xref: /linux/tools/testing/selftests/bpf/progs/percpu_alloc_fail.c (revision 2beb1b31a12b57e19cd5c82ea6d54e56520605e8)
1 #include "bpf_experimental.h"
2 #include "bpf_misc.h"
3 
4 struct val_t {
5 	long b, c, d;
6 };
7 
8 struct val2_t {
9 	long b;
10 };
11 
12 struct val_with_ptr_t {
13 	char *p;
14 };
15 
16 struct val_with_rb_root_t {
17 	struct bpf_spin_lock lock;
18 };
19 
20 struct val_600b_t {
21 	char b[600];
22 };
23 
24 struct elem {
25 	long sum;
26 	struct val_t __percpu_kptr *pc;
27 };
28 
29 struct {
30 	__uint(type, BPF_MAP_TYPE_ARRAY);
31 	__uint(max_entries, 1);
32 	__type(key, int);
33 	__type(value, struct elem);
34 } array SEC(".maps");
35 
36 struct kernel_percpu_elem {
37 	struct task_struct __percpu_kptr *task;
38 };
39 
40 struct {
41 	__uint(type, BPF_MAP_TYPE_ARRAY);
42 	__uint(max_entries, 1);
43 	__type(key, int);
44 	__type(value, struct kernel_percpu_elem);
45 } kernel_percpu_array SEC(".maps");
46 
47 struct task_struct *bpf_task_from_pid(s32 pid) __ksym;
48 void bpf_task_release(struct task_struct *p) __ksym;
49 
50 long ret;
51 
52 SEC("?fentry/bpf_fentry_test1")
53 __failure __msg("store to referenced kptr disallowed")
BPF_PROG(test_array_map_1)54 int BPF_PROG(test_array_map_1)
55 {
56 	struct val_t __percpu_kptr *p;
57 	struct elem *e;
58 	int index = 0;
59 
60 	e = bpf_map_lookup_elem(&array, &index);
61 	if (!e)
62 		return 0;
63 
64 	p = bpf_percpu_obj_new(struct val_t);
65 	if (!p)
66 		return 0;
67 
68 	p = bpf_kptr_xchg(&e->pc, p);
69 	if (p)
70 		bpf_percpu_obj_drop(p);
71 
72 	e->pc = (struct val_t __percpu_kptr *)ret;
73 	return 0;
74 }
75 
76 SEC("?fentry/bpf_fentry_test1")
77 __failure __msg("invalid kptr access, R2 type=percpu_ptr_val2_t expected=ptr_val_t")
BPF_PROG(test_array_map_2)78 int BPF_PROG(test_array_map_2)
79 {
80 	struct val2_t __percpu_kptr *p2;
81 	struct val_t __percpu_kptr *p;
82 	struct elem *e;
83 	int index = 0;
84 
85 	e = bpf_map_lookup_elem(&array, &index);
86 	if (!e)
87 		return 0;
88 
89 	p2 = bpf_percpu_obj_new(struct val2_t);
90 	if (!p2)
91 		return 0;
92 
93 	p = bpf_kptr_xchg(&e->pc, p2);
94 	if (p)
95 		bpf_percpu_obj_drop(p);
96 
97 	return 0;
98 }
99 
100 SEC("?fentry.s/bpf_fentry_test1")
101 __failure __msg("R1 type=scalar expected=percpu_ptr_, percpu_rcu_ptr_, percpu_trusted_ptr_")
BPF_PROG(test_array_map_3)102 int BPF_PROG(test_array_map_3)
103 {
104 	struct val_t __percpu_kptr *p, *p1;
105 	struct val_t *v;
106 	struct elem *e;
107 	int index = 0;
108 
109 	e = bpf_map_lookup_elem(&array, &index);
110 	if (!e)
111 		return 0;
112 
113 	p = bpf_percpu_obj_new(struct val_t);
114 	if (!p)
115 		return 0;
116 
117 	p1 = bpf_kptr_xchg(&e->pc, p);
118 	if (p1)
119 		bpf_percpu_obj_drop(p1);
120 
121 	v = bpf_this_cpu_ptr(p);
122 	ret = v->b;
123 	return 0;
124 }
125 
126 SEC("?fentry.s/bpf_fentry_test1")
127 __failure __msg("R1 expected for bpf_percpu_obj_drop()")
