From: Pu Lehui <pulehui@huawei.com> mainline inclusion from mainline-v6.14-rc1 commit 556a399406635566413f9c71b134d5d287b25b29 category: feature bugzilla: https://atomgit.com/openeuler/kernel/issues/8335 CVE: NA Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... ---------------------------------------------------------------------- When redirecting the split BTF to the vmlinux base BTF, we need to mark the distilled base struct/union members of split BTF structs/unions in id_map with BTF_IS_EMBEDDED. This indicates that these types must match both name and size later. So if a needed composite type, which is the member of composite type in the split BTF, has a different size in the base BTF we wish to relocate with, btf__relocate() should error out. Signed-off-by: Pu Lehui <pulehui@huawei.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20250115100241.4171581-4-pulehui@huaweicloud.com Signed-off-by: Luo Gengkun <luogengkun2@huawei.com> --- .../selftests/bpf/prog_tests/btf_distill.c | 72 +++++++++++++++++++ 1 file changed, 72 insertions(+) diff --git a/tools/testing/selftests/bpf/prog_tests/btf_distill.c b/tools/testing/selftests/bpf/prog_tests/btf_distill.c index b72b966df77b..fb67ae195a73 100644 --- a/tools/testing/selftests/bpf/prog_tests/btf_distill.c +++ b/tools/testing/selftests/bpf/prog_tests/btf_distill.c @@ -601,6 +601,76 @@ static void test_distilled_endianness(void) btf__free(base); } +/* If a needed composite type, which is the member of composite type + * in the split BTF, has a different size in the base BTF we wish to + * relocate with, btf__relocate() should error out. + */ +static void test_distilled_base_embedded_err(void) +{ + struct btf *btf1 = NULL, *btf2 = NULL, *btf3 = NULL, *btf4 = NULL, *btf5 = NULL; + + btf1 = btf__new_empty(); + if (!ASSERT_OK_PTR(btf1, "empty_main_btf")) + return; + + btf__add_int(btf1, "int", 4, BTF_INT_SIGNED); /* [1] int */ + btf__add_struct(btf1, "s1", 4); /* [2] struct s1 { */ + btf__add_field(btf1, "f1", 1, 0, 0); /* int f1; */ + /* } */ + VALIDATE_RAW_BTF( + btf1, + "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED", + "[2] STRUCT 's1' size=4 vlen=1\n" + "\t'f1' type_id=1 bits_offset=0"); + + btf2 = btf__new_empty_split(btf1); + if (!ASSERT_OK_PTR(btf2, "empty_split_btf")) + goto cleanup; + + btf__add_struct(btf2, "with_embedded", 8); /* [3] struct with_embedded { */ + btf__add_field(btf2, "e1", 2, 0, 0); /* struct s1 e1; */ + /* } */ + + VALIDATE_RAW_BTF( + btf2, + "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED", + "[2] STRUCT 's1' size=4 vlen=1\n" + "\t'f1' type_id=1 bits_offset=0", + "[3] STRUCT 'with_embedded' size=8 vlen=1\n" + "\t'e1' type_id=2 bits_offset=0"); + + if (!ASSERT_EQ(0, btf__distill_base(btf2, &btf3, &btf4), + "distilled_base") || + !ASSERT_OK_PTR(btf3, "distilled_base") || + !ASSERT_OK_PTR(btf4, "distilled_split") || + !ASSERT_EQ(2, btf__type_cnt(btf3), "distilled_base_type_cnt")) + goto cleanup; + + VALIDATE_RAW_BTF( + btf4, + "[1] STRUCT 's1' size=4 vlen=0", + "[2] STRUCT 'with_embedded' size=8 vlen=1\n" + "\t'e1' type_id=1 bits_offset=0"); + + btf5 = btf__new_empty(); + if (!ASSERT_OK_PTR(btf5, "empty_reloc_btf")) + goto cleanup; + + btf__add_int(btf5, "int", 4, BTF_INT_SIGNED); /* [1] int */ + /* struct with the same name but different size */ + btf__add_struct(btf5, "s1", 8); /* [2] struct s1 { */ + btf__add_field(btf5, "f1", 1, 0, 0); /* int f1; */ + /* } */ + + ASSERT_EQ(btf__relocate(btf4, btf5), -EINVAL, "relocate_split"); +cleanup: + btf__free(btf5); + btf__free(btf4); + btf__free(btf3); + btf__free(btf2); + btf__free(btf1); +} + void test_btf_distill(void) { if (test__start_subtest("distilled_base")) @@ -613,6 +683,8 @@ void test_btf_distill(void) test_distilled_base_multi_err(); if (test__start_subtest("distilled_base_multi_err2")) test_distilled_base_multi_err2(); + if (test__start_subtest("distilled_base_embedded_err")) + test_distilled_base_embedded_err(); if (test__start_subtest("distilled_base_vmlinux")) test_distilled_base_vmlinux(); if (test__start_subtest("distilled_endianness")) -- 2.34.1