Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0
2/* Copyright (c) 2020 Facebook */
3#include <test_progs.h>
4#include <bpf/btf.h>
5
6static char *dump_buf;
7static size_t dump_buf_sz;
8static FILE *dump_buf_file;
9
10static void btf_dump_printf(void *ctx, const char *fmt, va_list args)
11{
12 vfprintf(ctx, fmt, args);
13}
14
15/* Write raw BTF to file, return number of bytes written or negative errno */
16static ssize_t btf_raw_write(struct btf *btf, char *file)
17{
18 ssize_t written = 0;
19 const void *data;
20 __u32 size = 0;
21 int fd, ret;
22
23 fd = mkstemp(file);
24 if (!ASSERT_GE(fd, 0, "create_file"))
25 return -errno;
26
27 data = btf__raw_data(btf, &size);
28 if (!ASSERT_OK_PTR(data, "btf__raw_data")) {
29 close(fd);
30 return -EINVAL;
31 }
32 while (written < size) {
33 ret = write(fd, data + written, size - written);
34 if (!ASSERT_GE(ret, 0, "write succeeded")) {
35 close(fd);
36 return -errno;
37 }
38 written += ret;
39 }
40 close(fd);
41 return written;
42}
43
44static void __test_btf_split(bool multi)
45{
46 char multisplit_btf_file[] = "/tmp/test_btf_multisplit.XXXXXX";
47 char split_btf_file[] = "/tmp/test_btf_split.XXXXXX";
48 char base_btf_file[] = "/tmp/test_btf_base.XXXXXX";
49 ssize_t multisplit_btf_sz = 0, split_btf_sz = 0, base_btf_sz = 0;
50 struct btf_dump *d = NULL;
51 const struct btf_type *t, *ot;
52 struct btf *btf1 = NULL, *btf2 = NULL, *btf3 = NULL;
53 struct btf *btf4 = NULL, *btf5 = NULL, *btf6 = NULL;
54 int str_off, i, err;
55
56 btf1 = btf__new_empty();
57 if (!ASSERT_OK_PTR(btf1, "empty_main_btf"))
58 return;
59
60 btf__set_pointer_size(btf1, 8); /* enforce 64-bit arch */
61
62 btf__add_int(btf1, "int", 4, BTF_INT_SIGNED); /* [1] int */
63 btf__add_ptr(btf1, 1); /* [2] ptr to int */
64
65 btf__add_struct(btf1, "s1", 4); /* [3] struct s1 { */
66 btf__add_field(btf1, "f1", 1, 0, 0); /* int f1; */
67 /* } */
68
69 btf2 = btf__new_empty_split(btf1);
70 if (!ASSERT_OK_PTR(btf2, "empty_split_btf"))
71 goto cleanup;
72
73 /* pointer size should be "inherited" from main BTF */
74 ASSERT_EQ(btf__pointer_size(btf2), 8, "inherit_ptr_sz");
75
76 str_off = btf__find_str(btf2, "int");
77 ASSERT_NEQ(str_off, -ENOENT, "str_int_missing");
78
79 t = btf__type_by_id(btf2, 1);
80 if (!ASSERT_OK_PTR(t, "int_type"))
81 goto cleanup;
82 ASSERT_EQ(btf_is_int(t), true, "int_kind");
83 ASSERT_STREQ(btf__str_by_offset(btf2, t->name_off), "int", "int_name");
84
85 btf__add_struct(btf2, "s2", 16); /* [4] struct s2 { */
86 btf__add_field(btf2, "f1", 3, 0, 0); /* struct s1 f1; */
87 btf__add_field(btf2, "f2", 1, 32, 0); /* int f2; */
88 btf__add_field(btf2, "f3", 2, 64, 0); /* int *f3; */
89 /* } */
90
91 t = btf__type_by_id(btf1, 4);
92 ASSERT_NULL(t, "split_type_in_main");
93
94 t = btf__type_by_id(btf2, 4);
95 if (!ASSERT_OK_PTR(t, "split_struct_type"))
96 goto cleanup;
97 ASSERT_EQ(btf_is_struct(t), true, "split_struct_kind");
98 ASSERT_EQ(btf_vlen(t), 3, "split_struct_vlen");
99 ASSERT_STREQ(btf__str_by_offset(btf2, t->name_off), "s2", "split_struct_name");
100
101 if (multi) {
102 btf3 = btf__new_empty_split(btf2);
103 if (!ASSERT_OK_PTR(btf3, "multi_split_btf"))
104 goto cleanup;
105 } else {
106 btf3 = btf2;
107 }
108
109 btf__add_union(btf3, "u1", 16); /* [5] union u1 { */
110 btf__add_field(btf3, "f1", 4, 0, 0); /* struct s2 f1; */
111 btf__add_field(btf3, "uf2", 1, 0, 0); /* int f2; */
112 /* } */
113
