Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0
2/* Copyright (c) 2026 Xiaomi */
3
4#include <test_progs.h>
5#include <bpf/btf.h>
6#include "btf_helpers.h"
7
8static void permute_base_check(struct btf *btf)
9{
10 VALIDATE_RAW_BTF(
11 btf,
12 "[1] STRUCT 's2' size=4 vlen=1\n"
13 "\t'm' type_id=4 bits_offset=0",
14 "[2] FUNC 'f' type_id=6 linkage=static",
15 "[3] PTR '(anon)' type_id=4",
16 "[4] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
17 "[5] STRUCT 's1' size=4 vlen=1\n"
18 "\t'm' type_id=4 bits_offset=0",
19 "[6] FUNC_PROTO '(anon)' ret_type_id=4 vlen=1\n"
20 "\t'p' type_id=3");
21}
22
23/* Ensure btf__permute works as expected in the base-BTF scenario */
24static void test_permute_base(void)
25{
26 struct btf *btf;
27 __u32 permute_ids[7];
28 int err;
29
30 btf = btf__new_empty();
31 if (!ASSERT_OK_PTR(btf, "empty_main_btf"))
32 return;
33
34 btf__add_int(btf, "int", 4, BTF_INT_SIGNED); /* [1] int */
35 btf__add_ptr(btf, 1); /* [2] ptr to int */
36 btf__add_struct(btf, "s1", 4); /* [3] struct s1 { */
37 btf__add_field(btf, "m", 1, 0, 0); /* int m; */
38 /* } */
39 btf__add_struct(btf, "s2", 4); /* [4] struct s2 { */
40 btf__add_field(btf, "m", 1, 0, 0); /* int m; */
41 /* } */
42 btf__add_func_proto(btf, 1); /* [5] int (*)(int *p); */
43 btf__add_func_param(btf, "p", 2);
44 btf__add_func(btf, "f", BTF_FUNC_STATIC, 5); /* [6] int f(int *p); */
45
46 VALIDATE_RAW_BTF(
47 btf,
48 "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
49 "[2] PTR '(anon)' type_id=1",
50 "[3] STRUCT 's1' size=4 vlen=1\n"
51 "\t'm' type_id=1 bits_offset=0",
52 "[4] STRUCT 's2' size=4 vlen=1\n"
53 "\t'm' type_id=1 bits_offset=0",
54 "[5] FUNC_PROTO '(anon)' ret_type_id=1 vlen=1\n"
55 "\t'p' type_id=2",
56 "[6] FUNC 'f' type_id=5 linkage=static");
57
58 permute_ids[0] = 0; /* [0] -> [0] */
59 permute_ids[1] = 4; /* [1] -> [4] */
60 permute_ids[2] = 3; /* [2] -> [3] */
61 permute_ids[3] = 5; /* [3] -> [5] */
62 permute_ids[4] = 1; /* [4] -> [1] */
63 permute_ids[5] = 6; /* [5] -> [6] */
64 permute_ids[6] = 2; /* [6] -> [2] */
65 err = btf__permute(btf, permute_ids, ARRAY_SIZE(permute_ids), NULL);
66 if (!ASSERT_OK(err, "btf__permute_base"))
67 goto done;
68 permute_base_check(btf);
69
70 /* ids[0] must be 0 for base BTF */
71 permute_ids[0] = 4; /* [0] -> [0] */
72 permute_ids[1] = 0; /* [1] -> [4] */
73 permute_ids[2] = 3; /* [2] -> [3] */
74 permute_ids[3] = 5; /* [3] -> [5] */
75 permute_ids[4] = 1; /* [4] -> [1] */
76 permute_ids[5] = 6; /* [5] -> [6] */
77 permute_ids[6] = 2; /* [6] -> [2] */
78 err = btf__permute(btf, permute_ids, ARRAY_SIZE(permute_ids), NULL);
79 if (!ASSERT_ERR(err, "btf__permute_base"))
80 goto done;
81 /* BTF is not modified */
82 permute_base_check(btf);
83
84 /* id_map_cnt is invalid */
85 permute_ids[0] = 0; /* [0] -> [0] */
86 permute_ids[1] = 4; /* [1] -> [4] */
87 permute_ids[2] = 3; /* [2] -> [3] */
88 permute_ids[3] = 5; /* [3] -> [5] */
89 permute_ids[4] = 1; /* [4] -> [1] */
90 permute_ids[5] = 6; /* [5] -> [6] */
91 permute_ids[6] = 2; /* [6] -> [2] */
92 err = btf__permute(btf, permute_ids, ARRAY_SIZE(permute_ids) - 1, NULL);
93 if (!ASSERT_ERR(err, "btf__permute_base"))
94 goto done;
95 /* BTF is not modified */
96 permute_base_check(btf);
97
98 /* Multiple types can not be mapped to the same ID */
99 permute_ids[0] = 0;
100 permute_ids[1] = 4;
101 permute_ids[2] = 4;
102 permute_ids[3] = 5;
103 permute_ids[4] = 1;
104 permute_ids[5] = 6;
105 permute_ids[6] = 2;
106 err = btf__permute(btf, permute_ids, ARRAY_SIZE(permute_ids), NULL);
107 if (!ASSERT_ERR(err, "btf__permute_base"))
108 goto done;
109 /* BTF is not modified */
110 permute_base_check(btf);
111
112 /* Type ID must be valid */
113 permute_ids[0] = 0;
114 permute_ids[1] = 4;
115 permute_ids[2] = 3;
116 permute_ids[3] = 5;
117 permute_ids[4] = 1;
118 permute_ids[5] = 7;
119 permute_ids[6] = 2;
120 err = btf__permute(btf, permute_ids, ARRAY_SIZE(permute_ids), NULL);
121 if (!ASSERT_ERR(err, "btf__permute_base"))
122 goto done;
123 /* BTF is not modified */
