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, for two timewait structures, if CONFIG_INET=n,
use BTF_ID_UNUSED instead of BTF_ID to skip btf id generation
in resolve_btfids.
Fixes: fce557bcef11 ("bpf: Make btf_sock_ids global")
Reported-by: Michal Kubecek <mkube...@suse.cz>
Signed-off-by: Yonghong Song <y...@fb.com>
---
include/linux/btf_ids.h | 20 +++++++++++++++++---
net/core/filter.c | 1 +
2 files changed, 18 insertions(+), 3 deletions(-)
Changelog:
v1 -> v2:
. For unsupported socket times, using BTF_ID_UNUSED to
keep the id as 0. (Martin)
diff --git a/include/linux/btf_ids.h b/include/linux/btf_ids.h
index 4867d549e3c1..9c49bf89a9a7 100644
--- a/include/linux/btf_ids.h
+++ b/include/linux/btf_ids.h
@@ -102,23 +102,37 @@ 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)
+#ifdef CONFIG_INET
+#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)
+#else
+#define __BTF_SOCK_TW_TYPE_xxx \
+ BTF_SOCK_TYPE_UNUSED(BTF_SOCK_TYPE_INET_TW) \
+ BTF_SOCK_TYPE_UNUSED(BTF_SOCK_TYPE_TCP_TW)
+#endif
+
+#define BTF_SOCK_TYPE_xxx \
+ __BTF_SOCK_TYPE_xxx \
+ __BTF_SOCK_TW_TYPE_xxx
+
enum {
#define BTF_SOCK_TYPE(name, str) name,
+#define BTF_SOCK_TYPE_UNUSED(name) name,
BTF_SOCK_TYPE_xxx
#undef BTF_SOCK_TYPE
MAX_BTF_SOCK_TYPE,
diff --git a/net/core/filter.c b/net/core/filter.c
index 21eaf3b182f2..396fe928e202 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -9500,6 +9500,7 @@ void bpf_prog_change_xdp(struct bpf_prog *prev_prog,
struct bpf_prog *prog)
#ifdef CONFIG_DEBUG_INFO_BTF
BTF_ID_LIST_GLOBAL(btf_sock_ids)
#define BTF_SOCK_TYPE(name, type) BTF_ID(struct, type)
+#define BTF_SOCK_TYPE_UNUSED(name) BTF_ID_UNUSED
BTF_SOCK_TYPE_xxx
#undef BTF_SOCK_TYPE
#else
--
2.24.1
