xref: /xnu-8019.80.24/san/memory/ubsan_minimal.h (revision a325d9c4a84054e40bbe985afedcb50ab80993ea)
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28 
29 #ifndef _UBSAN_MINIMAL_H_
30 #define _UBSAN_MINIMAL_H_
31 
32 #if CONFIG_UBSAN_MINIMAL
33 /*
34  * This minimal runtime contains the handlers for checks that are suitable
35  * at runtime. To minimize codegen impact, the handlers simply act as a shim
36  * to a brk instruction, which gets then inlined by the compiler+LTO.
37  * This is similar to UBSAN trapping mode, but guarantees that we can fix
38  * and continue by simply stepping to the next instruction during the exception
39  * handler.
40  *
41  * UBSAN Minimal runtime is currently available only for iOS and only for
42  * signed overflow checks. It is only used on RELEASE and DEVELOPMENT kernels.
43  */
44 
45 #pragma GCC visibility push(hidden)
46 enum ubsan_minimal_trap_idx {
47 	UBSAN_MINIMAL_SIGNED_OVERFLOW = 0x1206,
48 	UBSAN_MINIMAL_TRAPS_END
49 };
50 #define UBSAN_MINIMAL_TRAPS_START       UBSAN_MINIMAL_SIGNED_OVERFLOW
51 #define UBSAN_MINIMAL_TRAPS_TOTAL       (UBSAN_MINIMAL_TRAPS_END - UBSAN_MINIMAL_TRAPS_START)
52 
53 /* Trap handler for telemetry */
54 void ubsan_handle_brk_trap(uint16_t, uintptr_t, uintptr_t);
55 
56 /* Setup ubsan minimal runtime */
57 void ubsan_minimal_init(void);
58 
59 /*
60  * signed-integer-overflow ABI
61  */
62 void __ubsan_handle_divrem_overflow_minimal(void);
63 void __ubsan_handle_negate_overflow_minimal(void);
64 void __ubsan_handle_mul_overflow_minimal(void);
65 void __ubsan_handle_sub_overflow_minimal(void);
66 void __ubsan_handle_add_overflow_minimal(void);
67 
68 #pragma GCC visibility pop
69 
70 #endif /* CONFIG_UBSAN_MINIMAL */
71 #endif /* _UBSAN_MINIMAL_H_ */
72