selftests: rtnetlink: Add bridge promiscuity tests

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".

Reviewed-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260526064818.272516-4-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/tools/testing/selftests/net/rtnetlink.sh b/tools/testing/selftests/net/rtnetlink.sh
index c499953d4885a7a3b78de3e8a84cf46ea652e9da..ace3a99023ed01dab7eea8998725c32a0b0e4ebc 100755 (executable)
--- 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 \