On Wed, Dec 18, 2024 at 11:24 PM Thomas Weißschuh <linux@xxxxxxxxxxxxxx> wrote: > > 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 The previous patch was already applied and it's too late to revert. Pls send an incremental fix with: Fixes: 00a5acdbf398 ("bpf: Fix configuration-dependent BTF function references") pw-bot: cr
