@@ -172,7 +172,7 @@ 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_SET8_START(hid_bpf_kfunc_ids, BTF_SET8_KFUNC)
BTF_ID_FLAGS(func, hid_bpf_get_data, KF_RET_NULL)
BTF_SET8_END(hid_bpf_kfunc_ids)
@@ -440,7 +440,7 @@ static const struct btf_kfunc_id_set hid_bpf_fmodret_set = {
};
/* for syscall HID-BPF */
-BTF_SET8_START(hid_bpf_syscall_kfunc_ids)
+BTF_SET8_START(hid_bpf_syscall_kfunc_ids, BTF_SET8_KFUNC)
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)
@@ -159,7 +159,7 @@ __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_SET8_START(fsverity_set_ids, BTF_SET8_KFUNC)
BTF_ID_FLAGS(func, bpf_get_fsverity_digest, KF_TRUSTED_ARGS)
BTF_SET8_END(fsverity_set_ids)
@@ -8,6 +8,9 @@ struct btf_id_set {
u32 ids[];
};
+/* This flag implies BTF_SET8 holds kfunc(s) */
+#define BTF_SET8_KFUNC (1 << 0)
+
struct btf_id_set8 {
u32 cnt;
u32 flags;
@@ -7769,6 +7769,9 @@ static int __register_btf_kfunc_id_set(enum btf_kfunc_hook hook,
struct btf *btf;
int ret, i;
+ /* All kfuncs need to be tagged as such in BTF */
+ WARN_ON(!(kset->set->flags & BTF_SET8_KFUNC));
+
btf = btf_get_module_btf(kset->owner);
if (!btf) {
if (!kset->owner && IS_ENABLED(CONFIG_DEBUG_INFO_BTF)) {
@@ -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_SET8_START(cpumask_kfunc_btf_ids, BTF_SET8_KFUNC)
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)
@@ -2543,7 +2543,7 @@ __bpf_kfunc void bpf_throw(u64 cookie)
__bpf_kfunc_end_defs();
-BTF_SET8_START(generic_btf_ids)
+BTF_SET8_START(generic_btf_ids, BTF_SET8_KFUNC)
#ifdef CONFIG_KEXEC_CORE
BTF_ID_FLAGS(func, crash_kexec, KF_DESTRUCTIVE)
#endif
@@ -2588,7 +2588,7 @@ BTF_ID(struct, cgroup)
BTF_ID(func, bpf_cgroup_release_dtor)
#endif
-BTF_SET8_START(common_btf_ids)
+BTF_SET8_START(common_btf_ids, BTF_SET8_KFUNC)
BTF_ID_FLAGS(func, bpf_cast_to_kern_ctx)
BTF_ID_FLAGS(func, bpf_rdonly_cast)
BTF_ID_FLAGS(func, bpf_rcu_read_lock)
@@ -213,7 +213,7 @@ __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_SET8_START(bpf_map_iter_kfunc_ids, BTF_SET8_KFUNC)
BTF_ID_FLAGS(func, bpf_map_sum_elem_count, KF_TRUSTED_ARGS)
BTF_SET8_END(bpf_map_iter_kfunc_ids)
@@ -520,7 +520,7 @@ 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_SET8_START(bpf_rstat_kfunc_ids, BTF_SET8_KFUNC)
BTF_ID_FLAGS(func, cgroup_rstat_updated)
BTF_ID_FLAGS(func, cgroup_rstat_flush, KF_SLEEPABLE)
BTF_SET8_END(bpf_rstat_kfunc_ids)
@@ -1412,7 +1412,7 @@ __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_SET8_START(key_sig_kfunc_set, BTF_SET8_KFUNC)
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)
@@ -1475,7 +1475,7 @@ __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_SET8_START(fs_kfunc_set_ids, BTF_SET8_KFUNC)
BTF_ID_FLAGS(func, bpf_get_file_xattr, KF_SLEEPABLE | KF_TRUSTED_ARGS)
BTF_SET8_END(fs_kfunc_set_ids)
@@ -617,7 +617,7 @@ CFI_NOSEAL(bpf_kfunc_call_memb_release_dtor);
__bpf_kfunc_end_defs();
-BTF_SET8_START(bpf_test_modify_return_ids)
+BTF_SET8_START(bpf_test_modify_return_ids, BTF_SET8_KFUNC)
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)
@@ -628,7 +628,7 @@ static const struct btf_kfunc_id_set bpf_test_modify_return_set = {
.set = &bpf_test_modify_return_ids,
};
-BTF_SET8_START(test_sk_check_kfunc_ids)
+BTF_SET8_START(test_sk_check_kfunc_ids, BTF_SET8_KFUNC)
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)
@@ -11853,15 +11853,15 @@ int bpf_dynptr_from_skb_rdonly(struct sk_buff *skb, u64 flags,
return 0;
}
-BTF_SET8_START(bpf_kfunc_check_set_skb)
+BTF_SET8_START(bpf_kfunc_check_set_skb, BTF_SET8_KFUNC)
BTF_ID_FLAGS(func, bpf_dynptr_from_skb)
BTF_SET8_END(bpf_kfunc_check_set_skb)
-BTF_SET8_START(bpf_kfunc_check_set_xdp)
+BTF_SET8_START(bpf_kfunc_check_set_xdp, BTF_SET8_KFUNC)
BTF_ID_FLAGS(func, bpf_dynptr_from_xdp)
BTF_SET8_END(bpf_kfunc_check_set_xdp)
-BTF_SET8_START(bpf_kfunc_check_set_sock_addr)
+BTF_SET8_START(bpf_kfunc_check_set_sock_addr, BTF_SET8_KFUNC)
BTF_ID_FLAGS(func, bpf_sock_addr_set_sun_path)
BTF_SET8_END(bpf_kfunc_check_set_sock_addr)
