From 9a49afe6f5a516eb33bec24be0f81cb35ca79445 Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Wed, 17 Nov 2021 11:41:14 -0800 Subject: [PATCH] selftests/bpf: Add btf_dedup case with duplicated structs within CU Add an artificial minimal example simulating compilers producing two different types within a single CU that correspond to identical struct definitions. Signed-off-by: Jiri Olsa Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20211117194114.347675-2-andrii@kernel.org --- .../selftests/bpf/prog_tests/btf_dedup_split.c | 113 +++++++++++++++++++++ 1 file changed, 113 insertions(+) diff --git a/tools/testing/selftests/bpf/prog_tests/btf_dedup_split.c b/tools/testing/selftests/bpf/prog_tests/btf_dedup_split.c index 9d3b8d7..94ff975 100644 --- a/tools/testing/selftests/bpf/prog_tests/btf_dedup_split.c +++ b/tools/testing/selftests/bpf/prog_tests/btf_dedup_split.c @@ -314,6 +314,117 @@ cleanup: btf__free(btf1); } +static void btf_add_dup_struct_in_cu(struct btf *btf, int start_id) +{ +#define ID(n) (start_id + n) + btf__set_pointer_size(btf, 8); /* enforce 64-bit arch */ + + btf__add_int(btf, "int", 4, BTF_INT_SIGNED); /* [1] int */ + + btf__add_struct(btf, "s", 8); /* [2] struct s { */ + btf__add_field(btf, "a", ID(3), 0, 0); /* struct anon a; */ + btf__add_field(btf, "b", ID(4), 0, 0); /* struct anon b; */ + /* } */ + + btf__add_struct(btf, "(anon)", 8); /* [3] struct anon { */ + btf__add_field(btf, "f1", ID(1), 0, 0); /* int f1; */ + btf__add_field(btf, "f2", ID(1), 32, 0); /* int f2; */ + /* } */ + + btf__add_struct(btf, "(anon)", 8); /* [4] struct anon { */ + btf__add_field(btf, "f1", ID(1), 0, 0); /* int f1; */ + btf__add_field(btf, "f2", ID(1), 32, 0); /* int f2; */ + /* } */ +#undef ID +} + +static void test_split_dup_struct_in_cu() +{ + struct btf *btf1, *btf2; + int err; + + /* generate the base data.. */ + btf1 = btf__new_empty(); + if (!ASSERT_OK_PTR(btf1, "empty_main_btf")) + return; + + btf_add_dup_struct_in_cu(btf1, 0); + + VALIDATE_RAW_BTF( + btf1, + "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED", + "[2] STRUCT 's' size=8 vlen=2\n" + "\t'a' type_id=3 bits_offset=0\n" + "\t'b' type_id=4 bits_offset=0", + "[3] STRUCT '(anon)' size=8 vlen=2\n" + "\t'f1' type_id=1 bits_offset=0\n" + "\t'f2' type_id=1 bits_offset=32", + "[4] STRUCT '(anon)' size=8 vlen=2\n" + "\t'f1' type_id=1 bits_offset=0\n" + "\t'f2' type_id=1 bits_offset=32"); + + /* ..dedup them... */ + err = btf__dedup(btf1, NULL, NULL); + if (!ASSERT_OK(err, "btf_dedup")) + goto cleanup; + + VALIDATE_RAW_BTF( + btf1, + "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED", + "[2] STRUCT 's' size=8 vlen=2\n" + "\t'a' type_id=3 bits_offset=0\n" + "\t'b' type_id=3 bits_offset=0", + "[3] STRUCT '(anon)' size=8 vlen=2\n" + "\t'f1' type_id=1 bits_offset=0\n" + "\t'f2' type_id=1 bits_offset=32"); + + /* and add the same data on top of it */ + btf2 = btf__new_empty_split(btf1); + if (!ASSERT_OK_PTR(btf2, "empty_split_btf")) + goto cleanup; + + btf_add_dup_struct_in_cu(btf2, 3); + + VALIDATE_RAW_BTF( + btf2, + "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED", + "[2] STRUCT 's' size=8 vlen=2\n" + "\t'a' type_id=3 bits_offset=0\n" + "\t'b' type_id=3 bits_offset=0", + "[3] STRUCT '(anon)' size=8 vlen=2\n" + "\t'f1' type_id=1 bits_offset=0\n" + "\t'f2' type_id=1 bits_offset=32", + "[4] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED", + "[5] STRUCT 's' size=8 vlen=2\n" + "\t'a' type_id=6 bits_offset=0\n" + "\t'b' type_id=7 bits_offset=0", + "[6] STRUCT '(anon)' size=8 vlen=2\n" + "\t'f1' type_id=4 bits_offset=0\n" + "\t'f2' type_id=4 bits_offset=32", + "[7] STRUCT '(anon)' size=8 vlen=2\n" + "\t'f1' type_id=4 bits_offset=0\n" + "\t'f2' type_id=4 bits_offset=32"); + + err = btf__dedup(btf2, NULL, NULL); + if (!ASSERT_OK(err, "btf_dedup")) + goto cleanup; + + /* after dedup it should match the original data */ + VALIDATE_RAW_BTF( + btf2, + "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED", + "[2] STRUCT 's' size=8 vlen=2\n" + "\t'a' type_id=3 bits_offset=0\n" + "\t'b' type_id=3 bits_offset=0", + "[3] STRUCT '(anon)' size=8 vlen=2\n" + "\t'f1' type_id=1 bits_offset=0\n" + "\t'f2' type_id=1 bits_offset=32"); + +cleanup: + btf__free(btf2); + btf__free(btf1); +} + void test_btf_dedup_split() { if (test__start_subtest("split_simple")) @@ -322,4 +433,6 @@ void test_btf_dedup_split() test_split_struct_duped(); if (test__start_subtest("split_fwd_resolve")) test_split_fwd_resolve(); + if (test__start_subtest("split_dup_struct_in_cu")) + test_split_dup_struct_in_cu(); } -- 2.7.4