7a2987cf94
run out of KVM through a mmap()/fork() bomb that allocates hundreds
of thousands of vm_map_entry structures.
Add panic to make null-pointer dereference crash a little more verbose.
Add a new sysctl, vm.max_proc_mmap, which specifies the maximum number
of mmap()'d spaces (discrete vm_map_entry's in the process). The value
defaults to around 9000 for a 128MB machine. The test is scaled for the
number of processes sharing a vmspace (aka linux threads). Setting
the value to 0 disables the feature.
PR: kern/16573
Approved by: jkh
533 lines
14 KiB
C
533 lines
14 KiB
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 8.3 (Berkeley) 1/4/94
|
|
* $FreeBSD$
|
|
*/
|
|
|
|
#include "opt_vm.h"
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/kernel.h>
|
|
#include <sys/malloc.h>
|
|
#include <sys/mbuf.h>
|
|
#include <sys/vmmeter.h>
|
|
#include <sys/lock.h>
|
|
|
|
#include <vm/vm.h>
|
|
#include <vm/vm_param.h>
|
|
#include <vm/vm_kern.h>
|
|
#include <vm/vm_extern.h>
|
|
#include <vm/pmap.h>
|
|
#include <vm/vm_map.h>
|
|
|
|
#if defined(INVARIANTS) && defined(__i386__)
|
|
#include <machine/cpu.h>
|
|
#endif
|
|
|
|
MALLOC_DEFINE(M_CACHE, "cache", "Various Dynamically allocated caches");
|
|
MALLOC_DEFINE(M_DEVBUF, "devbuf", "device driver memory");
|
|
MALLOC_DEFINE(M_TEMP, "temp", "misc temporary data buffers");
|
|
|
|
MALLOC_DEFINE(M_IP6OPT, "ip6opt", "IPv6 options");
|
|
MALLOC_DEFINE(M_IP6NDP, "ip6ndp", "IPv6 Neighbor Discovery");
|
|
|
|
static void kmeminit __P((void *));
|
|
SYSINIT(kmem, SI_SUB_KMEM, SI_ORDER_FIRST, kmeminit, NULL)
|
|
|
|
static MALLOC_DEFINE(M_FREE, "free", "should be on free list");
|
|
|
|
static struct malloc_type *kmemstatistics;
|
|
static struct kmembuckets bucket[MINBUCKET + 16];
|
|
static struct kmemusage *kmemusage;
|
|
static char *kmembase;
|
|
static char *kmemlimit;
|
|
|
|
u_int vm_kmem_size;
|
|
|
|
#ifdef INVARIANTS
|
|
/*
|
|
* This structure provides a set of masks to catch unaligned frees.
|
|
*/
|
|
static 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 0xdeadc0de
|
|
#define MAX_COPY 64
|
|
|
|
/*
|
|
* 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;
|
|
struct malloc_type *type;
|
|
long spare1;
|
|
caddr_t next;
|
|
};
|
|
#else /* !INVARIANTS */
|
|
struct freelist {
|
|
caddr_t next;
|
|
};
|
|
#endif /* INVARIANTS */
|
|
|
|
/*
|
|
* malloc:
|
|
*
|
|
* Allocate a block of memory.
|
|
*
|
|
* If M_NOWAIT is set, this routine will not block and return NULL if
|
|
* the allocation fails.
|
|
*
|
|
* If M_ASLEEP is set (M_NOWAIT must also be set), this routine
|
|
* will have the side effect of calling asleep() if it returns NULL,
|
|
* allowing the parent to await() at some future time.
