When loading struct_ops programs kernel requires BTF id of the struct_ops type and member index for attachment point inside that type. This makes it not possible to have same BPF program used in struct_ops maps that have different struct_ops type. Check if libbpf rejects such BPF objects files. Signed-off-by: Eduard Zingerman <eddyz87@xxxxxxxxx> --- .../selftests/bpf/bpf_testmod/bpf_testmod.c | 24 +++++++++++++ .../selftests/bpf/bpf_testmod/bpf_testmod.h | 4 +++ .../selftests/bpf/prog_tests/bad_struct_ops.c | 35 +++++++++++++++++++ .../selftests/bpf/progs/bad_struct_ops.c | 25 +++++++++++++ 4 files changed, 88 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/bad_struct_ops.c create mode 100644 tools/testing/selftests/bpf/progs/bad_struct_ops.c diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c index b9ff88e3d463..2de7e80dbb4b 100644 --- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c +++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c @@ -610,6 +610,29 @@ struct bpf_struct_ops bpf_bpf_testmod_ops = { .owner = THIS_MODULE, }; +static int bpf_dummy_reg2(void *kdata) +{ + struct bpf_testmod_ops2 *ops = kdata; + + ops->test_1(); + return 0; +} + +static struct bpf_testmod_ops2 __bpf_testmod_ops2 = { + .test_1 = bpf_testmod_test_1, +}; + +struct bpf_struct_ops bpf_testmod_ops2 = { + .verifier_ops = &bpf_testmod_verifier_ops, + .init = bpf_testmod_ops_init, + .init_member = bpf_testmod_ops_init_member, + .reg = bpf_dummy_reg2, + .unreg = bpf_dummy_unreg, + .cfi_stubs = &__bpf_testmod_ops2, + .name = "bpf_testmod_ops2", + .owner = THIS_MODULE, +}; + extern int bpf_fentry_test1(int a); static int bpf_testmod_init(void) @@ -621,6 +644,7 @@ static int bpf_testmod_init(void) ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, &bpf_testmod_kfunc_set); ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_SYSCALL, &bpf_testmod_kfunc_set); ret = ret ?: register_bpf_struct_ops(&bpf_bpf_testmod_ops, bpf_testmod_ops); + ret = ret ?: register_bpf_struct_ops(&bpf_testmod_ops2, bpf_testmod_ops2); if (ret < 0) return ret; if (bpf_fentry_test1(0) < 0) diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h index 971458acfac3..c51c4eae9ed5 100644 --- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h +++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h @@ -45,4 +45,8 @@ struct bpf_testmod_ops { int data; }; +struct bpf_testmod_ops2 { + int (*test_1)(void); +}; + #endif /* _BPF_TESTMOD_H */ diff --git a/tools/testing/selftests/bpf/prog_tests/bad_struct_ops.c b/tools/testing/selftests/bpf/prog_tests/bad_struct_ops.c new file mode 100644 index 000000000000..9f5dbefa0dd9 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/bad_struct_ops.c @@ -0,0 +1,35 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <test_progs.h> +#include "bad_struct_ops.skel.h" + +static void invalid_prog_reuse(void) +{ + struct bad_struct_ops *skel; + char *log = NULL; + int err; + + skel = bad_struct_ops__open(); + if (!ASSERT_OK_PTR(skel, "bad_struct_ops__open")) + return; + + if (start_libbpf_log_capture()) + goto cleanup; + + err = bad_struct_ops__load(skel); + log = stop_libbpf_log_capture(); + ASSERT_ERR(err, "bad_struct_ops__load should fail"); + ASSERT_HAS_SUBSTR(log, + "struct_ops init_kern testmod_2 func ptr test_1: invalid reuse of prog test_1", + "expected init_kern message"); + +cleanup: + free(log); + bad_struct_ops__destroy(skel); +} + +void test_bad_struct_ops(void) +{ + if (test__start_subtest("invalid_prog_reuse")) + invalid_prog_reuse(); +} diff --git a/tools/testing/selftests/bpf/progs/bad_struct_ops.c b/tools/testing/selftests/bpf/progs/bad_struct_ops.c new file mode 100644 index 000000000000..b7e175cd0af0 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/bad_struct_ops.c @@ -0,0 +1,25 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <vmlinux.h> +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_tracing.h> +#include "../bpf_testmod/bpf_testmod.h" + +char _license[] SEC("license") = "GPL"; + +SEC("struct_ops/test_1") +int BPF_PROG(test_1) { return 0; } + +SEC("struct_ops/test_2") +int BPF_PROG(test_2) { return 0; } + +SEC(".struct_ops.link") +struct bpf_testmod_ops testmod_1 = { + .test_1 = (void *)test_1, + .test_2 = (void *)test_2 +}; + +SEC(".struct_ops.link") +struct bpf_testmod_ops2 testmod_2 = { + .test_1 = (void *)test_1 +}; -- 2.43.0