--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -61,10 +61,13 @@ MODULE_AUTHOR("Paul E. McKenney <paulmck
 #define RCUTORTURE_RDR_RBH	 0x08	/*  ... rcu_read_lock_bh(). */
 #define RCUTORTURE_RDR_SCHED	 0x10	/*  ... rcu_read_lock_sched(). */
 #define RCUTORTURE_RDR_RCU	 0x20	/*  ... entering another RCU reader. */
-#define RCUTORTURE_RDR_NBITS	 6	/* Number of bits defined above. */
+#define RCUTORTURE_RDR_ATOM_BH	 0x40	/*  ... disabling bh while atomic */
+#define RCUTORTURE_RDR_ATOM_RBH	 0x80	/*  ... RBH while atomic */
+#define RCUTORTURE_RDR_NBITS	 8	/* Number of bits defined above. */
 #define RCUTORTURE_MAX_EXTEND	 \
 	(RCUTORTURE_RDR_BH | RCUTORTURE_RDR_IRQ | RCUTORTURE_RDR_PREEMPT | \
-	 RCUTORTURE_RDR_RBH | RCUTORTURE_RDR_SCHED)
+	 RCUTORTURE_RDR_RBH | RCUTORTURE_RDR_SCHED | \
+	 RCUTORTURE_RDR_ATOM_BH | RCUTORTURE_RDR_ATOM_RBH)
 #define RCUTORTURE_RDR_MAX_LOOPS 0x7	/* Maximum reader extensions. */
 					/* Must be power of two minus one. */
 #define RCUTORTURE_RDR_MAX_SEGS (RCUTORTURE_RDR_MAX_LOOPS + 3)
@@ -1429,31 +1432,53 @@ static void rcutorture_one_extend(int *r
 	WARN_ON_ONCE((idxold >> RCUTORTURE_RDR_SHIFT) > 1);
 	rtrsp->rt_readstate = newstate;
 
-	/* First, put new protection in place to avoid critical-section gap. */
+	/*
+	 * First, put new protection in place to avoid critical-section gap.
+	 * Disable preemption around the ATOM disables to ensure that
+	 * in_atomic() is true.
+	 */
 	if (statesnew & RCUTORTURE_RDR_BH)
 		local_bh_disable();
+	if (statesnew & RCUTORTURE_RDR_RBH)
+		rcu_read_lock_bh();
 	if (statesnew & RCUTORTURE_RDR_IRQ)
 		local_irq_disable();
 	if (statesnew & RCUTORTURE_RDR_PREEMPT)
 		preempt_disable();
-	if (statesnew & RCUTORTURE_RDR_RBH)
-		rcu_read_lock_bh();
 	if (statesnew & RCUTORTURE_RDR_SCHED)
 		rcu_read_lock_sched();
+	preempt_disable();
+	if (statesnew & RCUTORTURE_RDR_ATOM_BH)
+		local_bh_disable();
+	if (statesnew & RCUTORTURE_RDR_ATOM_RBH)
+		rcu_read_lock_bh();
+	preempt_enable();
 	if (statesnew & RCUTORTURE_RDR_RCU)
 		idxnew = cur_ops->readlock() << RCUTORTURE_RDR_SHIFT;
 
-	/* Next, remove old protection, irq first due to bh conflict. */
+	/*
+	 * Next, remove old protection, in decreasing order of strength
+	 * to avoid unlock paths that aren't safe in the stronger
+	 * context.  Disable preemption around the ATOM enables in
+	 * case the context was only atomic due to IRQ disabling.
+	 */
+	preempt_disable();
 	if (statesold & RCUTORTURE_RDR_IRQ)
 		local_irq_enable();
-	if (statesold & RCUTORTURE_RDR_BH)
+	if (statesold & RCUTORTURE_RDR_ATOM_BH)
 		local_bh_enable();
+	if (statesold & RCUTORTURE_RDR_ATOM_RBH)
+		rcu_read_unlock_bh();
+	preempt_enable();
 	if (statesold & RCUTORTURE_RDR_PREEMPT)
 		preempt_enable();
-	if (statesold & RCUTORTURE_RDR_RBH)
-		rcu_read_unlock_bh();
 	if (statesold & RCUTORTURE_RDR_SCHED)
 		rcu_read_unlock_sched();
+	if (statesold & RCUTORTURE_RDR_BH)
+		local_bh_enable();
+	if (statesold & RCUTORTURE_RDR_RBH)
+		rcu_read_unlock_bh();
+
 	if (statesold & RCUTORTURE_RDR_RCU) {
 		bool lockit = !statesnew && !(torture_random(trsp) & 0xffff);
 
