On 7/31/25 7:52 PM, chenyuan_fl@163.com wrote:

From: Yuan Chen chenyuan@kylinos.cn

Fix implicit function declaration errors in bpf_qdisc_xxx.c by adding the required kernel symbol declarations to the shared header file bpf_qdisc_common.h. This ensures all qdisc BPF programs can properly resolve these kernel functions.

The added declarations include:

• bpf_qdisc_skb_drop
• bpf_qdisc_bstats_update
• bpf_kfree_skb
• bpf_skb_get_hash
• bpf_qdisc_watchdog_schedule

Using a common header prevents duplication and ensures consistency across different qdisc implementations.

If you have proper and recent vmlinux.h (with recent pahole as well during kernel build), all the above declarations should be in vmlinux.h. How did you generate your vmlinux.h? Can you just generate a better one based on recent kernel/pahole?

Signed-off-by: Yuan Chen chenyuan@kylinos.cn

tools/testing/selftests/bpf/progs/bpf_qdisc_common.h | 9 +++++++++ 1 file changed, 9 insertions(+)

diff --git a/tools/testing/selftests/bpf/progs/bpf_qdisc_common.h b/tools/testing/selftests/bpf/progs/bpf_qdisc_common.h index 3754f581b328..4c896b3e0f65 100644 --- a/tools/testing/selftests/bpf/progs/bpf_qdisc_common.h +++ b/tools/testing/selftests/bpf/progs/bpf_qdisc_common.h @@ -14,6 +14,15 @@ struct bpf_sk_buff_ptr; +extern void bpf_qdisc_skb_drop(struct sk_buff *skb,

• 	       struct bpf_sk_buff_ptr *to_free_list) __ksym;
  

+extern void bpf_qdisc_bstats_update(struct Qdisc *sch,

• 		    const struct sk_buff *skb) __ksym;
  

+extern void bpf_kfree_skb(struct sk_buff *skb) __ksym; +extern u32 bpf_skb_get_hash(struct sk_buff *skb) __ksym; +extern void bpf_qdisc_watchdog_schedule(struct Qdisc *sch, u64 expire,

• 			u64 delta_ns) __ksym;
  

• static struct qdisc_skb_cb *qdisc_skb_cb(const struct sk_buff *skb) { return (struct qdisc_skb_cb *)skb->cb;