[bpf-next,v4,3/3] bpf: treewide: Annotate BPF kfuncs in BTF

  This commit marks kfuncs as such inside the .BTF_ids section. The upshot
of these annotations is that we'll be able to automatically generate
kfunc prototypes for downstream users. The process is as follows:

1. In source, use BTF_KFUNCS_START/END macro pair to mark kfuncs
2. During build, pahole injects into BTF a "bpf_kfunc" BTF_DECL_TAG for
   each function inside BTF_KFUNCS sets
3. At runtime, vmlinux or module BTF is made available in sysfs
4. At runtime, bpftool (or similar) can look at provided BTF and
   generate appropriate prototypes for functions with "bpf_kfunc" tag

To ensure future kfunc are similarly tagged, we now also return error
inside kfunc registration for untagged kfuncs. For vmlinux kfuncs,
we also WARN(), as initcall machinery does not handle errors.

Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
---
 Documentation/bpf/kfuncs.rst                  |  8 ++++----
 drivers/hid/bpf/hid_bpf_dispatch.c            |  8 ++++----
 fs/verity/measure.c                           |  4 ++--
 kernel/bpf/btf.c                              |  8 ++++++++
 kernel/bpf/cpumask.c                          |  4 ++--
 kernel/bpf/helpers.c                          |  8 ++++----
 kernel/bpf/map_iter.c                         |  4 ++--
 kernel/cgroup/rstat.c                         |  4 ++--
 kernel/trace/bpf_trace.c                      |  8 ++++----
 net/bpf/test_run.c                            |  8 ++++----
 net/core/filter.c                             | 20 +++++++++----------
 net/core/xdp.c                                |  4 ++--
 net/ipv4/bpf_tcp_ca.c                         |  4 ++--
 net/ipv4/fou_bpf.c                            |  4 ++--
 net/ipv4/tcp_bbr.c                            |  4 ++--
 net/ipv4/tcp_cubic.c                          |  4 ++--
 net/ipv4/tcp_dctcp.c                          |  4 ++--
 net/netfilter/nf_conntrack_bpf.c              |  4 ++--
 net/netfilter/nf_nat_bpf.c                    |  4 ++--
 net/xfrm/xfrm_interface_bpf.c                 |  4 ++--
 net/xfrm/xfrm_state_bpf.c                     |  4 ++--
 .../selftests/bpf/bpf_testmod/bpf_testmod.c   |  8 ++++----
 22 files changed, 70 insertions(+), 62 deletions(-)
  

On Jan 28 2024, Daniel Xu wrote:
> This commit marks kfuncs as such inside the .BTF_ids section. The upshot
> of these annotations is that we'll be able to automatically generate
> kfunc prototypes for downstream users. The process is as follows:
> 
> 1. In source, use BTF_KFUNCS_START/END macro pair to mark kfuncs
> 2. During build, pahole injects into BTF a "bpf_kfunc" BTF_DECL_TAG for
>    each function inside BTF_KFUNCS sets
> 3. At runtime, vmlinux or module BTF is made available in sysfs
> 4. At runtime, bpftool (or similar) can look at provided BTF and
>    generate appropriate prototypes for functions with "bpf_kfunc" tag
> 
> To ensure future kfunc are similarly tagged, we now also return error
> inside kfunc registration for untagged kfuncs. For vmlinux kfuncs,
> we also WARN(), as initcall machinery does not handle errors.
> 
> Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
> ---
>  Documentation/bpf/kfuncs.rst                  |  8 ++++----
>  drivers/hid/bpf/hid_bpf_dispatch.c            |  8 ++++----

For the HID changes (they shouldn't conflict with our current branch):
Acked-by: Benjamin Tissoires <bentiss@kernel.org>

