[PATCH net 3/3] selftests: rtnetlink: Add bridge promiscuity tests

[Ido Schimmel <idosch@nvidia.com>]

Add two test cases that always pass, but trigger sleeping in atomic
context BUGs without "bridge: Fix sleep in atomic context in netlink
path" and "bridge: Fix sleep in atomic context in sysfs path".

Assisted-by: Claude:claude-opus-4-7
Reviewed-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
---
 tools/testing/selftests/net/rtnetlink.sh | 63 ++++++++++++++++++++++++
 1 file changed, 63 insertions(+)

diff --git a/tools/testing/selftests/net/rtnetlink.sh b/tools/testing/selftests/net/rtnetlink.sh
index c499953d4885..ace3a99023ed 100755
--- a/tools/testing/selftests/net/rtnetlink.sh
+++ b/tools/testing/selftests/net/rtnetlink.sh
@@ -24,6 +24,8 @@ ALL_TESTS="
 	kci_test_macsec
 	kci_test_macsec_vlan
 	kci_test_team_bridge_macvlan
+	kci_test_bridge_promisc_netlink
+	kci_test_bridge_promisc_sysfs
 	kci_test_ipsec
 	kci_test_ipsec_offload
 	kci_test_fdb_get
@@ -61,6 +63,14 @@ check_fail()
 	fi
 }
 
+sysfs_write()
+{
+	local val="$1"
+	local path="$2"
+
+	echo "$val" > "$path"
+}
+
 run_cmd_common()
 {
 	local cmd="$*"
@@ -680,6 +690,59 @@ kci_test_team_bridge_macvlan()
 	end_test "PASS: team_bridge_macvlan"
 }
 
+# Test that changing bridge port flags via the netlink path does not sleep with
+# the bridge spin lock held.
+kci_test_bridge_promisc_netlink()
+{
+	local dummy="test_dummy1"
+	local bridge="test_br1"
+	local team="test_team1"
+	local ret=0
+
+	run_cmd ip link add $team up type team
+	run_cmd ip link add $bridge up type bridge vlan_filtering 1
+	run_cmd ip link add $dummy up type dummy
+	run_cmd ip link set $dummy master $bridge
+	run_cmd ip link set $team master $bridge
+
+	# This causes the bridge driver to sync all the static FDB entries to
+	# the team device (which supports unicast filtering) and remove it from
+	# promiscuous mode. The call to dev_set_promiscuity() can sleep due to
+	# Rx mode inlining, which is a problem if the bridge spin lock is held.
+	run_cmd bridge link set dev $dummy flood off learning off
+
+	run_cmd ip link del $dummy
+	run_cmd ip link del $bridge
+	run_cmd ip link del $team
+
+	end_test "PASS: bridge_promisc_netlink"
+}
+
+# Same as kci_test_bridge_promisc_netlink(), but the flags are changed via the
+# sysfs path.
+kci_test_bridge_promisc_sysfs()
+{
+	local dummy="test_dummy1"
+	local bridge="test_br1"
+	local team="test_team1"
+	local ret=0
+
+	run_cmd ip link add $team up type team
+	run_cmd ip link add $bridge up type bridge vlan_filtering 1
+	run_cmd ip link add $dummy up type dummy
+	run_cmd ip link set $dummy master $bridge
+	run_cmd ip link set $team master $bridge
+
+	run_cmd sysfs_write 0 /sys/class/net/$dummy/brport/unicast_flood
+	run_cmd sysfs_write 0 /sys/class/net/$dummy/brport/learning
+
+	run_cmd ip link del $dummy
+	run_cmd ip link del $bridge
+	run_cmd ip link del $team
+
+	end_test "PASS: bridge_promisc_sysfs"
+}
+
 #-------------------------------------------------------------------
 # Example commands
 #   ip x s add proto esp src 14.0.0.52 dst 14.0.0.70 \
-- 
2.54.0