On Wed, Sep 30, 2020 at 09:41:09AM -0700, Yonghong Song wrote:
> Michal reported a build failure likes below:
> BTFIDS vmlinux
> FAILED unresolved symbol tcp_timewait_sock
> make[1]: *** [/.../linux-5.9-rc7/Makefile:1176: vmlinux] Error 255
>
> This error can be triggered when config has CONFIG_NET enabled
> but CONFIG_INET disabled. In this case, there is no user of
> structs inet_timewait_sock and tcp_timewait_sock and hence vmlinux BTF
> types are not generated for these two structures.
>
> To fix the problem, omit the above two types for BTF_SOCK_TYPE_xxx
> macro if CONFIG_INET is not defined.
>
> Fixes: fce557bcef11 ("bpf: Make btf_sock_ids global")
> Reported-by: Michal Kubecek <mkubecek@xxxxxxx>
> Signed-off-by: Yonghong Song <yhs@xxxxxx>
> ---
> include/linux/btf_ids.h | 20 ++++++++++++++++----
> 1 file changed, 16 insertions(+), 4 deletions(-)
>
> diff --git a/include/linux/btf_ids.h b/include/linux/btf_ids.h
> index 4867d549e3c1..d9a1e18d0921 100644
> --- a/include/linux/btf_ids.h
> +++ b/include/linux/btf_ids.h
> @@ -102,24 +102,36 @@ asm( \
> * skc_to_*_sock() helpers. All these sockets should have
> * sock_common as the first argument in its memory layout.
> */
> -#define BTF_SOCK_TYPE_xxx \
> +
> +#define __BTF_SOCK_TYPE_xxx \
> BTF_SOCK_TYPE(BTF_SOCK_TYPE_INET, inet_sock) \
> BTF_SOCK_TYPE(BTF_SOCK_TYPE_INET_CONN, inet_connection_sock) \
> BTF_SOCK_TYPE(BTF_SOCK_TYPE_INET_REQ, inet_request_sock) \
> - BTF_SOCK_TYPE(BTF_SOCK_TYPE_INET_TW, inet_timewait_sock) \
> BTF_SOCK_TYPE(BTF_SOCK_TYPE_REQ, request_sock) \
> BTF_SOCK_TYPE(BTF_SOCK_TYPE_SOCK, sock) \
> BTF_SOCK_TYPE(BTF_SOCK_TYPE_SOCK_COMMON, sock_common) \
> BTF_SOCK_TYPE(BTF_SOCK_TYPE_TCP, tcp_sock) \
> BTF_SOCK_TYPE(BTF_SOCK_TYPE_TCP_REQ, tcp_request_sock) \
> - BTF_SOCK_TYPE(BTF_SOCK_TYPE_TCP_TW, tcp_timewait_sock) \
> BTF_SOCK_TYPE(BTF_SOCK_TYPE_TCP6, tcp6_sock) \
> BTF_SOCK_TYPE(BTF_SOCK_TYPE_UDP, udp_sock) \
> BTF_SOCK_TYPE(BTF_SOCK_TYPE_UDP6, udp6_sock)
>
> +#define __BTF_SOCK_TW_TYPE_xxx \
> + BTF_SOCK_TYPE(BTF_SOCK_TYPE_INET_TW, inet_timewait_sock) \
> + BTF_SOCK_TYPE(BTF_SOCK_TYPE_TCP_TW, tcp_timewait_sock)
> +
> +#ifdef CONFIG_INET
> +#define BTF_SOCK_TYPE_xxx \
> + __BTF_SOCK_TYPE_xxx \
> + __BTF_SOCK_TW_TYPE_xxx
> +#else
> +#define BTF_SOCK_TYPE_xxx __BTF_SOCK_TYPE_xxx
BTF_SOCK_TYPE_xxx is used in BTF_ID_LIST_GLOBAL(btf_sock_ids) in filter.c
which does not include BTF_SOCK_TYPE_TCP_TW.
However, btf_sock_ids[BTF_SOCK_TYPE_TCP_TW] is still used
in bpf_skc_to_tcp_timewait_sock_proto.
> +#endif
> +
> enum {
> #define BTF_SOCK_TYPE(name, str) name,
> -BTF_SOCK_TYPE_xxx
> +__BTF_SOCK_TYPE_xxx
> +__BTF_SOCK_TW_TYPE_xxx
BTF_SOCK_TYPE_TCP_TW is at the end of this enum.
Would btf_sock_ids[BTF_SOCK_TYPE_TCP_TW] always be 0?
> #undef BTF_SOCK_TYPE
> MAX_BTF_SOCK_TYPE,
> };
> --
> 2.24.1
>
