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NetBSD/sys/kern/kern_malloc.c

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/* $NetBSD: kern_malloc.c,v 1.126 2009/01/07 21:06:31 pooka 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 8.4 (Berkeley) 5/20/95
*/
/*
* Copyright (c) 1996 Christopher G. Demetriou. 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 <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: kern_malloc.c,v 1.126 2009/01/07 21:06:31 pooka Exp $");
#include <sys/param.h>
#include <sys/proc.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/systm.h>
#include <sys/debug.h>
#include <sys/mutex.h>
#include <sys/lockdebug.h>
#include <uvm/uvm_extern.h>
static struct vm_map_kernel 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"
#include "opt_malloc_debug.h"
#define MINALLOCSIZE (1 << MINBUCKET)
#define BUCKETINDX(size) \
((size) <= (MINALLOCSIZE * 128) \
? (size) <= (MINALLOCSIZE * 8) \
? (size) <= (MINALLOCSIZE * 2) \
? (size) <= (MINALLOCSIZE * 1) \
? (MINBUCKET + 0) \
: (MINBUCKET + 1) \
: (size) <= (MINALLOCSIZE * 4) \
? (MINBUCKET + 2) \
: (MINBUCKET + 3) \
: (size) <= (MINALLOCSIZE* 32) \
? (size) <= (MINALLOCSIZE * 16) \
? (MINBUCKET + 4) \
: (MINBUCKET + 5) \
: (size) <= (MINALLOCSIZE * 64) \
? (MINBUCKET + 6) \
: (MINBUCKET + 7) \
: (size) <= (MINALLOCSIZE * 2048) \
? (size) <= (MINALLOCSIZE * 512) \
? (size) <= (MINALLOCSIZE * 256) \
? (MINBUCKET + 8) \
: (MINBUCKET + 9) \
: (size) <= (MINALLOCSIZE * 1024) \
? (MINBUCKET + 10) \
: (MINBUCKET + 11) \
: (size) <= (MINALLOCSIZE * 8192) \
? (size) <= (MINALLOCSIZE * 4096) \
? (MINBUCKET + 12) \
: (MINBUCKET + 13) \
: (size) <= (MINALLOCSIZE * 16384) \
? (MINBUCKET + 14) \
: (MINBUCKET + 15))
/*
* Array of descriptors that describe the contents of each page
*/
struct kmemusage {
short ku_indx; /* bucket index */
union {
u_short freecnt;/* for small allocations, free pieces in page */
u_short pagecnt;/* for large allocations, pages alloced */
} ku_un;
};
#define ku_freecnt ku_un.freecnt
#define ku_pagecnt ku_un.pagecnt
struct kmembuckets kmembuckets[MINBUCKET + 16];
struct kmemusage *kmemusage;
char *kmembase, *kmemlimit;
#ifdef DEBUG
static void *malloc_freecheck;
#endif
/*
* Turn virtual addresses into kmem map indicies
*/
#define btokup(addr) (&kmemusage[((char *)(addr) - kmembase) >> PGSHIFT])
struct malloc_type *kmemstatistics;
#ifdef MALLOCLOG
#ifndef MALLOCLOGSIZE
#define MALLOCLOGSIZE 100000
#endif
struct malloclog {
void *addr;
long size;
struct malloc_type *type;
int action;
const char *file;
long line;
} malloclog[MALLOCLOGSIZE];
long malloclogptr;
/*
* Fuzz factor for neighbour address match this must be a mask of the lower
* bits we wish to ignore when comparing addresses
*/
__uintptr_t malloclog_fuzz = 0x7FL;
static void
domlog(void *a, long size, struct malloc_type *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(void *a)
{
struct malloclog *lp;
long l;
#define PRT do { \
lp = &malloclog[l]; \
if (lp->addr == a && lp->action) { \
printf("malloc log entry %ld:\n", l); \
printf("\taddr = %p\n", lp->addr); \
printf("\tsize = %ld\n", lp->size); \
printf("\ttype = %s\n", lp->type->ks_shortdesc); \
printf("\taction = %s\n", lp->action == 1 ? "alloc" : "free"); \
printf("\tfile = %s\n", lp->file); \
printf("\tline = %ld\n", lp->line); \
} \
} while (/* CONSTCOND */0)
/*
* Print fuzzy matched "neighbour" - look for the memory block that has
* been allocated below the address we are interested in. We look for a
* base address + size that is within malloclog_fuzz of our target
* address. If the base address and target address are the same then it is
* likely we have found a free (size is 0 in this case) so we won't report
* those, they will get reported by PRT anyway.
