4.4BSD/usr/src/sys/kern/kern_malloc.c
/*
* 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 8.1 (Berkeley) 6/10/93
*/
#include <sys/param.h>
#include <sys/proc.h>
#include <sys/map.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <vm/vm.h>
#include <vm/vm_kern.h>
struct kmembuckets bucket[MINBUCKET + 16];
struct kmemstats kmemstats[M_LAST];
struct kmemusage *kmemusage;
char *kmembase, *kmemlimit;
char *memname[] = INITKMEMNAMES;
#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 0xdeadbeef
#define MAX_COPY 32
/*
* Normally the first word of the structure is used to hold the list
* pointer for free objects. However, when running with diagnostics,
* we use the third and fourth fields, so as to catch modifications
* in the most commonly trashed first two words.
*/
struct freelist {
long spare0;
short type;
long spare1;
caddr_t next;
};
#else /* !DIAGNOSTIC */
struct freelist {
caddr_t next;
};
#endif /* DIAGNOSTIC */
/*
* Allocate a block of memory
*/
void *
malloc(size, type, flags)
unsigned long size;
int type, flags;
{
register struct kmembuckets *kbp;
register struct kmemusage *kup;
register struct freelist *freep;
long indx, npg, alloc, allocsize;
int s;
caddr_t va, cp, savedlist;
#ifdef DIAGNOSTIC
long *end, *lp;
int copysize;
char *savedtype;
#endif
#ifdef KMEMSTATS
register struct kmemstats *ksp = &kmemstats[type];
if (((unsigned long)type) > M_LAST)
panic("malloc - bogus type");
#endif
indx = BUCKETINDX(size);
kbp = &bucket[indx];
s = splimp();
#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, CLBYTES);
else
allocsize = 1 << indx;
npg = clrnd(btoc(allocsize));
va = (caddr_t) kmem_malloc(kmem_map, (vm_size_t)ctob(npg),
!(flags & M_NOWAIT));
if (va == NULL) {
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 * NBPG) - allocsize;
for (;;) {
freep = (struct freelist *)cp;
#ifdef DIAGNOSTIC
/*
* Copy in known text to detect modification
* after freeing.
*/
end = (long *)&cp[copysize];
for (lp = (long *)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 &&
!kernacc(kbp->kb_next, sizeof(struct freelist), 0)) {
printf("%s of object 0x%x size %d %s %s (invalid addr 0x%x)\n",
"Data modified on freelist: word 2.5", va, size,
"previous type", savedtype, kbp->kb_next);
kbp->kb_next = NULL;
}
#if BYTE_ORDER == BIG_ENDIAN
freep->type = WEIRD_ADDR >> 16;
#endif
#if BYTE_ORDER == LITTLE_ENDIAN
freep->type = WEIRD_ADDR;
#endif
if (((long)(&freep->next)) & 0x2)
freep->next = (caddr_t)((WEIRD_ADDR >> 16)|(WEIRD_ADDR << 16));
else
freep->next = (caddr_t)WEIRD_ADDR;
end = (long *)&va[copysize];
for (lp = (long *)va; lp < end; lp++) {
if (*lp == WEIRD_ADDR)
continue;
printf("%s %d of object 0x%x size %d %s %s (0x%x != 0x%x)\n",
"Data modified on freelist: word", lp - (long *)va,
va, size, "previous type", savedtype, *lp, WEIRD_ADDR);
break;
}
freep->spare0 = 0;
#endif /* DIAGNOSTIC */
#ifdef KMEMSTATS
kup = btokup(va);
if (kup->ku_indx != indx)
panic("malloc: wrong bucket");
if (kup->ku_freecnt == 0)
panic("malloc: lost data");
kup->ku_freecnt--;
kbp->kb_totalfree--;
ksp->ks_memuse += 1 << indx;
out:
kbp->kb_calls++;
ksp->ks_inuse++;
ksp->ks_calls++;
if (ksp->ks_memuse > ksp->ks_maxused)
ksp->ks_maxused = ksp->ks_memuse;
#else
out:
#endif
splx(s);
return ((void *) va);
}
/*
* Free a block of memory allocated by malloc.
*/
void
free(addr, type)
void *addr;
int type;
{
register struct kmembuckets *kbp;
register struct kmemusage *kup;
register struct freelist *freep;
long size;
int s;
#ifdef DIAGNOSTIC
caddr_t cp;
long *end, *lp, alloc, copysize;
#endif
#ifdef KMEMSTATS
register struct kmemstats *ksp = &kmemstats[type];
#endif
kup = btokup(addr);
size = 1 << kup->ku_indx;
kbp = &bucket[kup->ku_indx];
s = splimp();
#ifdef DIAGNOSTIC
/*
* Check for returns of data that do not point to the
* beginning of the allocation.