Cheers,
Benjamin

>  fs/verity/measure.c                           |  4 ++--
>  kernel/bpf/btf.c                              |  8 ++++++++
>  kernel/bpf/cpumask.c                          |  4 ++--
>  kernel/bpf/helpers.c                          |  8 ++++----
>  kernel/bpf/map_iter.c                         |  4 ++--
>  kernel/cgroup/rstat.c                         |  4 ++--
>  kernel/trace/bpf_trace.c                      |  8 ++++----
>  net/bpf/test_run.c                            |  8 ++++----
>  net/core/filter.c                             | 20 +++++++++----------
>  net/core/xdp.c                                |  4 ++--
>  net/ipv4/bpf_tcp_ca.c                         |  4 ++--
>  net/ipv4/fou_bpf.c                            |  4 ++--
>  net/ipv4/tcp_bbr.c                            |  4 ++--
>  net/ipv4/tcp_cubic.c                          |  4 ++--
>  net/ipv4/tcp_dctcp.c                          |  4 ++--
>  net/netfilter/nf_conntrack_bpf.c              |  4 ++--
>  net/netfilter/nf_nat_bpf.c                    |  4 ++--
>  net/xfrm/xfrm_interface_bpf.c                 |  4 ++--
>  net/xfrm/xfrm_state_bpf.c                     |  4 ++--
>  .../selftests/bpf/bpf_testmod/bpf_testmod.c   |  8 ++++----
>  22 files changed, 70 insertions(+), 62 deletions(-)
> 
> diff --git a/Documentation/bpf/kfuncs.rst b/Documentation/bpf/kfuncs.rst
> index 7985c6615f3c..a8f5782bd833 100644
> --- a/Documentation/bpf/kfuncs.rst
> +++ b/Documentation/bpf/kfuncs.rst
> @@ -177,10 +177,10 @@ In addition to kfuncs' arguments, verifier may need more information about the
>  type of kfunc(s) being registered with the BPF subsystem. To do so, we define
>  flags on a set of kfuncs as follows::
>  
> -        BTF_SET8_START(bpf_task_set)
> +        BTF_KFUNCS_START(bpf_task_set)
>          BTF_ID_FLAGS(func, bpf_get_task_pid, KF_ACQUIRE | KF_RET_NULL)
>          BTF_ID_FLAGS(func, bpf_put_pid, KF_RELEASE)
> -        BTF_SET8_END(bpf_task_set)
> +        BTF_KFUNCS_END(bpf_task_set)
>  
>  This set encodes the BTF ID of each kfunc listed above, and encodes the flags
>  along with it. Ofcourse, it is also allowed to specify no flags.
> @@ -347,10 +347,10 @@ Once the kfunc is prepared for use, the final step to making it visible is
>  registering it with the BPF subsystem. Registration is done per BPF program
>  type. An example is shown below::
>  
> -        BTF_SET8_START(bpf_task_set)
> +        BTF_KFUNCS_START(bpf_task_set)
>          BTF_ID_FLAGS(func, bpf_get_task_pid, KF_ACQUIRE | KF_RET_NULL)
>          BTF_ID_FLAGS(func, bpf_put_pid, KF_RELEASE)
> -        BTF_SET8_END(bpf_task_set)
> +        BTF_KFUNCS_END(bpf_task_set)
>  
>          static const struct btf_kfunc_id_set bpf_task_kfunc_set = {
>                  .owner = THIS_MODULE,
> diff --git a/drivers/hid/bpf/hid_bpf_dispatch.c b/drivers/hid/bpf/hid_bpf_dispatch.c
> index d9ef45fcaeab..02c441aaa217 100644
> --- a/drivers/hid/bpf/hid_bpf_dispatch.c
> +++ b/drivers/hid/bpf/hid_bpf_dispatch.c
> @@ -172,9 +172,9 @@ hid_bpf_get_data(struct hid_bpf_ctx *ctx, unsigned int offset, const size_t rdwr
>   * The following set contains all functions we agree BPF programs
>   * can use.
>   */
> -BTF_SET8_START(hid_bpf_kfunc_ids)
> +BTF_KFUNCS_START(hid_bpf_kfunc_ids)
>  BTF_ID_FLAGS(func, hid_bpf_get_data, KF_RET_NULL)
> -BTF_SET8_END(hid_bpf_kfunc_ids)
> +BTF_KFUNCS_END(hid_bpf_kfunc_ids)
>  
>  static const struct btf_kfunc_id_set hid_bpf_kfunc_set = {
>  	.owner = THIS_MODULE,
> @@ -440,12 +440,12 @@ static const struct btf_kfunc_id_set hid_bpf_fmodret_set = {
>  };
>  
>  /* for syscall HID-BPF */
> -BTF_SET8_START(hid_bpf_syscall_kfunc_ids)
> +BTF_KFUNCS_START(hid_bpf_syscall_kfunc_ids)
>  BTF_ID_FLAGS(func, hid_bpf_attach_prog)
>  BTF_ID_FLAGS(func, hid_bpf_allocate_context, KF_ACQUIRE | KF_RET_NULL)
>  BTF_ID_FLAGS(func, hid_bpf_release_context, KF_RELEASE)
>  BTF_ID_FLAGS(func, hid_bpf_hw_request)
> -BTF_SET8_END(hid_bpf_syscall_kfunc_ids)
> +BTF_KFUNCS_END(hid_bpf_syscall_kfunc_ids)
>  
>  static const struct btf_kfunc_id_set hid_bpf_syscall_kfunc_set = {
>  	.owner = THIS_MODULE,
> diff --git a/fs/verity/measure.c b/fs/verity/measure.c
> index bf7a5f4cccaf..3969d54158d1 100644
> --- a/fs/verity/measure.c
> +++ b/fs/verity/measure.c
> @@ -159,9 +159,9 @@ __bpf_kfunc int bpf_get_fsverity_digest(struct file *file, struct bpf_dynptr_ker
>  
>  __bpf_kfunc_end_defs();
>  
> -BTF_SET8_START(fsverity_set_ids)