|
|
*/
|
|
void *
|
|
malloc(size, type, flags)
|
|
unsigned long size;
|
|
struct malloc_type *type;
|
|
int flags;
|
|
{
|
|
register struct kmembuckets *kbp;
|
|
register struct kmemusage *kup;
|
|
register struct freelist *freep;
|
|
long indx, npg, allocsize;
|
|
int s;
|
|
caddr_t va, cp, savedlist;
|
|
#ifdef INVARIANTS
|
|
long *end, *lp;
|
|
int copysize;
|
|
const char *savedtype;
|
|
#endif
|
|
register struct malloc_type *ksp = type;
|
|
|
|
#if defined(INVARIANTS) && defined(__i386__)
|
|
if (flags == M_WAITOK)
|
|
KASSERT(intr_nesting_level == 0,
|
|
("malloc(M_WAITOK) in interrupt context"));
|
|
#endif
|
|
/*
|
|
* Must be at splmem() prior to initializing segment to handle
|
|
* potential initialization race.
|
|
*/
|
|
|
|
s = splmem();
|
|
|
|
if (type->ks_limit == 0)
|
|
malloc_init(type);
|
|
|
|
indx = BUCKETINDX(size);
|
|
kbp = &bucket[indx];
|
|
|
|
while (ksp->ks_memuse >= ksp->ks_limit) {
|
|
if (flags & M_ASLEEP) {
|
|
if (ksp->ks_limblocks < 65535)
|
|
ksp->ks_limblocks++;
|
|
asleep((caddr_t)ksp, PSWP+2, type->ks_shortdesc, 0);
|
|
}
|
|
if (flags & M_NOWAIT) {
|
|
splx(s);
|
|
return ((void *) NULL);
|
|
}
|
|
if (ksp->ks_limblocks < 65535)
|
|
ksp->ks_limblocks++;
|
|
tsleep((caddr_t)ksp, PSWP+2, type->ks_shortdesc, 0);
|
|
}
|
|
ksp->ks_size |= 1 << indx;
|
|
#ifdef INVARIANTS
|
|
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) kmem_malloc(kmem_map, (vm_size_t)ctob(npg), flags);
|
|
if (va == NULL) {
|
|
splx(s);
|
|
return ((void *) NULL);
|
|
}
|
|
kbp->kb_total += kbp->kb_elmpercl;
|
|
kup = btokup(va);
|
|
kup->ku_indx = indx;
|
|
if (allocsize > MAXALLOCSAVE) {
|
|
if (npg > 65535)
|
|
panic("malloc: allocation too large");
|
|
kup->ku_pagecnt = npg;
|
|
ksp->ks_memuse += allocsize;
|
|
goto out;
|
|
}
|
|
kup->ku_freecnt = kbp->kb_elmpercl;
|
|
kbp->kb_totalfree += kbp->kb_elmpercl;
|
|
/*
|
|
* 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 INVARIANTS
|
|
/*
|
|
* 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 /* INVARIANTS */
|
|
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 INVARIANTS
|
|
freep = (struct freelist *)va;
|
|
savedtype = (const char *) type->ks_shortdesc;
|
|
#if BYTE_ORDER == BIG_ENDIAN
|
|
freep->type = (struct malloc_type *)WEIRD_ADDR >> 16;
|
|
#endif
|
|
#if BYTE_ORDER == LITTLE_ENDIAN
|
|
freep->type = (struct malloc_type *)WEIRD_ADDR;
|
|
#endif
|
|
if ((intptr_t)(void *)&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 %ld of object %p size %lu %s %s (0x%lx != 0x%lx)\n",
|
|
"Data modified on freelist: word",
|
|
(long)(lp - (long *)va), (void *)va, size,
|
|
"previous type", savedtype, *lp, (u_long)WEIRD_ADDR);
|
|
break;
|
|
}
|
|
freep->spare0 = 0;
|
|
#endif /* INVARIANTS */
|
|
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;
|
|
splx(s);
|
|
return ((void *) va);
|
|
}
|
|
|
|
/*
|
|
* free:
|
|
*
|
|
* Free a block of memory allocated by malloc.
|
|
*
|
|
* This routine may not block.