114 if (multi) {
115 t = btf__type_by_id(btf2, 5);
116 ASSERT_NULL(t, "multisplit_type_in_first_split");
117 }
118
119 t = btf__type_by_id(btf3, 5);
120 if (!ASSERT_OK_PTR(t, "split_union_type"))
121 goto cleanup;
122 ASSERT_EQ(btf_is_union(t), true, "split_union_kind");
123 ASSERT_EQ(btf_vlen(t), 2, "split_union_vlen");
124 ASSERT_STREQ(btf__str_by_offset(btf3, t->name_off), "u1", "split_union_name");
125 ASSERT_EQ(btf__type_cnt(btf3), 6, "split_type_cnt");
126
127 t = btf__type_by_id(btf3, 1);
128 if (!ASSERT_OK_PTR(t, "split_base_type"))
129 goto cleanup;
130 ASSERT_EQ(btf_is_int(t), true, "split_base_int");
131 ASSERT_STREQ(btf__str_by_offset(btf3, t->name_off), "int", "split_base_type_name");
132
133 /* BTF-to-C dump of split BTF */
134 dump_buf_file = open_memstream(&dump_buf, &dump_buf_sz);
135 if (!ASSERT_OK_PTR(dump_buf_file, "dump_memstream"))
136 return;
137 d = btf_dump__new(btf3, btf_dump_printf, dump_buf_file, NULL);
138 if (!ASSERT_OK_PTR(d, "btf_dump__new"))
139 goto cleanup;
140 for (i = 1; i < btf__type_cnt(btf3); i++) {
141 err = btf_dump__dump_type(d, i);
142 ASSERT_OK(err, "dump_type_ok");
143 }
144 fflush(dump_buf_file);
145 dump_buf[dump_buf_sz] = 0; /* some libc implementations don't do this */
146 ASSERT_STREQ(dump_buf,
147"struct s1 {\n"
148" int f1;\n"
149"};\n\n"
150"struct s2 {\n"
151" struct s1 f1;\n"
152" int f2;\n"
153" int *f3;\n"
154"};\n\n"
155"union u1 {\n"
156" struct s2 f1;\n"
157" int uf2;\n"
158"};\n\n", "c_dump");
159
160 /* write base, split BTFs to files and ensure parsing succeeds */
161 base_btf_sz = btf_raw_write(btf1, base_btf_file);
162 if (base_btf_sz < 0)
163 goto cleanup;
164 split_btf_sz = btf_raw_write(btf2, split_btf_file);
165 if (split_btf_sz < 0)
166 goto cleanup;
167 btf4 = btf__parse(base_btf_file, NULL);
168 if (!ASSERT_OK_PTR(btf4, "parse_base"))
169 goto cleanup;
170 btf5 = btf__parse_split(split_btf_file, btf4);
171 if (!ASSERT_OK_PTR(btf5, "parse_split"))
172 goto cleanup;
173 if (multi) {
174 multisplit_btf_sz = btf_raw_write(btf3, multisplit_btf_file);
175 if (multisplit_btf_sz < 0)
176 goto cleanup;
177 btf6 = btf__parse_split(multisplit_btf_file, btf5);
178 if (!ASSERT_OK_PTR(btf6, "parse_multisplit"))
179 goto cleanup;
180 } else {
181 btf6 = btf5;
182 }
183
184 if (!ASSERT_EQ(btf__type_cnt(btf3), btf__type_cnt(btf6), "cmp_type_cnt"))
185 goto cleanup;
186
187 /* compare parsed to original BTF */
188 for (i = 1; i < btf__type_cnt(btf6); i++) {
189 t = btf__type_by_id(btf6, i);
190 if (!ASSERT_OK_PTR(t, "type_in_parsed_btf"))
191 goto cleanup;
192 ot = btf__type_by_id(btf3, i);
193 if (!ASSERT_OK_PTR(ot, "type_in_orig_btf"))
194 goto cleanup;
195 if (!ASSERT_EQ(memcmp(t, ot, sizeof(*ot)), 0, "cmp_parsed_orig_btf"))
196 goto cleanup;
197 }
198
199cleanup:
200 if (dump_buf_file)
201 fclose(dump_buf_file);
202 free(dump_buf);
203 btf_dump__free(d);
204 btf__free(btf1);
205 btf__free(btf2);
206 if (btf2 != btf3)
207 btf__free(btf3);
208 btf__free(btf4);
209 btf__free(btf5);
210 if (btf5 != btf6)
211 btf__free(btf6);
212 if (base_btf_sz > 0)
213 unlink(base_btf_file);
214 if (split_btf_sz > 0)
215 unlink(split_btf_file);
216 if (multisplit_btf_sz > 0)
217 unlink(multisplit_btf_file);
218}
219
220void test_btf_split(void)
221{
222 if (test__start_subtest("single_split"))
223 __test_btf_split(false);
224 if (test__start_subtest("multi_split"))
225 __test_btf_split(true);
226}