> +BTF_KFUNCS_START(fsverity_set_ids)
>  BTF_ID_FLAGS(func, bpf_get_fsverity_digest, KF_TRUSTED_ARGS)
> -BTF_SET8_END(fsverity_set_ids)
> +BTF_KFUNCS_END(fsverity_set_ids)
>  
>  static int bpf_get_fsverity_digest_filter(const struct bpf_prog *prog, u32 kfunc_id)
>  {
> diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
> index edef96ceffa3..bc446f37530c 100644
> --- a/kernel/bpf/btf.c
> +++ b/kernel/bpf/btf.c
> @@ -8041,6 +8041,14 @@ int register_btf_kfunc_id_set(enum bpf_prog_type prog_type,
>  {
>  	enum btf_kfunc_hook hook;
>  
> +	/* All kfuncs need to be tagged as such in BTF.
> +	 * WARN() for initcall registrations that do not check errors.
> +	 */
> +	if (!(kset->set->flags & BTF_SET8_KFUNCS)) {
> +		WARN_ON(!kset->owner);
> +		return -EINVAL;
> +	}
> +
>  	hook = bpf_prog_type_to_kfunc_hook(prog_type);
>  	return __register_btf_kfunc_id_set(hook, kset);
>  }
> diff --git a/kernel/bpf/cpumask.c b/kernel/bpf/cpumask.c
> index 2e73533a3811..dad0fb1c8e87 100644
> --- a/kernel/bpf/cpumask.c
> +++ b/kernel/bpf/cpumask.c
> @@ -424,7 +424,7 @@ __bpf_kfunc u32 bpf_cpumask_weight(const struct cpumask *cpumask)
>  
>  __bpf_kfunc_end_defs();
>  
> -BTF_SET8_START(cpumask_kfunc_btf_ids)
> +BTF_KFUNCS_START(cpumask_kfunc_btf_ids)
>  BTF_ID_FLAGS(func, bpf_cpumask_create, KF_ACQUIRE | KF_RET_NULL)
>  BTF_ID_FLAGS(func, bpf_cpumask_release, KF_RELEASE)
>  BTF_ID_FLAGS(func, bpf_cpumask_acquire, KF_ACQUIRE | KF_TRUSTED_ARGS)
> @@ -450,7 +450,7 @@ BTF_ID_FLAGS(func, bpf_cpumask_copy, KF_RCU)
>  BTF_ID_FLAGS(func, bpf_cpumask_any_distribute, KF_RCU)
>  BTF_ID_FLAGS(func, bpf_cpumask_any_and_distribute, KF_RCU)
>  BTF_ID_FLAGS(func, bpf_cpumask_weight, KF_RCU)
> -BTF_SET8_END(cpumask_kfunc_btf_ids)
> +BTF_KFUNCS_END(cpumask_kfunc_btf_ids)
>  
>  static const struct btf_kfunc_id_set cpumask_kfunc_set = {
>  	.owner = THIS_MODULE,
> diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
> index bcb951a2ecf4..4db1c658254c 100644
> --- a/kernel/bpf/helpers.c
> +++ b/kernel/bpf/helpers.c
> @@ -2544,7 +2544,7 @@ __bpf_kfunc void bpf_throw(u64 cookie)
>  
>  __bpf_kfunc_end_defs();
>  
> -BTF_SET8_START(generic_btf_ids)
> +BTF_KFUNCS_START(generic_btf_ids)
>  #ifdef CONFIG_KEXEC_CORE
>  BTF_ID_FLAGS(func, crash_kexec, KF_DESTRUCTIVE)
>  #endif
> @@ -2573,7 +2573,7 @@ BTF_ID_FLAGS(func, bpf_task_get_cgroup1, KF_ACQUIRE | KF_RCU | KF_RET_NULL)
>  #endif
>  BTF_ID_FLAGS(func, bpf_task_from_pid, KF_ACQUIRE | KF_RET_NULL)
>  BTF_ID_FLAGS(func, bpf_throw)
> -BTF_SET8_END(generic_btf_ids)
> +BTF_KFUNCS_END(generic_btf_ids)
>  
>  static const struct btf_kfunc_id_set generic_kfunc_set = {
>  	.owner = THIS_MODULE,
> @@ -2589,7 +2589,7 @@ BTF_ID(struct, cgroup)
>  BTF_ID(func, bpf_cgroup_release_dtor)
>  #endif
>  
> -BTF_SET8_START(common_btf_ids)
> +BTF_KFUNCS_START(common_btf_ids)
>  BTF_ID_FLAGS(func, bpf_cast_to_kern_ctx)
>  BTF_ID_FLAGS(func, bpf_rdonly_cast)
>  BTF_ID_FLAGS(func, bpf_rcu_read_lock)
> @@ -2618,7 +2618,7 @@ BTF_ID_FLAGS(func, bpf_dynptr_is_null)
>  BTF_ID_FLAGS(func, bpf_dynptr_is_rdonly)
>  BTF_ID_FLAGS(func, bpf_dynptr_size)
>  BTF_ID_FLAGS(func, bpf_dynptr_clone)
> -BTF_SET8_END(common_btf_ids)
> +BTF_KFUNCS_END(common_btf_ids)
>  
>  static const struct btf_kfunc_id_set common_kfunc_set = {
>  	.owner = THIS_MODULE,
> diff --git a/kernel/bpf/map_iter.c b/kernel/bpf/map_iter.c
> index 6abd7c5df4b3..9575314f40a6 100644
> --- a/kernel/bpf/map_iter.c
> +++ b/kernel/bpf/map_iter.c
> @@ -213,9 +213,9 @@ __bpf_kfunc s64 bpf_map_sum_elem_count(const struct bpf_map *map)
>  
>  __bpf_kfunc_end_defs();
>  
> -BTF_SET8_START(bpf_map_iter_kfunc_ids)
> +BTF_KFUNCS_START(bpf_map_iter_kfunc_ids)
>  BTF_ID_FLAGS(func, bpf_map_sum_elem_count, KF_TRUSTED_ARGS)
> -BTF_SET8_END(bpf_map_iter_kfunc_ids)
> +BTF_KFUNCS_END(bpf_map_iter_kfunc_ids)
>  
>  static const struct btf_kfunc_id_set bpf_map_iter_kfunc_set = {
>  	.owner = THIS_MODULE,
> diff --git a/kernel/cgroup/rstat.c b/kernel/cgroup/rstat.c
> index a8350d2d63e6..07e2284bb499 100644
> --- a/kernel/cgroup/rstat.c
> +++ b/kernel/cgroup/rstat.c
> @@ -562,10 +562,10 @@ void cgroup_base_stat_cputime_show(struct seq_file *seq)
>  }
>  
>  /* Add bpf kfuncs for cgroup_rstat_updated() and cgroup_rstat_flush() */
> -BTF_SET8_START(bpf_rstat_kfunc_ids)
> +BTF_KFUNCS_START(bpf_rstat_kfunc_ids)
>  BTF_ID_FLAGS(func, cgroup_rstat_updated)
>  BTF_ID_FLAGS(func, cgroup_rstat_flush, KF_SLEEPABLE)
> -BTF_SET8_END(bpf_rstat_kfunc_ids)
