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/* $NetBSD: kern_malloc.c,v 1.59 2001/06/05 04:39:02 thorpej 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;
struct vm_map *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#error NKMEMCLUSTERS is obsolete; remove it from your kernel config file and use NKMEMPAGES instead or let the kernel auto-size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"
struct kmembuckets bucket[MINBUCKET + 16];
struct kmemstats kmemstats[M_LAST];
struct kmemusage *kmemusage;
char *kmembase, *kmemlimit;
const char * const 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.
*/
const 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
#ifdef LOCKDEBUG
if ((flags & M_NOWAIT) == 0)
simple_lock_only_held(NULL, "malloc");
#endif
indx = BUCKETINDX(size);
kbp = &bucket[indx];
s = splvm();
#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)) {
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;
printf("%s %ld of object %p size %ld %s %s (0x%x != 0x%x)\n",
"Data modified on freelist: word",
(long)(lp - (int32_t *)va), va, size, "previous type",
savedtype, *lp, WEIRD_ADDR);
#ifdef MALLOCLOG
hitmlog(va);
#endif
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
#ifdef MALLOCLOG
domlog(va, size, type, 1, file, line);
#endif
splx(s);
return ((void *) va);
}
/*
* Free a block of memory allocated by malloc.
*/
#ifdef MALLOCLOG
void
_free(addr, type, file, line)
void *addr;
int type;
const char *file;
long line;
#else
void
free(addr, type)
void *addr;
int type;
#endif /* MALLOCLOG */
{
struct kmembuckets *kbp;
struct kmemusage *kup;
struct freelist *freep;
long size;
int s;
#ifdef DIAGNOSTIC
caddr_t cp;
int32_t *end, *lp;
long alloc, copysize;
#endif
#ifdef KMEMSTATS
struct kmemstats *ksp = &kmemstats[type];
#endif
#ifdef DIAGNOSTIC
/*
* Ensure that we're free'ing something that we could
* have allocated in the first place. That is, check
* to see that the address is within kmem_map.
*/
if (__predict_false((vaddr_t)addr < kmem_map->header.start ||
(vaddr_t)addr >= kmem_map->header.end))
panic("free: addr %p not within kmem_map", addr);
#endif
kup = btokup(addr);
size = 1 << kup->ku_indx;
kbp = &bucket[kup->ku_indx];
s = splvm();
#ifdef MALLOCLOG
domlog(addr, 0, type, 2, file, line);
#endif
#ifdef DIAGNOSTIC
/*
* Check for returns of data that do not point to the
* beginning of the allocation.
*/
if (size > PAGE_SIZE)
alloc = addrmask[BUCKETINDX(PAGE_SIZE)];
else
alloc = addrmask[kup->ku_indx];
if (((u_long)addr & alloc) != 0)
panic("free: unaligned addr %p, size %ld, type %s, mask %ld\n",
addr, size, memname[type], alloc);
#endif /* DIAGNOSTIC */
if (size > MAXALLOCSAVE) {
uvm_km_free(kmem_map, (vaddr_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 (__predict_false(freep->spare0 == WEIRD_ADDR)) {
for (cp = kbp->kb_next; cp;
cp = ((struct freelist *)cp)->next) {
if (addr != cp)
continue;
printf("multiply freed item %p\n", addr);
#ifdef MALLOCLOG
hitmlog(addr);
#endif
panic("free: duplicated free");
}
}
#ifdef LOCKDEBUG
/*
* Check if we're freeing a locked simple lock.
*/
simple_lock_freecheck(addr, (char *)addr + size);
#endif
/*
* 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 = (int32_t *)&((caddr_t)addr)[copysize];
for (lp = (int32_t *)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);
}
/*
* Change the size of a block of memory.
*/
void *
realloc(curaddr, newsize, type, flags)
void *curaddr;
unsigned long newsize;
int type, flags;
{
struct kmemusage *kup;
long cursize;
void *newaddr;
#ifdef DIAGNOSTIC
long alloc;
#endif
/*
* Realloc() with a NULL pointer is the same as malloc().
*/
if (curaddr == NULL)
return (malloc(newsize, type, flags));
/*
* Realloc() with zero size is the same as free().
*/
if (newsize == 0) {
free(curaddr, type);
return (NULL);
}
#ifdef LOCKDEBUG
if ((flags & M_NOWAIT) == 0)
simple_lock_only_held(NULL, "realloc");
#endif
/*
* Find out how large the old allocation was (and do some
* sanity checking).
