contrib/compiler-rt/lib/sanitizer_common/sanitizer_symbolizer_report.cc

   1 //===-- sanitizer_symbolizer_report.cc ------------------------------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 ///
  10 /// This file is shared between AddressSanitizer and other sanitizer run-time
  11 /// libraries and implements symbolized reports related functions.
  12 ///
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "sanitizer_common.h"
  16 #include "sanitizer_file.h"
  17 #include "sanitizer_flags.h"
  18 #include "sanitizer_procmaps.h"
  19 #include "sanitizer_report_decorator.h"
  20 #include "sanitizer_stacktrace.h"
  21 #include "sanitizer_stacktrace_printer.h"
  22 #include "sanitizer_symbolizer.h"
  23
  24 #if SANITIZER_POSIX
  25 # include "sanitizer_posix.h"
  26 # include <sys/mman.h>
  27 #endif
  28
  29 namespace __sanitizer {
  30
  31 #if !SANITIZER_GO
  32 void ReportErrorSummary(const char *error_type, const AddressInfo &info,
  33                         const char *alt_tool_name) {
  34   if (!common_flags()->print_summary) return;
  35   InternalScopedString buff(kMaxSummaryLength);
  36   buff.append("%s ", error_type);
  37   RenderFrame(&buff, "%L %F", 0, info, common_flags()->symbolize_vs_style,
  38               common_flags()->strip_path_prefix);
  39   ReportErrorSummary(buff.data(), alt_tool_name);
  40 }
  41 #endif
  42
  43 #if !SANITIZER_FUCHSIA
  44
  45 bool ReportFile::SupportsColors() {
  46   SpinMutexLock l(mu);
  47   ReopenIfNecessary();
  48   return SupportsColoredOutput(fd);
  49 }
  50
  51 static INLINE bool ReportSupportsColors() {
  52   return report_file.SupportsColors();
  53 }
  54
  55 #else  // SANITIZER_FUCHSIA
  56
  57 // Fuchsia's logs always go through post-processing that handles colorization.
  58 static INLINE bool ReportSupportsColors() { return true; }
  59
  60 #endif  // !SANITIZER_FUCHSIA
  61
  62 bool ColorizeReports() {
  63   // FIXME: Add proper Windows support to AnsiColorDecorator and re-enable color
  64   // printing on Windows.
  65   if (SANITIZER_WINDOWS)
  66     return false;
  67
  68   const char *flag = common_flags()->color;
  69   return internal_strcmp(flag, "always") == 0 ||
  70          (internal_strcmp(flag, "auto") == 0 && ReportSupportsColors());
  71 }
  72
  73 void ReportErrorSummary(const char *error_type, const StackTrace *stack,
  74                         const char *alt_tool_name) {
  75 #if !SANITIZER_GO
  76   if (!common_flags()->print_summary)
  77     return;
  78   if (stack->size == 0) {
  79     ReportErrorSummary(error_type);
  80     return;
  81   }
  82   // Currently, we include the first stack frame into the report summary.
  83   // Maybe sometimes we need to choose another frame (e.g. skip memcpy/etc).
  84   uptr pc = StackTrace::GetPreviousInstructionPc(stack->trace[0]);
  85   SymbolizedStack *frame = Symbolizer::GetOrInit()->SymbolizePC(pc);
  86   ReportErrorSummary(error_type, frame->info, alt_tool_name);
  87   frame->ClearAll();
  88 #endif
  89 }
  90
  91 void ReportMmapWriteExec(int prot) {
  92 #if SANITIZER_POSIX && (!SANITIZER_GO && !SANITIZER_ANDROID)
  93   if ((prot & (PROT_WRITE | PROT_EXEC)) != (PROT_WRITE | PROT_EXEC))
  94     return;
  95
  96   ScopedErrorReportLock l;
  97   SanitizerCommonDecorator d;
  98
  99   InternalMmapVector<BufferedStackTrace> stack_buffer(1);
 100   BufferedStackTrace *stack = stack_buffer.data();
 101   stack->Reset();
 102   uptr top = 0;
 103   uptr bottom = 0;
 104   GET_CALLER_PC_BP_SP;
 105   (void)sp;
 106   bool fast = common_flags()->fast_unwind_on_fatal;
 107   if (fast)
 108     GetThreadStackTopAndBottom(false, &top, &bottom);
 109   stack->Unwind(kStackTraceMax, pc, bp, nullptr, top, bottom, fast);
 110
 111   Printf("%s", d.Warning());
 112   Report("WARNING: %s: writable-executable page usage\n", SanitizerToolName);
 113   Printf("%s", d.Default());
 114
 115   stack->Print();
 116   ReportErrorSummary("w-and-x-usage", stack);
 117 #endif
 118 }
 119
 120 #if !SANITIZER_FUCHSIA && !SANITIZER_RTEMS && !SANITIZER_GO
 121 void StartReportDeadlySignal() {
 122   // Write the first message using fd=2, just in case.