> +BTF_KFUNCS_END(bpf_rstat_kfunc_ids)
>  
>  static const struct btf_kfunc_id_set bpf_rstat_kfunc_set = {
>  	.owner          = THIS_MODULE,
> diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
> index 64fdaf79d113..241ddf5e3895 100644
> --- a/kernel/trace/bpf_trace.c
> +++ b/kernel/trace/bpf_trace.c
> @@ -1412,14 +1412,14 @@ __bpf_kfunc int bpf_verify_pkcs7_signature(struct bpf_dynptr_kern *data_ptr,
>  
>  __bpf_kfunc_end_defs();
>  
> -BTF_SET8_START(key_sig_kfunc_set)
> +BTF_KFUNCS_START(key_sig_kfunc_set)
>  BTF_ID_FLAGS(func, bpf_lookup_user_key, KF_ACQUIRE | KF_RET_NULL | KF_SLEEPABLE)
>  BTF_ID_FLAGS(func, bpf_lookup_system_key, KF_ACQUIRE | KF_RET_NULL)
>  BTF_ID_FLAGS(func, bpf_key_put, KF_RELEASE)
>  #ifdef CONFIG_SYSTEM_DATA_VERIFICATION
>  BTF_ID_FLAGS(func, bpf_verify_pkcs7_signature, KF_SLEEPABLE)
>  #endif
> -BTF_SET8_END(key_sig_kfunc_set)
> +BTF_KFUNCS_END(key_sig_kfunc_set)
>  
>  static const struct btf_kfunc_id_set bpf_key_sig_kfunc_set = {
>  	.owner = THIS_MODULE,
> @@ -1475,9 +1475,9 @@ __bpf_kfunc int bpf_get_file_xattr(struct file *file, const char *name__str,
>  
>  __bpf_kfunc_end_defs();
>  
> -BTF_SET8_START(fs_kfunc_set_ids)
> +BTF_KFUNCS_START(fs_kfunc_set_ids)
>  BTF_ID_FLAGS(func, bpf_get_file_xattr, KF_SLEEPABLE | KF_TRUSTED_ARGS)
> -BTF_SET8_END(fs_kfunc_set_ids)
> +BTF_KFUNCS_END(fs_kfunc_set_ids)
>  
>  static int bpf_get_file_xattr_filter(const struct bpf_prog *prog, u32 kfunc_id)
>  {
> diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c
> index dfd919374017..5535f9adc658 100644
> --- a/net/bpf/test_run.c
> +++ b/net/bpf/test_run.c
> @@ -617,21 +617,21 @@ CFI_NOSEAL(bpf_kfunc_call_memb_release_dtor);
>  
>  __bpf_kfunc_end_defs();
>  
> -BTF_SET8_START(bpf_test_modify_return_ids)
> +BTF_KFUNCS_START(bpf_test_modify_return_ids)
>  BTF_ID_FLAGS(func, bpf_modify_return_test)
>  BTF_ID_FLAGS(func, bpf_modify_return_test2)
>  BTF_ID_FLAGS(func, bpf_fentry_test1, KF_SLEEPABLE)
> -BTF_SET8_END(bpf_test_modify_return_ids)
> +BTF_KFUNCS_END(bpf_test_modify_return_ids)
>  
>  static const struct btf_kfunc_id_set bpf_test_modify_return_set = {
>  	.owner = THIS_MODULE,
>  	.set   = &bpf_test_modify_return_ids,
>  };
>  
> -BTF_SET8_START(test_sk_check_kfunc_ids)
> +BTF_KFUNCS_START(test_sk_check_kfunc_ids)
>  BTF_ID_FLAGS(func, bpf_kfunc_call_test_release, KF_RELEASE)
>  BTF_ID_FLAGS(func, bpf_kfunc_call_memb_release, KF_RELEASE)
> -BTF_SET8_END(test_sk_check_kfunc_ids)
> +BTF_KFUNCS_END(test_sk_check_kfunc_ids)
>  
>  static void *bpf_test_init(const union bpf_attr *kattr, u32 user_size,
>  			   u32 size, u32 headroom, u32 tailroom)
> diff --git a/net/core/filter.c b/net/core/filter.c
> index 358870408a51..524adf1fa6d0 100644
> --- a/net/core/filter.c
> +++ b/net/core/filter.c
> @@ -11982,21 +11982,21 @@ int bpf_dynptr_from_skb_rdonly(struct sk_buff *skb, u64 flags,
>  	return 0;
>  }
>  
> -BTF_SET8_START(bpf_kfunc_check_set_skb)
> +BTF_KFUNCS_START(bpf_kfunc_check_set_skb)
>  BTF_ID_FLAGS(func, bpf_dynptr_from_skb)
> -BTF_SET8_END(bpf_kfunc_check_set_skb)
> +BTF_KFUNCS_END(bpf_kfunc_check_set_skb)
>  
> -BTF_SET8_START(bpf_kfunc_check_set_xdp)
> +BTF_KFUNCS_START(bpf_kfunc_check_set_xdp)
>  BTF_ID_FLAGS(func, bpf_dynptr_from_xdp)
> -BTF_SET8_END(bpf_kfunc_check_set_xdp)
> +BTF_KFUNCS_END(bpf_kfunc_check_set_xdp)
>  
> -BTF_SET8_START(bpf_kfunc_check_set_sock_addr)
> +BTF_KFUNCS_START(bpf_kfunc_check_set_sock_addr)
>  BTF_ID_FLAGS(func, bpf_sock_addr_set_sun_path)
> -BTF_SET8_END(bpf_kfunc_check_set_sock_addr)
> +BTF_KFUNCS_END(bpf_kfunc_check_set_sock_addr)
>  
> -BTF_SET8_START(bpf_kfunc_check_set_tcp_reqsk)
> +BTF_KFUNCS_START(bpf_kfunc_check_set_tcp_reqsk)
>  BTF_ID_FLAGS(func, bpf_sk_assign_tcp_reqsk, KF_TRUSTED_ARGS)
> -BTF_SET8_END(bpf_kfunc_check_set_tcp_reqsk)
> +BTF_KFUNCS_END(bpf_kfunc_check_set_tcp_reqsk)
>  
>  static const struct btf_kfunc_id_set bpf_kfunc_set_skb = {
>  	.owner = THIS_MODULE,
> @@ -12075,9 +12075,9 @@ __bpf_kfunc int bpf_sock_destroy(struct sock_common *sock)
>  
>  __bpf_kfunc_end_defs();
>  
> -BTF_SET8_START(bpf_sk_iter_kfunc_ids)
> +BTF_KFUNCS_START(bpf_sk_iter_kfunc_ids)
>  BTF_ID_FLAGS(func, bpf_sock_destroy, KF_TRUSTED_ARGS)
> -BTF_SET8_END(bpf_sk_iter_kfunc_ids)
> +BTF_KFUNCS_END(bpf_sk_iter_kfunc_ids)
>  
>  static int tracing_iter_filter(const struct bpf_prog *prog, u32 kfunc_id)
>  {
> diff --git a/net/core/xdp.c b/net/core/xdp.c
> index 4869c1c2d8f3..034fb80f3fbe 100644
> --- a/net/core/xdp.c
