kc3-lang/angle/util/posix/Posix_crash_handler.cpp

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• Hash : 351e8098
  Author :
  Date : 2019-06-21T10:35:06
  

  Increase demangled array size
  
  The call to abi::__cxa_demangle() with too small of a char[] can cause
  segfaults or hangs.   This change increases the array from 256 to 4096.
  
  Bug: angleproject:3553
  Test: Verify validation layers don't segfault/hang
  Change-Id: I6704ff00bfab62c99eb288f803ccda35a037dd9d
  Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1670580
  Reviewed-by: Jamie Madill <jmadill@chromium.org>
  Reviewed-by: Yuly Novikov <ynovikov@chromium.org>
  Commit-Queue: Tim Van Patten <timvp@google.com>
  

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• util/posix/Posix_crash_handler.cpp

• //
  // Copyright 2019 The ANGLE Project Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  //
  // system_utils_crash_handler:
  //    ANGLE's crash handling and stack walking code. Modified from Skia's:
  //     https://github.com/google/skia/blob/master/tools/CrashHandler.cpp
  //
  
  #include "util/system_utils.h"
  
  #include "common/angleutils.h"
  
  #include <stdio.h>
  #include <stdlib.h>
  
  #if !defined(ANGLE_PLATFORM_ANDROID) && !defined(ANGLE_PLATFORM_FUCHSIA)
  #    if defined(ANGLE_PLATFORM_APPLE)
  // We only use local unwinding, so we can define this to select a faster implementation.
  #        define UNW_LOCAL_ONLY
  #        include <cxxabi.h>
  #        include <libunwind.h>
  #        include <signal.h>
  #    elif defined(ANGLE_PLATFORM_POSIX)
  // We'd use libunwind here too, but it's a pain to get installed for
  // both 32 and 64 bit on bots.  Doesn't matter much: catchsegv is best anyway.
  #        include <cxxabi.h>
  #        include <dlfcn.h>
  #        include <execinfo.h>
  #        include <signal.h>
  #        include <string.h>
  #    endif  // defined(ANGLE_PLATFORM_APPLE)
  #endif      // !defined(ANGLE_PLATFORM_ANDROID) && !defined(ANGLE_PLATFORM_FUCHSIA)
  
  namespace angle
  {
  
  #if defined(ANGLE_PLATFORM_ANDROID) || defined(ANGLE_PLATFORM_FUCHSIA)
  
  void PrintStackBacktrace()
  {
      // No implementations yet.
  }
  
  void InitCrashHandler()
  {
      // No implementations yet.
  }
  
  void TerminateCrashHandler()
  {
      // No implementations yet.
  }
  
  #else
  
  #    if defined(ANGLE_PLATFORM_APPLE)
  
  void PrintStackBacktrace()
  {
      printf("Backtrace:\n");
  
      unw_context_t context;
      unw_getcontext(&context);
  
      unw_cursor_t cursor;
      unw_init_local(&cursor, &context);
  
      while (unw_step(&cursor) > 0)
      {
          static const size_t kMax = 256;
          char mangled[kMax], demangled[kMax];
          unw_word_t offset;
          unw_get_proc_name(&cursor, mangled, kMax, &offset);
  
          int ok;
          size_t len = kMax;
          abi::__cxa_demangle(mangled, demangled, &len, &ok);
  
          printf("    %s (+0x%zx)\n", ok == 0 ? demangled : mangled, (size_t)offset);
      }
      printf("\n");
  }
  
  static void Handler(int sig)
  {
      printf("\nSignal %d:\n", sig);
      PrintStackBacktrace();
  
      // Exit NOW.  Don't notify other threads, don't call anything registered with atexit().
      _Exit(sig);
  }
  
  #    elif defined(ANGLE_PLATFORM_POSIX)
  
  void PrintStackBacktrace()
  {
      printf("Backtrace:\n");
  
      void *stack[64];
      const int count = backtrace(stack, ArraySize(stack));
      char **symbols  = backtrace_symbols(stack, count);
  
      for (int i = 0; i < count; i++)
      {
          Dl_info info;
          if (dladdr(stack[i], &info) && info.dli_sname)
          {
              // Make sure this is large enough to hold the fully demangled names, otherwise we could
              // segault/hang here. For example, Vulkan validation layer errors can be deep enough
              // into the stack that very large symbol names are generated.
              char demangled[4096];
              size_t len = ArraySize(demangled);
              int ok;
  
              abi::__cxa_demangle(info.dli_sname, demangled, &len, &ok);
              if (ok == 0)
              {
                  printf("    %s\n", demangled);
                  continue;
              }
          }
          printf("    %s\n", symbols[i]);
      }
  }
  
  static void Handler(int sig)
  {
      printf("\nSignal %d [%s]:\n", sig, strsignal(sig));
      PrintStackBacktrace();
  
      // Exit NOW.  Don't notify other threads, don't call anything registered with atexit().
      _Exit(sig);
  }
  
  #    endif  // defined(ANGLE_PLATFORM_APPLE)
  
  static constexpr int kSignals[] = {
      SIGABRT, SIGBUS, SIGFPE, SIGILL, SIGSEGV, SIGTRAP,
  };
  
  void InitCrashHandler()
  {
      for (int sig : kSignals)
      {
          // Register our signal handler unless something's already done so (e.g. catchsegv).
          void (*prev)(int) = signal(sig, Handler);
          if (prev != SIG_DFL)
          {
              signal(sig, prev);
          }
      }
  }
  
  void TerminateCrashHandler()
  {
      for (int sig : kSignals)
      {
          void (*prev)(int) = signal(sig, SIG_DFL);
          if (prev != Handler && prev != SIG_DFL)
          {
              signal(sig, prev);
          }
      }
  }
  
  #endif  // defined(ANGLE_PLATFORM_ANDROID) || defined(ANGLE_PLATFORM_FUCHSIA)
  
  }  // namespace angle
  

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