Re: [PATCH net-next v6 0/4] net/sched: retpoline wrappers for tc

[Pedro Tammela]

On 27/12/2022 05:33, Rudi Heitbaum wrote:
> Hi Pedro,
>
> Compiling kernel 6.2-rc1 fails on x86_64 when CONFIG_NET_CLS or
> CONFIG_NET_CLS_ACT is not set, when CONFIG_RETPOLINE=y is set.
>
> Does tc_wrapper RETPOLINE need a dependency on NET_CLS/NET_CLS_ACT
> to be added? Or a default?
>
> net/sched/sch_api.c: In function 'pktsched_init':
> net/sched/sch_api.c:2306:9: error: implicit declaration of function
> 'tc_wrapper_init' [-Werror=implicit-function-declaration]
>   2306 |         tc_wrapper_init();
>        |         ^~~~~~~~~~~~~~~
> cc1: some warnings being treated as errors
> make[3]: *** [scripts/Makefile.build:252: net/sched/sch_api.o] Error 1
> make[2]: *** [scripts/Makefile.build:504: net/sched] Error 2
> make[1]: *** [scripts/Makefile.build:504: net] Error 2
>
> below is the relevent lines from the .config file.
>
> $ grep -e RETPOLINE -e NET_CLS projects/Generic/linux/linux.x86_64.conf
> CONFIG_RETPOLINE=y
> # CONFIG_NET_CLS_BASIC is not set
> # CONFIG_NET_CLS_TCINDEX is not set
> # CONFIG_NET_CLS_ROUTE4 is not set
> # CONFIG_NET_CLS_FW is not set
> # CONFIG_NET_CLS_U32 is not set
> # CONFIG_NET_CLS_RSVP is not set
> # CONFIG_NET_CLS_RSVP6 is not set
> # CONFIG_NET_CLS_FLOW is not set
> # CONFIG_NET_CLS_CGROUP is not set
> # CONFIG_NET_CLS_BPF is not set
> # CONFIG_NET_CLS_FLOWER is not set
> # CONFIG_NET_CLS_MATCHALL is not set
> # CONFIG_NET_CLS_ACT is not set

Hi Rudi,

Thanks for the report.
Could you try the following patch?

diff --git a/include/net/tc_wrapper.h b/include/net/tc_wrapper.h
index ceed2fc089ff..d323fffb839a 100644
--- a/include/net/tc_wrapper.h
+++ b/include/net/tc_wrapper.h
@@ -216,6 +216,8 @@ static inline int tc_classify(struct sk_buff *skb, 
const struct tcf_proto *tp,
        return tp->classify(skb, tp, res);
 }

+#endif /* CONFIG_NET_CLS */
+
 static inline void tc_wrapper_init(void)
 {
 #ifdef CONFIG_X86
@@ -224,8 +226,6 @@ static inline void tc_wrapper_init(void)
 #endif
 }

-#endif /* CONFIG_NET_CLS */
-
 #else

 #define TC_INDIRECT_SCOPE static