> +++ b/net/core/xdp.c
> @@ -771,11 +771,11 @@ __bpf_kfunc int bpf_xdp_metadata_rx_vlan_tag(const struct xdp_md *ctx,
>  
>  __bpf_kfunc_end_defs();
>  
> -BTF_SET8_START(xdp_metadata_kfunc_ids)
> +BTF_KFUNCS_START(xdp_metadata_kfunc_ids)
>  #define XDP_METADATA_KFUNC(_, __, name, ___) BTF_ID_FLAGS(func, name, KF_TRUSTED_ARGS)
>  XDP_METADATA_KFUNC_xxx
>  #undef XDP_METADATA_KFUNC
> -BTF_SET8_END(xdp_metadata_kfunc_ids)
> +BTF_KFUNCS_END(xdp_metadata_kfunc_ids)
>  
>  static const struct btf_kfunc_id_set xdp_metadata_kfunc_set = {
>  	.owner = THIS_MODULE,
> diff --git a/net/ipv4/bpf_tcp_ca.c b/net/ipv4/bpf_tcp_ca.c
> index 834edc18463a..7f518ea5f4ac 100644
> --- a/net/ipv4/bpf_tcp_ca.c
> +++ b/net/ipv4/bpf_tcp_ca.c
> @@ -201,13 +201,13 @@ bpf_tcp_ca_get_func_proto(enum bpf_func_id func_id,
>  	}
>  }
>  
> -BTF_SET8_START(bpf_tcp_ca_check_kfunc_ids)
> +BTF_KFUNCS_START(bpf_tcp_ca_check_kfunc_ids)
>  BTF_ID_FLAGS(func, tcp_reno_ssthresh)
>  BTF_ID_FLAGS(func, tcp_reno_cong_avoid)
>  BTF_ID_FLAGS(func, tcp_reno_undo_cwnd)
>  BTF_ID_FLAGS(func, tcp_slow_start)
>  BTF_ID_FLAGS(func, tcp_cong_avoid_ai)
> -BTF_SET8_END(bpf_tcp_ca_check_kfunc_ids)
> +BTF_KFUNCS_END(bpf_tcp_ca_check_kfunc_ids)
>  
>  static const struct btf_kfunc_id_set bpf_tcp_ca_kfunc_set = {
>  	.owner = THIS_MODULE,
> diff --git a/net/ipv4/fou_bpf.c b/net/ipv4/fou_bpf.c
> index 4da03bf45c9b..06e5572f296f 100644
> --- a/net/ipv4/fou_bpf.c
> +++ b/net/ipv4/fou_bpf.c
> @@ -100,10 +100,10 @@ __bpf_kfunc int bpf_skb_get_fou_encap(struct __sk_buff *skb_ctx,
>  
>  __bpf_kfunc_end_defs();
>  
> -BTF_SET8_START(fou_kfunc_set)
> +BTF_KFUNCS_START(fou_kfunc_set)
>  BTF_ID_FLAGS(func, bpf_skb_set_fou_encap)
>  BTF_ID_FLAGS(func, bpf_skb_get_fou_encap)
> -BTF_SET8_END(fou_kfunc_set)
> +BTF_KFUNCS_END(fou_kfunc_set)
>  
>  static const struct btf_kfunc_id_set fou_bpf_kfunc_set = {
>  	.owner = THIS_MODULE,
> diff --git a/net/ipv4/tcp_bbr.c b/net/ipv4/tcp_bbr.c
> index 22358032dd48..05dc2d05bc7c 100644
> --- a/net/ipv4/tcp_bbr.c
> +++ b/net/ipv4/tcp_bbr.c
> @@ -1155,7 +1155,7 @@ static struct tcp_congestion_ops tcp_bbr_cong_ops __read_mostly = {
>  	.set_state	= bbr_set_state,
>  };
>  
> -BTF_SET8_START(tcp_bbr_check_kfunc_ids)
> +BTF_KFUNCS_START(tcp_bbr_check_kfunc_ids)
>  #ifdef CONFIG_X86
>  #ifdef CONFIG_DYNAMIC_FTRACE
>  BTF_ID_FLAGS(func, bbr_init)
> @@ -1168,7 +1168,7 @@ BTF_ID_FLAGS(func, bbr_min_tso_segs)
>  BTF_ID_FLAGS(func, bbr_set_state)
>  #endif
>  #endif
> -BTF_SET8_END(tcp_bbr_check_kfunc_ids)
> +BTF_KFUNCS_END(tcp_bbr_check_kfunc_ids)
>  
>  static const struct btf_kfunc_id_set tcp_bbr_kfunc_set = {
>  	.owner = THIS_MODULE,
> diff --git a/net/ipv4/tcp_cubic.c b/net/ipv4/tcp_cubic.c
> index 0fd78ecb67e7..44869ea089e3 100644
> --- a/net/ipv4/tcp_cubic.c
> +++ b/net/ipv4/tcp_cubic.c
> @@ -485,7 +485,7 @@ static struct tcp_congestion_ops cubictcp __read_mostly = {
>  	.name		= "cubic",
>  };
>  
> -BTF_SET8_START(tcp_cubic_check_kfunc_ids)
> +BTF_KFUNCS_START(tcp_cubic_check_kfunc_ids)
>  #ifdef CONFIG_X86
>  #ifdef CONFIG_DYNAMIC_FTRACE
>  BTF_ID_FLAGS(func, cubictcp_init)
> @@ -496,7 +496,7 @@ BTF_ID_FLAGS(func, cubictcp_cwnd_event)
>  BTF_ID_FLAGS(func, cubictcp_acked)
>  #endif
>  #endif
> -BTF_SET8_END(tcp_cubic_check_kfunc_ids)
> +BTF_KFUNCS_END(tcp_cubic_check_kfunc_ids)
>  
>  static const struct btf_kfunc_id_set tcp_cubic_kfunc_set = {
>  	.owner = THIS_MODULE,
> diff --git a/net/ipv4/tcp_dctcp.c b/net/ipv4/tcp_dctcp.c
> index bb23bb5b387a..e33fbe4933e4 100644
> --- a/net/ipv4/tcp_dctcp.c
> +++ b/net/ipv4/tcp_dctcp.c
> @@ -260,7 +260,7 @@ static struct tcp_congestion_ops dctcp_reno __read_mostly = {
>  	.name		= "dctcp-reno",
>  };
>  
> -BTF_SET8_START(tcp_dctcp_check_kfunc_ids)
> +BTF_KFUNCS_START(tcp_dctcp_check_kfunc_ids)
>  #ifdef CONFIG_X86
>  #ifdef CONFIG_DYNAMIC_FTRACE
>  BTF_ID_FLAGS(func, dctcp_init)
> @@ -271,7 +271,7 @@ BTF_ID_FLAGS(func, dctcp_cwnd_undo)
>  BTF_ID_FLAGS(func, dctcp_state)
>  #endif
>  #endif
> -BTF_SET8_END(tcp_dctcp_check_kfunc_ids)
> +BTF_KFUNCS_END(tcp_dctcp_check_kfunc_ids)
>  
>  static const struct btf_kfunc_id_set tcp_dctcp_kfunc_set = {
>  	.owner = THIS_MODULE,
> diff --git a/net/netfilter/nf_conntrack_bpf.c b/net/netfilter/nf_conntrack_bpf.c
> index 475358ec8212..d2492d050fe6 100644
> --- a/net/netfilter/nf_conntrack_bpf.c
> +++ b/net/netfilter/nf_conntrack_bpf.c
> @@ -467,7 +467,7 @@ __bpf_kfunc int bpf_ct_change_status(struct nf_conn *nfct, u32 status)
