freebsd-skq/sys/vm/uma_dbg.c
Brian Feldman b23f72e98a * Add a "how" argument to uma_zone constructors and initialization functions
so that they know whether the allocation is supposed to be able to sleep
  or not.
* Allow uma_zone constructors and initialation functions to return either
  success or error.  Almost all of the ones in the tree currently return
  success unconditionally, but mbuf is a notable exception: the packet
  zone constructor wants to be able to fail if it cannot suballocate an
  mbuf cluster, and the mbuf allocators want to be able to fail in general
  in a MAC kernel if the MAC mbuf initializer fails.  This fixes the
  panics people are seeing when they run out of memory for mbuf clusters.
* Allow debug.nosleepwithlocks on WITNESS to be disabled, without changing
  the default.

Both bmilekic and jeff have reviewed the changes made to make failable
zone allocations work.
2004-08-02 00:18:36 +00:00

287 lines
6.5 KiB
C

/*
* Copyright (c) 2002, Jeffrey Roberson <jeff@freebsd.org>
* 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 unmodified, 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/
/*
* uma_dbg.c Debugging features for UMA users
*
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/types.h>
#include <sys/queue.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/malloc.h>
#include <vm/vm.h>
#include <vm/vm_object.h>
#include <vm/vm_page.h>
#include <vm/uma.h>
#include <vm/uma_int.h>
#include <vm/uma_dbg.h>
static const u_int32_t uma_junk = 0xdeadc0de;
/*
* Checks an item to make sure it hasn't been overwritten since it was freed,
* prior to subsequent reallocation.
*
* Complies with standard ctor arg/return
*
*/
int
trash_ctor(void *mem, int size, void *arg, int flags)
{
int cnt;
u_int32_t *p;
cnt = size / sizeof(uma_junk);
for (p = mem; cnt > 0; cnt--, p++)
if (*p != uma_junk)
panic("Memory modified after free %p(%d) val=%x @ %p\n",
mem, size, *p, p);
return (0);
}
/*
* Fills an item with predictable garbage
*
* Complies with standard dtor arg/return
*
*/
void
trash_dtor(void *mem, int size, void *arg)
{
int cnt;
u_int32_t *p;
cnt = size / sizeof(uma_junk);
for (p = mem; cnt > 0; cnt--, p++)
*p = uma_junk;
}
/*
* Fills an item with predictable garbage
*
* Complies with standard init arg/return
*
*/
int
trash_init(void *mem, int size, int flags)
{
trash_dtor(mem, size, NULL);
return (0);
}
/*
* Checks an item to make sure it hasn't been overwritten since it was freed.
*
* Complies with standard fini arg/return
*
*/
void
trash_fini(void *mem, int size)
{
(void)trash_ctor(mem, size, NULL, 0);
}
int
mtrash_ctor(void *mem, int size, void *arg, int flags)
{
struct malloc_type **ksp;
u_int32_t *p = mem;
int cnt;
size -= sizeof(struct malloc_type *);
ksp = (struct malloc_type **)mem;
ksp += size / sizeof(struct malloc_type *);
cnt = size / sizeof(uma_junk);
for (p = mem; cnt > 0; cnt--, p++)
if (*p != uma_junk) {
printf("Memory modified after free %p(%d) val=%x @ %p\n",
mem, size, *p, p);
panic("Most recently used by %s\n", (*ksp == NULL)?
"none" : (*ksp)->ks_shortdesc);
}
return (0);
}
/*
* Fills an item with predictable garbage
*
* Complies with standard dtor arg/return
*
*/
void
mtrash_dtor(void *mem, int size, void *arg)
{
int cnt;
u_int32_t *p;
size -= sizeof(struct malloc_type *);
cnt = size / sizeof(uma_junk);
for (p = mem; cnt > 0; cnt--, p++)
*p = uma_junk;
}
/*
* Fills an item with predictable garbage
*
* Complies with standard init arg/return
*
*/
int
mtrash_init(void *mem, int size, int flags)
{
struct malloc_type **ksp;
mtrash_dtor(mem, size, NULL);
ksp = (struct malloc_type **)mem;
ksp += (size / sizeof(struct malloc_type *)) - 1;
*ksp = NULL;
return (0);
}
/*
* Checks an item to make sure it hasn't been overwritten since it was freed,
* prior to freeing it back to available memory.
*
* Complies with standard fini arg/return
*
*/
void
mtrash_fini(void *mem, int size)
{
(void)mtrash_ctor(mem, size, NULL, 0);
}
static uma_slab_t
uma_dbg_getslab(uma_zone_t zone, void *item)
{
uma_slab_t slab;
uma_keg_t keg;
u_int8_t *mem;
keg = zone->uz_keg;
mem = (u_int8_t *)((unsigned long)item & (~UMA_SLAB_MASK));
if (keg->uk_flags & UMA_ZONE_MALLOC) {
slab = vtoslab((vm_offset_t)mem);
} else if (keg->uk_flags & UMA_ZONE_HASH) {
slab = hash_sfind(&keg->uk_hash, mem);
} else {
mem += keg->uk_pgoff;
slab = (uma_slab_t)mem;
}
return (slab);
}
/*
* Set up the slab's freei data such that uma_dbg_free can function.
*
*/
void
uma_dbg_alloc(uma_zone_t zone, uma_slab_t slab, void *item)
{
uma_keg_t keg;
int freei;
keg = zone->uz_keg;
if (slab == NULL) {
slab = uma_dbg_getslab(zone, item);
if (slab == NULL)
panic("uma: item %p did not belong to zone %s\n",
item, zone->uz_name);
}
freei = ((unsigned long)item - (unsigned long)slab->us_data)
/ keg->uk_rsize;
slab->us_freelist[freei].us_item = 255;
return;
}
/*
* Verifies freed addresses. Checks for alignment, valid slab membership
* and duplicate frees.
*
*/
void
uma_dbg_free(uma_zone_t zone, uma_slab_t slab, void *item)
{
uma_keg_t keg;
int freei;
keg = zone->uz_keg;
if (slab == NULL) {
slab = uma_dbg_getslab(zone, item);
if (slab == NULL)
panic("uma: Freed item %p did not belong to zone %s\n",
item, zone->uz_name);
}
freei = ((unsigned long)item - (unsigned long)slab->us_data)
/ keg->uk_rsize;
if (freei >= keg->uk_ipers)
panic("zone: %s(%p) slab %p freelist %d out of range 0-%d\n",
zone->uz_name, zone, slab, freei, keg->uk_ipers-1);
if (((freei * keg->uk_rsize) + slab->us_data) != item) {
printf("zone: %s(%p) slab %p freed address %p unaligned.\n",
zone->uz_name, zone, slab, item);
panic("should be %p\n",
(freei * keg->uk_rsize) + slab->us_data);
}
if (slab->us_freelist[freei].us_item != 255) {
printf("Slab at %p, freei %d = %d.\n",
slab, freei, slab->us_freelist[freei].us_item);
panic("Duplicate free of item %p from zone %p(%s)\n",
item, zone, zone->uz_name);
}
/*
* When this is actually linked into the slab this will change.
* Until then the count of valid slabs will make sure we don't
* accidentally follow this and assume it's a valid index.
*/
slab->us_freelist[freei].us_item = 0;
}