|
|
*/
|
|
void
|
|
free(addr, type)
|
|
void *addr;
|
|
struct malloc_type *type;
|
|
{
|
|
register struct kmembuckets *kbp;
|
|
register struct kmemusage *kup;
|
|
register struct freelist *freep;
|
|
long size;
|
|
int s;
|
|
#ifdef INVARIANTS
|
|
struct freelist *fp;
|
|
long *end, *lp, alloc, copysize;
|
|
#endif
|
|
register struct malloc_type *ksp = type;
|
|
|
|
if (type->ks_limit == 0)
|
|
panic("freeing with unknown type (%s)", type->ks_shortdesc);
|
|
|
|
KASSERT(kmembase <= (char *)addr && (char *)addr < kmemlimit,
|
|
("free: address %p out of range", (void *)addr));
|
|
kup = btokup(addr);
|
|
size = 1 << kup->ku_indx;
|
|
kbp = &bucket[kup->ku_indx];
|
|
s = splmem();
|
|
#ifdef INVARIANTS
|
|
/*
|
|
* 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 (((uintptr_t)(void *)addr & alloc) != 0)
|
|
panic("free: unaligned addr %p, size %ld, type %s, mask %ld",
|
|
(void *)addr, size, type->ks_shortdesc, alloc);
|
|
#endif /* INVARIANTS */
|
|
if (size > MAXALLOCSAVE) {
|
|
kmem_free(kmem_map, (vm_offset_t)addr, ctob(kup->ku_pagecnt));
|
|
size = kup->ku_pagecnt << PAGE_SHIFT;
|
|
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;
|
|
splx(s);
|
|
return;
|
|
}
|
|
freep = (struct freelist *)addr;
|
|
#ifdef INVARIANTS
|
|
/*
|
|
* Check for multiple frees. Use a quick check to see if
|
|
* it looks free before laboriously searching the freelist.
|
|
*/
|
|
if (freep->spare0 == WEIRD_ADDR) {
|
|
fp = (struct freelist *)kbp->kb_next;
|
|
while (fp) {
|
|
if (fp->spare0 != WEIRD_ADDR)
|
|
panic("free: free item %p modified", fp);
|
|
else if (addr == (caddr_t)fp)
|
|
panic("free: multiple freed item %p", addr);
|
|
fp = (struct freelist *)fp->next;
|
|
}
|
|
}
|
|
/*
|
|
* 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 /* INVARIANTS */
|
|
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--;
|
|
#ifdef OLD_MALLOC_MEMORY_POLICY
|
|
if (kbp->kb_next == NULL)
|
|
kbp->kb_next = addr;
|
|
else
|
|
((struct freelist *)kbp->kb_last)->next = addr;
|
|
freep->next = NULL;
|
|
kbp->kb_last = addr;
|
|
#else
|
|
/*
|
|
* Return memory to the head of the queue for quick reuse. This
|
|
* can improve performance by improving the probability of the
|
|
* item being in the cache when it is reused.
|
|
*/
|
|
if (kbp->kb_next == NULL) {
|
|
kbp->kb_next = addr;
|
|
kbp->kb_last = addr;
|
|
freep->next = NULL;
|
|
} else {
|
|
freep->next = kbp->kb_next;
|
|
kbp->kb_next = addr;
|
|
}
|
|
#endif
|
|
splx(s);
|
|
}
|
|
|
|
/*
|
|
* Initialize the kernel memory allocator
|
|
*/
|
|
/* ARGSUSED*/
|
|
static void
|
|
kmeminit(dummy)
|
|
void *dummy;
|
|
{
|
|
register long indx;
|
|
u_long npg;
|
|
u_long mem_size;
|
|
u_long xvm_kmem_size;
|
|
|
|
#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 < PAGE_SIZE)
|
|
#error "kmeminit: MAXALLOCSAVE too small"
|
|
#endif
|
|
|
|
/*
|
|
* Try to auto-tune the kernel memory size, so that it is
|
|
* more applicable for a wider range of machine sizes.