*/
#define NPRT do { \
__uintptr_t fuzz_mask = ~(malloclog_fuzz); \
lp = &malloclog[l]; \
if ((__uintptr_t)lp->addr != (__uintptr_t)a && \
(((__uintptr_t)lp->addr + lp->size + malloclog_fuzz) & fuzz_mask) \
== ((__uintptr_t)a & fuzz_mask) && lp->action) { \
printf("neighbour malloc log entry %ld:\n", l); \
printf("\taddr = %p\n", lp->addr); \
printf("\tsize = %ld\n", lp->size); \
printf("\ttype = %s\n", lp->type->ks_shortdesc); \
printf("\taction = %s\n", lp->action == 1 ? "alloc" : "free"); \
printf("\tfile = %s\n", lp->file); \
printf("\tline = %ld\n", lp->line); \
} \
} while (/* CONSTCOND */0)
for (l = malloclogptr; l < MALLOCLOGSIZE; l++) {
PRT;
NPRT;
}
for (l = 0; l < malloclogptr; l++) {
PRT;
NPRT;
}
#undef 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 ((uint32_t) 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
* 8/16 bytes of the structure is unused except for diagnostic information,
* and the free list pointer is at offset 8/16 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 {
uint32_t spare0;
#ifdef _LP64
uint32_t spare1; /* explicit padding */
#endif
struct malloc_type *type;
void * next;
};
#else /* !DIAGNOSTIC */
struct freelist {
void * next;
};
#endif /* DIAGNOSTIC */
kmutex_t malloc_lock;
/*
* Allocate a block of memory
*/
#ifdef MALLOCLOG
void *
_kern_malloc(unsigned long size, struct malloc_type *ksp, int flags,
const char *file, long line)
#else
void *
kern_malloc(unsigned long size, struct malloc_type *ksp, int flags)
#endif /* MALLOCLOG */
{
struct kmembuckets *kbp;
struct kmemusage *kup;
struct freelist *freep;
long indx, npg, allocsize;
char *va, *cp, *savedlist;
#ifdef DIAGNOSTIC
uint32_t *end, *lp;
int copysize;
#endif
#ifdef LOCKDEBUG
if ((flags & M_NOWAIT) == 0) {
ASSERT_SLEEPABLE();
}
#endif
#ifdef MALLOC_DEBUG
if (debug_malloc(size, ksp, flags, (void *) &va)) {
if (va != 0) {
FREECHECK_OUT(&malloc_freecheck, (void *)va);
}
return ((void *) va);
}
#endif
indx = BUCKETINDX(size);
kbp = &kmembuckets[indx];
mutex_spin_enter(&malloc_lock);
#ifdef KMEMSTATS
while (ksp->ks_memuse >= ksp->ks_limit) {
if (flags & M_NOWAIT) {
mutex_spin_exit(&malloc_lock);
return ((void *) NULL);
}
if (ksp->ks_limblocks < 65535)
ksp->ks_limblocks++;
mtsleep((void *)ksp, PSWP+2, ksp->ks_shortdesc, 0,
&malloc_lock);
}
ksp->ks_size |= 1 << indx;
#endif
#ifdef DIAGNOSTIC
copysize = 1 << indx < MAX_COPY ? 1 << indx : MAX_COPY;
#endif
if (kbp->kb_next == NULL) {
int s;
kbp->kb_last = NULL;
if (size > MAXALLOCSAVE)
allocsize = round_page(size);
else
allocsize = 1 << indx;
npg = btoc(allocsize);
mutex_spin_exit(&malloc_lock);
s = splvm();
va = (void *) uvm_km_alloc(kmem_map,
(vsize_t)ctob(npg), 0,
((flags & M_NOWAIT) ? UVM_KMF_NOWAIT : 0) |
((flags & M_CANFAIL) ? UVM_KMF_CANFAIL : 0) |
UVM_KMF_WIRED);
splx(s);
if (__predict_false(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 kmembuckets
* with too many free elements.)
