llvm-project

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// RUN: %clangxx_dfsan %s -fno-exceptions -o %t && %run %t
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// RUN: %clangxx_dfsan -DORIGIN_TRACKING -mllvm -dfsan-track-origins=1 %s -fno-exceptions -o %t && %run %t
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//
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// Use -fno-exceptions to turn off exceptions to avoid instrumenting
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// __cxa_begin_catch, std::terminate and __gxx_personality_v0.
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//
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// TODO: Support builtin atomics. For example, https://gcc.gnu.org/onlinedocs/gcc/_005f_005fatomic-Builtins.html
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// DFSan instrumentation pass cannot identify builtin callsites yet.
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#include <sanitizer/dfsan_interface.h>
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#include <assert.h>
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#include <atomic>
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#include <pthread.h>
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std::atomic<int> atomic_i{0};
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struct arg_struct {
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  size_t index;
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  dfsan_origin origin;
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};
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static void *ThreadFn(void *arg) {
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  if (((arg_struct *)arg)->index % 2) {
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    int i = 10;
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    dfsan_set_label(8, (void *)&i, sizeof(i));
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    atomic_i.store(i, std::memory_order_relaxed);
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    return 0;
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  }
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  int j = atomic_i.load();
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  assert(dfsan_get_label(j) == 0 || dfsan_get_label(j) == 2);
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#ifdef ORIGIN_TRACKING
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  if (dfsan_get_label(j) == 2)
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    assert(dfsan_get_init_origin(&j) == ((arg_struct *)arg)->origin);
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#endif
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  return 0;
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}
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int main(void) {
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  int i = 10;
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  dfsan_set_label(2, (void *)&i, sizeof(i));
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#ifdef ORIGIN_TRACKING
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  dfsan_origin origin = dfsan_get_origin(i);
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#endif
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  atomic_i.store(i, std::memory_order_relaxed);
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  const int kNumThreads = 24;
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  pthread_t t[kNumThreads];
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  arg_struct args[kNumThreads];
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  for (int i = 0; i < kNumThreads; ++i) {
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    args[i].index = i;
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#ifdef ORIGIN_TRACKING
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    args[i].origin = origin;
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#endif
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    pthread_create(&t[i], 0, ThreadFn, (void *)(args + i));
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  }
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  for (int i = 0; i < kNumThreads; ++i)
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    pthread_join(t[i], 0);
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  return 0;
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}
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