xref: /xnu-10002.61.3/san/memory/ubsan_minimal.h (revision 0f4c859e951fba394238ab619495c4e1d54d0f34)
1*0f4c859eSApple OSS Distributions /*
2*0f4c859eSApple OSS Distributions  * Copyright (c) 2021 Apple Inc. All rights reserved.
3*0f4c859eSApple OSS Distributions  *
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5*0f4c859eSApple OSS Distributions  *
6*0f4c859eSApple OSS Distributions  * This file contains Original Code and/or Modifications of Original Code
7*0f4c859eSApple OSS Distributions  * as defined in and that are subject to the Apple Public Source License
8*0f4c859eSApple OSS Distributions  * Version 2.0 (the 'License'). You may not use this file except in
9*0f4c859eSApple OSS Distributions  * compliance with the License. The rights granted to you under the License
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11*0f4c859eSApple OSS Distributions  * unlawful or unlicensed copies of an Apple operating system, or to
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14*0f4c859eSApple OSS Distributions  *
15*0f4c859eSApple OSS Distributions  * Please obtain a copy of the License at
16*0f4c859eSApple OSS Distributions  * http://www.opensource.apple.com/apsl/ and read it before using this file.
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21*0f4c859eSApple OSS Distributions  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
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27*0f4c859eSApple OSS Distributions  */
28*0f4c859eSApple OSS Distributions 
29*0f4c859eSApple OSS Distributions #ifndef _UBSAN_MINIMAL_H_
30*0f4c859eSApple OSS Distributions #define _UBSAN_MINIMAL_H_
31*0f4c859eSApple OSS Distributions 
32*0f4c859eSApple OSS Distributions #if CONFIG_UBSAN_MINIMAL
33*0f4c859eSApple OSS Distributions /*
34*0f4c859eSApple OSS Distributions  * This minimal runtime contains the handlers for checks that are suitable
35*0f4c859eSApple OSS Distributions  * at runtime. To minimize codegen impact, the handlers simply act as a shim
36*0f4c859eSApple OSS Distributions  * to a brk instruction, which gets then inlined by the compiler+LTO.
37*0f4c859eSApple OSS Distributions  * This is similar to UBSAN trapping mode, but guarantees that we can fix
38*0f4c859eSApple OSS Distributions  * and continue by simply stepping to the next instruction during the exception
39*0f4c859eSApple OSS Distributions  * handler.
40*0f4c859eSApple OSS Distributions  *
41*0f4c859eSApple OSS Distributions  * UBSAN Minimal runtime is currently available only for iOS and only for
42*0f4c859eSApple OSS Distributions  * signed overflow checks. It is only used on RELEASE and DEVELOPMENT kernels.
43*0f4c859eSApple OSS Distributions  */
44*0f4c859eSApple OSS Distributions 
45*0f4c859eSApple OSS Distributions #pragma GCC visibility push(hidden)
46*0f4c859eSApple OSS Distributions 
47*0f4c859eSApple OSS Distributions /* Trap handler for telemetry */
48*0f4c859eSApple OSS Distributions void ubsan_handle_brk_trap(void *, uint16_t);
49*0f4c859eSApple OSS Distributions 
50*0f4c859eSApple OSS Distributions /* Setup ubsan minimal runtime */
51*0f4c859eSApple OSS Distributions void ubsan_minimal_init(void);
52*0f4c859eSApple OSS Distributions 
53*0f4c859eSApple OSS Distributions /*
54*0f4c859eSApple OSS Distributions  * signed-integer-overflow ABI
55*0f4c859eSApple OSS Distributions  */
56*0f4c859eSApple OSS Distributions void __ubsan_handle_divrem_overflow_minimal(void);
57*0f4c859eSApple OSS Distributions void __ubsan_handle_negate_overflow_minimal(void);
58*0f4c859eSApple OSS Distributions void __ubsan_handle_mul_overflow_minimal(void);
59*0f4c859eSApple OSS Distributions void __ubsan_handle_sub_overflow_minimal(void);
60*0f4c859eSApple OSS Distributions void __ubsan_handle_add_overflow_minimal(void);
61*0f4c859eSApple OSS Distributions 
62*0f4c859eSApple OSS Distributions #pragma GCC visibility pop
63*0f4c859eSApple OSS Distributions 
64*0f4c859eSApple OSS Distributions #endif /* CONFIG_UBSAN_MINIMAL */
65*0f4c859eSApple OSS Distributions #endif /* _UBSAN_MINIMAL_H_ */
66