>  
>  __bpf_kfunc_end_defs();
>  
> -BTF_SET8_START(nf_ct_kfunc_set)
> +BTF_KFUNCS_START(nf_ct_kfunc_set)
>  BTF_ID_FLAGS(func, bpf_xdp_ct_alloc, KF_ACQUIRE | KF_RET_NULL)
>  BTF_ID_FLAGS(func, bpf_xdp_ct_lookup, KF_ACQUIRE | KF_RET_NULL)
>  BTF_ID_FLAGS(func, bpf_skb_ct_alloc, KF_ACQUIRE | KF_RET_NULL)
> @@ -478,7 +478,7 @@ BTF_ID_FLAGS(func, bpf_ct_set_timeout, KF_TRUSTED_ARGS)
>  BTF_ID_FLAGS(func, bpf_ct_change_timeout, KF_TRUSTED_ARGS)
>  BTF_ID_FLAGS(func, bpf_ct_set_status, KF_TRUSTED_ARGS)
>  BTF_ID_FLAGS(func, bpf_ct_change_status, KF_TRUSTED_ARGS)
> -BTF_SET8_END(nf_ct_kfunc_set)
> +BTF_KFUNCS_END(nf_ct_kfunc_set)
>  
>  static const struct btf_kfunc_id_set nf_conntrack_kfunc_set = {
>  	.owner = THIS_MODULE,
> diff --git a/net/netfilter/nf_nat_bpf.c b/net/netfilter/nf_nat_bpf.c
> index 6e3b2f58855f..481be15609b1 100644
> --- a/net/netfilter/nf_nat_bpf.c
> +++ b/net/netfilter/nf_nat_bpf.c
> @@ -54,9 +54,9 @@ __bpf_kfunc int bpf_ct_set_nat_info(struct nf_conn___init *nfct,
>  
>  __bpf_kfunc_end_defs();
>  
> -BTF_SET8_START(nf_nat_kfunc_set)
> +BTF_KFUNCS_START(nf_nat_kfunc_set)
>  BTF_ID_FLAGS(func, bpf_ct_set_nat_info, KF_TRUSTED_ARGS)
> -BTF_SET8_END(nf_nat_kfunc_set)
> +BTF_KFUNCS_END(nf_nat_kfunc_set)
>  
>  static const struct btf_kfunc_id_set nf_bpf_nat_kfunc_set = {
>  	.owner = THIS_MODULE,
> diff --git a/net/xfrm/xfrm_interface_bpf.c b/net/xfrm/xfrm_interface_bpf.c
> index 7d5e920141e9..5ea15037ebd1 100644
> --- a/net/xfrm/xfrm_interface_bpf.c
> +++ b/net/xfrm/xfrm_interface_bpf.c
> @@ -93,10 +93,10 @@ __bpf_kfunc int bpf_skb_set_xfrm_info(struct __sk_buff *skb_ctx, const struct bp
>  
>  __bpf_kfunc_end_defs();
>  
> -BTF_SET8_START(xfrm_ifc_kfunc_set)
> +BTF_KFUNCS_START(xfrm_ifc_kfunc_set)
>  BTF_ID_FLAGS(func, bpf_skb_get_xfrm_info)
>  BTF_ID_FLAGS(func, bpf_skb_set_xfrm_info)
> -BTF_SET8_END(xfrm_ifc_kfunc_set)
> +BTF_KFUNCS_END(xfrm_ifc_kfunc_set)
>  
>  static const struct btf_kfunc_id_set xfrm_interface_kfunc_set = {
>  	.owner = THIS_MODULE,
> diff --git a/net/xfrm/xfrm_state_bpf.c b/net/xfrm/xfrm_state_bpf.c
> index 9e20d4a377f7..2248eda741f8 100644
> --- a/net/xfrm/xfrm_state_bpf.c
> +++ b/net/xfrm/xfrm_state_bpf.c
> @@ -117,10 +117,10 @@ __bpf_kfunc void bpf_xdp_xfrm_state_release(struct xfrm_state *x)
>  
>  __bpf_kfunc_end_defs();
>  
> -BTF_SET8_START(xfrm_state_kfunc_set)
> +BTF_KFUNCS_START(xfrm_state_kfunc_set)
>  BTF_ID_FLAGS(func, bpf_xdp_get_xfrm_state, KF_RET_NULL | KF_ACQUIRE)
>  BTF_ID_FLAGS(func, bpf_xdp_xfrm_state_release, KF_RELEASE)
> -BTF_SET8_END(xfrm_state_kfunc_set)
> +BTF_KFUNCS_END(xfrm_state_kfunc_set)
>  
>  static const struct btf_kfunc_id_set xfrm_state_xdp_kfunc_set = {
>  	.owner = THIS_MODULE,
> diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
> index 8befaf17d454..53f73fc86baa 100644
> --- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
> +++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
> @@ -343,12 +343,12 @@ static struct bin_attribute bin_attr_bpf_testmod_file __ro_after_init = {
>  	.write = bpf_testmod_test_write,
>  };
>  
> -BTF_SET8_START(bpf_testmod_common_kfunc_ids)
> +BTF_KFUNCS_START(bpf_testmod_common_kfunc_ids)
>  BTF_ID_FLAGS(func, bpf_iter_testmod_seq_new, KF_ITER_NEW)
>  BTF_ID_FLAGS(func, bpf_iter_testmod_seq_next, KF_ITER_NEXT | KF_RET_NULL)
>  BTF_ID_FLAGS(func, bpf_iter_testmod_seq_destroy, KF_ITER_DESTROY)
>  BTF_ID_FLAGS(func, bpf_kfunc_common_test)
> -BTF_SET8_END(bpf_testmod_common_kfunc_ids)
> +BTF_KFUNCS_END(bpf_testmod_common_kfunc_ids)
>  
>  static const struct btf_kfunc_id_set bpf_testmod_common_kfunc_set = {
>  	.owner = THIS_MODULE,
> @@ -494,7 +494,7 @@ __bpf_kfunc static u32 bpf_kfunc_call_test_static_unused_arg(u32 arg, u32 unused
>  	return arg;
>  }
>  
> -BTF_SET8_START(bpf_testmod_check_kfunc_ids)
> +BTF_KFUNCS_START(bpf_testmod_check_kfunc_ids)
>  BTF_ID_FLAGS(func, bpf_testmod_test_mod_kfunc)
>  BTF_ID_FLAGS(func, bpf_kfunc_call_test1)
>  BTF_ID_FLAGS(func, bpf_kfunc_call_test2)
> @@ -520,7 +520,7 @@ BTF_ID_FLAGS(func, bpf_kfunc_call_test_ref, KF_TRUSTED_ARGS | KF_RCU)
>  BTF_ID_FLAGS(func, bpf_kfunc_call_test_destructive, KF_DESTRUCTIVE)
>  BTF_ID_FLAGS(func, bpf_kfunc_call_test_static_unused_arg)
>  BTF_ID_FLAGS(func, bpf_kfunc_call_test_offset)
> -BTF_SET8_END(bpf_testmod_check_kfunc_ids)
> +BTF_KFUNCS_END(bpf_testmod_check_kfunc_ids)
>  
>  static int bpf_testmod_ops_init(struct btf *btf)
>  {
> -- 
> 2.42.1
>
  

