[ARM|RT] Merging r24766 into 3.9.1

typedef unsigned semval_t;

#endif

// glibc 2.21 has introduced some changes in the way the semaphore value is

// handled for 32-bit platforms, but since these changes are not ABI-breaking

// they are not versioned. On newer platforms such as ARM, there is only one

// version of the symbol, so it's enough to check the glibc version. However,

// for old platforms such as i386, glibc contains two or even three versions of

// the sem_init symbol, and the sanitizers always pick the oldest one.

// Therefore, it is not enough to rely on the __GLIBC_PREREQ macro - we should

// instead check the platform as well to make sure we only expect the new

// behavior on platforms where the older symbols do not exist.

#if defined(__arm__) && __GLIBC_PREREQ(2, 21)

#define GET_SEM_VALUE(V) ((V) >> 1)

#else

#define GET_SEM_VALUE(V) (V)

#endif

void my_sem_init(bool priv, int value, semval_t *a, unsigned char *b) {

  sem_t sem;

  memset(&sem, 0xAB, sizeof(sem));

  unsigned char b;

  my_sem_init(false, 42, &a, &b);

  assert(a == 42);

  assert(GET_SEM_VALUE(a) == 42);

  assert(b != 0xAB);

  my_sem_init(true, 43, &a, &b);

  assert(a == 43);

  assert(GET_SEM_VALUE(a) == 43);

  assert(b != 0xAB);

}