lockdep/selftests: Skip the softirq related tests on PREEMPT_RT

The softirq context on PREEMPT_RT is different compared to !PREEMPT_RT.
As such lockdep_softirq_enter() is a nop and the all the "softirq safe"
tests fail on PREEMPT_RT because there is no difference.

Skip the softirq context tests on PREEMPT_RT.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20211129174654.668506-9-bigeasy@linutronix.de

lib/locking-selftest.c

@@ -26,6 +26,12 @@
 #include <linux/rtmutex.h>
 #include <linux/local_lock.h>
 
+#ifdef CONFIG_PREEMPT_RT
+# define NON_RT(...)
+#else
+# define NON_RT(...)	__VA_ARGS__
+#endif
+
 /*
  * Change this to 1 if you want to see the failure printouts:
  */
@@ -808,6 +814,7 @@ GENERATE_PERMUTATIONS_2_EVENTS(irqsafe1_hard_rlock)
 #include "locking-selftest-wlock-hardirq.h"
 GENERATE_PERMUTATIONS_2_EVENTS(irqsafe1_hard_wlock)
 
+#ifndef CONFIG_PREEMPT_RT
 #include "locking-selftest-spin-softirq.h"
 GENERATE_PERMUTATIONS_2_EVENTS(irqsafe1_soft_spin)
 
@@ -816,10 +823,12 @@ GENERATE_PERMUTATIONS_2_EVENTS(irqsafe1_soft_rlock)
 
 #include "locking-selftest-wlock-softirq.h"
 GENERATE_PERMUTATIONS_2_EVENTS(irqsafe1_soft_wlock)
+#endif
 
 #undef E1
 #undef E2
 
+#ifndef CONFIG_PREEMPT_RT
 /*
  * Enabling hardirqs with a softirq-safe lock held:
  */
@@ -852,6 +861,8 @@ GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2A_rlock)
 #undef E1
 #undef E2
 
+#endif
+
 /*
  * Enabling irqs with an irq-safe lock held:
  */
@@ -881,6 +892,7 @@ GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2B_hard_rlock)
 #include "locking-selftest-wlock-hardirq.h"
 GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2B_hard_wlock)
 
+#ifndef CONFIG_PREEMPT_RT
 #include "locking-selftest-spin-softirq.h"
 GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2B_soft_spin)
 
@@ -889,6 +901,7 @@ GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2B_soft_rlock)
 
 #include "locking-selftest-wlock-softirq.h"
 GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2B_soft_wlock)
+#endif
 
 #undef E1
 #undef E2
@@ -927,6 +940,7 @@ GENERATE_PERMUTATIONS_3_EVENTS(irqsafe3_hard_rlock)
 #include "locking-selftest-wlock-hardirq.h"
 GENERATE_PERMUTATIONS_3_EVENTS(irqsafe3_hard_wlock)
 
+#ifndef CONFIG_PREEMPT_RT
 #include "locking-selftest-spin-softirq.h"
 GENERATE_PERMUTATIONS_3_EVENTS(irqsafe3_soft_spin)
 
@@ -935,6 +949,7 @@ GENERATE_PERMUTATIONS_3_EVENTS(irqsafe3_soft_rlock)
 
 #include "locking-selftest-wlock-softirq.h"
 GENERATE_PERMUTATIONS_3_EVENTS(irqsafe3_soft_wlock)
+#endif
 
 #undef E1
 #undef E2
@@ -975,6 +990,7 @@ GENERATE_PERMUTATIONS_3_EVENTS(irqsafe4_hard_rlock)
 #include "locking-selftest-wlock-hardirq.h"
 GENERATE_PERMUTATIONS_3_EVENTS(irqsafe4_hard_wlock)
 
+#ifndef CONFIG_PREEMPT_RT
 #include "locking-selftest-spin-softirq.h"
 GENERATE_PERMUTATIONS_3_EVENTS(irqsafe4_soft_spin)
 
@@ -983,6 +999,7 @@ GENERATE_PERMUTATIONS_3_EVENTS(irqsafe4_soft_rlock)
 
 #include "locking-selftest-wlock-softirq.h"
 GENERATE_PERMUTATIONS_3_EVENTS(irqsafe4_soft_wlock)
+#endif
 
 #undef E1
 #undef E2
@@ -1037,6 +1054,7 @@ GENERATE_PERMUTATIONS_3_EVENTS(irq_inversion_hard_rlock)
 #include "locking-selftest-wlock-hardirq.h"
 GENERATE_PERMUTATIONS_3_EVENTS(irq_inversion_hard_wlock)
 
+#ifndef CONFIG_PREEMPT_RT
 #include "locking-selftest-spin-softirq.h"
 GENERATE_PERMUTATIONS_3_EVENTS(irq_inversion_soft_spin)
 
@@ -1045,6 +1063,7 @@ GENERATE_PERMUTATIONS_3_EVENTS(irq_inversion_soft_rlock)
 