Hello,

kernel test robot noticed "WARNING:at_kernel/bpf/btf.c:#register_btf_kfunc_id_set" on:

commit: 918c4c7dda155568c619b4082fa83ca90ab578a6 ("[PATCH bpf-next v4 3/3] bpf: treewide: Annotate BPF kfuncs in BTF")
url: https://github.com/intel-lab-lkp/linux/commits/Daniel-Xu/bpf-btf-Support-flags-for-BTF_SET8-sets/20240129-092732
base: https://git.kernel.org/cgit/linux/kernel/git/bpf/bpf-next.git master
patch link: https://lore.kernel.org/all/e55150ceecbf0a5d961e608941165c0bee7bc943.1706491398.git.dxu@dxuuu.xyz/
patch subject: [PATCH bpf-next v4 3/3] bpf: treewide: Annotate BPF kfuncs in BTF

in testcase: boot

compiler: clang-17
test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 16G

(please refer to attached dmesg/kmsg for entire log/backtrace)


+-----------------------------------------------------------------+------------+------------+
|                                                                 | 05221438c4 | 918c4c7dda |
+-----------------------------------------------------------------+------------+------------+
| WARNING:at_kernel/bpf/btf.c:#register_btf_kfunc_id_set          | 0          | 7          |
| EIP:register_btf_kfunc_id_set                                   | 0          | 7          |
| calltrace:do_softirq_own_stack                                  | 0          | 7          |
+-----------------------------------------------------------------+------------+------------+


If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-lkp/202402041610.775e7f75-lkp@intel.com


[   49.044594][    T1] ------------[ cut here ]------------
[ 49.045857][ T1] WARNING: CPU: 1 PID: 1 at kernel/bpf/btf.c:8048 register_btf_kfunc_id_set (??:?) 
[   49.048024][    T1] Modules linked in:
[   49.048925][    T1] CPU: 1 PID: 1 Comm: swapper/0 Tainted: G        W          6.8.0-rc1-00457-g918c4c7dda15 #6
[   49.051230][    T1] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
[ 49.053616][ T1] EIP: register_btf_kfunc_id_set (??:?) 
[ 49.054969][ T1] Code: 04 01 75 0b b8 ea ff ff ff 83 3a 00 74 1c c3 b9 0d 00 00 00 83 f8 20 77 07 8b 0c 85 28 a2 71 d7 55 89 e5 e8 13 00 00 00 5d c3 <0f> 0b c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 89 e5 53 57
All code
========
   0:	04 01                	add    $0x1,%al
   2:	75 0b                	jne    0xf
   4:	b8 ea ff ff ff       	mov    $0xffffffea,%eax
   9:	83 3a 00             	cmpl   $0x0,(%rdx)
   c:	74 1c                	je     0x2a
   e:	c3                   	retq   
   f:	b9 0d 00 00 00       	mov    $0xd,%ecx
  14:	83 f8 20             	cmp    $0x20,%eax
  17:	77 07                	ja     0x20
  19:	8b 0c 85 28 a2 71 d7 	mov    -0x288e5dd8(,%rax,4),%ecx
  20:	55                   	push   %rbp
  21:	89 e5                	mov    %esp,%ebp
  23:	e8 13 00 00 00       	callq  0x3b
  28:	5d                   	pop    %rbp
  29:	c3                   	retq   
  2a:*	0f 0b                	ud2    		<-- trapping instruction
  2c:	c3                   	retq   
  2d:	90                   	nop
  2e:	90                   	nop
  2f:	90                   	nop
  30:	90                   	nop
  31:	90                   	nop
  32:	90                   	nop
  33:	90                   	nop
  34:	90                   	nop
  35:	90                   	nop
  36:	90                   	nop
  37:	90                   	nop
  38:	90                   	nop
  39:	90                   	nop
  3a:	90                   	nop
  3b:	55                   	push   %rbp
  3c:	89 e5                	mov    %esp,%ebp
  3e:	53                   	push   %rbx
  3f:	57                   	push   %rdi

