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//===-- InstrumentationRuntimeUBSan.cpp -----------------------------------===//
//
// 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 "InstrumentationRuntimeUBSan.h"
#include "Plugins/Process/Utility/HistoryThread.h"
#include "lldb/Breakpoint/StoppointCallbackContext.h"
#include "lldb/Core/Debugger.h"
#include "lldb/Core/Module.h"
#include "lldb/Core/PluginInterface.h"
#include "lldb/Core/PluginManager.h"
#include "lldb/Core/StreamFile.h"
#include "lldb/Core/ValueObject.h"
#include "lldb/Expression/UserExpression.h"
#include "lldb/Interpreter/CommandReturnObject.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/SectionLoadList.h"
#include "lldb/Target/StopInfo.h"
#include "lldb/Target/Target.h"
#include "lldb/Target/Thread.h"
#include "lldb/Utility/RegularExpression.h"
#include "lldb/Utility/Stream.h"
#include <ctype.h>
#include <memory>
using namespace lldb;
using namespace lldb_private;
LLDB_PLUGIN_DEFINE(InstrumentationRuntimeUBSan)
InstrumentationRuntimeUBSan::~InstrumentationRuntimeUBSan() { Deactivate(); }
lldb::InstrumentationRuntimeSP
InstrumentationRuntimeUBSan::CreateInstance(const lldb::ProcessSP &process_sp) {
return InstrumentationRuntimeSP(new InstrumentationRuntimeUBSan(process_sp));
}
void InstrumentationRuntimeUBSan::Initialize() {
PluginManager::RegisterPlugin(
GetPluginNameStatic(),
"UndefinedBehaviorSanitizer instrumentation runtime plugin.",
CreateInstance, GetTypeStatic);
}
void InstrumentationRuntimeUBSan::Terminate() {
PluginManager::UnregisterPlugin(CreateInstance);
}
lldb_private::ConstString InstrumentationRuntimeUBSan::GetPluginNameStatic() {
return ConstString("UndefinedBehaviorSanitizer");
}
lldb::InstrumentationRuntimeType InstrumentationRuntimeUBSan::GetTypeStatic() {
return eInstrumentationRuntimeTypeUndefinedBehaviorSanitizer;
}
static const char *ub_sanitizer_retrieve_report_data_prefix = R"(
extern "C" {
void
__ubsan_get_current_report_data(const char **OutIssueKind,
const char **OutMessage, const char **OutFilename, unsigned *OutLine,
unsigned *OutCol, char **OutMemoryAddr);
}
struct data {
const char *issue_kind;
const char *message;
const char *filename;
unsigned line;
unsigned col;
char *memory_addr;
};
)";
static const char *ub_sanitizer_retrieve_report_data_command = R"(
data t;
__ubsan_get_current_report_data(&t.issue_kind, &t.message, &t.filename, &t.line,
&t.col, &t.memory_addr);
t;
)";
static addr_t RetrieveUnsigned(ValueObjectSP return_value_sp,
ProcessSP process_sp,
const std::string &expression_path) {
return return_value_sp->GetValueForExpressionPath(expression_path.c_str())
->GetValueAsUnsigned(0);
}
static std::string RetrieveString(ValueObjectSP return_value_sp,
ProcessSP process_sp,
const std::string &expression_path) {
addr_t ptr = RetrieveUnsigned(return_value_sp, process_sp, expression_path);
std::string str;
Status error;
process_sp->ReadCStringFromMemory(ptr, str, error);
return str;
}
StructuredData::ObjectSP InstrumentationRuntimeUBSan::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();
StreamFileSP Stream = target.GetDebugger().GetOutputStreamSP();
EvaluateExpressionOptions options;
options.SetUnwindOnError(true);
options.SetTryAllThreads(true);
options.SetStopOthers(true);
options.SetIgnoreBreakpoints(true);
options.SetTimeout(process_sp->GetUtilityExpressionTimeout());
options.SetPrefix(ub_sanitizer_retrieve_report_data_prefix);
options.SetAutoApplyFixIts(false);
options.SetLanguage(eLanguageTypeObjC_plus_plus);
ValueObjectSP main_value;
ExecutionContext exe_ctx;
Status eval_error;
frame_sp->CalculateExecutionContext(exe_ctx);
ExpressionResults result = UserExpression::Evaluate(
exe_ctx, options, ub_sanitizer_retrieve_report_data_command, "",
main_value, eval_error);
if (result != eExpressionCompleted) {
target.GetDebugger().GetAsyncOutputStream()->Printf(
"Warning: Cannot evaluate UndefinedBehaviorSanitizer expression:\n%s\n",
eval_error.AsCString());
return StructuredData::ObjectSP();
}
// Gather the PCs of the user frames in the backtrace.
