stack_trace_posix.cc | Explore in Territory

// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifdef UNSAFE_BUFFERS_BUILD
// TODO(crbug.com/40284755): Remove this and spanify to fix the errors.
#pragma allow_unsafe_buffers
#endif

#include "base/debug/stack_trace.h"

#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <unistd.h>

#include <algorithm>
#include <map>
#include <memory>
#include <ostream>
#include <string>
#include <tuple>
#include <vector>

#include "base/memory/raw_ptr.h"
#include "build/build_config.h"

// Controls whether `dladdr(...)` is used to print the callstack. This is
// only used on iOS Official build where `backtrace_symbols(...)` prints
// misleading symbols (as the binary is stripped).
#if BUILDFLAG(IS_IOS) && defined(OFFICIAL_BUILD)
#define HAVE_DLADDR
#include <dlfcn.h>
#endif

// Surprisingly, uClibc defines __GLIBC__ in some build configs, but
// execinfo.h and backtrace(3) are really only present in glibc and in macOS
// libc.
#if BUILDFLAG(IS_APPLE) || \
    (defined(__GLIBC__) && !defined(__UCLIBC__) && !defined(__AIX))
#define HAVE_BACKTRACE
#include <execinfo.h>
#endif

// Controls whether to include code to demangle C++ symbols.
#if !defined(USE_SYMBOLIZE) && defined(HAVE_BACKTRACE) && !defined(HAVE_DLADDR)
#define DEMANGLE_SYMBOLS
#endif

#if defined(DEMANGLE_SYMBOLS)
#include <cxxabi.h>
#endif

#if BUILDFLAG(IS_APPLE)
#include <AvailabilityMacros.h>
#endif

#if BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS)
#include <sys/prctl.h>

#include "base/debug/proc_maps_linux.h"
#endif

#include "base/cfi_buildflags.h"
#include "base/debug/debugger.h"
#include "base/debug/debugging_buildflags.h"
#include "base/debug/stack_trace.h"
#include "base/files/scoped_file.h"
#include "base/logging.h"
#include "base/memory/free_deleter.h"
#include "base/memory/singleton.h"
#include "base/numerics/safe_conversions.h"
#include "base/posix/eintr_wrapper.h"
#include "base/strings/string_number_conversions.h"
#include "base/strings/string_util.h"
#include "build/build_config.h"

#if defined(USE_SYMBOLIZE)
#include "base/third_party/symbolize/symbolize.h"  // nogncheck

#if BUILDFLAG(ENABLE_STACK_TRACE_LINE_NUMBERS)
#include "base/debug/dwarf_line_no.h"  // nogncheck
#endif

#endif

namespace base::debug {

namespace {

volatile sig_atomic_t in_signal_handler = …;

#if !BUILDFLAG(IS_NACL)
bool (*try_handle_signal)(int, siginfo_t*, void*) = …;
#endif

#if defined(DEMANGLE_SYMBOLS)
// The prefix used for mangled symbols, per the Itanium C++ ABI:
// http://www.codesourcery.com/cxx-abi/abi.html#mangling
const char kMangledSymbolPrefix[] = "_Z";

// Characters that can be used for symbols, generated by Ruby:
// (('a'..'z').to_a+('A'..'Z').to_a+('0'..'9').to_a + ['_']).join
const char kSymbolCharacters[] =
    "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_";

// Demangles C++ symbols in the given text. Example:
//
// "out/Debug/base_unittests(_ZN10StackTraceC1Ev+0x20) [0x817778c]"
// =>
// "out/Debug/base_unittests(StackTrace::StackTrace()+0x20) [0x817778c]"
void DemangleSymbols(std::string* text) {
  // Note: code in this function is NOT async-signal safe (std::string uses
  // malloc internally).

  std::string::size_type search_from = 0;
  while (search_from < text->size()) {
    // Look for the start of a mangled symbol, from search_from.
    std::string::size_type mangled_start =
        text->find(kMangledSymbolPrefix, search_from);
    if (mangled_start == std::string::npos) {
      break;  // Mangled symbol not found.
    }