Code starting with the faulting instruction
===========================================
   0:	0f 0b                	ud2    
   2:	c3                   	retq   
   3:	90                   	nop
   4:	90                   	nop
   5:	90                   	nop
   6:	90                   	nop
   7:	90                   	nop
   8:	90                   	nop
   9:	90                   	nop
   a:	90                   	nop
   b:	90                   	nop
   c:	90                   	nop
   d:	90                   	nop
   e:	90                   	nop
   f:	90                   	nop
  10:	90                   	nop
  11:	55                   	push   %rbp
  12:	89 e5                	mov    %esp,%ebp
  14:	53                   	push   %rbx
  15:	57                   	push   %rdi
[   49.059550][    T1] EAX: ffffffea EBX: 00000000 ECX: d9356fb0 EDX: d7c2b154
[   49.061229][    T1] ESI: 00000000 EDI: 0000019a EBP: c028dc48 ESP: c028dc38
[   49.062886][    T1] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 EFLAGS: 00010246
[   49.064685][    T1] CR0: 80050033 CR2: 00000000 CR3: 189ab000 CR4: 000406f0
[   49.066358][    T1] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
[   49.068020][    T1] DR6: fffe0ff0 DR7: 00000400
[   49.069132][    T1] Call Trace:
[ 49.069902][ T1] ? show_regs (??:?) 
[ 49.070890][ T1] ? register_btf_kfunc_id_set (??:?) 
[ 49.072187][ T1] ? __warn (??:?) 
[ 49.073151][ T1] ? register_btf_kfunc_id_set (??:?) 
[ 49.074480][ T1] ? register_btf_kfunc_id_set (??:?) 
[ 49.075751][ T1] ? report_bug (??:?) 
[ 49.076858][ T1] ? exc_overflow (??:?) 
[ 49.077925][ T1] ? handle_bug (traps.c:?) 
[ 49.078947][ T1] ? exc_invalid_op (??:?) 
[ 49.080030][ T1] ? handle_exception (init_task.c:?) 
[ 49.081174][ T1] ? get_seg_base_limit (insn-eval.c:?) 
[ 49.082393][ T1] ? mutex_lock_killable_nested (??:?) 
[ 49.083707][ T1] ? exc_overflow (??:?) 
[ 49.084782][ T1] ? register_btf_kfunc_id_set (??:?) 
[ 49.086126][ T1] ? mutex_lock_killable_nested (??:?) 
[ 49.087468][ T1] ? exc_overflow (??:?) 
[ 49.088520][ T1] ? register_btf_kfunc_id_set (??:?) 
[ 49.089864][ T1] ? cubictcp_register (tcp_cubic.c:?) 
[ 49.090991][ T1] do_one_initcall (??:?) 
[ 49.092136][ T1] ? pvclock_clocksource_read_nowd (??:?) 
[ 49.093607][ T1] ? __lock_acquire (lockdep.c:?) 
[ 49.094756][ T1] ? kvm_sched_clock_read (kvmclock.c:?) 
[ 49.095985][ T1] ? sched_clock_noinstr (??:?) 
[ 49.097144][ T1] ? local_clock_noinstr (??:?) 
[ 49.098393][ T1] ? __lock_acquire (lockdep.c:?) 
[ 49.099575][ T1] ? sched_clock_noinstr (??:?) 
[ 49.100746][ T1] ? local_clock_noinstr (??:?) 
[ 49.101997][ T1] ? pvclock_clocksource_read_nowd (??:?) 
[ 49.103439][ T1] ? kvm_sched_clock_read (kvmclock.c:?) 
[ 49.104673][ T1] ? pvclock_clocksource_read_nowd (??:?) 
[ 49.106095][ T1] ? kvm_sched_clock_read (kvmclock.c:?) 
[ 49.107310][ T1] ? sched_clock_noinstr (??:?) 
[ 49.109773][ T1] ? local_clock_noinstr (??:?) 
[ 49.111018][ T1] ? __this_cpu_preempt_check (??:?) 
[ 49.112289][ T1] ? irqtime_account_irq (??:?) 
[ 49.113534][ T1] ? irqtime_account_delta (build_policy.c:?) 
[ 49.114812][ T1] ? irqentry_exit (??:?) 
[ 49.115860][ T1] ? __this_cpu_preempt_check (??:?) 
[ 49.117126][ T1] ? lockdep_hardirqs_on (??:?) 
[ 49.118370][ T1] ? sysvec_reboot (??:?) 
[ 49.119450][ T1] ? trace_hardirqs_on (??:?) 
[ 49.120623][ T1] ? irqentry_exit (??:?) 
[ 49.121703][ T1] ? sysvec_reschedule_ipi (??:?) 
[ 49.122962][ T1] ? handle_exception (init_task.c:?) 
[ 49.124130][ T1] ? strlen (??:?) 
[ 49.125054][ T1] ? next_arg (??:?) 
[ 49.126086][ T1] ? parse_args (??:?) 
[ 49.127134][ T1] ? tcp_diag_init (tcp_cubic.c:?) 
[ 49.128257][ T1] do_initcall_level (main.c:?) 
[ 49.129398][ T1] ? kernel_init (main.c:?) 
[ 49.130474][ T1] do_initcalls (main.c:?) 
[ 49.131494][ T1] do_basic_setup (main.c:?) 
[ 49.132558][ T1] kernel_init_freeable (main.c:?) 
[ 49.133781][ T1] ? rest_init (main.c:?) 
[ 49.134848][ T1] ? rest_init (main.c:?) 
[ 49.135885][ T1] kernel_init (main.c:?) 
[ 49.136958][ T1] ret_from_fork (??:?) 
[ 49.137979][ T1] ret_from_fork_asm (??:?) 
[ 49.139078][ T1] entry_INT80_32 (init_task.c:?) 
[   49.140171][    T1] irq event stamp: 16737757
[ 49.141202][ T1] hardirqs last enabled at (16737765): console_unlock (??:?) 
[ 49.143298][ T1] hardirqs last disabled at (16737774): console_unlock (??:?) 
[ 49.145355][ T1] softirqs last enabled at (16737610): do_softirq_own_stack (??:?) 
[ 49.147553][ T1] softirqs last disabled at (16737605): do_softirq_own_stack (??:?) 
[   49.149757][    T1] ---[ end trace 0000000000000000 ]---
[   49.151671][    T1] NET: Registered PF_INET6 protocol family
[   49.156896][    T1] Segment Routing with IPv6
[   49.158068][    T1] In-situ OAM (IOAM) with IPv6
[   49.159300][    T1] sit: IPv6, IPv4 and MPLS over IPv4 tunneling driver
[   49.162798][    T1] NET: Registered PF_PACKET protocol family
[   49.164686][    T1] 9pnet: Installing 9P2000 support
[   49.166257][    T1] start plist test
[   49.168281][    T1] end plist test
[   49.173855][    T1] IPI shorthand broadcast: enabled
[   49.175165][    C0] ... APIC ID:      00000000 (0)
[   49.176383][    C0] ... APIC VERSION: 00050014
[   49.177486][    C0] 0000000000000000000000000000000000000000000000000000000000000000
[   49.177486][    C0] 0000000000000000000000000000000000000000000000000000000008001000


The kernel config and materials to reproduce are available at:
https://download.01.org/0day-ci/archive/20240204/202402041610.775e7f75-lkp@intel.com