mozglue/build/AsanOptions.cpp

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
   4  * You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #include "mozilla/Attributes.h"
   7
   8 #ifndef _MSC_VER  // Not supported by clang-cl yet
   9
  10 // When running with AddressSanitizer, we need to explicitly set some
  11 // options specific to our codebase to prevent errors during runtime.
  12 // To override these, set the ASAN_OPTIONS environment variable.
  13 //
  14 // Currently, these are:
  15 //
  16 //   allow_user_segv_handler=1 - Tell ASan to allow our code to use its
  17 //   own SIGSEGV handlers. This is required by ASM.js internally.
  18 //
  19 //   alloc_dealloc_mismatch=0 - Disable alloc-dealloc mismatch checking
  20 //   in ASan. This is required because we define our own new/delete
  21 //   operators that are backed by malloc/free. If one of them gets inlined
  22 //   while the other doesn't, ASan will report false positives.
  23 //
  24 //   detect_leaks=0 - Disable LeakSanitizer. This is required because
  25 //   otherwise leak checking will be enabled for various building and
  26 //   testing executables where we don't care much about leaks. Enabling
  27 //   this will also likely require setting LSAN_OPTIONS with a suppression
  28 //   file, as in build/sanitizers/lsan_suppressions.txt.
  29 //
  30 //   allocator_may_return_null=1 - Tell ASan to return NULL when an allocation
  31 //   fails instead of aborting the program. This allows us to handle failing
  32 //   allocations the same way we would handle them with a regular allocator and
  33 //   also uncovers potential bugs that might occur in these situations.
  34 //
  35 //   max_malloc_fill_size - Tell ASan to initialize memory to a certain value
  36 //   when it is allocated. This option specifies the maximum allocation size
  37 //   for which ASan should still initialize the memory. The value we specify
  38 //   here is exactly 256MiB.
  39 //
  40 //   max_free_fill_size - Similar to max_malloc_fill_size, tell ASan to
  41 //   overwrite memory with a certain value when it is freed. Again, the value
  42 //   here specifies the maximum allocation size, larger allocations will
  43 //   skipped.
  44 //
  45 //   malloc_fill_byte / free_fill_byte - These values specify the byte values
  46 //   used to initialize/overwrite memory in conjunction with the previous
  47 //   options max_malloc_fill_size and max_free_fill_size. The values used here
  48 //   are 0xe4 and 0xe5 to match the kAllocPoison and kAllocJunk constants used
  49 //   by mozjemalloc.
  50 //
  51 //   malloc_context_size - This value specifies how many stack frames are
  52 //   stored for each malloc and free call. Since Firefox can have lots of deep
  53 //   stacks with allocations, we limit the default size here further to save
  54 //   some memory.
  55 //
  56 extern "C" MOZ_ASAN_BLACKLIST const char* __asan_default_options() {
  57   return "allow_user_segv_handler=1:alloc_dealloc_mismatch=0:detect_leaks=0"
  58 #  ifdef MOZ_ASAN_REPORTER
  59          ":malloc_context_size=20"
  60 #  endif
  61          ":max_free_fill_size=268435456:max_malloc_fill_size=268435456"
  62          ":malloc_fill_byte=228:free_fill_byte=229"
  63          ":handle_sigill=1"
  64          ":allocator_may_return_null=1";
  65 }
  66
  67 #endif