xref: /freebsd/sys/amd64/include/msan.h (revision faf25f48d601ae39f5752602f3020e2e92605625)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2021 The FreeBSD Foundation
5  *
6  * This software was developed by Mark Johnston under sponsorship from the
7  * FreeBSD Foundation.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions are
11  * met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in
16  *    the documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 #ifndef _MACHINE_MSAN_H_
32 #define	_MACHINE_MSAN_H_
33 
34 #ifdef KMSAN
35 
36 #include <vm/vm.h>
37 #include <vm/pmap.h>
38 #include <vm/vm_page.h>
39 #include <machine/vmparam.h>
40 
41 typedef uint32_t msan_orig_t;
42 
43 /*
44  * Our 32-bit origin cells encode a 2-bit type and 30-bit pointer.  The pointer
45  * is compressed by making it a positive offset relative to KERNBASE.
46  */
47 #define	KMSAN_ORIG_TYPE_SHIFT	30u
48 #define	KMSAN_ORIG_PTR_MASK	((1u << KMSAN_ORIG_TYPE_SHIFT) - 1)
49 
50 static inline msan_orig_t
51 kmsan_md_orig_encode(int type, uintptr_t ptr)
52 {
53 	return ((type << KMSAN_ORIG_TYPE_SHIFT) |
54 	    ((ptr & KMSAN_ORIG_PTR_MASK)));
55 }
56 
57 static inline void
58 kmsan_md_orig_decode(msan_orig_t orig, int *type, uintptr_t *ptr)
59 {
60 	*type = orig >> KMSAN_ORIG_TYPE_SHIFT;
61 	*ptr = (orig & KMSAN_ORIG_PTR_MASK) | KERNBASE;
62 }
63 
64 static inline vm_offset_t
65 kmsan_md_addr_to_shad(vm_offset_t addr)
66 {
67 	return (addr - VM_MIN_KERNEL_ADDRESS + KMSAN_SHAD_MIN_ADDRESS);
68 }
69 
70 static inline vm_offset_t
71 kmsan_md_addr_to_orig(vm_offset_t addr)
72 {
73 	return (addr - VM_MIN_KERNEL_ADDRESS + KMSAN_ORIG_MIN_ADDRESS);
74 }
75 
76 static inline bool
77 kmsan_md_unsupported(vm_offset_t addr)
78 {
79 	return (addr < VM_MIN_KERNEL_ADDRESS || addr >= KERNBASE);
80 }
81 
82 #endif /* KMSAN */
83 
84 #endif /* !_MACHINE_MSAN_H_ */
85