cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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LB+unlocklockonceonce+poacquireonce.litmus (719B)

      1C LB+unlocklockonceonce+poacquireonce
      2
      3(*
      4 * Result: Never
      5 *
      6 * If two locked critical sections execute on the same CPU, all accesses
      7 * in the first must execute before any accesses in the second, even if the
      8 * critical sections are protected by different locks.  Note: Even when a
      9 * write executes before a read, their memory effects can be reordered from
     10 * the viewpoint of another CPU (the kind of reordering allowed by TSO).
     11 *)
     12
     13{}
     14
     15P0(spinlock_t *s, spinlock_t *t, int *x, int *y)
     16{
     17	int r1;
     18
     19	spin_lock(s);
     20	r1 = READ_ONCE(*x);
     21	spin_unlock(s);
     22	spin_lock(t);
     23	WRITE_ONCE(*y, 1);
     24	spin_unlock(t);
     25}
     26
     27P1(int *x, int *y)
     28{
     29	int r2;
     30
     31	r2 = smp_load_acquire(y);
     32	WRITE_ONCE(*x, 1);
     33}
     34
     35exists (0:r1=1 /\ 1:r2=1)