1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2020 Facebook */
3 #include <linux/btf.h>
4 #include <linux/btf_ids.h>
5 #include <linux/error-injection.h>
6 #include <linux/init.h>
7 #include <linux/module.h>
8 #include <linux/percpu-defs.h>
9 #include <linux/sysfs.h>
10 #include <linux/tracepoint.h>
11 #include "bpf_testmod.h"
12
13 #define CREATE_TRACE_POINTS
14 #include "bpf_testmod-events.h"
15
16 typedef int (*func_proto_typedef)(long);
17 typedef int (*func_proto_typedef_nested1)(func_proto_typedef);
18 typedef int (*func_proto_typedef_nested2)(func_proto_typedef_nested1);
19
20 DEFINE_PER_CPU(int, bpf_testmod_ksym_percpu) = 123;
21 long bpf_testmod_test_struct_arg_result;
22
23 struct bpf_testmod_struct_arg_1 {
24 int a;
25 };
26 struct bpf_testmod_struct_arg_2 {
27 long a;
28 long b;
29 };
30
31 noinline int
bpf_testmod_test_struct_arg_1(struct bpf_testmod_struct_arg_2 a,int b,int c)32 bpf_testmod_test_struct_arg_1(struct bpf_testmod_struct_arg_2 a, int b, int c) {
33 bpf_testmod_test_struct_arg_result = a.a + a.b + b + c;
34 return bpf_testmod_test_struct_arg_result;
35 }
36
37 noinline int
bpf_testmod_test_struct_arg_2(int a,struct bpf_testmod_struct_arg_2 b,int c)38 bpf_testmod_test_struct_arg_2(int a, struct bpf_testmod_struct_arg_2 b, int c) {
39 bpf_testmod_test_struct_arg_result = a + b.a + b.b + c;
40 return bpf_testmod_test_struct_arg_result;
41 }
42
43 noinline int
bpf_testmod_test_struct_arg_3(int a,int b,struct bpf_testmod_struct_arg_2 c)44 bpf_testmod_test_struct_arg_3(int a, int b, struct bpf_testmod_struct_arg_2 c) {
45 bpf_testmod_test_struct_arg_result = a + b + c.a + c.b;
46 return bpf_testmod_test_struct_arg_result;
47 }
48
49 noinline int
bpf_testmod_test_struct_arg_4(struct bpf_testmod_struct_arg_1 a,int b,int c,int d,struct bpf_testmod_struct_arg_2 e)50 bpf_testmod_test_struct_arg_4(struct bpf_testmod_struct_arg_1 a, int b,
51 int c, int d, struct bpf_testmod_struct_arg_2 e) {
52 bpf_testmod_test_struct_arg_result = a.a + b + c + d + e.a + e.b;
53 return bpf_testmod_test_struct_arg_result;
54 }
55
56 noinline int
bpf_testmod_test_struct_arg_5(void)57 bpf_testmod_test_struct_arg_5(void) {
58 bpf_testmod_test_struct_arg_result = 1;
59 return bpf_testmod_test_struct_arg_result;
60 }
61
62 __bpf_kfunc void
bpf_testmod_test_mod_kfunc(int i)63 bpf_testmod_test_mod_kfunc(int i)
64 {
65 *(int *)this_cpu_ptr(&bpf_testmod_ksym_percpu) = i;
66 }
67
68 struct bpf_testmod_btf_type_tag_1 {
69 int a;
70 };
71
72 struct bpf_testmod_btf_type_tag_2 {
73 struct bpf_testmod_btf_type_tag_1 __user *p;
74 };
75
76 struct bpf_testmod_btf_type_tag_3 {
77 struct bpf_testmod_btf_type_tag_1 __percpu *p;
78 };
79
80 noinline int
bpf_testmod_test_btf_type_tag_user_1(struct bpf_testmod_btf_type_tag_1 __user * arg)81 bpf_testmod_test_btf_type_tag_user_1(struct bpf_testmod_btf_type_tag_1 __user *arg) {
82 BTF_TYPE_EMIT(func_proto_typedef);
83 BTF_TYPE_EMIT(func_proto_typedef_nested1);
84 BTF_TYPE_EMIT(func_proto_typedef_nested2);
