ReportRetriever.cpp

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//===-- ReportRetriever.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 "ReportRetriever.h"
#include "Utility.h"
 
#include "lldb/Breakpoint/StoppointCallbackContext.h"
#include "lldb/Core/Debugger.h"
#include "lldb/Core/Module.h"
#include "lldb/Expression/UserExpression.h"
#include "lldb/Target/InstrumentationRuntimeStopInfo.h"
#include "lldb/ValueObject/ValueObject.h"
 
using namespace lldb;
using namespace lldb_private;
 
const char *address_sanitizer_retrieve_report_data_prefix = R"(
extern "C"
{
int __asan_report_present();
void *__asan_get_report_pc();
void *__asan_get_report_bp();
void *__asan_get_report_sp();
void *__asan_get_report_address();
const char *__asan_get_report_description();
int __asan_get_report_access_type();
size_t __asan_get_report_access_size();
}
)";
 
const char *address_sanitizer_retrieve_report_data_command = R"(
struct {
    int present;
    int access_type;
    void *pc;
    void *bp;
    void *sp;
    void *address;
    size_t access_size;
    const char *description;
} t;
 
t.present = __asan_report_present();
t.access_type = __asan_get_report_access_type();
t.pc = __asan_get_report_pc();
t.bp = __asan_get_report_bp();
t.sp = __asan_get_report_sp();
t.address = __asan_get_report_address();
t.access_size = __asan_get_report_access_size();
t.description = __asan_get_report_description();
t
)";
 
StructuredData::ObjectSP
ReportRetriever::RetrieveReportData(const ProcessSP process_sp) {
  if (!process_sp)
    return StructuredData::ObjectSP();
 
  ThreadSP thread_sp =
      process_sp->GetThreadList().GetExpressionExecutionThread();
 
  if (!thread_sp)
    return StructuredData::ObjectSP();
 
  StackFrameSP frame_sp =
      thread_sp->GetSelectedFrame(DoNoSelectMostRelevantFrame);
 
  if (!frame_sp)
    return StructuredData::ObjectSP();
 
  EvaluateExpressionOptions options;
  options.SetUnwindOnError(true);
  options.SetTryAllThreads(true);
  options.SetStopOthers(true);
  options.SetIgnoreBreakpoints(true);
  options.SetTimeout(process_sp->GetUtilityExpressionTimeout());
  options.SetPrefix(address_sanitizer_retrieve_report_data_prefix);
  options.SetAutoApplyFixIts(false);
  options.SetLanguage(eLanguageTypeObjC_plus_plus);
 
  if (auto [m, _] = GetPreferredAsanModule(process_sp->GetTarget()); m) {
    SymbolContextList sc_list;
    sc_list.Append(SymbolContext(std::move(m)));
    options.SetPreferredSymbolContexts(std::move(sc_list));
  }
 
  ValueObjectSP return_value_sp;
  ExecutionContext exe_ctx;
  frame_sp->CalculateExecutionContext(exe_ctx);
  ExpressionResults result = UserExpression::Evaluate(
      exe_ctx, options, address_sanitizer_retrieve_report_data_command, "",
      return_value_sp);
  if (result != eExpressionCompleted) {
    StreamString ss;
    ss << "cannot evaluate AddressSanitizer expression:\n";
    if (return_value_sp)
      ss << return_value_sp->GetError().AsCString();
    Debugger::ReportWarning(ss.GetString().str(),
                            process_sp->GetTarget().GetDebugger().GetID());
    return StructuredData::ObjectSP();
  }
 
  int present = return_value_sp->GetValueForExpressionPath(".present")
                    ->GetValueAsUnsigned(0);
  if (present != 1)
    return StructuredData::ObjectSP();
 
  addr_t pc =
      return_value_sp->GetValueForExpressionPath(".pc")->GetValueAsUnsigned(0);
  addr_t bp =
      return_value_sp->GetValueForExpressionPath(".bp")->GetValueAsUnsigned(0);
  addr_t sp =
      return_value_sp->GetValueForExpressionPath(".sp")->GetValueAsUnsigned(0);
  addr_t address = return_value_sp->GetValueForExpressionPath(".address")
                       ->GetValueAsUnsigned(0);
  addr_t access_type =
      return_value_sp->GetValueForExpressionPath(".access_type")
          ->GetValueAsUnsigned(0);
  addr_t access_size =
      return_value_sp->GetValueForExpressionPath(".access_size")
          ->GetValueAsUnsigned(0);
  addr_t description_ptr =
      return_value_sp->GetValueForExpressionPath(".description")
          ->GetValueAsUnsigned(0);
  std::string description;
  Status error;
  process_sp->ReadCStringFromMemory(description_ptr, description, error);
 
  auto dict = std::make_shared<StructuredData::Dictionary>();
  if (!dict)
    return StructuredData::ObjectSP();
 
