selftests/bpf/test_offload.py: Remove check for program load flags match

Since we just removed the xdp_attachment_flags_ok() callback, also remove
the check for it in test_offload.py, and replace it with a test for the new
ambiguity-avoid check when multiple programs are loaded.

Fixes: 7f0a8382 ("bpf, xdp: Maintain info on attached XDP BPF programs in net_device")
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/bpf/160752225858.110217.13036901876869496246.stgit@toke.dk

tools/testing/selftests/bpf/test_offload.py

@@ -716,13 +716,11 @@ def test_multi_prog(simdev, sim, obj, modename, modeid):
     fail(ret == 0, "Replaced one of programs without -force")
     check_extack(err, "XDP program already attached.", args)
 
-    if modename == "" or modename == "drv":
-        othermode = "" if modename == "drv" else "drv"
-        start_test("Test multi-attachment XDP - detach...")
-        ret, _, err = sim.unset_xdp(othermode, force=True,
-                                    fail=False, include_stderr=True)
-        fail(ret == 0, "Removed program with a bad mode")
-        check_extack(err, "program loaded with different flags.", args)
+    start_test("Test multi-attachment XDP - remove without mode...")
+    ret, _, err = sim.unset_xdp("", force=True,
+                                fail=False, include_stderr=True)
+    fail(ret == 0, "Removed program without a mode flag")
+    check_extack(err, "More than one program loaded, unset mode is ambiguous.", args)
 
     sim.unset_xdp("offload")
     xdp = sim.ip_link_show(xdp=True)["xdp"]
@@ -1001,16 +999,6 @@ try:
     check_extack(err,
                  "native and generic XDP can't be active at the same time.",
                  args)
-    ret, _, err = sim.set_xdp(obj, "", force=True,
-                              fail=False, include_stderr=True)
-    fail(ret == 0, "Replaced XDP program with a program in different mode")
-    check_extack(err, "program loaded with different flags.", args)
-
-    start_test("Test XDP prog remove with bad flags...")
-    ret, _, err = sim.unset_xdp("", force=True,
-                                fail=False, include_stderr=True)
-    fail(ret == 0, "Removed program with a bad mode")
-    check_extack(err, "program loaded with different flags.", args)
 
     start_test("Test MTU restrictions...")
     ret, _ = sim.set_mtu(9000, fail=False)