xref: /linux/tools/testing/selftests/bpf/verifier/atomic_cmpxchg.c (revision 78964fcac47fc1525ecb4c37cd5fbc873c28320b)
1 {
2 	"atomic compare-and-exchange smoketest - 64bit",
3 	.insns = {
4 		/* val = 3; */
5 		BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 3),
6 		/* old = atomic_cmpxchg(&val, 2, 4); */
7 		BPF_MOV64_IMM(BPF_REG_1, 4),
8 		BPF_MOV64_IMM(BPF_REG_0, 2),
9 		BPF_ATOMIC_OP(BPF_DW, BPF_CMPXCHG, BPF_REG_10, BPF_REG_1, -8),
10 		/* if (old != 3) exit(2); */
11 		BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 3, 2),
12 		BPF_MOV64_IMM(BPF_REG_0, 2),
13 		BPF_EXIT_INSN(),
14 		/* if (val != 3) exit(3); */
15 		BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_10, -8),
16 		BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 3, 2),
17 		BPF_MOV64_IMM(BPF_REG_0, 3),
18 		BPF_EXIT_INSN(),
19 		/* old = atomic_cmpxchg(&val, 3, 4); */
20 		BPF_MOV64_IMM(BPF_REG_1, 4),
21 		BPF_MOV64_IMM(BPF_REG_0, 3),
22 		BPF_ATOMIC_OP(BPF_DW, BPF_CMPXCHG, BPF_REG_10, BPF_REG_1, -8),
23 		/* if (old != 3) exit(4); */
24 		BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 3, 2),
25 		BPF_MOV64_IMM(BPF_REG_0, 4),
26 		BPF_EXIT_INSN(),
27 		/* if (val != 4) exit(5); */
28 		BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_10, -8),
29 		BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 4, 2),
30 		BPF_MOV64_IMM(BPF_REG_0, 5),
31 		BPF_EXIT_INSN(),
32 		/* exit(0); */
33 		BPF_MOV64_IMM(BPF_REG_0, 0),
34 		BPF_EXIT_INSN(),
35 	},
36 	.result = ACCEPT,
37 },
38 {
39 	"atomic compare-and-exchange smoketest - 32bit",
40 	.insns = {
41 		/* val = 3; */
42 		BPF_ST_MEM(BPF_W, BPF_REG_10, -4, 3),
43 		/* old = atomic_cmpxchg(&val, 2, 4); */
44 		BPF_MOV32_IMM(BPF_REG_1, 4),
45 		BPF_MOV32_IMM(BPF_REG_0, 2),
46 		BPF_ATOMIC_OP(BPF_W, BPF_CMPXCHG, BPF_REG_10, BPF_REG_1, -4),
47 		/* if (old != 3) exit(2); */
48 		BPF_JMP32_IMM(BPF_JEQ, BPF_REG_0, 3, 2),
49 		BPF_MOV32_IMM(BPF_REG_0, 2),
50 		BPF_EXIT_INSN(),
51 		/* if (val != 3) exit(3); */
52 		BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_10, -4),
53 		BPF_JMP32_IMM(BPF_JEQ, BPF_REG_0, 3, 2),
54 		BPF_MOV32_IMM(BPF_REG_0, 3),
55 		BPF_EXIT_INSN(),
56 		/* old = atomic_cmpxchg(&val, 3, 4); */
57 		BPF_MOV32_IMM(BPF_REG_1, 4),
58 		BPF_MOV32_IMM(BPF_REG_0, 3),
59 		BPF_ATOMIC_OP(BPF_W, BPF_CMPXCHG, BPF_REG_10, BPF_REG_1, -4),
60 		/* if (old != 3) exit(4); */
61 		BPF_JMP32_IMM(BPF_JEQ, BPF_REG_0, 3, 2),
62 		BPF_MOV32_IMM(BPF_REG_0, 4),
63 		BPF_EXIT_INSN(),
64 		/* if (val != 4) exit(5); */
65 		BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_10, -4),
66 		BPF_JMP32_IMM(BPF_JEQ, BPF_REG_0, 4, 2),
67 		BPF_MOV32_IMM(BPF_REG_0, 5),
68 		BPF_EXIT_INSN(),
69 		/* exit(0); */
70 		BPF_MOV32_IMM(BPF_REG_0, 0),
71 		BPF_EXIT_INSN(),
72 	},
73 	.result = ACCEPT,
74 },