 123   // It may actually fail to write in case stderr is closed.
 124   CatastrophicErrorWrite(SanitizerToolName, internal_strlen(SanitizerToolName));
 125   static const char kDeadlySignal[] = ":DEADLYSIGNAL\n";
 126   CatastrophicErrorWrite(kDeadlySignal, sizeof(kDeadlySignal) - 1);
 127 }
 128
 129 static void MaybeReportNonExecRegion(uptr pc) {
 130 #if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD
 131   MemoryMappingLayout proc_maps(/*cache_enabled*/ true);
 132   MemoryMappedSegment segment;
 133   while (proc_maps.Next(&segment)) {
 134     if (pc >= segment.start && pc < segment.end && !segment.IsExecutable())
 135       Report("Hint: PC is at a non-executable region. Maybe a wild jump?\n");
 136   }
 137 #endif
 138 }
 139
 140 static void PrintMemoryByte(InternalScopedString *str, const char *before,
 141                             u8 byte) {
 142   SanitizerCommonDecorator d;
 143   str->append("%s%s%x%x%s ", before, d.MemoryByte(), byte >> 4, byte & 15,
 144               d.Default());
 145 }
 146
 147 static void MaybeDumpInstructionBytes(uptr pc) {
 148   if (!common_flags()->dump_instruction_bytes || (pc < GetPageSizeCached()))
 149     return;
 150   InternalScopedString str(1024);
 151   str.append("First 16 instruction bytes at pc: ");
 152   if (IsAccessibleMemoryRange(pc, 16)) {
 153     for (int i = 0; i < 16; ++i) {
 154       PrintMemoryByte(&str, "", ((u8 *)pc)[i]);
 155     }
 156     str.append("\n");
 157   } else {
 158     str.append("unaccessible\n");
 159   }
 160   Report("%s", str.data());
 161 }
 162
 163 static void MaybeDumpRegisters(void *context) {
 164   if (!common_flags()->dump_registers) return;
 165   SignalContext::DumpAllRegisters(context);
 166 }
 167
 168 static void ReportStackOverflowImpl(const SignalContext &sig, u32 tid,
 169                                     UnwindSignalStackCallbackType unwind,
 170                                     const void *unwind_context) {
 171   SanitizerCommonDecorator d;
 172   Printf("%s", d.Warning());
 173   static const char kDescription[] = "stack-overflow";
 174   Report("ERROR: %s: %s on address %p (pc %p bp %p sp %p T%d)\n",
 175          SanitizerToolName, kDescription, (void *)sig.addr, (void *)sig.pc,
 176          (void *)sig.bp, (void *)sig.sp, tid);
 177   Printf("%s", d.Default());
 178   InternalMmapVector<BufferedStackTrace> stack_buffer(1);
 179   BufferedStackTrace *stack = stack_buffer.data();
 180   stack->Reset();
 181   unwind(sig, unwind_context, stack);
 182   stack->Print();
 183   ReportErrorSummary(kDescription, stack);
 184 }
 185
 186 static void ReportDeadlySignalImpl(const SignalContext &sig, u32 tid,
 187                                    UnwindSignalStackCallbackType unwind,
 188                                    const void *unwind_context) {
 189   SanitizerCommonDecorator d;
 190   Printf("%s", d.Warning());
 191   const char *description = sig.Describe();
 192   Report("ERROR: %s: %s on unknown address %p (pc %p bp %p sp %p T%d)\n",
 193          SanitizerToolName, description, (void *)sig.addr, (void *)sig.pc,
 194          (void *)sig.bp, (void *)sig.sp, tid);
 195   Printf("%s", d.Default());
 196   if (sig.pc < GetPageSizeCached())
 197     Report("Hint: pc points to the zero page.\n");
