Commit 8d829bdb authored by Daniel Borkmann's avatar Daniel Borkmann Committed by David S. Miller
Browse files

bpf, cls: consolidate prog deletion path 



Commit 18cdb37e ("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: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 1afaf661

net/sched/cls_bpf.c

+13 −17
Original line number Diff line number Diff line
@@ -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);

	}

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