libsanitizer/sanitizer_common/sanitizer_symbolizer_fuchsia.cc

//===-- sanitizer_symbolizer_fuchsia.cc -----------------------------------===//
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file is shared between various sanitizers' runtime libraries.
//
// Implementation of Fuchsia-specific symbolizer.
//===----------------------------------------------------------------------===//

#include "sanitizer_platform.h"
#if SANITIZER_FUCHSIA

#include "sanitizer_fuchsia.h"
#include "sanitizer_symbolizer.h"

namespace __sanitizer {

// For Fuchsia we don't do any actual symbolization per se.
// Instead, we emit text containing raw addresses and raw linkage
// symbol names, embedded in Fuchsia's symbolization markup format.
// Fuchsia's logging infrastructure emits enough information about
// process memory layout that a post-processing filter can do the
// symbolization and pretty-print the markup.  See the spec at:
// https://fuchsia.googlesource.com/zircon/+/master/docs/symbolizer_markup.md

// This is used by UBSan for type names, and by ASan for global variable names.
constexpr const char *kFormatDemangle = "{{{symbol:%s}}}";
constexpr uptr kFormatDemangleMax = 1024;  // Arbitrary.

// Function name or equivalent from PC location.
constexpr const char *kFormatFunction = "{{{pc:%p}}}";
constexpr uptr kFormatFunctionMax = 64;  // More than big enough for 64-bit hex.

// Global variable name or equivalent from data memory address.
constexpr const char *kFormatData = "{{{data:%p}}}";

// One frame in a backtrace (printed on a line by itself).
constexpr const char *kFormatFrame = "{{{bt:%u:%p}}}";

// This is used by UBSan for type names, and by ASan for global variable names.
// It's expected to return a static buffer that will be reused on each call.
const char *Symbolizer::Demangle(const char *name) {
  static char buffer[kFormatDemangleMax];
  internal_snprintf(buffer, sizeof(buffer), kFormatDemangle, name);
  return buffer;
}

// This is used mostly for suppression matching.  Making it work
// would enable "interceptor_via_lib" suppressions.  It's also used
// once in UBSan to say "in module ..." in a message that also
// includes an address in the module, so post-processing can already
// pretty-print that so as to indicate the module.
bool Symbolizer::GetModuleNameAndOffsetForPC(uptr pc, const char **module_name,
                                             uptr *module_address) {
  return false;
}

// This is used in some places for suppression checking, which we
// don't really support for Fuchsia.  It's also used in UBSan to
// identify a PC location to a function name, so we always fill in
// the function member with a string containing markup around the PC
// value.
// TODO(mcgrathr): Under SANITIZER_GO, it's currently used by TSan
// to render stack frames, but that should be changed to use
// RenderStackFrame.
SymbolizedStack *Symbolizer::SymbolizePC(uptr addr) {
  SymbolizedStack *s = SymbolizedStack::New(addr);
  char buffer[kFormatFunctionMax];
  internal_snprintf(buffer, sizeof(buffer), kFormatFunction, addr);
  s->info.function = internal_strdup(buffer);
  return s;
}

// Always claim we succeeded, so that RenderDataInfo will be called.
bool Symbolizer::SymbolizeData(uptr addr, DataInfo *info) {
  info->Clear();
  info->start = addr;
  return true;
}

// We ignore the format argument to __sanitizer_symbolize_global.
void RenderData(InternalScopedString *buffer, const char *format,
                const DataInfo *DI, const char *strip_path_prefix) {
  buffer->append(kFormatData, DI->start);
}

// We don't support the stack_trace_format flag at all.
void RenderFrame(InternalScopedString *buffer, const char *format, int frame_no,
                 const AddressInfo &info, bool vs_style,
                 const char *strip_path_prefix, const char *strip_func_prefix) {
  buffer->append(kFormatFrame, frame_no, info.address);
}

Symbolizer *Symbolizer::PlatformInit() {
  return new (symbolizer_allocator_) Symbolizer({});
}

void Symbolizer::LateInitialize() { Symbolizer::GetOrInit(); }

}  // namespace __sanitizer

#endif  // SANITIZER_FUCHSIA