|
|
* On an X86, a VM_KMEM_SIZE_SCALE value of 4 is good, while
|
|
* a VM_KMEM_SIZE of 12MB is a fair compromise. The
|
|
* VM_KMEM_SIZE_MAX is dependent on the maximum KVA space
|
|
* available, and on an X86 with a total KVA space of 256MB,
|
|
* try to keep VM_KMEM_SIZE_MAX at 80MB or below.
|
|
*
|
|
* Note that the kmem_map is also used by the zone allocator,
|
|
* so make sure that there is enough space.
|
|
*/
|
|
xvm_kmem_size = VM_KMEM_SIZE;
|
|
mem_size = cnt.v_page_count * PAGE_SIZE;
|
|
|
|
#if defined(VM_KMEM_SIZE_SCALE)
|
|
if ((mem_size / VM_KMEM_SIZE_SCALE) > xvm_kmem_size)
|
|
xvm_kmem_size = mem_size / VM_KMEM_SIZE_SCALE;
|
|
#endif
|
|
|
|
#if defined(VM_KMEM_SIZE_MAX)
|
|
if (xvm_kmem_size >= VM_KMEM_SIZE_MAX)
|
|
xvm_kmem_size = VM_KMEM_SIZE_MAX;
|
|
#endif
|
|
|
|
/* Allow final override from the kernel environment */
|
|
TUNABLE_INT_FETCH("kern.vm.kmem.size", xvm_kmem_size, vm_kmem_size);
|
|
|
|
/*
|
|
* Limit kmem virtual size to twice the physical memory.
|
|
* This allows for kmem map sparseness, but limits the size
|
|
* to something sane. Be careful to not overflow the 32bit
|
|
* ints while doing the check.
|
|
*/
|
|
if ((vm_kmem_size / 2) > (cnt.v_page_count * PAGE_SIZE))
|
|
vm_kmem_size = 2 * cnt.v_page_count * PAGE_SIZE;
|
|
|
|
npg = (nmbufs * MSIZE + nmbclusters * MCLBYTES + vm_kmem_size)
|
|
/ PAGE_SIZE;
|
|
|
|
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 * PAGE_SIZE));
|
|
kmem_map->system_map = 1;
|
|
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;
|
|
}
|
|
}
|
|
|
|
void
|
|
malloc_init(data)
|
|
void *data;
|
|
{
|
|
struct malloc_type *type = (struct malloc_type *)data;
|
|
|
|
if (type->ks_magic != M_MAGIC)
|
|
panic("malloc type lacks magic");
|
|
|
|
if (type->ks_limit != 0)
|
|
return;
|
|
|
|
if (cnt.v_page_count == 0)
|
|
panic("malloc_init not allowed before vm init");
|
|
|
|
/*
|
|
* The default limits for each malloc region is 1/2 of the
|
|
* malloc portion of the kmem map size.
|
|
*/
|
|
type->ks_limit = vm_kmem_size / 2;
|
|
type->ks_next = kmemstatistics;
|
|
kmemstatistics = type;
|
|
}
|
|
|
|
void
|
|
malloc_uninit(data)
|
|
void *data;
|
|
{
|
|
struct malloc_type *type = (struct malloc_type *)data;
|
|
struct malloc_type *t;
|
|
|
|
if (type->ks_magic != M_MAGIC)
|
|
panic("malloc type lacks magic");
|
|
|
|
if (cnt.v_page_count == 0)
|
|
panic("malloc_uninit not allowed before vm init");
|
|
|
|
if (type->ks_limit == 0)
|
|
panic("malloc_uninit on uninitialized type");
|
|
|
|
if (type == kmemstatistics)
|
|
kmemstatistics = type->ks_next;
|
|
else {
|
|
for (t = kmemstatistics; t->ks_next != NULL; t = t->ks_next) {
|
|
if (t->ks_next == type) {
|
|
t->ks_next = type->ks_next;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
type->ks_next = NULL;
|
|
type->ks_limit = 0;
|
|
}
|