[RFC] ipv4: remove useless arg

[RFC] ipv4: remove useless arg

[tianyu2]

When I wanted to kprobe the ip_rcv_finish_core, I found that using x1 to
pass "struct sk_buff *skb"."struct sock *sk" was not used in the
function, causing the compiler to optimize away. This resulted in a
hard to use kprobe. Why not delete him?

Signed-off-by: tianyu2 <tianyu2@kernelsoft.com>
---
 net/ipv4/ip_input.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c
index e7196ecffafc..2ff88c598988 100644
--- a/net/ipv4/ip_input.c
+++ b/net/ipv4/ip_input.c
@@ -314,7 +314,7 @@ static bool ip_can_use_hint(const struct sk_buff *skb, const struct iphdr *iph,
 
 int tcp_v4_early_demux(struct sk_buff *skb);
 int udp_v4_early_demux(struct sk_buff *skb);
-static int ip_rcv_finish_core(struct net *net, struct sock *sk,
+static int ip_rcv_finish_core(struct net *net,
 			      struct sk_buff *skb, struct net_device *dev,
 			      const struct sk_buff *hint)
 {
@@ -444,7 +444,7 @@ static int ip_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
 	if (!skb)
 		return NET_RX_SUCCESS;
 
-	ret = ip_rcv_finish_core(net, sk, skb, dev, NULL);
+	ret = ip_rcv_finish_core(net, skb, dev, NULL);
 	if (ret != NET_RX_DROP)
 		ret = dst_input(skb);
 	return ret;
@@ -610,7 +610,7 @@ static void ip_list_rcv_finish(struct net *net, struct sock *sk,
 		skb = l3mdev_ip_rcv(skb);
 		if (!skb)
 			continue;
-		if (ip_rcv_finish_core(net, sk, skb, dev, hint) == NET_RX_DROP)
+		if (ip_rcv_finish_core(net, skb, dev, hint) == NET_RX_DROP)
 			continue;
 
 		dst = skb_dst(skb);
-- 
2.27.0

Re: [RFC] ipv4: remove useless arg

[Eric Dumazet]

On 11/26/24 2:19 PM, tianyu2 wrote:
> When I wanted to kprobe the ip_rcv_finish_core, I found that using x1 to
> pass "struct sk_buff *skb"."struct sock *sk" was not used in the
> function, causing the compiler to optimize away. This resulted in a
> hard to use kprobe. Why not delete him?
>
> Signed-off-by: tianyu2 <tianyu2@kernelsoft.com>
> ---

This is great seeing compilers being smart.

SGTM, please send this next week when net-next is open again.

Also do the same for ip_list_rcv_finish()

Re: Re: [RFC] ipv4: remove useless arg

[田宇2]

> On 11/26/24 2:19 PM, tianyu2 wrote:
> > When I wanted to kprobe the ip_rcv_finish_core, I found that using x1 to
> > pass "struct sk_buff *skb"."struct sock *sk" was not used in the
> > function, causing the compiler to optimize away. This resulted in a
> > hard to use kprobe. Why not delete him?
> >
> > Signed-off-by: tianyu2 <tianyu2@kernelsoft.com>
> > ---
> 
> This is great seeing compilers being smart.
> 
> SGTM, please send this next week when net-next is open again.
> 
> Also do the same for ip_list_rcv_finish()
> 
Okay, thanks for the reply.