85 return arg->a;
86 }
87
88 noinline int
bpf_testmod_test_btf_type_tag_user_2(struct bpf_testmod_btf_type_tag_2 * arg)89 bpf_testmod_test_btf_type_tag_user_2(struct bpf_testmod_btf_type_tag_2 *arg) {
90 return arg->p->a;
91 }
92
93 noinline int
bpf_testmod_test_btf_type_tag_percpu_1(struct bpf_testmod_btf_type_tag_1 __percpu * arg)94 bpf_testmod_test_btf_type_tag_percpu_1(struct bpf_testmod_btf_type_tag_1 __percpu *arg) {
95 return arg->a;
96 }
97
98 noinline int
bpf_testmod_test_btf_type_tag_percpu_2(struct bpf_testmod_btf_type_tag_3 * arg)99 bpf_testmod_test_btf_type_tag_percpu_2(struct bpf_testmod_btf_type_tag_3 *arg) {
100 return arg->p->a;
101 }
102
bpf_testmod_loop_test(int n)103 noinline int bpf_testmod_loop_test(int n)
104 {
105 int i, sum = 0;
106
107 /* the primary goal of this test is to test LBR. Create a lot of
108 * branches in the function, so we can catch it easily.
109 */
110 for (i = 0; i < n; i++)
111 sum += i;
112 return sum;
113 }
114
bpf_testmod_return_ptr(int arg)115 __weak noinline struct file *bpf_testmod_return_ptr(int arg)
116 {
117 static struct file f = {};
118
119 switch (arg) {
120 case 1: return (void *)EINVAL; /* user addr */
121 case 2: return (void *)0xcafe4a11; /* user addr */
122 case 3: return (void *)-EINVAL; /* canonical, but invalid */
123 case 4: return (void *)(1ull << 60); /* non-canonical and invalid */
124 case 5: return (void *)~(1ull << 30); /* trigger extable */
125 case 6: return &f; /* valid addr */
126 case 7: return (void *)((long)&f | 1); /* kernel tricks */
127 default: return NULL;
128 }
129 }
130
bpf_testmod_fentry_test1(int a)131 noinline int bpf_testmod_fentry_test1(int a)
132 {
133 return a + 1;
134 }
135
bpf_testmod_fentry_test2(int a,u64 b)136 noinline int bpf_testmod_fentry_test2(int a, u64 b)
137 {
138 return a + b;
139 }
140
bpf_testmod_fentry_test3(char a,int b,u64 c)141 noinline int bpf_testmod_fentry_test3(char a, int b, u64 c)
142 {
143 return a + b + c;
144 }
145
146 int bpf_testmod_fentry_ok;
147
148 noinline ssize_t
bpf_testmod_test_read(struct file * file,struct kobject * kobj,struct bin_attribute * bin_attr,char * buf,loff_t off,size_t len)149 bpf_testmod_test_read(struct file *file, struct kobject *kobj,
150 struct bin_attribute *bin_attr,
151 char *buf, loff_t off, size_t len)
152 {
153 struct bpf_testmod_test_read_ctx ctx = {
154 .buf = buf,
155 .off = off,
156 .len = len,
157 };
158 struct bpf_testmod_struct_arg_1 struct_arg1 = {10};
159 struct bpf_testmod_struct_arg_2 struct_arg2 = {2, 3};
160 int i = 1;
161
162 while (bpf_testmod_return_ptr(i))
163 i++;
164
165 (void)bpf_testmod_test_struct_arg_1(struct_arg2, 1, 4);
166 (void)bpf_testmod_test_struct_arg_2(1, struct_arg2, 4);
167 (void)bpf_testmod_test_struct_arg_3(1, 4, struct_arg2);
168 (void)bpf_testmod_test_struct_arg_4(struct_arg1, 1, 2, 3, struct_arg2);
169 (void)bpf_testmod_test_struct_arg_5();
170
171 /* This is always true. Use the check to make sure the compiler
172 * doesn't remove bpf_testmod_loop_test.