@@ -1496,6 +1521,12 @@ rcutorture_extend_mask(int oldmask, stru
 	int mask = rcutorture_extend_mask_max();
 	unsigned long randmask1 = torture_random(trsp) >> 8;
 	unsigned long randmask2 = randmask1 >> 3;
+	unsigned long preempts = RCUTORTURE_RDR_PREEMPT | RCUTORTURE_RDR_SCHED;
+	unsigned long preempts_irq = preempts | RCUTORTURE_RDR_IRQ;
+	unsigned long nonatomic_bhs = RCUTORTURE_RDR_BH | RCUTORTURE_RDR_RBH;
+	unsigned long atomic_bhs = RCUTORTURE_RDR_ATOM_BH |
+				   RCUTORTURE_RDR_ATOM_RBH;
+	unsigned long tmp;
 
 	WARN_ON_ONCE(mask >> RCUTORTURE_RDR_SHIFT);
 	/* Mostly only one bit (need preemption!), sometimes lots of bits. */
@@ -1503,11 +1534,46 @@ rcutorture_extend_mask(int oldmask, stru
 		mask = mask & randmask2;
 	else
 		mask = mask & (1 << (randmask2 % RCUTORTURE_RDR_NBITS));
-	/* Can't enable bh w/irq disabled. */
-	if ((mask & RCUTORTURE_RDR_IRQ) &&
-	    ((!(mask & RCUTORTURE_RDR_BH) && (oldmask & RCUTORTURE_RDR_BH)) ||
-	     (!(mask & RCUTORTURE_RDR_RBH) && (oldmask & RCUTORTURE_RDR_RBH))))
-		mask |= RCUTORTURE_RDR_BH | RCUTORTURE_RDR_RBH;
+
+	/*
+	 * Can't enable bh w/irq disabled.
+	 */
+	tmp = atomic_bhs | nonatomic_bhs;
+	if (mask & RCUTORTURE_RDR_IRQ)
+		mask |= oldmask & tmp;
+
+	/*
+	 * Ideally these sequences would be detected in debug builds
+	 * (regardless of RT), but until then don't stop testing
+	 * them on non-RT.
+	 */
+	if (IS_ENABLED(CONFIG_PREEMPT_RT)) {
+		/*
+		 * Can't disable bh in atomic context if bh was already
+		 * disabled by another task on the same CPU. Instead of
+		 * attempting to track this, just avoid disabling bh in atomic
+		 * context.
+		 */
+		mask &= ~atomic_bhs;
+		/*
+		 * Can't release the outermost rcu lock in an irq disabled
+		 * section without preemption also being disabled, if irqs
+		 * had ever been enabled during this RCU critical section
+		 * (could leak a special flag and delay reporting the qs).
+		 */
+		if ((oldmask & RCUTORTURE_RDR_RCU) &&
+		    (mask & RCUTORTURE_RDR_IRQ) &&
+		    !(mask & preempts))
+			mask |= RCUTORTURE_RDR_RCU;
+
+		/* Can't modify non-atomic bh in atomic context */
+		tmp = nonatomic_bhs;
+		if (oldmask & preempts_irq)
+			mask &= ~tmp;
+		if ((oldmask | mask) & preempts_irq)
+			mask |= oldmask & tmp;
+	}
+
 	return mask ?: RCUTORTURE_RDR_RCU;
 }
 
