From 00a5acdbf39816ad23b8db3255c366bbc77e69af Mon Sep 17 00:00:00 2001 From: =?utf8?q?Thomas=20Wei=C3=9Fschuh?= Date: Fri, 13 Dec 2024 00:00:30 +0100 Subject: [PATCH] bpf: Fix configuration-dependent BTF function references MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 Signed-off-by: Andrii Nakryiko Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20241213-bpf-cond-ids-v1-1-881849997219@weissschuh.net --- kernel/bpf/helpers.c | 4 ++++ kernel/bpf/verifier.c | 8 ++++++++ 2 files changed, 12 insertions(+) diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 532ea74d4850..cd5f9884d85b 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -3104,7 +3104,9 @@ 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 = { @@ -3150,7 +3152,9 @@ 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 c0e772996c52..8a9433a94007 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -5681,7 +5681,9 @@ 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 @@ -5689,7 +5691,9 @@ 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) @@ -11722,8 +11726,10 @@ 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) @@ -11751,8 +11757,10 @@ 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) +#endif BTF_ID(func, bpf_dynptr_slice) BTF_ID(func, bpf_dynptr_slice_rdwr) BTF_ID(func, bpf_dynptr_clone) -- 2.25.1