*/
if ((flags & (M_NOWAIT|M_CANFAIL)) == 0)
panic("malloc: out of space in kmem_map");
return (NULL);
}
mutex_spin_enter(&malloc_lock);
#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
* kmembucket, 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 = (uint32_t *)&cp[copysize];
for (lp = (uint32_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 (savedlist == NULL)
kbp->kb_last = (void *)freep;
}
va = kbp->kb_next;
kbp->kb_next = ((struct freelist *)va)->next;
#ifdef DIAGNOSTIC
freep = (struct freelist *)va;
/* XXX potential to get garbage pointer here. */
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("Data modified on freelist: "
"word %ld of object %p size %ld previous type %s "
"(invalid addr %p)\n",
(long)((int32_t *)&kbp->kb_next - (int32_t *)kbp),
va, size, "foo", kbp->kb_next);
#ifdef MALLOCLOG
hitmlog(va);
#endif
kbp->kb_next = NULL;
}
}
/* Fill the fields that we've used with WEIRD_ADDR */
#ifdef _LP64
freep->type = (struct malloc_type *)
(WEIRD_ADDR | (((u_long) WEIRD_ADDR) << 32));
#else
freep->type = (struct malloc_type *) WEIRD_ADDR;
#endif
end = (uint32_t *)&freep->next +
(sizeof(freep->next) / sizeof(int32_t));
for (lp = (uint32_t *)&freep->next; lp < end; lp++)
*lp = WEIRD_ADDR;
/* and check that the data hasn't been modified. */
end = (uint32_t *)&va[copysize];
for (lp = (uint32_t *)va; lp < end; lp++) {
if (__predict_true(*lp == WEIRD_ADDR))
continue;
printf("Data modified on freelist: "
"word %ld of object %p size %ld previous type %s "
"(0x%x != 0x%x)\n",
(long)(lp - (uint32_t *)va), va, size,
"bar", *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, ksp, 1, file, line);
#endif
mutex_spin_exit(&malloc_lock);
if ((flags & M_ZERO) != 0)
memset(va, 0, size);
FREECHECK_OUT(&malloc_freecheck, (void *)va);
return ((void *) va);
}
/*
* Free a block of memory allocated by malloc.
