uma_dbg.c

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/*-
 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
 *
 * Copyright (c) 2002, 2003, 2004, 2005 Jeffrey Roberson <jeff@FreeBSD.org>
 * Copyright (c) 2004, 2005 Bosko Milekic <bmilekic@FreeBSD.org>
 * All rights reserved.
 *
 * 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.
 */
 
/*
 * uma_dbg.c    Debugging features for UMA users
 *
 */
 
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
 
#include "opt_vm.h"
 
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bitset.h>
#include <sys/kernel.h>
#include <sys/types.h>
#include <sys/queue.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/malloc.h>
 
#include <vm/vm.h>
#include <vm/vm_object.h>
#include <vm/vm_page.h>
#include <vm/uma.h>
#include <vm/uma_int.h>
#include <vm/uma_dbg.h>
#include <vm/memguard.h>
 
static const uint32_t uma_junk = 0xdeadc0de;
 
/*
 * Checks an item to make sure it hasn't been overwritten since it was freed,
 * prior to subsequent reallocation.
 *
 * Complies with standard ctor arg/return
 */
int
trash_ctor(void *mem, int size, void *arg, int flags)
{
        int cnt;
        uint32_t *p;
 
#ifdef DEBUG_MEMGUARD
        if (is_memguard_addr(mem))
                return (0);
#endif
 
        cnt = size / sizeof(uma_junk);
 
        for (p = mem; cnt > 0; cnt--, p++)
                if (*p != uma_junk) {
#ifdef INVARIANTS
                        panic("Memory modified after free %p(%d) val=%x @ %p\n",
                            mem, size, *p, p);
#else
                        printf("Memory modified after free %p(%d) val=%x @ %p\n",
                            mem, size, *p, p);
#endif
                        return (0);
                }
        return (0);
}
 
/*
 * Fills an item with predictable garbage
 *
 * Complies with standard dtor arg/return
 *
 */
void
trash_dtor(void *mem, int size, void *arg)
{
        int cnt;
        uint32_t *p;
 
#ifdef DEBUG_MEMGUARD
        if (is_memguard_addr(mem))
                return;
#endif
 
        cnt = size / sizeof(uma_junk);
 
        for (p = mem; cnt > 0; cnt--, p++)
                *p = uma_junk;
}
 
/*
 * Fills an item with predictable garbage
 *
 * Complies with standard init arg/return
 *
 */
int
trash_init(void *mem, int size, int flags)
{
        trash_dtor(mem, size, NULL);
        return (0);
}
 
/*
 * Checks an item to make sure it hasn't been overwritten since it was freed.
 *
 * Complies with standard fini arg/return
 *
 */
void
trash_fini(void *mem, int size)
{
        (void)trash_ctor(mem, size, NULL, 0);
}
 
int
mtrash_ctor(void *mem, int size, void *arg, int flags)
{
        struct malloc_type **ksp;
        uint32_t *p = mem;
        int cnt;
 
#ifdef DEBUG_MEMGUARD
        if (is_memguard_addr(mem))
                return (0);
#endif
 
        size -= sizeof(struct malloc_type *);
        ksp = (struct malloc_type **)mem;
        ksp += size / sizeof(struct malloc_type *);
        cnt = size / sizeof(uma_junk);
 
        for (p = mem; cnt > 0; cnt--, p++)
                if (*p != uma_junk) {
                        printf("Memory modified after free %p(%d) val=%x @ %p\n",
                            mem, size, *p, p);
                        panic("Most recently used by %s\n", (*ksp == NULL)?
                            "none" : (*ksp)->ks_shortdesc);
                }
        return (0);
}
 
/*
 * Fills an item with predictable garbage
 *
 * Complies with standard dtor arg/return
 *
 */
void
mtrash_dtor(void *mem, int size, void *arg)
{
        int cnt;
        uint32_t *p;
 
#ifdef DEBUG_MEMGUARD
        if (is_memguard_addr(mem))
                return;
#endif
 
        size -= sizeof(struct malloc_type *);
        cnt = size / sizeof(uma_junk);
 
        for (p = mem; cnt > 0; cnt--, p++)
                *p = uma_junk;
}
 
/*
 * Fills an item with predictable garbage
 *
 * Complies with standard init arg/return
 *
 */
int
mtrash_init(void *mem, int size, int flags)
{
        struct malloc_type **ksp;
 
#ifdef DEBUG_MEMGUARD
        if (is_memguard_addr(mem))
                return (0);
#endif
 
        mtrash_dtor(mem, size, NULL);
 
        ksp = (struct malloc_type **)mem;
        ksp += (size / sizeof(struct malloc_type *)) - 1;
        *ksp = NULL;
        return (0);
}
 
/*
 * Checks an item to make sure it hasn't been overwritten since it was freed,
 * prior to freeing it back to available memory.
 *
 * Complies with standard fini arg/return
 *
 */
void
mtrash_fini(void *mem, int size)
{
        (void)mtrash_ctor(mem, size, NULL, 0);
}