BPF_PROG(test_array_map_4)128 int BPF_PROG(test_array_map_4)
129 {
130 	struct val_t __percpu_kptr *p;
131 
132 	p = bpf_percpu_obj_new(struct val_t);
133 	if (!p)
134 		return 0;
135 
136 	bpf_obj_drop(p);
137 	return 0;
138 }
139 
140 SEC("?fentry.s/bpf_fentry_test1")
141 __failure __msg("R1 expected for bpf_obj_drop()")
BPF_PROG(test_array_map_5)142 int BPF_PROG(test_array_map_5)
143 {
144 	struct val_t *p;
145 
146 	p = bpf_obj_new(struct val_t);
147 	if (!p)
148 		return 0;
149 
150 	bpf_percpu_obj_drop(p);
151 	return 0;
152 }
153 
154 SEC("?syscall")
155 __failure __msg("invalid kptr access, R2 type=trusted_ptr_ expected=ptr_task_struct")
reject_kernel_ptr_into_percpu_kptr(void * ctx)156 int reject_kernel_ptr_into_percpu_kptr(void *ctx)
157 {
158 	struct kernel_percpu_elem *e;
159 	struct task_struct *p, *old;
160 	int index = 0;
161 
162 	e = bpf_map_lookup_elem(&kernel_percpu_array, &index);
163 	if (!e)
164 		return 0;
165 
166 	p = bpf_task_from_pid(1);
167 	if (!p)
168 		return 0;
169 
170 	old = bpf_kptr_xchg(&e->task, p);
171 	if (old)
172 		bpf_task_release(old);
173 	return 0;
174 }
175 
176 SEC("?fentry.s/bpf_fentry_test1")
177 __failure __msg("invalid kptr access, R2 type=ptr_ expected=ptr_val_t")
BPF_PROG(reject_plain_alloc_into_percpu_kptr)178 int BPF_PROG(reject_plain_alloc_into_percpu_kptr)
179 {
180 	struct val_t __percpu_kptr *old;
181 	struct val_t *p;
182 	struct elem *e;
183 	int index = 0;
184 
185 	e = bpf_map_lookup_elem(&array, &index);
186 	if (!e)
187 		return 0;
188 
189 	p = bpf_obj_new(struct val_t);
190 	if (!p)
191 		return 0;
192 
193 	old = bpf_kptr_xchg(&e->pc, p);
194 	if (old)
195 		bpf_percpu_obj_drop(old);
196 	return 0;
197 }
198 
199 SEC("?fentry.s/bpf_fentry_test1")
200 __failure __msg("bpf_percpu_obj_new type ID argument must be of a struct of scalars")
BPF_PROG(test_array_map_6)201 int BPF_PROG(test_array_map_6)
202 {
203 	struct val_with_ptr_t __percpu_kptr *p;
204 
205 	p = bpf_percpu_obj_new(struct val_with_ptr_t);
206 	if (!p)
207 		return 0;
208 
209 	bpf_percpu_obj_drop(p);
210 	return 0;
211 }
212 
213 SEC("?fentry.s/bpf_fentry_test1")
214 __failure __msg("bpf_percpu_obj_new type ID argument must not contain special fields")
BPF_PROG(test_array_map_7)215 int BPF_PROG(test_array_map_7)
216 {
217 	struct val_with_rb_root_t __percpu_kptr *p;
218 
219 	p = bpf_percpu_obj_new(struct val_with_rb_root_t);
220 	if (!p)
221 		return 0;
222 
223 	bpf_percpu_obj_drop(p);
224 	return 0;
225 }
226 
227 SEC("?fentry.s/bpf_fentry_test1")
228 __failure __msg("bpf_percpu_obj_new type size (600) is greater than 512")
BPF_PROG(test_array_map_8)229 int BPF_PROG(test_array_map_8)
230 {
231 	struct val_600b_t __percpu_kptr *p;
232 
233 	p = bpf_percpu_obj_new(struct val_600b_t);
234 	if (!p)
235 		return 0;
236 
237 	bpf_percpu_obj_drop(p);
238 	return 0;
239 }
240 
241 char _license[] SEC("license") = "GPL";
242