bpf, cls: consolidate prog deletion path

Commit 18cdb37ebf4c ("net: sched: do not use tcf_proto 'tp' argument from
call_rcu") removed the last usage of tp from cls_bpf_delete_prog(), so also
remove it from the function as argument to not give a wrong impression. tp
is illegal to access from this callback, since it could already have been
freed.

Refactor the deletion code a bit, so that cls_bpf_destroy() can call into
the same code for prog deletion as cls_bpf_delete() op, instead of having
it unnecessarily duplicated.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 13 insertions, 17 deletions

diff --git a/net/sched/cls_bpf.c b/net/sched/cls_bpf.c
index c37aa8b77fb5..f70e03d2d2c8 100644
--- a/net/sched/cls_bpf.c
+++ b/net/sched/cls_bpf.c
@@ -241,7 +241,7 @@ static int cls_bpf_init(struct tcf_proto *tp)
         return 0;
 }
 
-static void cls_bpf_delete_prog(struct tcf_proto *tp, struct cls_bpf_prog *prog)
+static void __cls_bpf_delete_prog(struct cls_bpf_prog *prog)
 {
         tcf_exts_destroy(&prog->exts);
 
@@ -255,22 +255,22 @@ static void cls_bpf_delete_prog(struct tcf_proto *tp, struct cls_bpf_prog *prog)
         kfree(prog);
 }
 
-static void __cls_bpf_delete_prog(struct rcu_head *rcu)
+static void cls_bpf_delete_prog_rcu(struct rcu_head *rcu)
 {
-        struct cls_bpf_prog *prog = container_of(rcu, struct cls_bpf_prog, rcu);
-
-        cls_bpf_delete_prog(prog->tp, prog);
+        __cls_bpf_delete_prog(container_of(rcu, struct cls_bpf_prog, rcu));
 }
 
-static int cls_bpf_delete(struct tcf_proto *tp, unsigned long arg)
+static void __cls_bpf_delete(struct tcf_proto *tp, struct cls_bpf_prog *prog)
 {
-        struct cls_bpf_prog *prog = (struct cls_bpf_prog *) arg;
-
         cls_bpf_stop_offload(tp, prog);
         list_del_rcu(&prog->link);
         tcf_unbind_filter(tp, &prog->res);
-        call_rcu(&prog->rcu, __cls_bpf_delete_prog);
+        call_rcu(&prog->rcu, cls_bpf_delete_prog_rcu);
+}
 
+static int cls_bpf_delete(struct tcf_proto *tp, unsigned long arg)
+{
+        __cls_bpf_delete(tp, (struct cls_bpf_prog *) arg);
         return 0;
 }
 
@@ -282,12 +282,8 @@ static bool cls_bpf_destroy(struct tcf_proto *tp, bool force)
         if (!force && !list_empty(&head->plist))
                 return false;
 
-        list_for_each_entry_safe(prog, tmp, &head->plist, link) {
-                cls_bpf_stop_offload(tp, prog);
-                list_del_rcu(&prog->link);
-                tcf_unbind_filter(tp, &prog->res);
-                call_rcu(&prog->rcu, __cls_bpf_delete_prog);
-        }
+        list_for_each_entry_safe(prog, tmp, &head->plist, link)
+                __cls_bpf_delete(tp, prog);
 
         kfree_rcu(head, rcu);
         return true;
@@ -511,14 +507,14 @@ static int cls_bpf_change(struct net *net, struct sk_buff *in_skb,
 
         ret = cls_bpf_offload(tp, prog, oldprog);
         if (ret) {
-                cls_bpf_delete_prog(tp, prog);
+                __cls_bpf_delete_prog(prog);
                 return ret;
         }
 
         if (oldprog) {
                 list_replace_rcu(&oldprog->link, &prog->link);
                 tcf_unbind_filter(tp, &oldprog->res);
-                call_rcu(&oldprog->rcu, __cls_bpf_delete_prog);
+                call_rcu(&oldprog->rcu, cls_bpf_delete_prog_rcu);
         } else {
                 list_add_rcu(&prog->link, &head->plist);
         }