Merge branch 'net-sched-fix-parsing-of-tca_ext_warn_msg-for-tc-action'

Hangbin Liu says:

====================
net/sched: fix parsing of TCA_EXT_WARN_MSG for tc action

In my previous commit 0349b87 ("sched: add new attr TCA_EXT_WARN_MSG
to report tc extact message") I didn't notice the tc action use different
enum with filter. So we can't use TCA_EXT_WARN_MSG directly for tc action.

Let's rever the previous fix 923b2e3 ("net/sched: act_api: move
TCA_EXT_WARN_MSG to the correct hierarchy") and add a new
TCA_ROOT_EXT_WARN_MSG for tc action specifically.

Here is the tdc test result:

1..1119
ok 1 d959 - Add cBPF action with valid bytecode
ok 2 f84a - Add cBPF action with invalid bytecode
ok 3 e939 - Add eBPF action with valid object-file
ok 4 282d - Add eBPF action with invalid object-file
ok 5 d819 - Replace cBPF bytecode and action control
ok 6 6ae3 - Delete cBPF action
ok 7 3e0d - List cBPF actions
ok 8 55ce - Flush BPF actions
ok 9 ccc3 - Add cBPF action with duplicate index
ok 10 89c7 - Add cBPF action with invalid index
[...]
ok 1115 2348 - Show TBF class
ok 1116 84a0 - Create TEQL with default setting
ok 1117 7734 - Create TEQL with multiple device
ok 1118 34a9 - Delete TEQL with valid handle
ok 1119 6289 - Show TEQL stats
====================

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

Author: kuba-moo

include/uapi/linux/rtnetlink.h

@@ -789,6 +789,7 @@ enum {
 	TCA_ROOT_FLAGS,
 	TCA_ROOT_COUNT,
 	TCA_ROOT_TIME_DELTA, /* in msecs */
+	TCA_ROOT_EXT_WARN_MSG,
 	__TCA_ROOT_MAX,
 #define	TCA_ROOT_MAX (__TCA_ROOT_MAX - 1)
 };

net/sched/act_api.c

@@ -1589,17 +1589,17 @@ static int tca_get_fill(struct sk_buff *skb, struct tc_action *actions[],
 	t->tca__pad1 = 0;
 	t->tca__pad2 = 0;
 
+	if (extack && extack->_msg &&
+	    nla_put_string(skb, TCA_ROOT_EXT_WARN_MSG, extack->_msg))
+		goto out_nlmsg_trim;
+
 	nest = nla_nest_start_noflag(skb, TCA_ACT_TAB);
 	if (!nest)
 		goto out_nlmsg_trim;
 
 	if (tcf_action_dump(skb, actions, bind, ref, false) < 0)
 		goto out_nlmsg_trim;
 
-	if (extack && extack->_msg &&
-	    nla_put_string(skb, TCA_EXT_WARN_MSG, extack->_msg))
-		goto out_nlmsg_trim;
-
 	nla_nest_end(skb, nest);
 
 	nlh->nlmsg_len = skb_tail_pointer(skb) - b;