*/
#ifdef MALLOCLOG
void
_kern_free(void *addr, struct malloc_type *ksp, const char *file, long line)
#else
void
kern_free(void *addr, struct malloc_type *ksp)
#endif /* MALLOCLOG */
{
struct kmembuckets *kbp;
struct kmemusage *kup;
struct freelist *freep;
long size;
#ifdef DIAGNOSTIC
void *cp;
int32_t *end, *lp;
long alloc, copysize;
#endif
FREECHECK_IN(&malloc_freecheck, addr);
#ifdef MALLOC_DEBUG
if (debug_free(addr, ksp))
return;
#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 < vm_map_min(kmem_map) ||
(vaddr_t)addr >= vm_map_max(kmem_map)))
panic("free: addr %p not within kmem_map", addr);
#endif
kup = btokup(addr);
size = 1 << kup->ku_indx;
kbp = &kmembuckets[kup->ku_indx];
LOCKDEBUG_MEM_CHECK(addr,
size <= MAXALLOCSAVE ? size : ctob(kup->ku_pagecnt));
mutex_spin_enter(&malloc_lock);
#ifdef MALLOCLOG
domlog(addr, 0, ksp, 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",
addr, size, ksp->ks_shortdesc, alloc);
#endif /* DIAGNOSTIC */
if (size > MAXALLOCSAVE) {
uvm_km_free(kmem_map, (vaddr_t)addr, ctob(kup->ku_pagecnt),
UVM_KMF_WIRED);
#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((void *)ksp);
#ifdef DIAGNOSTIC
if (ksp->ks_inuse == 0)
panic("free 1: inuse 0, probable double free");
#endif
ksp->ks_inuse--;
kbp->kb_total -= 1;
#endif
mutex_spin_exit(&malloc_lock);
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");
}
}
/*
* 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 *)&((char *)addr)[copysize];
for (lp = (int32_t *)addr; lp < end; lp++)
*lp = WEIRD_ADDR;
freep->type = ksp;
#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((void *)ksp);
#ifdef DIAGNOSTIC
if (ksp->ks_inuse == 0)
panic("free 2: inuse 0, probable double free");
#endif
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;
mutex_spin_exit(&malloc_lock);
}
/*
* Change the size of a block of memory.
*/
void *
kern_realloc(void *curaddr, unsigned long newsize, struct malloc_type *ksp,
int flags)
{
struct kmemusage *kup;
unsigned 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, ksp, flags));
/*
* realloc() with zero size is the same as free().
*/
if (newsize == 0) {
free(curaddr, ksp);
return (NULL);
}
#ifdef LOCKDEBUG
if ((flags & M_NOWAIT) == 0) {
ASSERT_SLEEPABLE();
}
#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, ksp->ks_shortdesc, 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, ksp, 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, ksp);
return (newaddr);
}
/*
* Roundup size to the actual allocation size.
*/
unsigned long
malloc_roundup(unsigned long size)
{
if (size > MAXALLOCSAVE)
return (roundup(size, PAGE_SIZE));
else
return (1 << BUCKETINDX(size));
}
/*
* Add a malloc type to the system.
*/
void
malloc_type_attach(struct malloc_type *type)
{
if (nkmempages == 0)
panic("malloc_type_attach: nkmempages == 0");
if (type->ks_magic != M_MAGIC)
panic("malloc_type_attach: bad magic");
#ifdef DIAGNOSTIC
{
struct malloc_type *ksp;
for (ksp = kmemstatistics; ksp != NULL; ksp = ksp->ks_next) {
if (ksp == type)
panic("malloc_type_attach: already on list");
}
}
#endif
#ifdef KMEMSTATS
if (type->ks_limit == 0)
type->ks_limit = ((u_long)nkmempages << PAGE_SHIFT) * 6U / 10U;
#else
type->ks_limit = 0;
#endif
type->ks_next = kmemstatistics;
kmemstatistics = type;
}
/*
* Remove a malloc type from the system..
*/
void
malloc_type_detach(struct malloc_type *type)
{
struct malloc_type *ksp;
#ifdef DIAGNOSTIC
if (type->ks_magic != M_MAGIC)
panic("malloc_type_detach: bad magic");
#endif
if (type == kmemstatistics)
kmemstatistics = type->ks_next;
else {
for (ksp = kmemstatistics; ksp->ks_next != NULL;
ksp = ksp->ks_next) {
if (ksp->ks_next == type) {
ksp->ks_next = type->ks_next;
break;
}
}
#ifdef DIAGNOSTIC
if (ksp->ks_next == NULL)
panic("malloc_type_detach: not on list");
#endif
}
type->ks_next = NULL;
}
/*
* Set the limit on a malloc type.
*/
void
malloc_type_setlimit(struct malloc_type *type, u_long limit)
{
#ifdef KMEMSTATS
mutex_spin_enter(&malloc_lock);
type->ks_limit = limit;
mutex_spin_exit(&malloc_lock);
#endif
}
/*
* Compute the number of pages that kmem_map will map, that is,
* the size of the kernel malloc arena.
