diff options
author | Kui-Feng Lee <thinker.li@gmail.com> | 2024-02-28 22:45:23 -0800 |
---|---|---|
committer | Andrii Nakryiko <andrii@kernel.org> | 2024-02-29 14:23:53 -0800 |
commit | 0623e73317940d052216fb6eef4efd55a0a7f602 (patch) | |
tree | 524cfad5f7755ea83210ec355b43fa650219b237 /tools | |
parent | f2e81192e07e87897ff1296c96775eceea8f582a (diff) |
selftests/bpf: Test if shadow types work correctly.
Change the values of fields, including scalar types and function pointers,
and check if the struct_ops map works as expected.
The test changes the field "test_2" of "testmod_1" from the pointer to
test_2() to pointer to test_3() and the field "data" to 13. The function
test_2() and test_3() both compute a new value for "test_2_result", but in
different way. By checking the value of "test_2_result", it ensures the
struct_ops map works as expected with changes through shadow types.
Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240229064523.2091270-6-thinker.li@gmail.com
Diffstat (limited to 'tools')
4 files changed, 41 insertions, 5 deletions
diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c index 66787e99ba1b..098ddd067224 100644 --- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c +++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c @@ -539,6 +539,15 @@ static int bpf_testmod_ops_init_member(const struct btf_type *t, const struct btf_member *member, void *kdata, const void *udata) { + if (member->offset == offsetof(struct bpf_testmod_ops, data) * 8) { + /* For data fields, this function has to copy it and return + * 1 to indicate that the data has been handled by the + * struct_ops type, or the verifier will reject the map if + * the value of the data field is not zero. + */ + ((struct bpf_testmod_ops *)kdata)->data = ((struct bpf_testmod_ops *)udata)->data; + return 1; + } return 0; } @@ -559,7 +568,7 @@ static int bpf_dummy_reg(void *kdata) * initialized, so we need to check for NULL. */ if (ops->test_2) - ops->test_2(4, 3); + ops->test_2(4, ops->data); return 0; } diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h index c3b0cf788f9f..971458acfac3 100644 --- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h +++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h @@ -35,6 +35,14 @@ struct bpf_testmod_ops { void (*test_2)(int a, int b); /* Used to test nullable arguments. */ int (*test_maybe_null)(int dummy, struct task_struct *task); + + /* The following fields are used to test shadow copies. */ + char onebyte; + struct { + int a; + int b; + } unsupported; + int data; }; #endif /* _BPF_TESTMOD_H */ diff --git a/tools/testing/selftests/bpf/prog_tests/test_struct_ops_module.c b/tools/testing/selftests/bpf/prog_tests/test_struct_ops_module.c index 8d833f0c7580..7d6facf46ebb 100644 --- a/tools/testing/selftests/bpf/prog_tests/test_struct_ops_module.c +++ b/tools/testing/selftests/bpf/prog_tests/test_struct_ops_module.c @@ -32,17 +32,23 @@ cleanup: static void test_struct_ops_load(void) { - DECLARE_LIBBPF_OPTS(bpf_object_open_opts, opts); struct struct_ops_module *skel; struct bpf_map_info info = {}; struct bpf_link *link; int err; u32 len; - skel = struct_ops_module__open_opts(&opts); + skel = struct_ops_module__open(); if (!ASSERT_OK_PTR(skel, "struct_ops_module_open")) return; + skel->struct_ops.testmod_1->data = 13; + skel->struct_ops.testmod_1->test_2 = skel->progs.test_3; + /* Since test_2() is not being used, it should be disabled from + * auto-loading, or it will fail to load. + */ + bpf_program__set_autoload(skel->progs.test_2, false); + err = struct_ops_module__load(skel); if (!ASSERT_OK(err, "struct_ops_module_load")) goto cleanup; @@ -56,8 +62,13 @@ static void test_struct_ops_load(void) link = bpf_map__attach_struct_ops(skel->maps.testmod_1); ASSERT_OK_PTR(link, "attach_test_mod_1"); - /* test_2() will be called from bpf_dummy_reg() in bpf_testmod.c */ - ASSERT_EQ(skel->bss->test_2_result, 7, "test_2_result"); + /* test_3() will be called from bpf_dummy_reg() in bpf_testmod.c + * + * In bpf_testmod.c it will pass 4 and 13 (the value of data) to + * .test_2. So, the value of test_2_result should be 20 (4 + 13 + + * 3). + */ + ASSERT_EQ(skel->bss->test_2_result, 20, "check_shadow_variables"); bpf_link__destroy(link); diff --git a/tools/testing/selftests/bpf/progs/struct_ops_module.c b/tools/testing/selftests/bpf/progs/struct_ops_module.c index b78746b3cef3..25952fa09348 100644 --- a/tools/testing/selftests/bpf/progs/struct_ops_module.c +++ b/tools/testing/selftests/bpf/progs/struct_ops_module.c @@ -21,9 +21,17 @@ void BPF_PROG(test_2, int a, int b) test_2_result = a + b; } +SEC("struct_ops/test_3") +int BPF_PROG(test_3, int a, int b) +{ + test_2_result = a + b + 3; + return a + b + 3; +} + SEC(".struct_ops.link") struct bpf_testmod_ops testmod_1 = { .test_1 = (void *)test_1, .test_2 = (void *)test_2, + .data = 0x1, }; |