1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (C) 2018 The FreeBSD Foundation. All rights reserved.
5 * Copyright (C) 2018, 2019 Andrew Turner
6 *
7 * This software was developed by Mitchell Horne under sponsorship of
8 * the FreeBSD Foundation.
9 *
10 * This software was developed by SRI International and the University of
11 * Cambridge Computer Laboratory under DARPA/AFRL contract FA8750-10-C-0237
12 * ("CTSRD"), as part of the DARPA CRASH research programme.
13 *
14 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions
16 * are met:
17 * 1. Redistributions of source code must retain the above copyright
18 * notice, this list of conditions and the following disclaimer.
19 * 2. Redistributions in binary form must reproduce the above copyright
20 * notice, this list of conditions and the following disclaimer in the
21 * documentation and/or other materials provided with the distribution.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36 #ifdef SAN_NEEDS_INTERCEPTORS
37 #define SAN_RUNTIME
38 #endif
39
40 #include <sys/param.h>
41 #include <sys/coverage.h>
42
43 #include <machine/atomic.h>
44
45 void __sanitizer_cov_trace_pc(void);
46 void __sanitizer_cov_trace_cmp1(uint8_t, uint8_t);
47 void __sanitizer_cov_trace_cmp2(uint16_t, uint16_t);
48 void __sanitizer_cov_trace_cmp4(uint32_t, uint32_t);
49 void __sanitizer_cov_trace_cmp8(uint64_t, uint64_t);
50 void __sanitizer_cov_trace_const_cmp1(uint8_t, uint8_t);
51 void __sanitizer_cov_trace_const_cmp2(uint16_t, uint16_t);
52 void __sanitizer_cov_trace_const_cmp4(uint32_t, uint32_t);
53 void __sanitizer_cov_trace_const_cmp8(uint64_t, uint64_t);
54 void __sanitizer_cov_trace_switch(uint64_t, uint64_t *);
55
56 static cov_trace_pc_t cov_trace_pc;
57 static cov_trace_cmp_t cov_trace_cmp;
58
59 void
cov_register_pc(cov_trace_pc_t trace_pc)60 cov_register_pc(cov_trace_pc_t trace_pc)
61 {
62
63 atomic_store_ptr(&cov_trace_pc, trace_pc);
64 }
65
66 void
cov_unregister_pc(void)67 cov_unregister_pc(void)
68 {
69
70 atomic_store_ptr(&cov_trace_pc, NULL);
71 }
72
73 void
cov_register_cmp(cov_trace_cmp_t trace_cmp)74 cov_register_cmp(cov_trace_cmp_t trace_cmp)
75 {
76
77 atomic_store_ptr(&cov_trace_cmp, trace_cmp);
78 }
79
80 void
cov_unregister_cmp(void)81 cov_unregister_cmp(void)
82 {
83
84 atomic_store_ptr(&cov_trace_cmp, NULL);
85 }
86
87 /*
88 * Main entry point. A call to this function will be inserted
89 * at every edge, and if coverage is enabled for the thread
90 * this function will add the PC to the buffer.
91 */
92 void
__sanitizer_cov_trace_pc(void)93 __sanitizer_cov_trace_pc(void)
94 {
95 cov_trace_pc_t trace_pc;
96
97 trace_pc = atomic_load_ptr(&cov_trace_pc);
98 if (trace_pc != NULL)
99 trace_pc((uint64_t)__builtin_return_address(0));
100 }
101
102 /*
103 * Comparison entry points. When the kernel performs a comparison
104 * operation the compiler inserts a call to one of the following
105 * functions to record the operation.
