Commit c1b93c07 authored by Eduard Zingerman's avatar Eduard Zingerman Committed by Andrii Nakryiko
Browse files

selftests/bpf: Bad_struct_ops test 



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 impossible to use same BPF program in several
struct_ops maps that have different struct_ops type.
Check if libbpf rejects such BPF objects files.

Signed-off-by: default avatarEduard Zingerman <eddyz87@gmail.com>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Acked-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240306104529.6453-7-eddyz87@gmail.com
parent c8617e8b

tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c

+24 −0
Original line number Diff line number Diff line
@@ -611,6 +611,29 @@ 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)
@@ -622,6 +645,7 @@ 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)

tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h

+4 −0
Original line number Diff line number Diff line
@@ -89,4 +89,8 @@ struct bpf_testmod_ops { 
	int (*tramp_40)(int value);

};



struct bpf_testmod_ops2 {

	int (*test_1)(void);

};



#endif /* _BPF_TESTMOD_H */

tools/testing/selftests/bpf/prog_tests/bad_struct_ops.c

0 → 100644
+35 −0
Original line number Diff line number Diff line 
// 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();

}

tools/testing/selftests/bpf/progs/bad_struct_ops.c

0 → 100644
+25 −0
Original line number Diff line number Diff line 
// 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

};