These BTF functions are not available unconditionally, only reference them when they are available. Avoid the following build warnings: BTF .tmp_vmlinux1.btf.o btf_encoder__tag_kfunc: failed to find kfunc 'bpf_send_signal_task' in BTF btf_encoder__tag_kfuncs: failed to tag kfunc 'bpf_send_signal_task' NM .tmp_vmlinux1.syms KSYMS .tmp_vmlinux1.kallsyms.S AS .tmp_vmlinux1.kallsyms.o LD .tmp_vmlinux2 NM .tmp_vmlinux2.syms KSYMS .tmp_vmlinux2.kallsyms.S AS .tmp_vmlinux2.kallsyms.o LD vmlinux BTFIDS vmlinux WARN: resolve_btfids: unresolved symbol prog_test_ref_kfunc WARN: resolve_btfids: unresolved symbol bpf_crypto_ctx WARN: resolve_btfids: unresolved symbol bpf_send_signal_task WARN: resolve_btfids: unresolved symbol bpf_modify_return_test_tp WARN: resolve_btfids: unresolved symbol bpf_dynptr_from_xdp WARN: resolve_btfids: unresolved symbol bpf_dynptr_from_skb Signed-off-by: Thomas Weißschuh <linux@xxxxxxxxxxxxxx> --- Changes in v2: - Properly use BTF_ID_UNUSED in special_kfunc_list() - Link to v1: https://lore.kernel.org/r/20241213-bpf-cond-ids-v1-1-881849997219@xxxxxxxxxxxxxx --- kernel/bpf/helpers.c | 4 ++++ kernel/bpf/verifier.c | 11 +++++++++++ 2 files changed, 15 insertions(+) diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 751c150f9e1cd7f56e6a2b68a7ebb4ae89a30d2d..5edf5436a7804816b7dcf1bbef2624d71a985f20 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -3089,7 +3089,9 @@ BTF_ID_FLAGS(func, bpf_task_get_cgroup1, KF_ACQUIRE | KF_RCU | KF_RET_NULL) BTF_ID_FLAGS(func, bpf_task_from_pid, KF_ACQUIRE | KF_RET_NULL) BTF_ID_FLAGS(func, bpf_task_from_vpid, KF_ACQUIRE | KF_RET_NULL) BTF_ID_FLAGS(func, bpf_throw) +#ifdef CONFIG_BPF_EVENTS BTF_ID_FLAGS(func, bpf_send_signal_task, KF_TRUSTED_ARGS) +#endif BTF_KFUNCS_END(generic_btf_ids) static const struct btf_kfunc_id_set generic_kfunc_set = { @@ -3135,7 +3137,9 @@ 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) +#ifdef CONFIG_NET BTF_ID_FLAGS(func, bpf_modify_return_test_tp) +#endif BTF_ID_FLAGS(func, bpf_wq_init) BTF_ID_FLAGS(func, bpf_wq_set_callback_impl) BTF_ID_FLAGS(func, bpf_wq_start) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 77f56674aaa99a0b88ced5100ba57409e255fd29..2704fa4477ee2504897c82f0416aa7d61fb086ed 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -5507,7 +5507,9 @@ static bool in_rcu_cs(struct bpf_verifier_env *env) /* Once GCC supports btf_type_tag the following mechanism will be replaced with tag check */ BTF_SET_START(rcu_protected_types) +#ifdef CONFIG_NET BTF_ID(struct, prog_test_ref_kfunc) +#endif #ifdef CONFIG_CGROUPS BTF_ID(struct, cgroup) #endif @@ -5515,7 +5517,9 @@ BTF_ID(struct, cgroup) BTF_ID(struct, bpf_cpumask) #endif BTF_ID(struct, task_struct) +#ifdef CONFIG_CRYPTO BTF_ID(struct, bpf_crypto_ctx) +#endif BTF_SET_END(rcu_protected_types) static bool rcu_protected_object(const struct btf *btf, u32 btf_id) @@ -11486,8 +11490,10 @@ BTF_ID(func, bpf_rdonly_cast) BTF_ID(func, bpf_rbtree_remove) BTF_ID(func, bpf_rbtree_add_impl) BTF_ID(func, bpf_rbtree_first) +#ifdef CONFIG_NET BTF_ID(func, bpf_dynptr_from_skb) BTF_ID(func, bpf_dynptr_from_xdp) +#endif BTF_ID(func, bpf_dynptr_slice) BTF_ID(func, bpf_dynptr_slice_rdwr) BTF_ID(func, bpf_dynptr_clone) @@ -11515,8 +11521,13 @@ BTF_ID(func, bpf_rcu_read_unlock) BTF_ID(func, bpf_rbtree_remove) BTF_ID(func, bpf_rbtree_add_impl) BTF_ID(func, bpf_rbtree_first) +#ifdef CONFIG_NET BTF_ID(func, bpf_dynptr_from_skb) BTF_ID(func, bpf_dynptr_from_xdp) +#else +BTF_ID_UNUSED +BTF_ID_UNUSED +#endif BTF_ID(func, bpf_dynptr_slice) BTF_ID(func, bpf_dynptr_slice_rdwr) BTF_ID(func, bpf_dynptr_clone) --- base-commit: d9df5df183eede1041cbd5ff1d776e94757e338b change-id: 20241212-bpf-cond-ids-9bfbc64dd77b Best regards, -- Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