*/
kup = btokup(curaddr);
cursize = 1 << kup->ku_indx;
#ifdef DIAGNOSTIC
/*
* Check for returns of data that do not point to the
* beginning of the allocation.
*/
if (cursize > PAGE_SIZE)
alloc = addrmask[BUCKETINDX(PAGE_SIZE)];
else
alloc = addrmask[kup->ku_indx];
if (((u_long)curaddr & alloc) != 0)
panic("realloc: unaligned addr %p, size %ld, type %s, mask %ld\n",
curaddr, cursize, memname[type], alloc);
#endif /* DIAGNOSTIC */
if (cursize > MAXALLOCSAVE)
cursize = ctob(kup->ku_pagecnt);
/*
* If we already actually have as much as they want, we're done.
*/
if (newsize <= cursize)
return (curaddr);
/*
* Can't satisfy the allocation with the existing block.
* Allocate a new one and copy the data.
*/
newaddr = malloc(newsize, type, flags);
if (__predict_false(newaddr == NULL)) {
/*
* Malloc() failed, because flags included M_NOWAIT.
* Return NULL to indicate that failure. The old
* pointer is still valid.
*/
return NULL;
}
memcpy(newaddr, curaddr, cursize);
/*
* We were successful: free the old allocation and return
* the new one.
*/
free(curaddr, type);
return (newaddr);
}
/*
* Compute the number of pages that kmem_map will map, that is,
* the size of the kernel malloc arena.
*/
void
kmeminit_nkmempages()
{
int npages;
if (nkmempages != 0) {
/*
* It's already been set (by us being here before, or
* by patching or kernel config options), bail out now.
*/
return;
}
/*
* We use the following (simple) formula:
*
* - Starting point is physical memory / 4.
*
* - Clamp it down to NKMEMPAGES_MAX.
*
* - Round it up to NKMEMPAGES_MIN.
*/
npages = physmem / 4;
if (npages > NKMEMPAGES_MAX)
npages = NKMEMPAGES_MAX;
if (npages < NKMEMPAGES_MIN)
npages = NKMEMPAGES_MIN;
nkmempages = npages;
}
/*
* Initialize the kernel memory allocator
*/
void
kmeminit()
{
#ifdef KMEMSTATS
long indx;
#endif
#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 < NBPG)
ERROR!_kmeminit:_MAXALLOCSAVE_too_small
#endif
if (sizeof(struct freelist) > (1 << MINBUCKET))
panic("minbucket too small/struct freelist too big");
/*
* Compute the number of kmem_map pages, if we have not
* done so already.
*/
kmeminit_nkmempages();
kmemusage = (struct kmemusage *) uvm_km_zalloc(kernel_map,
(vsize_t)(nkmempages * sizeof(struct kmemusage)));
kmem_map = uvm_km_suballoc(kernel_map, (vaddr_t *)&kmembase,
(vaddr_t *)&kmemlimit, (vsize_t)(nkmempages << PAGE_SHIFT),
VM_MAP_INTRSAFE, FALSE, &kmem_map_store.vmi_map);
#ifdef KMEMSTATS
for (indx = 0; indx < MINBUCKET + 16; indx++) {
if (1 << indx >= PAGE_SIZE)
bucket[indx].kb_elmpercl = 1;
else
bucket[indx].kb_elmpercl = PAGE_SIZE / (1 << indx);
bucket[indx].kb_highwat = 5 * bucket[indx].kb_elmpercl;
}
for (indx = 0; indx < M_LAST; indx++)
kmemstats[indx].ks_limit = (nkmempages << PAGE_SHIFT) * 6 / 10;
#endif
}
#ifdef DDB
#include <ddb/db_output.h>
/*
* Dump kmem statistics from ddb.
*
* usage: call dump_kmemstats
*/
void dump_kmemstats __P((void));
void
dump_kmemstats()
{
#ifdef KMEMSTATS
const char *name;
int i;
for (i = 0; i < M_LAST; i++) {
name = memname[i] ? memname[i] : "";
db_printf("%2d %s%.*s %ld\n", i, name,
(int)(20 - strlen(name)), " ",
kmemstats[i].ks_memuse);
}
#else
db_printf("Kmem stats are not being collected.\n");
#endif /* KMEMSTATS */
}
#endif /* DDB */
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