173 */
174 if (bpf_testmod_loop_test(101) > 100)
175 trace_bpf_testmod_test_read(current, &ctx);
176
177 /* Magic number to enable writable tp */
178 if (len == 64) {
179 struct bpf_testmod_test_writable_ctx writable = {
180 .val = 1024,
181 };
182 trace_bpf_testmod_test_writable_bare(&writable);
183 if (writable.early_ret)
184 return snprintf(buf, len, "%d\n", writable.val);
185 }
186
187 if (bpf_testmod_fentry_test1(1) != 2 ||
188 bpf_testmod_fentry_test2(2, 3) != 5 ||
189 bpf_testmod_fentry_test3(4, 5, 6) != 15)
190 goto out;
191
192 bpf_testmod_fentry_ok = 1;
193 out:
194 return -EIO; /* always fail */
195 }
196 EXPORT_SYMBOL(bpf_testmod_test_read);
197 ALLOW_ERROR_INJECTION(bpf_testmod_test_read, ERRNO);
198
199 noinline ssize_t
bpf_testmod_test_write(struct file * file,struct kobject * kobj,struct bin_attribute * bin_attr,char * buf,loff_t off,size_t len)200 bpf_testmod_test_write(struct file *file, struct kobject *kobj,
201 struct bin_attribute *bin_attr,
202 char *buf, loff_t off, size_t len)
203 {
204 struct bpf_testmod_test_write_ctx ctx = {
205 .buf = buf,
206 .off = off,
207 .len = len,
208 };
209
210 trace_bpf_testmod_test_write_bare(current, &ctx);
211
212 return -EIO; /* always fail */
213 }
214 EXPORT_SYMBOL(bpf_testmod_test_write);
215 ALLOW_ERROR_INJECTION(bpf_testmod_test_write, ERRNO);
216
217 static struct bin_attribute bin_attr_bpf_testmod_file __ro_after_init = {
218 .attr = { .name = "bpf_testmod", .mode = 0666, },
219 .read = bpf_testmod_test_read,
220 .write = bpf_testmod_test_write,
221 };
222
223 BTF_SET8_START(bpf_testmod_check_kfunc_ids)
224 BTF_ID_FLAGS(func, bpf_testmod_test_mod_kfunc)
225 BTF_SET8_END(bpf_testmod_check_kfunc_ids)
226
227 static const struct btf_kfunc_id_set bpf_testmod_kfunc_set = {
228 .owner = THIS_MODULE,
229 .set = &bpf_testmod_check_kfunc_ids,
230 };
231
232 extern int bpf_fentry_test1(int a);
233
bpf_testmod_init(void)234 static int bpf_testmod_init(void)
235 {
236 int ret;
237
238 ret = register_btf_kfunc_id_set(BPF_PROG_TYPE_SCHED_CLS, &bpf_testmod_kfunc_set);
239 if (ret < 0)
240 return ret;
241 if (bpf_fentry_test1(0) < 0)
242 return -EINVAL;
243 return sysfs_create_bin_file(kernel_kobj, &bin_attr_bpf_testmod_file);
244 }
245
bpf_testmod_exit(void)246 static void bpf_testmod_exit(void)
247 {
248 return sysfs_remove_bin_file(kernel_kobj, &bin_attr_bpf_testmod_file);
249 }
250
251 module_init(bpf_testmod_init);
252 module_exit(bpf_testmod_exit);
253
254 MODULE_AUTHOR("Andrii Nakryiko");
255 MODULE_DESCRIPTION("BPF selftests module");
256 MODULE_LICENSE("Dual BSD/GPL");
257