Merge branch 'fix-BPF-offload-related-bugs'

Jakub Kicinski says:

====================
fix BPF offload related bugs

test_offload.py catches some recently added bugs.

First of a bug in test_offload.py itself after recent changes
to netdevsim is fixed.

Second patch fixes a bug in cls_bpf, and last one addresses
a problem with the recently added XDP installation optimization.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

net/core/dev.c

@@ -8421,7 +8421,8 @@ int dev_change_xdp_fd(struct net_device *dev, struct netlink_ext_ack *extack,
 			return -EINVAL;
 		}
 
-		if (prog->aux->id == prog_id) {
+		/* prog->aux->id may be 0 for orphaned device-bound progs */
+		if (prog->aux->id && prog->aux->id == prog_id) {
 			bpf_prog_put(prog);
 			return 0;
 		}

net/sched/cls_bpf.c

@@ -162,16 +162,20 @@ static int cls_bpf_offload_cmd(struct tcf_proto *tp, struct cls_bpf_prog *prog,
 	cls_bpf.name = obj->bpf_name;
 	cls_bpf.exts_integrated = obj->exts_integrated;
 
-	if (oldprog)
+	if (oldprog && prog)
 		err = tc_setup_cb_replace(block, tp, TC_SETUP_CLSBPF, &cls_bpf,
 					  skip_sw, &oldprog->gen_flags,
 					  &oldprog->in_hw_count,
 					  &prog->gen_flags, &prog->in_hw_count,
 					  true);
-	else
+	else if (prog)
 		err = tc_setup_cb_add(block, tp, TC_SETUP_CLSBPF, &cls_bpf,
 				      skip_sw, &prog->gen_flags,
 				      &prog->in_hw_count, true);
+	else
+		err = tc_setup_cb_destroy(block, tp, TC_SETUP_CLSBPF, &cls_bpf,
+					  skip_sw, &oldprog->gen_flags,
+					  &oldprog->in_hw_count, true);
 
 	if (prog && err) {
 		cls_bpf_offload_cmd(tp, oldprog, prog, extack);

tools/testing/selftests/bpf/test_offload.py

@@ -22,6 +22,7 @@
 import pprint
 import random
 import re
+import stat
 import string
 import struct
 import subprocess
@@ -311,7 +312,11 @@ def _debugfs_dir_read(self, path):
         for f in out.split():
             if f == "ports":
                 continue
+
             p = os.path.join(path, f)
+            if not os.stat(p).st_mode & stat.S_IRUSR:
+                continue
+
             if os.path.isfile(p):
                 _, out = cmd('cat %s/%s' % (path, f))
                 dfs[f] = out.strip()