HardenedBSD/sys/vm/vm_dumpset.h

/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2020, Scott Phillips <scottph@freebsd.org>
 *
 * 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 unmodified, 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 ``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 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	_SYS_DUMPSET_H_
#define	_SYS_DUMPSET_H_

#include <sys/_bitset.h>
#include <sys/bitset.h>

extern struct bitset *vm_page_dump;
extern long vm_page_dump_pages;
extern vm_paddr_t dump_avail[PHYS_AVAIL_COUNT];

/* For the common case: add/remove a page from the minidump bitset. */
#define	dump_add_page(pa)	vm_page_dump_add(vm_page_dump, pa)
#define	dump_drop_page(pa)	vm_page_dump_drop(vm_page_dump, pa)

static inline void
vm_page_dump_add(struct bitset *bitset, vm_paddr_t pa)
{
	vm_pindex_t adj;
	int i;

	adj = 0;
	for (i = 0; dump_avail[i + 1] != 0; i += 2) {
		if (pa >= dump_avail[i] && pa < dump_avail[i + 1]) {
			BIT_SET_ATOMIC(vm_page_dump_pages,
			    (pa >> PAGE_SHIFT) - (dump_avail[i] >> PAGE_SHIFT) +
			    adj, bitset);
			return;
		}
		adj += howmany(dump_avail[i + 1], PAGE_SIZE) -
		    dump_avail[i] / PAGE_SIZE;
	}
}

static inline void
vm_page_dump_drop(struct bitset *bitset, vm_paddr_t pa)
{
	vm_pindex_t adj;
	int i;

	adj = 0;
	for (i = 0; dump_avail[i + 1] != 0; i += 2) {
		if (pa >= dump_avail[i] && pa < dump_avail[i + 1]) {
			BIT_CLR_ATOMIC(vm_page_dump_pages,
			    (pa >> PAGE_SHIFT) - (dump_avail[i] >> PAGE_SHIFT) +
			    adj, bitset);
			return;
		}
		adj += howmany(dump_avail[i + 1], PAGE_SIZE) -
		    dump_avail[i] / PAGE_SIZE;
	}
}

static inline vm_paddr_t
vm_page_dump_index_to_pa(int bit)
{
	int i, tot;

	for (i = 0; dump_avail[i + 1] != 0; i += 2) {
		tot = howmany(dump_avail[i + 1], PAGE_SIZE) -
		    dump_avail[i] / PAGE_SIZE;
		if (bit < tot)
			return ((vm_paddr_t)bit * PAGE_SIZE +
			    (dump_avail[i] & ~PAGE_MASK));
		bit -= tot;
	}
	return (0);
}

#define VM_PAGE_DUMP_FOREACH(bitset, pa)				\
	for (vm_pindex_t __b = BIT_FFS(vm_page_dump_pages, bitset);	\
	    (pa) = vm_page_dump_index_to_pa(__b - 1), __b != 0;		\
	    __b = BIT_FFS_AT(vm_page_dump_pages, bitset, __b))

#endif	/* _SYS_DUMPSET_H_ */