kernel/linux.git/tools/testing/selftests/bpf/progs/percpu_alloc_fail.c, branch v7.1

bpf: Support struct btf_struct_meta via KF_IMPLICIT_ARGS

2026-03-29T16:56:06+00:00

The following kfuncs currently accept void *meta__ign argument: * bpf_obj_new_impl * bpf_obj_drop_impl * bpf_percpu_obj_new_impl * bpf_percpu_obj_drop_impl * bpf_refcount_acquire_impl * bpf_list_push_back_impl * bpf_list_push_front_impl * bpf_rbtree_add_impl The __ign suffix is an indicator for the verifier to skip the argument in check_kfunc_args(). Then, in fixup_kfunc_call() the verifier may set the value of this argument to struct btf_struct_meta * kptr_struct_meta from insn_aux_data. BPF programs must pass a dummy NULL value when calling these kfuncs. Additionally, the list and rbtree _impl kfuncs also accept an implicit u64 argument, which doesn't require __ign suffix because it's a scalar, and BPF programs explicitly pass 0. Add new kfuncs with KF_IMPLICIT_ARGS [1], that correspond to each _impl kfunc accepting meta__ign. The existing _impl kfuncs remain unchanged for backwards compatibility. To support this, add "btf_struct_meta" to the list of recognized implicit argument types in resolve_btfids. Implement is_kfunc_arg_implicit() in the verifier, that determines implicit args by inspecting both a non-_impl BTF prototype of the kfunc. Update the special_kfunc_list in the verifier and relevant checks to support both the old _impl and the new KF_IMPLICIT_ARGS variants of btf_struct_meta users. [1] https://lore.kernel.org/bpf/20260120222638.3976562-1-ihor.solodrai@linux.dev/ Signed-off-by: Ihor Solodrai Acked-by: Jiri Olsa Link: https://lore.kernel.org/r/20260327203241.3365046-1-ihor.solodrai@linux.dev Signed-off-by: Alexei Starovoitov

selftests/bpf: Add a selftest with > 512-byte percpu allocation size

2024-01-04T05:08:26+00:00

Add a selftest to capture the verification failure when the allocation size is greater than 512. Acked-by: Hou Tao Signed-off-by: Yonghong Song Link: https://lore.kernel.org/r/20231222031812.1293190-1-yonghong.song@linux.dev Signed-off-by: Alexei Starovoitov

selftests/bpf: Add some negative tests

2023-09-08T15:42:18+00:00

Add a few negative tests for common mistakes with using percpu kptr including: - store to percpu kptr. - type mistach in bpf_kptr_xchg arguments. - sleepable prog with untrusted arg for bpf_this_cpu_ptr(). - bpf_percpu_obj_new && bpf_obj_drop, and bpf_obj_new && bpf_percpu_obj_drop - struct with ptr for bpf_percpu_obj_new - struct with special field (e.g., bpf_spin_lock) for bpf_percpu_obj_new Signed-off-by: Yonghong Song Link: https://lore.kernel.org/r/20230827152832.2002421-1-yonghong.song@linux.dev Signed-off-by: Alexei Starovoitov