compiler-rt/test/fuzzer/SymbolizeDeadlock.cpp

   1 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   2 // See https://llvm.org/LICENSE.txt for license information.
   3 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   4
   5 // Tests that deadlocks do not occur when an OOM occurs during symbolization.
   6
   7 #include <cassert>
   8 #include <cstdint>
   9 #include <cstdio>
  10 #include <cstdlib>
  11 #include <cstring>
  12
  13 #include "Bingo.h"
  14
  15 volatile unsigned Sink = 0;
  16
  17 // Do not inline this function.  We want to trigger NEW_FUNC symbolization when
  18 // libFuzzer finds this function.  We use a macro to make the name as long
  19 // possible, hoping to increase the time spent in symbolization and increase the
  20 // chances of triggering a deadlock.
  21 __attribute__((noinline)) void BINGO() {
  22   // Busy work.  Inserts a delay here so the deadlock is more likely to trigger.
  23   for (unsigned i = 0; i < 330000000; i++) Sink += i;
  24 }
  25
  26 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
  27   assert(Data);
  28   if (Size < 3) return 0;
  29   if (Data[0] == 'F' &&
  30       Data[1] == 'U' &&
  31       Data[2] == 'Z')
  32     BINGO();
  33   return 0;
  34 }
  35