  dict->AddStringItem("instrumentation_class", "AddressSanitizer");
  dict->AddStringItem("stop_type", "fatal_error");
  dict->AddIntegerItem("pc", pc);
  dict->AddIntegerItem("bp", bp);
  dict->AddIntegerItem("sp", sp);
  dict->AddIntegerItem("address", address);
  dict->AddIntegerItem("access_type", access_type);
  dict->AddIntegerItem("access_size", access_size);
  dict->AddStringItem("description", description);
 
  return StructuredData::ObjectSP(dict);
}
 
std::string
ReportRetriever::FormatDescription(StructuredData::ObjectSP report) {
  std::string description = std::string(report->GetAsDictionary()
                                            ->GetValueForKey("description")
                                            ->GetAsString()
                                            ->GetValue());
  return llvm::StringSwitch<std::string>(description)
      .Case("heap-use-after-free", "Use of deallocated memory")
      .Case("heap-buffer-overflow", "Heap buffer overflow")
      .Case("stack-buffer-underflow", "Stack buffer underflow")
      .Case("initialization-order-fiasco", "Initialization order problem")
      .Case("stack-buffer-overflow", "Stack buffer overflow")
      .Case("stack-use-after-return", "Use of stack memory after return")
      .Case("use-after-poison", "Use of poisoned memory")
      .Case("container-overflow", "Container overflow")
      .Case("stack-use-after-scope", "Use of out-of-scope stack memory")
      .Case("global-buffer-overflow", "Global buffer overflow")
      .Case("unknown-crash", "Invalid memory access")
      .Case("stack-overflow", "Stack space exhausted")
      .Case("null-deref", "Dereference of null pointer")
      .Case("wild-jump", "Jump to non-executable address")
      .Case("wild-addr-write", "Write through wild pointer")
      .Case("wild-addr-read", "Read from wild pointer")
      .Case("wild-addr", "Access through wild pointer")
      .Case("signal", "Deadly signal")
      .Case("double-free", "Deallocation of freed memory")
      .Case("new-delete-type-mismatch",
            "Deallocation size different from allocation size")
      .Case("bad-free", "Deallocation of non-allocated memory")
      .Case("alloc-dealloc-mismatch",
            "Mismatch between allocation and deallocation APIs")
      .Case("bad-malloc_usable_size", "Invalid argument to malloc_usable_size")
      .Case("bad-__sanitizer_get_allocated_size",
            "Invalid argument to __sanitizer_get_allocated_size")
      .Case("param-overlap",
            "Call to function disallowing overlapping memory ranges")
      .Case("negative-size-param", "Negative size used when accessing memory")
      .Case("bad-__sanitizer_annotate_contiguous_container",
            "Invalid argument to __sanitizer_annotate_contiguous_container")
      .Case("odr-violation", "Symbol defined in multiple translation units")
      .Case(
          "invalid-pointer-pair",
          "Comparison or arithmetic on pointers from different memory regions")
      // for unknown report codes just show the code
      .Default("AddressSanitizer detected: " + description);
}
 
bool ReportRetriever::NotifyBreakpointHit(ProcessSP process_sp,
                                          StoppointCallbackContext *context,
                                          user_id_t break_id,
                                          user_id_t break_loc_id) {
  // Make sure this is the right process
  if (!process_sp || process_sp != context->exe_ctx_ref.GetProcessSP())
    return false;
 
  if (process_sp->GetModIDRef().IsLastResumeForUserExpression())
    return false;
 
  StructuredData::ObjectSP report = RetrieveReportData(process_sp);
  if (!report || report->GetType() != lldb::eStructuredDataTypeDictionary)
    return false;
 
  std::string description = FormatDescription(report);
 
  if (ThreadSP thread_sp = context->exe_ctx_ref.GetThreadSP())
    thread_sp->SetStopInfo(
        InstrumentationRuntimeStopInfo::CreateStopReasonWithInstrumentationData(
            *thread_sp, description, report));
 
  if (StreamSP stream_sp =
          process_sp->GetTarget().GetDebugger().GetAsyncOutputStream())
    stream_sp->Printf("AddressSanitizer report breakpoint hit. Use 'thread "
                      "info -s' to get extended information about the "
                      "report.\n");
 
  return true; // Return true to stop the target
}
 
Breakpoint *ReportRetriever::SetupBreakpoint(ModuleSP module_sp,
                                             ProcessSP process_sp,
                                             ConstString symbol_name) {
  if (!module_sp || !process_sp)
    return nullptr;
 
  const Symbol *symbol =
      module_sp->FindFirstSymbolWithNameAndType(symbol_name, eSymbolTypeCode);
 
  if (symbol == nullptr)
    return nullptr;
 
  if (!symbol->ValueIsAddress() || !symbol->GetAddressRef().IsValid())
    return nullptr;
 
  const Address &address = symbol->GetAddressRef();
  const bool internal = true;
  const bool hardware = false;
 
  Breakpoint *breakpoint = process_sp->GetTarget()
                               .CreateBreakpoint(address, internal, hardware)
                               .get();
 
  return breakpoint;
}