kern_malloc.c

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/*	$NetBSD: kern_malloc.c,v 1.55 2000/11/24 00:34:32 chs Exp $	*/

/*
 * Copyright (c) 1996 Christopher G. Demetriou.  All rights reserved.
 * Copyright (c) 1987, 1991, 1993
 *	The Regents of the University of California.  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, 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
 *
 *	@(#)kern_malloc.c	8.4 (Berkeley) 5/20/95
 */

#include "opt_lockdebug.h"

#include <sys/param.h>
#include <sys/proc.h>
#include <sys/map.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/systm.h>

#include <uvm/uvm_extern.h>

static struct vm_map_intrsafe kmem_map_store;
vm_map_t kmem_map = NULL;

#include "opt_kmempages.h"

#ifdef NKMEMCLUSTERS
#error NKMEMCLUSTERS is obsolete; remove it from your kernel config file and use NKMEMPAGES instead or let the kernel auto-size
#endif

/*
 * Default number of pages in kmem_map.  We attempt to calculate this
 * at run-time, but allow it to be either patched or set in the kernel
 * config file.
 */
#ifndef NKMEMPAGES
#define	NKMEMPAGES	0
#endif
int	nkmempages = NKMEMPAGES;

/*
 * Defaults for lower- and upper-bounds for the kmem_map page count.
 * Can be overridden by kernel config options.
 */
#ifndef	NKMEMPAGES_MIN
#define	NKMEMPAGES_MIN	NKMEMPAGES_MIN_DEFAULT
#endif

#ifndef NKMEMPAGES_MAX
#define	NKMEMPAGES_MAX	NKMEMPAGES_MAX_DEFAULT
#endif

#include "opt_kmemstats.h"
#include "opt_malloclog.h"

#ifdef OSKIT
#include <oskit/gdb.h>
#include "oskit_uvm_internal.h"
#endif

struct kmembuckets bucket[MINBUCKET + 16];
struct kmemstats kmemstats[M_LAST];
struct kmemusage *kmemusage;
char *kmembase, *kmemlimit;
const char *memname[] = INITKMEMNAMES;

#ifdef MALLOCLOG
#ifndef MALLOCLOGSIZE
#define	MALLOCLOGSIZE	100000
#endif

struct malloclog {
	void *addr;
	long size;
	int type;
	int action;
	const char *file;
	long line;
} malloclog[MALLOCLOGSIZE];

long	malloclogptr;

static void domlog __P((void *a, long size, int type, int action,
	const char *file, long line));
static void hitmlog __P((void *a));

static void
domlog(a, size, type, action, file, line)
	void *a;
	long size;
	int type;
	int action;
	const char *file;
	long line;
{

	malloclog[malloclogptr].addr = a;
	malloclog[malloclogptr].size = size;
	malloclog[malloclogptr].type = type;
	malloclog[malloclogptr].action = action;
	malloclog[malloclogptr].file = file;
	malloclog[malloclogptr].line = line;
	malloclogptr++;
	if (malloclogptr >= MALLOCLOGSIZE)
		malloclogptr = 0;
}

static void
hitmlog(a)
	void *a;
{
	struct malloclog *lp;
	long l;

#define	PRT \
	if (malloclog[l].addr == a && malloclog[l].action) { \
		lp = &malloclog[l]; \
		printf("malloc log entry %ld:\n", l); \
		printf("\taddr = %p\n", lp->addr); \
		printf("\tsize = %ld\n", lp->size); \
		printf("\ttype = %s\n", memname[lp->type]); \
		printf("\taction = %s\n", lp->action == 1 ? "alloc" : "free"); \
		printf("\tfile = %s\n", lp->file); \
		printf("\tline = %ld\n", lp->line); \
	}

	for (l = malloclogptr; l < MALLOCLOGSIZE; l++)
		PRT

	for (l = 0; l < malloclogptr; l++)
		PRT
}
#endif /* MALLOCLOG */

#ifdef DIAGNOSTIC

/*
 * This structure provides a set of masks to catch unaligned frees.
 */
long addrmask[] = { 0,
	0x00000001, 0x00000003, 0x00000007, 0x0000000f,
	0x0000001f, 0x0000003f, 0x0000007f, 0x000000ff,
	0x000001ff, 0x000003ff, 0x000007ff, 0x00000fff,
	0x00001fff, 0x00003fff, 0x00007fff, 0x0000ffff,
};

/*
 * The WEIRD_ADDR is used as known text to copy into free objects so
 * that modifications after frees can be detected.
 */
#define WEIRD_ADDR	((unsigned) 0xdeadbeef)
#ifdef DEBUG
#define MAX_COPY	PAGE_SIZE
#else
#define MAX_COPY	32
#endif

/*
 * Normally the freelist structure is used only to hold the list pointer
 * for free objects.  However, when running with diagnostics, the first
 * 8 bytes of the structure is unused except for diagnostic information,
 * and the free list pointer is at offst 8 in the structure.  Since the
 * first 8 bytes is the portion of the structure most often modified, this
 * helps to detect memory reuse problems and avoid free list corruption.
 */
struct freelist {
	int32_t	spare0;
	int16_t	type;
	int16_t	spare1;
	caddr_t	next;
};
#else /* !DIAGNOSTIC */
struct freelist {
	caddr_t	next;
};
#endif /* DIAGNOSTIC */