75 {
76 	"Can't use cmpxchg on uninit src reg",
77 	.insns = {
78 		BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 3),
79 		BPF_MOV64_IMM(BPF_REG_0, 3),
80 		BPF_ATOMIC_OP(BPF_DW, BPF_CMPXCHG, BPF_REG_10, BPF_REG_2, -8),
81 		BPF_EXIT_INSN(),
82 	},
83 	.result = REJECT,
84 	.errstr = "!read_ok",
85 },
86 {
87 	"Can't use cmpxchg on uninit memory",
88 	.insns = {
89 		BPF_MOV64_IMM(BPF_REG_0, 3),
90 		BPF_MOV64_IMM(BPF_REG_2, 4),
91 		BPF_ATOMIC_OP(BPF_DW, BPF_CMPXCHG, BPF_REG_10, BPF_REG_2, -8),
92 		BPF_EXIT_INSN(),
93 	},
94 	.result = REJECT,
95 	.errstr = "invalid read from stack",
96 },
97 {
98 	"BPF_W cmpxchg should zero top 32 bits",
99 	.insns = {
100 		/* r0 = U64_MAX; */
101 		BPF_MOV64_IMM(BPF_REG_0, 0),
102 		BPF_ALU64_IMM(BPF_SUB, BPF_REG_0, 1),
103 		/* u64 val = r0; */
104 		BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, -8),
105 		/* r0 = (u32)atomic_cmpxchg((u32 *)&val, r0, 1); */
106 		BPF_MOV32_IMM(BPF_REG_1, 1),
107 		BPF_ATOMIC_OP(BPF_W, BPF_CMPXCHG, BPF_REG_10, BPF_REG_1, -8),
108 		/* r1 = 0x00000000FFFFFFFFull; */
109 		BPF_MOV64_IMM(BPF_REG_1, 1),
110 		BPF_ALU64_IMM(BPF_LSH, BPF_REG_1, 32),
111 		BPF_ALU64_IMM(BPF_SUB, BPF_REG_1, 1),
112 		/* if (r0 != r1) exit(1); */
113 		BPF_JMP_REG(BPF_JEQ, BPF_REG_0, BPF_REG_1, 2),
114 		BPF_MOV32_IMM(BPF_REG_0, 1),
115 		BPF_EXIT_INSN(),
116 		/* exit(0); */
117 		BPF_MOV32_IMM(BPF_REG_0, 0),
118 		BPF_EXIT_INSN(),
119 	},
120 	.result = ACCEPT,
121 },
122 {
123 	"Dest pointer in r0 - fail",
124 	.insns = {
125 		/* val = 0; */
126 		BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
127 		/* r0 = &val */
128 		BPF_MOV64_REG(BPF_REG_0, BPF_REG_10),
129 		/* r0 = atomic_cmpxchg(&val, r0, 1); */
130 		BPF_MOV64_IMM(BPF_REG_1, 1),
131 		BPF_ATOMIC_OP(BPF_DW, BPF_CMPXCHG, BPF_REG_10, BPF_REG_1, -8),
132 		/* if (r0 != 0) exit(1); */
133 		BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2),
134 		BPF_MOV64_IMM(BPF_REG_0, 1),
135 		BPF_EXIT_INSN(),
136 		/* exit(0); */
137 		BPF_MOV64_IMM(BPF_REG_0, 0),
138 		BPF_EXIT_INSN(),
139 	},
140 	.result = ACCEPT,
141 	.result_unpriv = REJECT,
142 	.errstr_unpriv = "R0 leaks addr into mem",
143 },
144 {
145 	"Dest pointer in r0 - succeed",
146 	.insns = {
147 		/* r0 = &val */
148 		BPF_MOV64_REG(BPF_REG_0, BPF_REG_10),
149 		/* val = r0; */
150 		BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, -8),
151 		/* r0 = atomic_cmpxchg(&val, r0, 0); */
152 		BPF_MOV64_IMM(BPF_REG_1, 0),
153 		BPF_ATOMIC_OP(BPF_DW, BPF_CMPXCHG, BPF_REG_10, BPF_REG_1, -8),
154 		/* r1 = *r0 */
155 		BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0, -8),
156 		/* exit(0); */
157 		BPF_MOV64_IMM(BPF_REG_0, 0),
158 		BPF_EXIT_INSN(),
159 	},
160 	.result = ACCEPT,
161 	.result_unpriv = REJECT,
162 	.errstr_unpriv = "R0 leaks addr into mem",