*/
if (size > NBPG * CLSIZE)
alloc = addrmask[BUCKETINDX(NBPG * CLSIZE)];
else
alloc = addrmask[kup->ku_indx];
if (((u_long)addr & alloc) != 0)
panic("free: unaligned addr 0x%x, size %d, type %s, mask %d\n",
addr, size, memname[type], alloc);
#endif /* DIAGNOSTIC */
if (size > MAXALLOCSAVE) {
kmem_free(kmem_map, (vm_offset_t)addr, ctob(kup->ku_pagecnt));
#ifdef KMEMSTATS
size = kup->ku_pagecnt << PGSHIFT;
ksp->ks_memuse -= size;
kup->ku_indx = 0;
kup->ku_pagecnt = 0;
if (ksp->ks_memuse + size >= ksp->ks_limit &&
ksp->ks_memuse < ksp->ks_limit)
wakeup((caddr_t)ksp);
ksp->ks_inuse--;
kbp->kb_total -= 1;
#endif
splx(s);
return;
}
freep = (struct freelist *)addr;
#ifdef DIAGNOSTIC
/*
* Check for multiple frees. Use a quick check to see if
* it looks free before laboriously searching the freelist.
*/
if (freep->spare0 == WEIRD_ADDR) {
for (cp = kbp->kb_next; cp; cp = *(caddr_t *)cp) {
if (addr != cp)
continue;
printf("multiply freed item 0x%x\n", addr);
panic("free: duplicated free");
}
}
/*
* Copy in known text to detect modification after freeing
* and to make it look free. Also, save the type being freed
* so we can list likely culprit if modification is detected
* when the object is reallocated.
*/
copysize = size < MAX_COPY ? size : MAX_COPY;
end = (long *)&((caddr_t)addr)[copysize];
for (lp = (long *)addr; lp < end; lp++)
*lp = WEIRD_ADDR;
freep->type = type;
#endif /* DIAGNOSTIC */
#ifdef KMEMSTATS
kup->ku_freecnt++;
if (kup->ku_freecnt >= kbp->kb_elmpercl)
if (kup->ku_freecnt > kbp->kb_elmpercl)
panic("free: multiple frees");
else if (kbp->kb_totalfree > kbp->kb_highwat)
kbp->kb_couldfree++;
kbp->kb_totalfree++;
ksp->ks_memuse -= size;
if (ksp->ks_memuse + size >= ksp->ks_limit &&
ksp->ks_memuse < ksp->ks_limit)
wakeup((caddr_t)ksp);
ksp->ks_inuse--;
#endif
if (kbp->kb_next == NULL)
kbp->kb_next = addr;
else
((struct freelist *)kbp->kb_last)->next = addr;
freep->next = NULL;
kbp->kb_last = addr;
splx(s);
}
/*
* Initialize the kernel memory allocator
*/
kmeminit()
{
register long indx;
int npg;
#if ((MAXALLOCSAVE & (MAXALLOCSAVE - 1)) != 0)
ERROR!_kmeminit:_MAXALLOCSAVE_not_power_of_2
#endif
#if (MAXALLOCSAVE > MINALLOCSIZE * 32768)
ERROR!_kmeminit:_MAXALLOCSAVE_too_big
#endif
#if (MAXALLOCSAVE < CLBYTES)
ERROR!_kmeminit:_MAXALLOCSAVE_too_small
#endif
npg = VM_KMEM_SIZE/ NBPG;
kmemusage = (struct kmemusage *) kmem_alloc(kernel_map,
(vm_size_t)(npg * sizeof(struct kmemusage)));
kmem_map = kmem_suballoc(kernel_map, (vm_offset_t *)&kmembase,
(vm_offset_t *)&kmemlimit, (vm_size_t)(npg * NBPG), FALSE);
#ifdef KMEMSTATS
for (indx = 0; indx < MINBUCKET + 16; indx++) {
if (1 << indx >= CLBYTES)
bucket[indx].kb_elmpercl = 1;
else
bucket[indx].kb_elmpercl = CLBYTES / (1 << indx);
bucket[indx].kb_highwat = 5 * bucket[indx].kb_elmpercl;
}
for (indx = 0; indx < M_LAST; indx++)
kmemstats[indx].ks_limit = npg * NBPG * 6 / 10;
#endif
}