The gtest in runtime/test_os_linux.cpp tests for a failed MMAP using != NULL instead of MAP_FAILED (which is defined as

#define MAP_FAILED ((void *) -1)

) but the code uses NULL (twice):

  char* const mapping = (char*) ::mmap(NULL, mapping_size,
      PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE,
      -1, 0);
  ASSERT_TRUE(mapping != NULL) << " mmap failed, mapping_size = " << mapping_size;
  // Unmap the mapping, it will serve as a value for a "good" req_addr
  ::munmap(mapping, mapping_size);

All other mmap uses check for MAP_FAILED manual inspection via grep shows.

Fix this.