 198   if (sig.is_memory_access) {
 199     const char *access_type =
 200         sig.write_flag == SignalContext::WRITE
 201             ? "WRITE"
 202             : (sig.write_flag == SignalContext::READ ? "READ" : "UNKNOWN");
 203     Report("The signal is caused by a %s memory access.\n", access_type);
 204     if (sig.addr < GetPageSizeCached())
 205       Report("Hint: address points to the zero page.\n");
 206   }
 207   MaybeReportNonExecRegion(sig.pc);
 208   InternalMmapVector<BufferedStackTrace> stack_buffer(1);
 209   BufferedStackTrace *stack = stack_buffer.data();
 210   stack->Reset();
 211   unwind(sig, unwind_context, stack);
 212   stack->Print();
 213   MaybeDumpInstructionBytes(sig.pc);
 214   MaybeDumpRegisters(sig.context);
 215   Printf("%s can not provide additional info.\n", SanitizerToolName);
 216   ReportErrorSummary(description, stack);
 217 }
 218
 219 void ReportDeadlySignal(const SignalContext &sig, u32 tid,
 220                         UnwindSignalStackCallbackType unwind,
 221                         const void *unwind_context) {
 222   if (sig.IsStackOverflow())
 223     ReportStackOverflowImpl(sig, tid, unwind, unwind_context);
 224   else
 225     ReportDeadlySignalImpl(sig, tid, unwind, unwind_context);
 226 }
 227
 228 void HandleDeadlySignal(void *siginfo, void *context, u32 tid,
 229                         UnwindSignalStackCallbackType unwind,
 230                         const void *unwind_context) {
 231   StartReportDeadlySignal();
 232   ScopedErrorReportLock rl;
 233   SignalContext sig(siginfo, context);
 234   ReportDeadlySignal(sig, tid, unwind, unwind_context);
 235   Report("ABORTING\n");
 236   Die();
 237 }
 238
 239 #endif  // !SANITIZER_FUCHSIA && !SANITIZER_GO
 240
 241 static atomic_uintptr_t reporting_thread = {0};
 242 static StaticSpinMutex CommonSanitizerReportMutex;
 243
 244 ScopedErrorReportLock::ScopedErrorReportLock() {
 245   uptr current = GetThreadSelf();
 246   for (;;) {
 247     uptr expected = 0;
 248     if (atomic_compare_exchange_strong(&reporting_thread, &expected, current,
 249                                        memory_order_relaxed)) {
 250       // We've claimed reporting_thread so proceed.
 251       CommonSanitizerReportMutex.Lock();
 252       return;
 253     }
 254
 255     if (expected == current) {
 256       // This is either asynch signal or nested error during error reporting.
 257       // Fail simple to avoid deadlocks in Report().
 258
 259       // Can't use Report() here because of potential deadlocks in nested
 260       // signal handlers.
 261       CatastrophicErrorWrite(SanitizerToolName,
 262                              internal_strlen(SanitizerToolName));
 263       static const char msg[] = ": nested bug in the same thread, aborting.\n";
 264       CatastrophicErrorWrite(msg, sizeof(msg) - 1);
 265
 266       internal__exit(common_flags()->exitcode);
 267     }
 268
 269     internal_sched_yield();
 270   }
 271 }
 272
 273 ScopedErrorReportLock::~ScopedErrorReportLock() {
 274   CommonSanitizerReportMutex.Unlock();
 275   atomic_store_relaxed(&reporting_thread, 0);
 276 }
 277
 278 void ScopedErrorReportLock::CheckLocked() {
 279   CommonSanitizerReportMutex.CheckLocked();
 280 }
 281
 282 }  // namespace __sanitizer