/* $OpenBSD: kern_malloc.c,v 1.70 2007/05/29 00:17:32 thib Exp $ */
/* $NetBSD: kern_malloc.c,v 1.15.4.2 1996/06/13 17:10:56 cgd Exp $ */
/*
* 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. 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 8.3 (Berkeley) 1/4/94
*/
#include <sys/param.h>
#include <sys/proc.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/systm.h>
#include <sys/sysctl.h>
#include <sys/time.h>
#include <sys/rwlock.h>
#include <uvm/uvm_extern.h>
static struct vm_map kmem_map_store;
struct vm_map *kmem_map = NULL;
#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#error NKMEMCLUSTERS is obsolete; remove it from your kernel config file and use NKMEMPAGES instead or let the kernel auto-size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
u_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
u_int nkmempages_min = 0;
#ifndef NKMEMPAGES_MAX
#define NKMEMPAGES_MAX NKMEMPAGES_MAX_DEFAULT
#endif
u_int nkmempages_max = 0;
struct kmembuckets bucket[MINBUCKET + 16];
struct kmemstats kmemstats[M_LAST];
struct kmemusage *kmemusage;
char *kmembase, *kmemlimit;
char buckstring[16 * sizeof("123456,")];
int buckstring_init = 0;
#if defined(KMEMSTATS) || defined(DIAGNOSTIC) || defined(FFS_SOFTUPDATES)
char *memname[] = INITKMEMNAMES;
char *memall = NULL;
struct rwlock sysctl_kmemlock = RWLOCK_INITIALIZER("sysctlklk");
#endif
#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.
*/
#ifdef DEADBEEF0
#define WEIRD_ADDR ((unsigned) DEADBEEF0)
#else
#define WEIRD_ADDR ((unsigned) 0xdeadbeef)
#endif
#define MAX_COPY 32
/*
* 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 offset 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 */
#ifndef SMALL_KERNEL
struct timeval malloc_errintvl = { 5, 0 };
struct timeval malloc_lasterr;
#endif
/*
* Allocate a block of memory
*/
void *
malloc(unsigned long size, int type, int flags)
{
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;
char *savedtype;
#endif
#ifdef KMEMSTATS
struct kmemstats *ksp = &kmemstats[type];
if (((unsigned long)type) >= M_LAST)
panic("malloc - bogus type");
#endif
#ifdef MALLOC_DEBUG
if (debug_malloc(size, type, flags, (void **)&va))
return (va);
#endif
if (size > 65535 * PAGE_SIZE) {
if (flags & M_CANFAIL) {
#ifndef SMALL_KERNEL
if (ratecheck(&malloc_lasterr, &malloc_errintvl))
printf("malloc(): allocation too large, "
"type = %d, size = %lu\n", type, size);
#endif
return (NULL);
} else
panic("malloc: allocation too large");
}
indx = BUCKETINDX(size);
kbp = &bucket[indx];
s = splvm();
#ifdef KMEMSTATS
while (ksp->ks_memuse >= ksp->ks_limit) {
if (flags & M_NOWAIT) {
splx(s);
return (NULL);
}
if (ksp->ks_limblocks < 65535)
ksp->ks_limblocks++;
tsleep(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 = round_page(size);
else
allocsize = 1 << indx;
npg = btoc(allocsize);
va = (caddr_t) uvm_km_kmemalloc(kmem_map, NULL,
(vsize_t)ctob(npg),
((flags & M_NOWAIT) ? UVM_KMF_NOWAIT : 0) |
((flags & M_CANFAIL) ? UVM_KMF_CANFAIL : 0));
if (va == NULL) {
/*
* Kmem_malloc() can return NULL, even if it can
* wait, if there is no map space available, 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|M_CANFAIL)) == 0)
panic("malloc: out of space in kmem_map");
splx(s);
return (NULL);
}
#ifdef KMEMSTATS
kbp->kb_total += kbp->kb_elmpercl;
#endif
kup = btokup(va);
kup->ku_indx = indx;
if (allocsize > MAXALLOCSAVE) {
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_SIZE) - 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 (!rv) {
printf("%s %d of object %p size 0x%lx %s %s (invalid addr %p)\n",
"Data modified on freelist: word",
(int32_t *)&kbp->kb_next - (int32_t *)kbp, va, size,
"previous type", savedtype, kbp->kb_next);
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 (*lp == WEIRD_ADDR)
continue;
printf("%s %d of object %p size 0x%lx %s %s (0x%x != 0x%x)\n",
"Data modified on freelist: word", lp - (int32_t *)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 (va);
}
/*
* Free a block of memory allocated by malloc.
*/
void
free(void *addr, int type)
{
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 MALLOC_DEBUG
if (debug_free(addr, type))
return;
#endif
#ifdef DIAGNOSTIC
if (addr < (void *)kmembase || addr >= (void *)kmemlimit)
panic("free: non-malloced addr %p type %s", addr,
memname[type]);
#endif
kup = btokup(addr);
size = 1 << kup->ku_indx;
kbp = &bucket[kup->ku_indx];
s = splvm();
#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",
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(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 = ((struct freelist *)cp)->next) {
if (addr != cp)
continue;
printf("multiply freed item %p\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 = (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(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);
}
/*
* Compute the number of pages that kmem_map will map, that is,
* the size of the kernel malloc arena.
*/
void
kmeminit_nkmempages(void)
{
u_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 can't initialize these variables at compilation time, since
* the page size may not be known (on sparc GENERIC kernels, for
* example). But we still want the MD code to be able to provide
* better values.