163 },
164 {
165 	"Dest pointer in r0 - succeed, check 2",
166 	.insns = {
167 		/* r0 = &val */
168 		BPF_MOV64_REG(BPF_REG_0, BPF_REG_10),
169 		/* val = r0; */
170 		BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, -8),
171 		/* r5 = &val */
172 		BPF_MOV64_REG(BPF_REG_5, BPF_REG_10),
173 		/* r0 = atomic_cmpxchg(&val, r0, r5); */
174 		BPF_ATOMIC_OP(BPF_DW, BPF_CMPXCHG, BPF_REG_10, BPF_REG_5, -8),
175 		/* r1 = *r0 */
176 		BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0, -8),
177 		/* exit(0); */
178 		BPF_MOV64_IMM(BPF_REG_0, 0),
179 		BPF_EXIT_INSN(),
180 	},
181 	.result = ACCEPT,
182 	.result_unpriv = REJECT,
183 	.errstr_unpriv = "R0 leaks addr into mem",
184 },
185 {
186 	"Dest pointer in r0 - succeed, check 3",
187 	.insns = {
188 		/* r0 = &val */
189 		BPF_MOV64_REG(BPF_REG_0, BPF_REG_10),
190 		/* val = r0; */
191 		BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, -8),
192 		/* r5 = &val */
193 		BPF_MOV64_REG(BPF_REG_5, BPF_REG_10),
194 		/* r0 = atomic_cmpxchg(&val, r0, r5); */
195 		BPF_ATOMIC_OP(BPF_W, BPF_CMPXCHG, BPF_REG_10, BPF_REG_5, -8),
196 		/* exit(0); */
197 		BPF_MOV64_IMM(BPF_REG_0, 0),
198 		BPF_EXIT_INSN(),
199 	},
200 	.result = REJECT,
201 	.errstr = "invalid size of register fill",
202 	.errstr_unpriv = "R0 leaks addr into mem",
203 },
204 {
205 	"Dest pointer in r0 - succeed, check 4",
206 	.insns = {
207 		/* r0 = &val */
208 		BPF_MOV32_REG(BPF_REG_0, BPF_REG_10),
209 		/* val = r0; */
210 		BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_0, -8),
211 		/* r5 = &val */
212 		BPF_MOV32_REG(BPF_REG_5, BPF_REG_10),
213 		/* r0 = atomic_cmpxchg(&val, r0, r5); */
214 		BPF_ATOMIC_OP(BPF_W, BPF_CMPXCHG, BPF_REG_10, BPF_REG_5, -8),
215 		/* r1 = *r10 */
216 		BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_10, -8),
217 		/* exit(0); */
218 		BPF_MOV64_IMM(BPF_REG_0, 0),
219 		BPF_EXIT_INSN(),
220 	},
221 	.result = ACCEPT,
222 	.result_unpriv = REJECT,
223 	.errstr_unpriv = "R10 partial copy of pointer",
224 },
225 {
226 	"Dest pointer in r0 - succeed, check 5",
227 	.insns = {
228 		/* r0 = &val */
229 		BPF_MOV32_REG(BPF_REG_0, BPF_REG_10),
230 		/* val = r0; */
231 		BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_0, -8),
232 		/* r5 = &val */
233 		BPF_MOV32_REG(BPF_REG_5, BPF_REG_10),
234 		/* r0 = atomic_cmpxchg(&val, r0, r5); */
235 		BPF_ATOMIC_OP(BPF_W, BPF_CMPXCHG, BPF_REG_10, BPF_REG_5, -8),
236 		/* r1 = *r0 */
237 		BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_0, -8),
238 		/* exit(0); */
239 		BPF_MOV64_IMM(BPF_REG_0, 0),
240 		BPF_EXIT_INSN(),
241 	},
242 	.result = REJECT,
243 	.errstr = "R0 invalid mem access",
244 	.errstr_unpriv = "R10 partial copy of pointer",
245 	.flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS,
246 },
247