
}
lldb::addr_t PC = addr.GetLoadAddress(&target);
trace->AddItem(StructuredData::ObjectSP(new StructuredData::Integer(PC)));
}
auto *d = new StructuredData::Dictionary();
auto dict_sp = StructuredData::ObjectSP(d);
d->AddStringItem("instrumentation_class", "MainThreadChecker");
d->AddStringItem("api_name", apiName);
d->AddStringItem("class_name", className);
d->AddStringItem("selector", selector);
d->AddStringItem("description",
apiName + " must be used from main thread only");
d->AddIntegerItem("tid", thread_sp->GetIndexID());
d->AddItem("trace", trace_sp);
return dict_sp;
}
bool MainThreadCheckerRuntime::NotifyBreakpointHit(
void *baton, StoppointCallbackContext *context, user_id_t break_id,
user_id_t break_loc_id) {
assert(baton && "null baton");
if (!baton)
return false; //< false => resume execution.
MainThreadCheckerRuntime *const instance =
static_cast<MainThreadCheckerRuntime *>(baton);
ProcessSP process_sp = instance->GetProcessSP();
ThreadSP thread_sp = context->exe_ctx_ref.GetThreadSP();
if (!process_sp || !thread_sp ||
process_sp != context->exe_ctx_ref.GetProcessSP())
return false;
if (process_sp->GetModIDRef().IsLastResumeForUserExpression())
return false;
StructuredData::ObjectSP report =
instance->RetrieveReportData(context->exe_ctx_ref);
if (report) {
std::string description = report->GetAsDictionary()
->GetValueForKey("description")
->GetAsString()
->GetValue();
thread_sp->SetStopInfo(
InstrumentationRuntimeStopInfo::CreateStopReasonWithInstrumentationData(
*thread_sp, description, report));
return true;
}
return false;
}
void MainThreadCheckerRuntime::Activate() {
if (IsActive())
return;
ProcessSP process_sp = GetProcessSP();
if (!process_sp)
return;
ModuleSP runtime_module_sp = GetRuntimeModuleSP();
ConstString symbol_name("__main_thread_checker_on_report");
const Symbol *symbol = runtime_module_sp->FindFirstSymbolWithNameAndType(
symbol_name, eSymbolTypeCode);
if (symbol == nullptr)
return;
if (!symbol->ValueIsAddress() || !symbol->GetAddressRef().IsValid())
return;
Target &target = process_sp->GetTarget();
addr_t symbol_address = symbol->GetAddressRef().GetOpcodeLoadAddress(&target);
if (symbol_address == LLDB_INVALID_ADDRESS)
return;
Breakpoint *breakpoint =
process_sp->GetTarget()
.CreateBreakpoint(symbol_address, /*internal=*/true,
/*hardware=*/false)
.get();
breakpoint->SetCallback(MainThreadCheckerRuntime::NotifyBreakpointHit, this,
true);
breakpoint->SetBreakpointKind("main-thread-checker-report");
SetBreakpointID(breakpoint->GetID());
SetActive(true);
}
void MainThreadCheckerRuntime::Deactivate() {
SetActive(false);
auto BID = GetBreakpointID();
if (BID == LLDB_INVALID_BREAK_ID)
return;
if (ProcessSP process_sp = GetProcessSP()) {
process_sp->GetTarget().RemoveBreakpointByID(BID);
SetBreakpointID(LLDB_INVALID_BREAK_ID);
}
}
lldb::ThreadCollectionSP
MainThreadCheckerRuntime::GetBacktracesFromExtendedStopInfo(
StructuredData::ObjectSP info) {
ThreadCollectionSP threads;
threads = std::make_shared<ThreadCollection>();
ProcessSP process_sp = GetProcessSP();
if (info->GetObjectForDotSeparatedPath("instrumentation_class")
->GetStringValue() != "MainThreadChecker")
return threads;
std::vector<lldb::addr_t> PCs;
auto trace = info->GetObjectForDotSeparatedPath("trace")->GetAsArray();
trace->ForEach([&PCs](StructuredData::Object *PC) -> bool {
PCs.push_back(PC->GetAsInteger()->GetValue());
return true;
});
if (PCs.empty())
return threads;
StructuredData::ObjectSP thread_id_obj =
info->GetObjectForDotSeparatedPath("tid");
tid_t tid = thread_id_obj ? thread_id_obj->GetIntegerValue() : 0;
HistoryThread *history_thread = new HistoryThread(*process_sp, tid, PCs);
ThreadSP new_thread_sp(history_thread);
// Save this in the Process' ExtendedThreadList so a strong pointer retains
// the object
process_sp->GetExtendedThreadList().AddThread(new_thread_sp);
threads->AddThread(new_thread_sp);
return threads;
}
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