memory/mozalloc/mozalloc_abort.cpp

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
   2  * vim: sw=2 ts=4 et :
   3  */
   4 /* This Source Code Form is subject to the terms of the Mozilla Public
   5  * License, v. 2.0. If a copy of the MPL was not distributed with this
   6  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   7
   8 #include "mozilla/mozalloc_abort.h"
   9
  10 #ifdef ANDROID
  11 #  include <android/log.h>
  12 #endif
  13 #ifdef MOZ_WIDGET_ANDROID
  14 #  include "APKOpen.h"
  15 #  include "dlfcn.h"
  16 #endif
  17 #include <stdio.h>
  18 #include <string.h>
  19
  20 #include "mozilla/Assertions.h"
  21 #include "mozilla/Sprintf.h"
  22
  23 void mozalloc_abort(const char* const msg) {
  24 #ifndef ANDROID
  25   fputs(msg, stderr);
  26   fputs("\n", stderr);
  27 #else
  28   __android_log_print(ANDROID_LOG_ERROR, "Gecko", "mozalloc_abort: %s", msg);
  29 #endif
  30
  31 #ifdef MOZ_WIDGET_ANDROID
  32   abortThroughJava(msg);
  33 #endif
  34
  35   MOZ_CRASH_UNSAFE(msg);
  36 }
  37
  38 #ifdef MOZ_WIDGET_ANDROID
  39 template <size_t N>
  40 void fillAbortMessage(char (&msg)[N], uintptr_t retAddress) {
  41   /*
  42    * On Android, we often don't have reliable backtrace when crashing inside
  43    * abort(). Therefore, we try to find out who is calling abort() and add
  44    * that to the message.
  45    */
  46   Dl_info info = {};
  47   dladdr(reinterpret_cast<void*>(retAddress), &info);
  48
  49   const char* const module = info.dli_fname ? info.dli_fname : "";
  50   const char* const base_module = strrchr(module, '/');
  51   const void* const module_offset =
  52       reinterpret_cast<void*>(retAddress - uintptr_t(info.dli_fbase));
  53   const char* const sym = info.dli_sname ? info.dli_sname : "";
  54
  55   SprintfLiteral(msg, "abort() called from %s:%p (%s)",
  56                  base_module ? base_module + 1 : module, module_offset, sym);
  57 }
  58 #endif
  59
  60 #if defined(XP_UNIX) && !defined(MOZ_ASAN) && !defined(MOZ_TSAN) && \
  61     !defined(LIBFUZZER)
  62 // Define abort() here, so that it is used instead of the system abort(). This
  63 // lets us control the behavior when aborting, in order to get better results
  64 // on *NIX platforms. See mozalloc_abort for details.
  65 //
  66 // For AddressSanitizer, we must not redefine system abort because the ASan
  67 // option "abort_on_error=1" calls abort() and therefore causes the following
  68 // call chain with our redefined abort:
  69 //
  70 // ASan -> abort() -> moz_abort() -> MOZ_CRASH() -> Segmentation fault
  71 //
  72 // That segmentation fault will be interpreted as another bug by ASan and as a
  73 // result, ASan will just exit(1) instead of aborting.
  74 //
  75 // The same applies to ThreadSanitizer when run with "halt_on_error=1" in
  76 // combination with "abort_on_error=1".
  77 //
  78 // When building with libFuzzer, it pulls in the UndefinedBehaviorSanitizer
  79 // runtime which also requires the same workaround as with ASan or TSan.
  80 extern "C" void abort(void) {
  81 #  ifdef MOZ_WIDGET_ANDROID
  82   char msg[64] = {};
  83   fillAbortMessage(msg, uintptr_t(__builtin_return_address(0)));
  84 #  else
  85   const char* const msg = "Redirecting call to abort() to mozalloc_abort\n";
  86 #  endif
  87
  88   mozalloc_abort(msg);
  89
  90   // We won't reach here because mozalloc_abort() is MOZ_NORETURN. But that
  91   // annotation isn't used on ARM (see mozalloc_abort.h for why) so we add a
  92   // unreachable marker here to avoid a "'noreturn' function does return"
  93   // warning.
  94   MOZ_ASSUME_UNREACHABLE_MARKER();
  95 }
  96 #endif