*/
void
kmeminit_nkmempages(void)
{
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;
}
npages = physmem;
if (npages > NKMEMPAGES_MAX)
npages = NKMEMPAGES_MAX;
if (npages < NKMEMPAGES_MIN)
npages = NKMEMPAGES_MIN;
nkmempages = npages;
}
/*
* Initialize the kernel memory allocator
*/
void
kmeminit(void)
{
__link_set_decl(malloc_types, struct malloc_type);
struct malloc_type * const *ksp;
vaddr_t kmb, kml;
#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");
mutex_init(&malloc_lock, MUTEX_DEFAULT, IPL_VM);
/*
* Compute the number of kmem_map pages, if we have not
* done so already.
*/
kmeminit_nkmempages();
kmemusage = (struct kmemusage *) uvm_km_alloc(kernel_map,
(vsize_t)(nkmempages * sizeof(struct kmemusage)), 0,
UVM_KMF_WIRED|UVM_KMF_ZERO);
kmb = 0;
kmem_map = uvm_km_suballoc(kernel_map, &kmb,
&kml, ((vsize_t)nkmempages << PAGE_SHIFT),
VM_MAP_INTRSAFE, false, &kmem_map_store);
uvm_km_vacache_init(kmem_map, "kvakmem", 0);
kmembase = (char *)kmb;
kmemlimit = (char *)kml;
#ifdef KMEMSTATS
for (indx = 0; indx < MINBUCKET + 16; indx++) {
if (1 << indx >= PAGE_SIZE)
kmembuckets[indx].kb_elmpercl = 1;
else
kmembuckets[indx].kb_elmpercl = PAGE_SIZE / (1 << indx);
kmembuckets[indx].kb_highwat =
5 * kmembuckets[indx].kb_elmpercl;
}
#endif
/* Attach all of the statically-linked malloc types. */
__link_set_foreach(ksp, malloc_types)
malloc_type_attach(*ksp);
}
#ifdef DDB
#include <ddb/db_output.h>
/*
* Dump kmem statistics from ddb.
*
* usage: call dump_kmemstats
*/
void dump_kmemstats(void);
void
dump_kmemstats(void)
{
#ifdef KMEMSTATS
struct malloc_type *ksp;
for (ksp = kmemstatistics; ksp != NULL; ksp = ksp->ks_next) {
if (ksp->ks_memuse == 0)
continue;
db_printf("%s%.*s %ld\n", ksp->ks_shortdesc,
(int)(20 - strlen(ksp->ks_shortdesc)),
" ",
ksp->ks_memuse);
}
#else
db_printf("Kmem stats are not being collected.\n");
#endif /* KMEMSTATS */
}
#endif /* DDB */
#if 0
/*
* Diagnostic messages about "Data modified on
* freelist" indicate a memory corruption, but
* they do not help tracking it down.
* This function can be called at various places
* to sanity check malloc's freelist and discover
* where does the corruption take place.
*/
int
freelist_sanitycheck(void) {
int i,j;
struct kmembuckets *kbp;
struct freelist *freep;
int rv = 0;
for (i = MINBUCKET; i <= MINBUCKET + 15; i++) {
kbp = &kmembuckets[i];
freep = (struct freelist *)kbp->kb_next;
j = 0;
while(freep) {
vm_map_lock(kmem_map);
rv = uvm_map_checkprot(kmem_map, (vaddr_t)freep,
(vaddr_t)freep + sizeof(struct freelist),
VM_PROT_WRITE);
vm_map_unlock(kmem_map);
if ((rv == 0) || (*(int *)freep != WEIRD_ADDR)) {
printf("bucket %i, chunck %d at %p modified\n",
i, j, freep);
return 1;
}
freep = (struct freelist *)freep->next;
j++;
}
}
return 0;
}
#endif
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