124 permute_base_check(btf);
125
126done:
127 btf__free(btf);
128}
129
130static void permute_split_check(struct btf *btf)
131{
132 VALIDATE_RAW_BTF(
133 btf,
134 "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
135 "[2] PTR '(anon)' type_id=1",
136 "[3] STRUCT 's2' size=4 vlen=1\n"
137 "\t'm' type_id=1 bits_offset=0",
138 "[4] FUNC 'f' type_id=5 linkage=static",
139 "[5] FUNC_PROTO '(anon)' ret_type_id=1 vlen=1\n"
140 "\t'p' type_id=2",
141 "[6] STRUCT 's1' size=4 vlen=1\n"
142 "\t'm' type_id=1 bits_offset=0");
143}
144
145/* Ensure btf__permute works as expected in the split-BTF scenario */
146static void test_permute_split(void)
147{
148 struct btf *split_btf = NULL, *base_btf = NULL;
149 __u32 permute_ids[4];
150 int err, start_id;
151
152 base_btf = btf__new_empty();
153 if (!ASSERT_OK_PTR(base_btf, "empty_main_btf"))
154 return;
155
156 btf__add_int(base_btf, "int", 4, BTF_INT_SIGNED); /* [1] int */
157 btf__add_ptr(base_btf, 1); /* [2] ptr to int */
158 VALIDATE_RAW_BTF(
159 base_btf,
160 "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
161 "[2] PTR '(anon)' type_id=1");
162 split_btf = btf__new_empty_split(base_btf);
163 if (!ASSERT_OK_PTR(split_btf, "empty_split_btf"))
164 goto cleanup;
165 btf__add_struct(split_btf, "s1", 4); /* [3] struct s1 { */
166 btf__add_field(split_btf, "m", 1, 0, 0); /* int m; */
167 /* } */
168 btf__add_struct(split_btf, "s2", 4); /* [4] struct s2 { */
169 btf__add_field(split_btf, "m", 1, 0, 0); /* int m; */
170 /* } */
171 btf__add_func_proto(split_btf, 1); /* [5] int (*)(int p); */
172 btf__add_func_param(split_btf, "p", 2);
173 btf__add_func(split_btf, "f", BTF_FUNC_STATIC, 5); /* [6] int f(int *p); */
174
175 VALIDATE_RAW_BTF(
176 split_btf,
177 "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
178 "[2] PTR '(anon)' type_id=1",
179 "[3] STRUCT 's1' size=4 vlen=1\n"
180 "\t'm' type_id=1 bits_offset=0",
181 "[4] STRUCT 's2' size=4 vlen=1\n"
182 "\t'm' type_id=1 bits_offset=0",
183 "[5] FUNC_PROTO '(anon)' ret_type_id=1 vlen=1\n"
184 "\t'p' type_id=2",
185 "[6] FUNC 'f' type_id=5 linkage=static");
186
187 start_id = btf__type_cnt(base_btf);
188 permute_ids[3 - start_id] = 6; /* [3] -> [6] */
189 permute_ids[4 - start_id] = 3; /* [4] -> [3] */
190 permute_ids[5 - start_id] = 5; /* [5] -> [5] */
191 permute_ids[6 - start_id] = 4; /* [6] -> [4] */
192 err = btf__permute(split_btf, permute_ids, ARRAY_SIZE(permute_ids), NULL);
193 if (!ASSERT_OK(err, "btf__permute_split"))
194 goto cleanup;
195 permute_split_check(split_btf);
196
197 /*
198 * For split BTF, id_map_cnt must equal to the number of types
199 * added on top of base BTF
200 */
201 permute_ids[3 - start_id] = 4;
202 permute_ids[4 - start_id] = 3;
203 permute_ids[5 - start_id] = 5;
204 permute_ids[6 - start_id] = 6;
205 err = btf__permute(split_btf, permute_ids, ARRAY_SIZE(permute_ids) - 1, NULL);
206 if (!ASSERT_ERR(err, "btf__permute_split"))
207 goto cleanup;
208 /* BTF is not modified */
209 permute_split_check(split_btf);
210
211 /* Multiple types can not be mapped to the same ID */
212 permute_ids[3 - start_id] = 4;
213 permute_ids[4 - start_id] = 3;
214 permute_ids[5 - start_id] = 3;
215 permute_ids[6 - start_id] = 6;
216 err = btf__permute(split_btf, permute_ids, ARRAY_SIZE(permute_ids), NULL);
217 if (!ASSERT_ERR(err, "btf__permute_split"))
218 goto cleanup;
219 /* BTF is not modified */
220 permute_split_check(split_btf);
221
222 /* Can not map to base ID */
223 permute_ids[3 - start_id] = 4;
224 permute_ids[4 - start_id] = 2;
225 permute_ids[5 - start_id] = 5;
226 permute_ids[6 - start_id] = 6;
227 err = btf__permute(split_btf, permute_ids, ARRAY_SIZE(permute_ids), NULL);
228 if (!ASSERT_ERR(err, "btf__permute_split"))
229 goto cleanup;
230 /* BTF is not modified */
231 permute_split_check(split_btf);
232
233cleanup:
234 btf__free(split_btf);
235 btf__free(base_btf);
236}
237
238void test_btf_permute(void)
239{
240 if (test__start_subtest("permute_base"))
241 test_permute_base();
242 if (test__start_subtest("permute_split"))
243 test_permute_split();
244}