106 */
107 void
__sanitizer_cov_trace_cmp1(uint8_t arg1,uint8_t arg2)108 __sanitizer_cov_trace_cmp1(uint8_t arg1, uint8_t arg2)
109 {
110 cov_trace_cmp_t trace_cmp;
111
112 trace_cmp = atomic_load_ptr(&cov_trace_cmp);
113 if (trace_cmp != NULL)
114 trace_cmp(COV_CMP_SIZE(0), arg1, arg2,
115 (uint64_t)__builtin_return_address(0));
116 }
117
118 void
__sanitizer_cov_trace_cmp2(uint16_t arg1,uint16_t arg2)119 __sanitizer_cov_trace_cmp2(uint16_t arg1, uint16_t arg2)
120 {
121 cov_trace_cmp_t trace_cmp;
122
123 trace_cmp = atomic_load_ptr(&cov_trace_cmp);
124 if (trace_cmp != NULL)
125 trace_cmp(COV_CMP_SIZE(1), arg1, arg2,
126 (uint64_t)__builtin_return_address(0));
127 }
128
129 void
__sanitizer_cov_trace_cmp4(uint32_t arg1,uint32_t arg2)130 __sanitizer_cov_trace_cmp4(uint32_t arg1, uint32_t arg2)
131 {
132 cov_trace_cmp_t trace_cmp;
133
134 trace_cmp = atomic_load_ptr(&cov_trace_cmp);
135 if (trace_cmp != NULL)
136 trace_cmp(COV_CMP_SIZE(2), arg1, arg2,
137 (uint64_t)__builtin_return_address(0));
138 }
139
140 void
__sanitizer_cov_trace_cmp8(uint64_t arg1,uint64_t arg2)141 __sanitizer_cov_trace_cmp8(uint64_t arg1, uint64_t arg2)
142 {
143 cov_trace_cmp_t trace_cmp;
144
145 trace_cmp = atomic_load_ptr(&cov_trace_cmp);
146 if (trace_cmp != NULL)
147 trace_cmp(COV_CMP_SIZE(3), arg1, arg2,
148 (uint64_t)__builtin_return_address(0));
149 }
150
151 void
__sanitizer_cov_trace_const_cmp1(uint8_t arg1,uint8_t arg2)152 __sanitizer_cov_trace_const_cmp1(uint8_t arg1, uint8_t arg2)
153 {
154 cov_trace_cmp_t trace_cmp;
155
156 trace_cmp = atomic_load_ptr(&cov_trace_cmp);
157 if (trace_cmp != NULL)
158 trace_cmp(COV_CMP_SIZE(0) | COV_CMP_CONST, arg1, arg2,
159 (uint64_t)__builtin_return_address(0));
160 }
161
162 void
__sanitizer_cov_trace_const_cmp2(uint16_t arg1,uint16_t arg2)163 __sanitizer_cov_trace_const_cmp2(uint16_t arg1, uint16_t arg2)
164 {
165 cov_trace_cmp_t trace_cmp;
166
167 trace_cmp = atomic_load_ptr(&cov_trace_cmp);
168 if (trace_cmp != NULL)
169 trace_cmp(COV_CMP_SIZE(1) | COV_CMP_CONST, arg1, arg2,
170 (uint64_t)__builtin_return_address(0));
171 }
172
173 void
__sanitizer_cov_trace_const_cmp4(uint32_t arg1,uint32_t arg2)174 __sanitizer_cov_trace_const_cmp4(uint32_t arg1, uint32_t arg2)
175 {
176 cov_trace_cmp_t trace_cmp;
177
178 trace_cmp = atomic_load_ptr(&cov_trace_cmp);
179 if (trace_cmp != NULL)
180 trace_cmp(COV_CMP_SIZE(2) | COV_CMP_CONST, arg1, arg2,
181 (uint64_t)__builtin_return_address(0));
182 }
183
184 void
__sanitizer_cov_trace_const_cmp8(uint64_t arg1,uint64_t arg2)185 __sanitizer_cov_trace_const_cmp8(uint64_t arg1, uint64_t arg2)
186 {
187 cov_trace_cmp_t trace_cmp;
188
189 trace_cmp = atomic_load_ptr(&cov_trace_cmp);
190 if (trace_cmp != NULL)
191 trace_cmp(COV_CMP_SIZE(3) | COV_CMP_CONST, arg1, arg2,
192 (uint64_t)__builtin_return_address(0));
193 }
194
195 /*
196 * val is the switch operand
197 * cases[0] is the number of case constants
198 * cases[1] is the size of val in bits
199 * cases[2..n] are the case constants
200 */
201 void
__sanitizer_cov_trace_switch(uint64_t val,uint64_t * cases)202 __sanitizer_cov_trace_switch(uint64_t val, uint64_t *cases)
203 {
204 uint64_t i, count, ret, type;
205 cov_trace_cmp_t trace_cmp;
206
207 trace_cmp = atomic_load_ptr(&cov_trace_cmp);
208 if (trace_cmp == NULL)
209 return;
210
211 count = cases[0];
212 ret = (uint64_t)__builtin_return_address(0);
213
214 switch (cases[1]) {
215 case 8:
216 type = COV_CMP_SIZE(0);
217 break;
218 case 16:
219 type = COV_CMP_SIZE(1);
220 break;
221 case 32:
222 type = COV_CMP_SIZE(2);
223 break;
224 case 64:
225 type = COV_CMP_SIZE(3);
226 break;
227 default:
228 return;
229 }
230
231 val |= COV_CMP_CONST;
232
233 for (i = 0; i < count; i++)
234 if (!trace_cmp(type, val, cases[i + 2], ret))
235 return;
236 }
237