bpf: Refactor cleanup of bpf_prog_test_run_skb

This bit of refactoring aims to simplify how we free memory in
bpf_prog_test_run_skb to avoid code duplication.

Signed-off-by: Paul Chaignon <[email protected]>
Signed-off-by: Martin KaFai Lau <[email protected]>
Tested-by: [email protected]
Link: https://patch.msgid.link/8971e01ae87b84f5af6b8b40defd3c310faf1c0f.1760037899.git.paul.chaignon@gmail.com

Author: pchaigno

net/bpf/test_run.c

@@ -979,10 +979,10 @@ int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr,
 	u32 size = kattr->test.data_size_in;
 	u32 repeat = kattr->test.repeat;
 	struct __sk_buff *ctx = NULL;
+	struct sk_buff *skb = NULL;
+	struct sock *sk = NULL;
 	u32 retval, duration;
 	int hh_len = ETH_HLEN;
-	struct sk_buff *skb;
-	struct sock *sk;
 	void *data;
 	int ret;
 
@@ -1001,8 +1001,9 @@ int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr,
 
 	ctx = bpf_ctx_init(kattr, sizeof(struct __sk_buff));
 	if (IS_ERR(ctx)) {
-		kfree(data);
-		return PTR_ERR(ctx);
+		ret = PTR_ERR(ctx);
+		ctx = NULL;
+		goto out;
 	}
 
 	switch (prog->type) {
@@ -1022,21 +1023,20 @@ int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr,
 
 	sk = sk_alloc(net, AF_UNSPEC, GFP_USER, &bpf_dummy_proto, 1);
 	if (!sk) {
-		kfree(data);
-		kfree(ctx);
-		return -ENOMEM;
+		ret = -ENOMEM;
+		goto out;
 	}
 	sock_init_data(NULL, sk);
 
 	skb = slab_build_skb(data);
 	if (!skb) {
-		kfree(data);
-		kfree(ctx);
-		sk_free(sk);
-		return -ENOMEM;
+		ret = -ENOMEM;
+		goto out;
 	}
 	skb->sk = sk;
 
+	data = NULL; /* data released via kfree_skb */
+
 	skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN);
 	__skb_put(skb, size);
 
@@ -1131,7 +1131,9 @@ int bpf_prog_test_run_skb(struct bpf_prog *prog, const union bpf_attr *kattr,
 	if (dev && dev != net->loopback_dev)
 		dev_put(dev);
 	kfree_skb(skb);
-	sk_free(sk);
+	kfree(data);
+	if (sk)
+		sk_free(sk);
 	kfree(ctx);
 	return ret;
 }