/*
 * Allocate a block of memory
 */
#ifdef MALLOCLOG
void *
_malloc(size, type, flags, file, line)
	unsigned long size;
	int type, flags;
	const char *file;
	long line;
#else
void *
malloc(size, type, flags)
	unsigned long size;
	int type, flags;
#endif /* MALLOCLOG */
{
	struct kmembuckets *kbp;
	struct kmemusage *kup;
	struct freelist *freep;
	long indx, npg, allocsize;
	int s;
	caddr_t va, cp, savedlist;
#ifdef DIAGNOSTIC
	int32_t *end, *lp;
	int copysize;
	const char *savedtype;
#endif
#ifdef KMEMSTATS
	struct kmemstats *ksp = &kmemstats[type];

	if (__predict_false(((unsigned long)type) > M_LAST))
		panic("malloc - bogus type");
#endif
	indx = BUCKETINDX(size);
	kbp = &bucket[indx];
	s = splmem();
#ifdef KMEMSTATS
	while (ksp->ks_memuse >= ksp->ks_limit) {
		if (flags & M_NOWAIT) {
			splx(s);
			return ((void *) NULL);
		}
		if (ksp->ks_limblocks < 65535)
			ksp->ks_limblocks++;
		tsleep((caddr_t)ksp, PSWP+2, memname[type], 0);
	}
	ksp->ks_size |= 1 << indx;
#endif
#ifdef DIAGNOSTIC
	copysize = 1 << indx < MAX_COPY ? 1 << indx : MAX_COPY;
#endif
	if (kbp->kb_next == NULL) {
		kbp->kb_last = NULL;
		if (size > MAXALLOCSAVE)
			allocsize = roundup(size, PAGE_SIZE);
		else
			allocsize = 1 << indx;
		npg = btoc(allocsize);
		va = (caddr_t) uvm_km_kmemalloc(kmem_map, uvmexp.kmem_object,
				(vsize_t)ctob(npg), 
				(flags & M_NOWAIT) ? UVM_KMF_NOWAIT : 0);
		if (__predict_false(va == NULL)) {
			/*
			 * Kmem_malloc() can return NULL, even if it can
			 * wait, if there is no map space avaiable, because
			 * it can't fix that problem.  Neither can we,
			 * right now.  (We should release pages which
			 * are completely free and which are in buckets
			 * with too many free elements.)
			 */
			if ((flags & M_NOWAIT) == 0)
				panic("malloc: out of space in kmem_map");
			splx(s);
			return ((void *) NULL);
		}
#ifdef KMEMSTATS
		kbp->kb_total += kbp->kb_elmpercl;
#endif
		kup = btokup(va);
		kup->ku_indx = indx;
		if (allocsize > MAXALLOCSAVE) {
			if (npg > 65535)
				panic("malloc: allocation too large");
			kup->ku_pagecnt = npg;
#ifdef KMEMSTATS
			ksp->ks_memuse += allocsize;
#endif
			goto out;
		}
#ifdef KMEMSTATS
		kup->ku_freecnt = kbp->kb_elmpercl;
		kbp->kb_totalfree += kbp->kb_elmpercl;
#endif
		/*
		 * Just in case we blocked while allocating memory,
		 * and someone else also allocated memory for this
		 * bucket, don't assume the list is still empty.
		 */
		savedlist = kbp->kb_next;
		kbp->kb_next = cp = va + (npg << PAGE_SHIFT) - allocsize;
		for (;;) {
			freep = (struct freelist *)cp;
#ifdef DIAGNOSTIC
			/*
			 * Copy in known text to detect modification
			 * after freeing.
			 */
			end = (int32_t *)&cp[copysize];
			for (lp = (int32_t *)cp; lp < end; lp++)
				*lp = WEIRD_ADDR;
			freep->type = M_FREE;
#endif /* DIAGNOSTIC */
			if (cp <= va)
				break;
			cp -= allocsize;
			freep->next = cp;
		}
		freep->next = savedlist;
		if (kbp->kb_last == NULL)
			kbp->kb_last = (caddr_t)freep;
	}
	va = kbp->kb_next;
	kbp->kb_next = ((struct freelist *)va)->next;
#ifdef DIAGNOSTIC
	freep = (struct freelist *)va;
	savedtype = (unsigned)freep->type < M_LAST ?
		memname[freep->type] : "???";
	if (kbp->kb_next) {
		int rv;
		vaddr_t addr = (vaddr_t)kbp->kb_next;

		vm_map_lock(kmem_map);
		rv = uvm_map_checkprot(kmem_map, addr,
				       addr + sizeof(struct freelist),
				       VM_PROT_WRITE);
		vm_map_unlock(kmem_map);

		if (__predict_false(rv == 0)) {
#ifdef OSKIT
		    gdb_breakpoint();
#endif
			printf(
		    "%s %ld of object %p size %ld %s %s (invalid addr %p)\n",
			    "Data modified on freelist: word", 
			    (long)((int32_t *)&kbp->kb_next - (int32_t *)kbp),
			    va, size, "previous type", savedtype, kbp->kb_next);
#ifdef MALLOCLOG
			hitmlog(va);
#endif
			kbp->kb_next = NULL;
		}
	}

	/* Fill the fields that we've used with WEIRD_ADDR */
#if BYTE_ORDER == BIG_ENDIAN
	freep->type = WEIRD_ADDR >> 16;
#endif
#if BYTE_ORDER == LITTLE_ENDIAN
	freep->type = (short)WEIRD_ADDR;
#endif
	end = (int32_t *)&freep->next +
	    (sizeof(freep->next) / sizeof(int32_t));
	for (lp = (int32_t *)&freep->next; lp < end; lp++)
		*lp = WEIRD_ADDR;

	/* and check that the data hasn't been modified. */
	end = (int32_t *)&va[copysize];
	for (lp = (int32_t *)va; lp < end; lp++) {
		if (__predict_true(*lp == WEIRD_ADDR))
			continue;
#ifdef OSKIT