[PATCH v2 6/8] selftests/rcutorture: Wire atomic SRCU into srcu_lockdep.sh

["Paul E. McKenney" <paulmck@kernel.org>]

From: Kunwu Chan <kunwu.chan@gmail.com>

Add testtypes 4 (atomic SRCU same-type deadlock) and 5 (atomic SRCU
+ raw_spinlock dependency cycle) to the deadlock-detection loop.
Add a separate loop for testtype 6 (rcu_read_lock() →
synchronize_srcu_atomic()), which also verifies via console.log that
no lockdep warning is triggered.

Co-developed-by: Zqiang <qiang.zhang@linux.dev>
Signed-off-by: Zqiang <qiang.zhang@linux.dev>
Signed-off-by: Kunwu Chan <kunwu.chan@gmail.com>
Acked-by: Boqun Feng <boqun@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 .../selftests/rcutorture/bin/srcu_lockdep.sh  | 39 ++++++++++++++++++-
 1 file changed, 38 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/rcutorture/bin/srcu_lockdep.sh b/tools/testing/selftests/rcutorture/bin/srcu_lockdep.sh
index 4e98c697def48..72791499dd96b 100755
--- a/tools/testing/selftests/rcutorture/bin/srcu_lockdep.sh
+++ b/tools/testing/selftests/rcutorture/bin/srcu_lockdep.sh
@@ -44,7 +44,7 @@ nerrs=0
 # Test lockdep's handling of deadlocks.
 for d in 0 1
 do
-	for t in 0 1 2
+	for t in 0 1 2 4 5
 	do
 		for c in 1 2 3
 		do
@@ -79,6 +79,43 @@ do
 	done
 done
 
+# Verify that synchronize_srcu_atomic() does not trigger lockdep
+# warnings when called inside rcu_read_lock().
+for c in 1 2 3
+do
+	err=
+	val=$((6*10+c))
+	tools/testing/selftests/rcutorture/bin/kvm.sh --allcpus --duration 5s \
+		--configs "SRCU-P" \
+		--kconfig "CONFIG_FORCE_NEED_SRCU_NMI_SAFE=y" \
+		--bootargs "rcutorture.test_srcu_lockdep=$val" \
+		--trust-make --datestamp "$ds/$val" > "$T/kvm.sh.out" 2>&1
+	ret=$?
+	mv "$T/kvm.sh.out" "$RCUTORTURE/res/$ds/$val"
+	if ! grep -q '^CONFIG_PROVE_LOCKING=y' .config
+	then
+		echo "rcu_torture_init_srcu_lockdep:Error: CONFIG_PROVE_LOCKING" \
+				"disabled in rcutorture SRCU-P scenario"
+		err=1
+	fi
+	if test "$ret" -ne 0
+	then
+		err=1
+		echo -n Unexpected failure for > "$RCUTORTURE/res/$ds/$val/kvm.sh.err"
+	elif grep -qE "WARNING: possible (recursive locking|circular locking dependency)" \
+		"$RCUTORTURE/res/$ds/$val/SRCU-P/console.log"
+	then
+		err=1
+		echo -n Unexpected lockdep warning for > "$RCUTORTURE/res/$ds/$val/kvm.sh.err"
+	fi
+	if test -n "$err"
+	then
+		grep "rcu_torture_init_srcu_lockdep: test_srcu_lockdep = " "$RCUTORTURE/res/$ds/$val/SRCU-P/console.log" | sed -e 's/^.*rcu_torture_init_srcu_lockdep://' >> "$RCUTORTURE/res/$ds/$val/kvm.sh.err"
+		cat "$RCUTORTURE/res/$ds/$val/kvm.sh.err"
+		nerrs=$((nerrs+1))
+	fi
+done
+
 # Test lockdep-enabled testing of mixed SRCU readers.
 for val in 0x1 0xf
 do
-- 
2.40.1