libsanitizer/sanitizer_common/sanitizer_symbolizer_fuchsia.cc

   1 //===-- sanitizer_symbolizer_fuchsia.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 Fuchsia-specific symbolizer.
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "sanitizer_platform.h"
  14 #if SANITIZER_FUCHSIA
  15
  16 #include "sanitizer_fuchsia.h"
  17 #include "sanitizer_symbolizer.h"
  18
  19 namespace __sanitizer {
  20
  21 // For Fuchsia we don't do any actual symbolization per se.
  22 // Instead, we emit text containing raw addresses and raw linkage
  23 // symbol names, embedded in Fuchsia's symbolization markup format.
  24 // Fuchsia's logging infrastructure emits enough information about
  25 // process memory layout that a post-processing filter can do the
  26 // symbolization and pretty-print the markup.  See the spec at:
  27 // https://fuchsia.googlesource.com/zircon/+/master/docs/symbolizer_markup.md
  28
  29 // This is used by UBSan for type names, and by ASan for global variable names.
  30 constexpr const char *kFormatDemangle = "{{{symbol:%s}}}";
  31 constexpr uptr kFormatDemangleMax = 1024;  // Arbitrary.
  32
  33 // Function name or equivalent from PC location.
  34 constexpr const char *kFormatFunction = "{{{pc:%p}}}";
  35 constexpr uptr kFormatFunctionMax = 64;  // More than big enough for 64-bit hex.
  36
  37 // Global variable name or equivalent from data memory address.
  38 constexpr const char *kFormatData = "{{{data:%p}}}";
  39
  40 // One frame in a backtrace (printed on a line by itself).
  41 constexpr const char *kFormatFrame = "{{{bt:%u:%p}}}";
  42
  43 // This is used by UBSan for type names, and by ASan for global variable names.
  44 // It's expected to return a static buffer that will be reused on each call.
  45 const char *Symbolizer::Demangle(const char *name) {
  46   static char buffer[kFormatDemangleMax];
  47   internal_snprintf(buffer, sizeof(buffer), kFormatDemangle, name);
  48   return buffer;
  49 }
  50
  51 // This is used mostly for suppression matching.  Making it work
  52 // would enable "interceptor_via_lib" suppressions.  It's also used
  53 // once in UBSan to say "in module ..." in a message that also
  54 // includes an address in the module, so post-processing can already
  55 // pretty-print that so as to indicate the module.
  56 bool Symbolizer::GetModuleNameAndOffsetForPC(uptr pc, const char **module_name,
  57                                              uptr *module_address) {
  58   return false;
  59 }
  60
  61 // This is used in some places for suppression checking, which we
  62 // don't really support for Fuchsia.  It's also used in UBSan to
  63 // identify a PC location to a function name, so we always fill in
  64 // the function member with a string containing markup around the PC
  65 // value.
  66 // TODO(mcgrathr): Under SANITIZER_GO, it's currently used by TSan
  67 // to render stack frames, but that should be changed to use
  68 // RenderStackFrame.
  69 SymbolizedStack *Symbolizer::SymbolizePC(uptr addr) {
  70   SymbolizedStack *s = SymbolizedStack::New(addr);
  71   char buffer[kFormatFunctionMax];
  72   internal_snprintf(buffer, sizeof(buffer), kFormatFunction, addr);
  73   s->info.function = internal_strdup(buffer);
  74   return s;
  75 }
  76
  77 // Always claim we succeeded, so that RenderDataInfo will be called.
  78 bool Symbolizer::SymbolizeData(uptr addr, DataInfo *info) {
  79   info->Clear();
  80   info->start = addr;
  81   return true;
  82 }
  83
  84 // We ignore the format argument to __sanitizer_symbolize_global.
  85 void RenderData(InternalScopedString *buffer, const char *format,
  86                 const DataInfo *DI, const char *strip_path_prefix) {
  87   buffer->append(kFormatData, DI->start);
  88 }
  89
  90 // We don't support the stack_trace_format flag at all.
  91 void RenderFrame(InternalScopedString *buffer, const char *format, int frame_no,
  92                  const AddressInfo &info, bool vs_style,
  93                  const char *strip_path_prefix, const char *strip_func_prefix) {
  94   buffer->append(kFormatFrame, frame_no, info.address);
  95 }
  96
  97 Symbolizer *Symbolizer::PlatformInit() {
  98   return new (symbolizer_allocator_) Symbolizer({});
  99 }
 100
 101 void Symbolizer::LateInitialize() { Symbolizer::GetOrInit(); }
 102
 103 }  // namespace __sanitizer
 104
 105 #endif  // SANITIZER_FUCHSIA