rcutorture: Make rcutorture_one_extend_check() account for hard IRQs

This commit retrospectively prepares for testing of RCU readers invoked
from hardware interrupt handlers (for example, HRTIMER_MODE_HARD hrtimer
handlers) in kernels built with CONFIG_RCU_TORTURE_TEST_CHK_RDR_STATE=y,
which is rarely used but sometimes extremely useful.  This preparation
involves taking early exits if in_hardirq(), and, while we are in the
area, a very early exit if in_nmi().

This means that a number of insoftirq parameters are no longer needed,
but that is the subject of a later commit.

Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202505140917.8ee62cc6-lkp@intel.com
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Tested-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Neeraj Upadhyay (AMD) <neeraj.upadhyay@kernel.org>

Author: paulmckrcu

kernel/rcu/rcutorture.c

@@ -1920,10 +1920,10 @@ static void rcutorture_one_extend_check(char *s, int curstate, int new, int old,
 {
 	int mask;
 
-	if (!IS_ENABLED(CONFIG_RCU_TORTURE_TEST_CHK_RDR_STATE))
+	if (!IS_ENABLED(CONFIG_RCU_TORTURE_TEST_CHK_RDR_STATE) || in_nmi())
 		return;
 
-	WARN_ONCE(!(curstate & RCUTORTURE_RDR_IRQ) && irqs_disabled(), ROEC_ARGS);
+	WARN_ONCE(!(curstate & RCUTORTURE_RDR_IRQ) && irqs_disabled() && !in_hardirq(), ROEC_ARGS);
 	WARN_ONCE((curstate & RCUTORTURE_RDR_IRQ) && !irqs_disabled(), ROEC_ARGS);
 
 	// If CONFIG_PREEMPT_COUNT=n, further checks are unreliable.
@@ -1938,9 +1938,9 @@ static void rcutorture_one_extend_check(char *s, int curstate, int new, int old,
 		  (curstate & (RCUTORTURE_RDR_RCU_1 | RCUTORTURE_RDR_RCU_2)) &&
 		  cur_ops->readlock_nesting() == 0, ROEC_ARGS);
 
-	// Timer handlers have all sorts of stuff disabled, so ignore
+	// Interrupt handlers have all sorts of stuff disabled, so ignore
 	// unintended disabling.
-	if (insoftirq)
+	if (in_serving_softirq() || in_hardirq())
 		return;
 
 	WARN_ONCE(cur_ops->extendables &&