 #include "locking-selftest-wlock-softirq.h"
 GENERATE_PERMUTATIONS_3_EVENTS(irq_inversion_soft_wlock)
+#endif
 
 #undef E1
 #undef E2
@@ -1212,12 +1231,14 @@ GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion_hard_rlock)
 #include "locking-selftest-wlock.h"
 GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion_hard_wlock)
 
+#ifndef CONFIG_PREEMPT_RT
 #include "locking-selftest-softirq.h"
 #include "locking-selftest-rlock.h"
 GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion_soft_rlock)
 
 #include "locking-selftest-wlock.h"
 GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion_soft_wlock)
+#endif
 
 #undef E1
 #undef E2
@@ -1258,12 +1279,14 @@ GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion2_hard_rlock)
 #include "locking-selftest-wlock.h"
 GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion2_hard_wlock)
 
+#ifndef CONFIG_PREEMPT_RT
 #include "locking-selftest-softirq.h"
 #include "locking-selftest-rlock.h"
 GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion2_soft_rlock)
 
 #include "locking-selftest-wlock.h"
 GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion2_soft_wlock)
+#endif
 
 #undef E1
 #undef E2
@@ -1312,12 +1335,14 @@ GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion3_hard_rlock)
 #include "locking-selftest-wlock.h"
 GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion3_hard_wlock)
 
+#ifndef CONFIG_PREEMPT_RT
 #include "locking-selftest-softirq.h"
 #include "locking-selftest-rlock.h"
 GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion3_soft_rlock)
 
 #include "locking-selftest-wlock.h"
 GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion3_soft_wlock)
+#endif
 
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 # define I_SPINLOCK(x)	lockdep_reset_lock(&lock_##x.dep_map)
@@ -1523,7 +1548,7 @@ static inline void print_testname(const char *testname)
 
 #define DO_TESTCASE_2x2RW(desc, name, nr)			\
 	DO_TESTCASE_2RW("hard-"desc, name##_hard, nr)		\
-	DO_TESTCASE_2RW("soft-"desc, name##_soft, nr)		\
+	NON_RT(DO_TESTCASE_2RW("soft-"desc, name##_soft, nr))	\
 
 #define DO_TESTCASE_6x2x2RW(desc, name)				\
 	DO_TESTCASE_2x2RW(desc, name, 123);			\
@@ -1571,19 +1596,19 @@ static inline void print_testname(const char *testname)
 
 #define DO_TESTCASE_2I(desc, name, nr)				\
 	DO_TESTCASE_1("hard-"desc, name##_hard, nr);		\
-	DO_TESTCASE_1("soft-"desc, name##_soft, nr);
+	NON_RT(DO_TESTCASE_1("soft-"desc, name##_soft, nr));
 
 #define DO_TESTCASE_2IB(desc, name, nr)				\
 	DO_TESTCASE_1B("hard-"desc, name##_hard, nr);		\
-	DO_TESTCASE_1B("soft-"desc, name##_soft, nr);
+	NON_RT(DO_TESTCASE_1B("soft-"desc, name##_soft, nr));
 
 #define DO_TESTCASE_6I(desc, name, nr)				\
 	DO_TESTCASE_3("hard-"desc, name##_hard, nr);		\
-	DO_TESTCASE_3("soft-"desc, name##_soft, nr);
+	NON_RT(DO_TESTCASE_3("soft-"desc, name##_soft, nr));
 
 #define DO_TESTCASE_6IRW(desc, name, nr)			\
 	DO_TESTCASE_3RW("hard-"desc, name##_hard, nr);		\
-	DO_TESTCASE_3RW("soft-"desc, name##_soft, nr);
+	NON_RT(DO_TESTCASE_3RW("soft-"desc, name##_soft, nr));
 
 #define DO_TESTCASE_2x3(desc, name)				\
 	DO_TESTCASE_3(desc, name, 12);				\
@@ -2909,12 +2934,11 @@ void locking_selftest(void)
 	DO_TESTCASE_6x1RR("rlock W1R2/R2R3/W3W1", W1R2_R2R3_W3W1);
 
 	printk("  --------------------------------------------------------------------------\n");
-
 	/*
 	 * irq-context testcases:
 	 */
 	DO_TESTCASE_2x6("irqs-on + irq-safe-A", irqsafe1);
-	DO_TESTCASE_2x3("sirq-safe-A => hirqs-on", irqsafe2A);
+	NON_RT(DO_TESTCASE_2x3("sirq-safe-A => hirqs-on", irqsafe2A));
 	DO_TESTCASE_2x6("safe-A + irqs-on", irqsafe2B);
 	DO_TESTCASE_6x6("safe-A + unsafe-B #1", irqsafe3);
 	DO_TESTCASE_6x6("safe-A + unsafe-B #2", irqsafe4);