arm64: Add msan.h

This is mostly a copy of amd64's msan.h, except that we currently do not
avoid shadowing the kernel itself, and we need a more restrictive upper
bound in kmsan_md_unsupported() to avoid probing non-existent shadow
mappings of device mappings.

Reviewed by:	imp
MFC after:	2 weeks
Sponsored by:	Klara, Inc.
Sponsored by:	Juniper Networks, Inc.
Differential Revision:	https://reviews.freebsd.org/D43156
This commit is contained in:
Mark Johnston 2024-02-08 11:00:40 -05:00
parent c05d7bdaf6
commit 90010126b0

91
sys/arm64/include/msan.h Normal file
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/*-
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2021 The FreeBSD Foundation
* Copyright (c) 2023 Juniper Networks, Inc.
*
* This software was developed by Mark Johnston under sponsorship from the
* FreeBSD Foundation.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef _MACHINE_MSAN_H_
#define _MACHINE_MSAN_H_
#ifdef KMSAN
#include <vm/vm.h>
#include <vm/pmap.h>
#include <vm/vm_page.h>
#include <machine/vmparam.h>
typedef uint32_t msan_orig_t;
/*
* Our 32-bit origin cells encode a 2-bit type and 30-bit pointer to a kernel
* instruction. The pointer is compressed by making it a positive offset
* relative to KERNBASE.
*/
#define KMSAN_ORIG_TYPE_SHIFT 30u
#define KMSAN_ORIG_PTR_MASK ((1ul << KMSAN_ORIG_TYPE_SHIFT) - 1)
static inline msan_orig_t
kmsan_md_orig_encode(int type, uintptr_t ptr)
{
return ((type << KMSAN_ORIG_TYPE_SHIFT) |
((ptr & KMSAN_ORIG_PTR_MASK)));
}
static inline void
kmsan_md_orig_decode(msan_orig_t orig, int *type, uintptr_t *ptr)
{
*type = orig >> KMSAN_ORIG_TYPE_SHIFT;
*ptr = (orig & KMSAN_ORIG_PTR_MASK) | KERNBASE;
}
static inline vm_offset_t
kmsan_md_addr_to_shad(vm_offset_t addr)
{
return (addr - VM_MIN_KERNEL_ADDRESS + KMSAN_SHAD_MIN_ADDRESS);
}
static inline vm_offset_t
kmsan_md_addr_to_orig(vm_offset_t addr)
{
return (addr - VM_MIN_KERNEL_ADDRESS + KMSAN_ORIG_MIN_ADDRESS);
}
static inline bool
kmsan_md_unsupported(vm_offset_t addr)
{
/*
* It would be cheaper to use VM_MAX_KERNEL_ADDRESS as the upper bound,
* but we need to exclude device mappings above kernel_vm_end but within
* the kernel map.
*/
return (addr < VM_MIN_KERNEL_ADDRESS || addr >= kernel_vm_end);
}
#endif /* KMSAN */
#endif /* !_MACHINE_MSAN_H_ */