@@ -11936,7 +11936,7 @@ __bpf_kfunc int bpf_sock_destroy(struct sock_common *sock)
__bpf_kfunc_end_defs();
-BTF_SET8_START(bpf_sk_iter_kfunc_ids)
+BTF_SET8_START(bpf_sk_iter_kfunc_ids, BTF_SET8_KFUNC)
BTF_ID_FLAGS(func, bpf_sock_destroy, KF_TRUSTED_ARGS)
BTF_SET8_END(bpf_sk_iter_kfunc_ids)
@@ -771,7 +771,7 @@ __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_SET8_START(xdp_metadata_kfunc_ids, BTF_SET8_KFUNC)
#define XDP_METADATA_KFUNC(_, __, name, ___) BTF_ID_FLAGS(func, name, KF_TRUSTED_ARGS)
XDP_METADATA_KFUNC_xxx
#undef XDP_METADATA_KFUNC
@@ -195,7 +195,7 @@ bpf_tcp_ca_get_func_proto(enum bpf_func_id func_id,
}
}
-BTF_SET8_START(bpf_tcp_ca_check_kfunc_ids)
+BTF_SET8_START(bpf_tcp_ca_check_kfunc_ids, BTF_SET8_KFUNC)
BTF_ID_FLAGS(func, tcp_reno_ssthresh)
BTF_ID_FLAGS(func, tcp_reno_cong_avoid)
BTF_ID_FLAGS(func, tcp_reno_undo_cwnd)
@@ -100,7 +100,7 @@ __bpf_kfunc int bpf_skb_get_fou_encap(struct __sk_buff *skb_ctx,
__bpf_kfunc_end_defs();
-BTF_SET8_START(fou_kfunc_set)
+BTF_SET8_START(fou_kfunc_set, BTF_SET8_KFUNC)
BTF_ID_FLAGS(func, bpf_skb_set_fou_encap)
BTF_ID_FLAGS(func, bpf_skb_get_fou_encap)
BTF_SET8_END(fou_kfunc_set)
@@ -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_SET8_START(tcp_bbr_check_kfunc_ids, BTF_SET8_KFUNC)
#ifdef CONFIG_X86
#ifdef CONFIG_DYNAMIC_FTRACE
BTF_ID_FLAGS(func, bbr_init)
@@ -485,7 +485,7 @@ static struct tcp_congestion_ops cubictcp __read_mostly = {
.name = "cubic",
};
-BTF_SET8_START(tcp_cubic_check_kfunc_ids)
+BTF_SET8_START(tcp_cubic_check_kfunc_ids, BTF_SET8_KFUNC)
#ifdef CONFIG_X86
#ifdef CONFIG_DYNAMIC_FTRACE
BTF_ID_FLAGS(func, cubictcp_init)
@@ -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_SET8_START(tcp_dctcp_check_kfunc_ids, BTF_SET8_KFUNC)
#ifdef CONFIG_X86
#ifdef CONFIG_DYNAMIC_FTRACE
BTF_ID_FLAGS(func, dctcp_init)
@@ -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_SET8_START(nf_ct_kfunc_set, BTF_SET8_KFUNC)
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)
@@ -54,7 +54,7 @@ __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_SET8_START(nf_nat_kfunc_set, BTF_SET8_KFUNC)
BTF_ID_FLAGS(func, bpf_ct_set_nat_info, KF_TRUSTED_ARGS)
BTF_SET8_END(nf_nat_kfunc_set)
@@ -93,7 +93,7 @@ __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_SET8_START(xfrm_ifc_kfunc_set, BTF_SET8_KFUNC)
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)
@@ -117,7 +117,7 @@ __bpf_kfunc void bpf_xdp_xfrm_state_release(struct xfrm_state *x)
__bpf_kfunc_end_defs();
-BTF_SET8_START(xfrm_state_kfunc_set)
+BTF_SET8_START(xfrm_state_kfunc_set, BTF_SET8_KFUNC)
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)
@@ -341,7 +341,7 @@ 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_SET8_START(bpf_testmod_common_kfunc_ids, BTF_SET8_KFUNC)
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)
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, tag kfunc BTF_SET8 sets with BTF_SET8_KFUNC flag 2. During build, pahole injects into BTF a "bpf_kfunc" BTF_DECL_TAG for each function inside BTF_SET8_KFUNC 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 add a WARN_ON() inside kfunc registration so developers will notice issues duringn development. Signed-off-by: Daniel Xu <dxu@dxuuu.xyz> --- drivers/hid/bpf/hid_bpf_dispatch.c | 4 ++-- fs/verity/measure.c | 2 +- include/linux/btf_ids.h | 3 +++ kernel/bpf/btf.c | 3 +++ kernel/bpf/cpumask.c | 2 +- kernel/bpf/helpers.c | 4 ++-- kernel/bpf/map_iter.c | 2 +- kernel/cgroup/rstat.c | 2 +- kernel/trace/bpf_trace.c | 4 ++-- net/bpf/test_run.c | 4 ++-- net/core/filter.c | 8 ++++---- net/core/xdp.c | 2 +- net/ipv4/bpf_tcp_ca.c | 2 +- net/ipv4/fou_bpf.c | 2 +- net/ipv4/tcp_bbr.c | 2 +- net/ipv4/tcp_cubic.c | 2 +- net/ipv4/tcp_dctcp.c | 2 +- net/netfilter/nf_conntrack_bpf.c | 2 +- net/netfilter/nf_nat_bpf.c | 2 +- net/xfrm/xfrm_interface_bpf.c | 2 +- net/xfrm/xfrm_state_bpf.c | 2 +- tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c | 2 +- 22 files changed, 33 insertions(+), 27 deletions(-)