    // Look for the end of the mangled symbol.
    std::string::size_type mangled_end =
        text->find_first_not_of(kSymbolCharacters, mangled_start);
    if (mangled_end == std::string::npos) {
      mangled_end = text->size();
    }
    std::string mangled_symbol =
        text->substr(mangled_start, mangled_end - mangled_start);

    // Try to demangle the mangled symbol candidate.
    int status = 0;
    std::unique_ptr<char, base::FreeDeleter> demangled_symbol(
        abi::__cxa_demangle(mangled_symbol.c_str(), nullptr, 0, &status));
    if (status == 0) {  // Demangling is successful.
      // Remove the mangled symbol.
      text->erase(mangled_start, mangled_end - mangled_start);
      // Insert the demangled symbol.
      text->insert(mangled_start, demangled_symbol.get());
      // Next time, we'll start right after the demangled symbol we inserted.
      search_from = mangled_start + strlen(demangled_symbol.get());
    } else {
      // Failed to demangle.  Retry after the "_Z" we just found.
      search_from = mangled_start + 2;
    }
  }
}
#endif  // defined(DEMANGLE_SYMBOLS)

class BacktraceOutputHandler { … };

#if defined(HAVE_BACKTRACE)
void OutputPointer(const void* pointer, BacktraceOutputHandler* handler) { … }

#if defined(HAVE_DLADDR) || defined(USE_SYMBOLIZE)
void OutputValue(size_t value, BacktraceOutputHandler* handler) { … }
#endif  // defined(HAVE_DLADDR) || defined(USE_SYMBOLIZE)

#if defined(USE_SYMBOLIZE)
void OutputFrameId(size_t frame_id, BacktraceOutputHandler* handler) { … }
#endif  // defined(USE_SYMBOLIZE)

void ProcessBacktrace(span<const void* const> traces,
                      cstring_view prefix_string,
                      BacktraceOutputHandler* handler) { … }
#endif  // defined(HAVE_BACKTRACE)

void PrintToStderr(const char* output) { … }

#if BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_ANDROID) || BUILDFLAG(IS_CHROMEOS)
void AlarmSignalHandler(int signal, siginfo_t* info, void* void_context) { … }
#endif  // BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_ANDROID) ||
        // BUILDFLAG(IS_CHROMEOS)

void StackDumpSignalHandler(int signal, siginfo_t* info, void* void_context) { … }

class PrintBacktraceOutputHandler : public BacktraceOutputHandler { … };

class StreamBacktraceOutputHandler : public BacktraceOutputHandler { … };

void WarmUpBacktrace() { … }

#if defined(USE_SYMBOLIZE)

// class SandboxSymbolizeHelper.
//
// The purpose of this class is to prepare and install a "file open" callback
// needed by the stack trace symbolization code
// (base/third_party/symbolize/symbolize.h) so that it can function properly
// in a sandboxed process.  The caveat is that this class must be instantiated
// before the sandboxing is enabled so that it can get the chance to open all
// the object files that are loaded in the virtual address space of the current
// process.
class SandboxSymbolizeHelper { … };
#endif  // USE_SYMBOLIZE

}  // namespace

bool EnableInProcessStackDumping() { … }

#if !BUILDFLAG(IS_NACL)
bool SetStackDumpFirstChanceCallback(bool (*handler)(int, siginfo_t*, void*)) { … }
#endif

size_t CollectStackTrace(span<const void*> trace) { … }

// static
void StackTrace::PrintMessageWithPrefix(cstring_view prefix_string,
                                        cstring_view message) { … }

void StackTrace::PrintWithPrefixImpl(cstring_view prefix_string) const { … }

#if defined(HAVE_BACKTRACE)
void StackTrace::OutputToStreamWithPrefixImpl(
    std::ostream* os,
    cstring_view prefix_string) const { … }
#endif

namespace internal {

// NOTE: code from sandbox/linux/seccomp-bpf/demo.cc.
char* itoa_r(intptr_t i, char* buf, size_t sz, int base, size_t padding) { … }

}  // namespace internal

}  // namespace base::debug
chromium/base/debug/stack_trace_posix.cc
