From e939f3d16d77a88e5f363394ef73db4c898c4107 Mon Sep 17 00:00:00 2001 From: Ihor Solodrai Date: Tue, 20 Jan 2026 14:26:31 -0800 Subject: selftests/bpf: Add tests for KF_IMPLICIT_ARGS Add trivial end-to-end tests to validate that KF_IMPLICIT_ARGS flag is properly handled by both resolve_btfids and the verifier. Declare kfuncs in bpf_testmod. Check that bpf_prog_aux pointer is set in the kfunc implementation. Verify that calls with implicit args and a legacy case all work. Acked-by: Eduard Zingerman Signed-off-by: Ihor Solodrai Link: https://lore.kernel.org/r/20260120222638.3976562-7-ihor.solodrai@linux.dev Signed-off-by: Alexei Starovoitov --- .../selftests/bpf/progs/kfunc_implicit_args.c | 41 ++++++++++++++++++++++ 1 file changed, 41 insertions(+) create mode 100644 tools/testing/selftests/bpf/progs/kfunc_implicit_args.c (limited to 'tools/testing/selftests/bpf/progs/kfunc_implicit_args.c') diff --git a/tools/testing/selftests/bpf/progs/kfunc_implicit_args.c b/tools/testing/selftests/bpf/progs/kfunc_implicit_args.c new file mode 100644 index 000000000000..89b6a47e22dd --- /dev/null +++ b/tools/testing/selftests/bpf/progs/kfunc_implicit_args.c @@ -0,0 +1,41 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2026 Meta Platforms, Inc. and affiliates. */ + +#include +#include +#include "bpf_misc.h" + +extern int bpf_kfunc_implicit_arg(int a) __weak __ksym; +extern int bpf_kfunc_implicit_arg_impl(int a, struct bpf_prog_aux *aux) __weak __ksym; /* illegal */ +extern int bpf_kfunc_implicit_arg_legacy(int a, int b) __weak __ksym; +extern int bpf_kfunc_implicit_arg_legacy_impl(int a, int b, struct bpf_prog_aux *aux) __weak __ksym; + +char _license[] SEC("license") = "GPL"; + +SEC("syscall") +__retval(5) +int test_kfunc_implicit_arg(void *ctx) +{ + return bpf_kfunc_implicit_arg(5); +} + +SEC("syscall") +__failure __msg("cannot find address for kernel function bpf_kfunc_implicit_arg_impl") +int test_kfunc_implicit_arg_impl_illegal(void *ctx) +{ + return bpf_kfunc_implicit_arg_impl(5, NULL); +} + +SEC("syscall") +__retval(7) +int test_kfunc_implicit_arg_legacy(void *ctx) +{ + return bpf_kfunc_implicit_arg_legacy(3, 4); +} + +SEC("syscall") +__retval(11) +int test_kfunc_implicit_arg_legacy_impl(void *ctx) +{ + return bpf_kfunc_implicit_arg_legacy_impl(5, 6, NULL); +} -- cgit v1.2.3