StructuredData::Array *trace = new StructuredData::Array();
auto trace_sp = StructuredData::ObjectSP(trace);
for (unsigned I = 0; I < thread_sp->GetStackFrameCount(); ++I) {
const Address FCA =
thread_sp->GetStackFrameAtIndex(I)->GetFrameCodeAddress();
if (FCA.GetModule() == runtime_module_sp) // Skip PCs from the runtime.
continue;
lldb::addr_t PC = FCA.GetLoadAddress(&target);
trace->AddItem(StructuredData::ObjectSP(new StructuredData::Integer(PC)));
}
std::string IssueKind = RetrieveString(main_value, process_sp, ".issue_kind");
std::string ErrMessage = RetrieveString(main_value, process_sp, ".message");
std::string Filename = RetrieveString(main_value, process_sp, ".filename");
unsigned Line = RetrieveUnsigned(main_value, process_sp, ".line");
unsigned Col = RetrieveUnsigned(main_value, process_sp, ".col");
uintptr_t MemoryAddr =
RetrieveUnsigned(main_value, process_sp, ".memory_addr");
auto *d = new StructuredData::Dictionary();
auto dict_sp = StructuredData::ObjectSP(d);
d->AddStringItem("instrumentation_class", "UndefinedBehaviorSanitizer");
d->AddStringItem("description", IssueKind);
d->AddStringItem("summary", ErrMessage);
d->AddStringItem("filename", Filename);
d->AddIntegerItem("line", Line);
d->AddIntegerItem("col", Col);
d->AddIntegerItem("memory_address", MemoryAddr);
d->AddIntegerItem("tid", thread_sp->GetID());
d->AddItem("trace", trace_sp);
return dict_sp;
}
static std::string GetStopReasonDescription(StructuredData::ObjectSP report) {
llvm::StringRef stop_reason_description_ref;
report->GetAsDictionary()->GetValueForKeyAsString(
"description", stop_reason_description_ref);
std::string stop_reason_description =
std::string(stop_reason_description_ref);
if (!stop_reason_description.size()) {
stop_reason_description = "Undefined behavior detected";
} else {
stop_reason_description[0] = toupper(stop_reason_description[0]);
for (unsigned I = 1; I < stop_reason_description.size(); ++I)
if (stop_reason_description[I] == '-')
stop_reason_description[I] = ' ';
}
return stop_reason_description;
}
bool InstrumentationRuntimeUBSan::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.
InstrumentationRuntimeUBSan *const instance =
static_cast<InstrumentationRuntimeUBSan *>(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) {
thread_sp->SetStopInfo(
InstrumentationRuntimeStopInfo::CreateStopReasonWithInstrumentationData(
*thread_sp, GetStopReasonDescription(report), report));
return true;
}
return false;
}
const RegularExpression &
InstrumentationRuntimeUBSan::GetPatternForRuntimeLibrary() {
static RegularExpression regex(llvm::StringRef("libclang_rt\\.(a|t|ub)san_"));
return regex;
}
bool InstrumentationRuntimeUBSan::CheckIfRuntimeIsValid(
const lldb::ModuleSP module_sp) {
static ConstString ubsan_test_sym("__ubsan_on_report");
const Symbol *symbol = module_sp->FindFirstSymbolWithNameAndType(
ubsan_test_sym, lldb::eSymbolTypeAny);
return symbol != nullptr;
}
// FIXME: Factor out all the logic we have in common with the {a,t}san plugins.
void InstrumentationRuntimeUBSan::Activate() {
if (IsActive())
return;
ProcessSP process_sp = GetProcessSP();
if (!process_sp)
return;
ModuleSP runtime_module_sp = GetRuntimeModuleSP();
ConstString symbol_name("__ubsan_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(InstrumentationRuntimeUBSan::NotifyBreakpointHit,
this, true);
breakpoint->SetBreakpointKind("undefined-behavior-sanitizer-report");
SetBreakpointID(breakpoint->GetID());
SetActive(true);
}
void InstrumentationRuntimeUBSan::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
InstrumentationRuntimeUBSan::GetBacktracesFromExtendedStopInfo(
StructuredData::ObjectSP info) {
ThreadCollectionSP threads;
threads = std::make_shared<ThreadCollection>();
ProcessSP process_sp = GetProcessSP();
if (info->GetObjectForDotSeparatedPath("instrumentation_class")
->GetStringValue() != "UndefinedBehaviorSanitizer")
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);
std::string stop_reason_description = GetStopReasonDescription(info);
new_thread_sp->SetName(stop_reason_description.c_str());
// 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;
}