Subject: Re: [PATCH net-next v2 3/4] net: use indirect call wrappers at GRO transport layer

From: Stephen Hemminger <[email-masked]>
Date: Thu, 20 Dec 2018 18:57:22 -0800

On Wed,  5 Dec 2018 19:13:41 +0100
Paolo Abeni <[email-masked]> wrote:

> This avoids an indirect call in the receive path for TCP and UDP
> packets. TCP takes precedence on UDP, so that we have a single
> additional conditional in the common case.
> 
> v1 -> v2:
>  - adapted to INDIRECT_CALL_ changes
> 
> Signed-off-by: Paolo Abeni <[email-masked]>

This introduces a bunch of new warnings when kernel is built with W=1.
Please add the necessary prototypes in header files.

Putting prototypes in C file for global function is not the right way to fix
this.

net/ipv4/tcp_offload.c:310:17: warning: no previous prototype for ‘tcp4_gro_receive’ [-Wmissing-prototypes]
 struct sk_buff *tcp4_gro_receive(struct list_head *head, struct sk_buff *skb)
                 ^~~~~~~~~~~~~~~~
net/ipv4/tcp_offload.c:323:29: warning: no previous prototype for ‘tcp4_gro_complete’ [-Wmissing-prototypes]
 INDIRECT_CALLABLE_SCOPE int tcp4_gro_complete(struct sk_buff *skb, int thoff)
                             ^~~~~~~~~~~~~~~~~
  CC      net/ipv4/datagram.o
  CC      net/ipv4/udp_offload.o
net/ipv4/udp_offload.c:459:17: warning: no previous prototype for ‘udp4_gro_receive’ [-Wmissing-prototypes]
 struct sk_buff *udp4_gro_receive(struct list_head *head, struct sk_buff *skb)
                 ^~~~~~~~~~~~~~~~
net/ipv4/udp_offload.c:533:29: warning: no previous prototype for ‘udp4_gro_complete’ [-Wmissing-prototypes]
 INDIRECT_CALLABLE_SCOPE int udp4_gro_complete(struct sk_buff *skb, int nhoff)
                             ^~~~~~~~~~~~~~~~~
  CC      net/ipv4/arp.o
  CC      net/ipv6/ip6_offload.o
net/ipv6/ip6_offload.c:188:41: warning: no previous prototype for ‘ipv6_gro_receive’ [-Wmissing-prototypes]
 INDIRECT_CALLABLE_SCOPE struct sk_buff *ipv6_gro_receive(struct list_head *head,
                                         ^~~~~~~~~~~~~~~~
net/ipv6/ip6_offload.c:328:29: warning: no previous prototype for ‘ipv6_gro_complete’ [-Wmissing-prototypes]
 INDIRECT_CALLABLE_SCOPE int ipv6_gro_complete(struct sk_buff *skb, int nhoff)
                             ^~~~~~~~~~~~~~~~~
  CC      net/ipv6/tcpv6_offload.o
net/ipv6/tcpv6_offload.c:20:17: warning: no previous prototype for ‘tcp6_gro_receive’ [-Wmissing-prototypes]
 struct sk_buff *tcp6_gro_receive(struct list_head *head, struct sk_buff *skb)
                 ^~~~~~~~~~~~~~~~
net/ipv6/tcpv6_offload.c:33:29: warning: no previous prototype for ‘tcp6_gro_complete’ [-Wmissing-prototypes]
 INDIRECT_CALLABLE_SCOPE int tcp6_gro_complete(struct sk_buff *skb, int thoff)
                             ^~~~~~~~~~~~~~~~~
  CC      net/ipv6/exthdrs_offload.o