libsanitizer/sanitizer_common/sanitizer_symbolizer_markup.cc

   1 //===-- sanitizer_symbolizer_markup.cc ------------------------------------===//
   2 //
   3 // This file is distributed under the University of Illinois Open Source
   4 // License. See LICENSE.TXT for details.
   5 //
   6 //===----------------------------------------------------------------------===//
   7 //
   8 // This file is shared between various sanitizers' runtime libraries.
   9 //
  10 // Implementation of offline markup symbolizer.
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "sanitizer_platform.h"
  14 #if SANITIZER_SYMBOLIZER_MARKUP
  15
  16 #if SANITIZER_FUCHSIA
  17 #include "sanitizer_symbolizer_fuchsia.h"
  18 #elif SANITIZER_RTEMS
  19 #include "sanitizer_symbolizer_rtems.h"
  20 #endif
  21 #include "sanitizer_stacktrace.h"
  22 #include "sanitizer_symbolizer.h"
  23
  24 #include <limits.h>
  25 #include <unwind.h>
  26
  27 namespace __sanitizer {
  28
  29 // This generic support for offline symbolizing is based on the
  30 // Fuchsia port.  We don't do any actual symbolization per se.
  31 // Instead, we emit text containing raw addresses and raw linkage
  32 // symbol names, embedded in Fuchsia's symbolization markup format.
  33 // Fuchsia's logging infrastructure emits enough information about
  34 // process memory layout that a post-processing filter can do the
  35 // symbolization and pretty-print the markup.  See the spec at:
  36 // https://fuchsia.googlesource.com/zircon/+/master/docs/symbolizer_markup.md
  37
  38 // This is used by UBSan for type names, and by ASan for global variable names.
  39 // It's expected to return a static buffer that will be reused on each call.
  40 const char *Symbolizer::Demangle(const char *name) {
  41   static char buffer[kFormatDemangleMax];
  42   internal_snprintf(buffer, sizeof(buffer), kFormatDemangle, name);
  43   return buffer;
  44 }
  45
  46 // This is used mostly for suppression matching.  Making it work
  47 // would enable "interceptor_via_lib" suppressions.  It's also used
  48 // once in UBSan to say "in module ..." in a message that also
  49 // includes an address in the module, so post-processing can already
  50 // pretty-print that so as to indicate the module.
  51 bool Symbolizer::GetModuleNameAndOffsetForPC(uptr pc, const char **module_name,
  52                                              uptr *module_address) {
  53   return false;
  54 }
  55
  56 // This is used in some places for suppression checking, which we
  57 // don't really support for Fuchsia.  It's also used in UBSan to
  58 // identify a PC location to a function name, so we always fill in
  59 // the function member with a string containing markup around the PC
  60 // value.
  61 // TODO(mcgrathr): Under SANITIZER_GO, it's currently used by TSan
  62 // to render stack frames, but that should be changed to use
  63 // RenderStackFrame.
  64 SymbolizedStack *Symbolizer::SymbolizePC(uptr addr) {
  65   SymbolizedStack *s = SymbolizedStack::New(addr);
  66   char buffer[kFormatFunctionMax];
  67   internal_snprintf(buffer, sizeof(buffer), kFormatFunction, addr);
  68   s->info.function = internal_strdup(buffer);
  69   return s;
  70 }
  71
  72 // Always claim we succeeded, so that RenderDataInfo will be called.
  73 bool Symbolizer::SymbolizeData(uptr addr, DataInfo *info) {
  74   info->Clear();
  75   info->start = addr;
  76   return true;
  77 }
  78
  79 // We ignore the format argument to __sanitizer_symbolize_global.
  80 void RenderData(InternalScopedString *buffer, const char *format,
  81                 const DataInfo *DI, const char *strip_path_prefix) {
  82   buffer->append(kFormatData, DI->start);
  83 }
  84
  85 // We don't support the stack_trace_format flag at all.
  86 void RenderFrame(InternalScopedString *buffer, const char *format, int frame_no,
  87                  const AddressInfo &info, bool vs_style,
  88                  const char *strip_path_prefix, const char *strip_func_prefix) {
  89   buffer->append(kFormatFrame, frame_no, info.address);
  90 }
  91
  92 Symbolizer *Symbolizer::PlatformInit() {
  93   return new (symbolizer_allocator_) Symbolizer({});
  94 }
  95
  96 void Symbolizer::LateInitialize() { Symbolizer::GetOrInit(); }
  97
  98 void StartReportDeadlySignal() {}
  99 void ReportDeadlySignal(const SignalContext &sig, u32 tid,
 100                         UnwindSignalStackCallbackType unwind,
 101                         const void *unwind_context) {}
 102
 103 #if SANITIZER_CAN_SLOW_UNWIND
 104 struct UnwindTraceArg {
 105   BufferedStackTrace *stack;
 106   u32 max_depth;
 107 };
 108
 109 _Unwind_Reason_Code Unwind_Trace(struct _Unwind_Context *ctx, void *param) {
 110   UnwindTraceArg *arg = static_cast<UnwindTraceArg *>(param);
 111   CHECK_LT(arg->stack->size, arg->max_depth);
 112   uptr pc = _Unwind_GetIP(ctx);
 113   if (pc < PAGE_SIZE) return _URC_NORMAL_STOP;
 114   arg->stack->trace_buffer[arg->stack->size++] = pc;
 115   return (arg->stack->size == arg->max_depth ? _URC_NORMAL_STOP
 116                                              : _URC_NO_REASON);
 117 }
 118
 119 void BufferedStackTrace::SlowUnwindStack(uptr pc, u32 max_depth) {
 120   CHECK_GE(max_depth, 2);
 121   size = 0;
 122   UnwindTraceArg arg = {this, Min(max_depth + 1, kStackTraceMax)};
 123   _Unwind_Backtrace(Unwind_Trace, &arg);
 124   CHECK_GT(size, 0);
 125   // We need to pop a few frames so that pc is on top.
 126   uptr to_pop = LocatePcInTrace(pc);
 127   // trace_buffer[0] belongs to the current function so we always pop it,
 128   // unless there is only 1 frame in the stack trace (1 frame is always better
 129   // than 0!).
 130   PopStackFrames(Min(to_pop, static_cast<uptr>(1)));
 131   trace_buffer[0] = pc;
 132 }
 133
 134 void BufferedStackTrace::SlowUnwindStackWithContext(uptr pc, void *context,
 135                                                     u32 max_depth) {
 136   CHECK_NE(context, nullptr);
 137   UNREACHABLE("signal context doesn't exist");
 138 }
 139 #endif  // SANITIZER_CAN_SLOW_UNWIND
 140
 141 }  // namespace __sanitizer
 142
 143 #endif  // SANITIZER_SYMBOLIZER_MARKUP