*/
if (nkmempages_min == 0)
nkmempages_min = NKMEMPAGES_MIN;
if (nkmempages_max == 0)
nkmempages_max = NKMEMPAGES_MAX;
/*
* 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(void)
{
vaddr_t base, limit;
#ifdef KMEMSTATS
long indx;
#endif
#ifdef DIAGNOSTIC
if (sizeof(struct freelist) > (1 << MINBUCKET))
panic("kmeminit: minbucket too small/struct freelist too big");
#endif
/*
* Compute the number of kmem_map pages, if we have not
* done so already.
*/
kmeminit_nkmempages();
base = vm_map_min(kernel_map);
kmem_map = uvm_km_suballoc(kernel_map, &base, &limit,
(vsize_t)(nkmempages * PAGE_SIZE), VM_MAP_INTRSAFE, FALSE,
&kmem_map_store);
kmembase = (char *)base;
kmemlimit = (char *)limit;
kmemusage = (struct kmemusage *) uvm_km_zalloc(kernel_map,
(vsize_t)(nkmempages * sizeof(struct kmemusage)));
#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_SIZE * 6 / 10;
#endif
#ifdef MALLOC_DEBUG
debug_malloc_init();
#endif
}
/*
* Return kernel malloc statistics information.
*/
int
sysctl_malloc(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp,
size_t newlen, struct proc *p)
{
struct kmembuckets kb;
int i, siz;
if (namelen != 2 && name[0] != KERN_MALLOC_BUCKETS &&
name[0] != KERN_MALLOC_KMEMNAMES)
return (ENOTDIR); /* overloaded */
switch (name[0]) {
case KERN_MALLOC_BUCKETS:
/* Initialize the first time */
if (buckstring_init == 0) {
buckstring_init = 1;
bzero(buckstring, sizeof(buckstring));
for (siz = 0, i = MINBUCKET; i < MINBUCKET + 16; i++) {
snprintf(buckstring + siz,
sizeof buckstring - siz,
"%d,", (u_int)(1<<i));
siz += strlen(buckstring + siz);
}
/* Remove trailing comma */
if (siz)
buckstring[siz - 1] = '\0';
}
return (sysctl_rdstring(oldp, oldlenp, newp, buckstring));
case KERN_MALLOC_BUCKET:
bcopy(&bucket[BUCKETINDX(name[1])], &kb, sizeof(kb));
kb.kb_next = kb.kb_last = 0;
return (sysctl_rdstruct(oldp, oldlenp, newp, &kb, sizeof(kb)));
case KERN_MALLOC_KMEMSTATS:
#ifdef KMEMSTATS
if ((name[1] < 0) || (name[1] >= M_LAST))
return (EINVAL);
return (sysctl_rdstruct(oldp, oldlenp, newp,
&kmemstats[name[1]], sizeof(struct kmemstats)));
#else
return (EOPNOTSUPP);
#endif
case KERN_MALLOC_KMEMNAMES:
#if defined(KMEMSTATS) || defined(DIAGNOSTIC) || defined(FFS_SOFTUPDATES)
if (memall == NULL) {
int totlen;
i = rw_enter(&sysctl_kmemlock, RW_WRITE|RW_INTR);
if (i)
return (i);
/* Figure out how large a buffer we need */
for (totlen = 0, i = 0; i < M_LAST; i++) {
if (memname[i])
totlen += strlen(memname[i]);
totlen++;
}
memall = malloc(totlen + M_LAST, M_SYSCTL, M_WAITOK);
bzero(memall, totlen + M_LAST);
for (siz = 0, i = 0; i < M_LAST; i++) {
snprintf(memall + siz,
totlen + M_LAST - siz,
"%s,", memname[i] ? memname[i] : "");
siz += strlen(memall + siz);
}
/* Remove trailing comma */
if (siz)
memall[siz - 1] = '\0';
/* Now, convert all spaces to underscores */
for (i = 0; i < totlen; i++)
if (memall[i] == ' ')
memall[i] = '_';
rw_exit_write(&sysctl_kmemlock);
}
return (sysctl_rdstring(oldp, oldlenp, newp, memall));
#else
return (EOPNOTSUPP);
#endif
default:
return (EOPNOTSUPP);
}
/* NOTREACHED */
}
/*
* Round up a size to how much malloc would actually allocate.
*/
size_t
malloc_roundup(size_t sz)
{
if (sz > MAXALLOCSAVE)
return round_page(sz);
return (1 << BUCKETINDX(sz));
}
#if defined(DDB)
#include <machine/db_machdep.h>
#include <ddb/db_interface.h>
#include <ddb/db_output.h>
void
malloc_printit(int (*pr)(const char *, ...))
{
#ifdef KMEMSTATS
struct kmemstats *km;
int i;
(*pr)("%15s %5s %6s %7s %6s %9s %8s %8s\n",
"Type", "InUse", "MemUse", "HighUse", "Limit", "Requests",
"Type Lim", "Kern Lim");
for (i = 0, km = kmemstats; i < M_LAST; i++, km++) {
if (!km->ks_calls || !memname[i])
continue;
(*pr)("%15s %5ld %6ldK %7ldK %6ldK %9ld %8d %8d\n",
memname[i], km->ks_inuse, km->ks_memuse / 1024,
km->ks_maxused / 1024, km->ks_limit / 1024,
km->ks_calls, km->ks_limblocks, km->ks_mapblocks);
}
#else
(*pr)("No KMEMSTATS compiled in\n");
#endif
}
#endif /* DDB */
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