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Fix for memory corruption caused by overruning the magazine

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when repopulating it.  Plus I fixed a few more suble races in
that part of the code which were catching me.  Finally I fixed
a small race in kmem_test8.



git-svn-id: https://outreach.scidac.gov/svn/spl/trunk@137 7e1ea52c-4ff2-0310-8f11-9dd32ca42a1c
This commit is contained in:
behlendo 2008-06-26 19:49:42 +00:00
parent 4afaaefa05
commit e9d7a2bef5
3 changed files with 94 additions and 62 deletions
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2
include/sys/kmem.h
View File

@ -49,7 +49,7 @@ extern "C" {
#define KM_SLEEP GFP_KERNEL
#define KM_NOSLEEP GFP_ATOMIC
#undef KM_PANIC /* No linux analog */
#define KM_PUSHPAGE (GFP_KERNEL | __GFP_HIGH)
#define KM_PUSHPAGE (KM_SLEEP | __GFP_HIGH)
#define KM_VMFLAGS GFP_LEVEL_MASK
#define KM_FLAGS __GFP_BITS_MASK

151
modules/spl/spl-kmem.c
View File

@ -319,9 +319,9 @@ spl_magazine_size(spl_kmem_cache_t *skc)
else if (skc->skc_obj_size > (PAGE_SIZE / 4))
size = 32;
else if (skc->skc_obj_size > (PAGE_SIZE / 16))
size = 64;
size = 48;
else
size = 128;
size = 64;
RETURN(size);
}
@ -408,12 +408,12 @@ spl_kmem_cache_create(char *name, size_t size, size_t align,
/* We may be called when there is a non-zero preempt_count or
* interrupts are disabled is which case we must not sleep.
*/
if (current_thread_info()->preempt_count || irqs_disabled())
if (current_thread_info()->preempt_count || irqs_disabled())
kmem_flags = KM_NOSLEEP;
/* Allocate new cache memory and initialize. */
skc = (spl_kmem_cache_t *)kmem_alloc(sizeof(*skc), kmem_flags);
if (skc == NULL)
skc = (spl_kmem_cache_t *)kmem_alloc(sizeof(*skc), kmem_flags);
if (skc == NULL)
RETURN(NULL);
skc->skc_magic = SKC_MAGIC;
@ -425,9 +425,9 @@ spl_kmem_cache_create(char *name, size_t size, size_t align,
}
strncpy(skc->skc_name, name, skc->skc_name_size);
skc->skc_ctor = ctor;
skc->skc_dtor = dtor;
skc->skc_reclaim = reclaim;
skc->skc_ctor = ctor;
skc->skc_dtor = dtor;
skc->skc_reclaim = reclaim;
skc->skc_private = priv;
skc->skc_vmp = vmp;
skc->skc_flags = flags;
@ -455,9 +455,9 @@ spl_kmem_cache_create(char *name, size_t size, size_t align,
INIT_LIST_HEAD(&skc->skc_complete_list);
INIT_LIST_HEAD(&skc->skc_partial_list);
spin_lock_init(&skc->skc_lock);
skc->skc_slab_fail = 0;
skc->skc_slab_create = 0;
skc->skc_slab_destroy = 0;
skc->skc_slab_fail = 0;
skc->skc_slab_create = 0;
skc->skc_slab_destroy = 0;
skc->skc_slab_total = 0;
skc->skc_slab_alloc = 0;
skc->skc_slab_max = 0;
@ -476,10 +476,10 @@ spl_kmem_cache_create(char *name, size_t size, size_t align,
}
down_write(&spl_kmem_cache_sem);
list_add_tail(&skc->skc_list, &spl_kmem_cache_list);
list_add_tail(&skc->skc_list, &spl_kmem_cache_list);
up_write(&spl_kmem_cache_sem);
RETURN(skc);
RETURN(skc);
}
EXPORT_SYMBOL(spl_kmem_cache_create);
@ -492,9 +492,11 @@ spl_kmem_cache_destroy(spl_kmem_cache_t *skc)
spl_kmem_slab_t *sks, *m;
ENTRY;
down_write(&spl_kmem_cache_sem);
list_del_init(&skc->skc_list);
up_write(&spl_kmem_cache_sem);
ASSERT(skc->skc_magic == SKC_MAGIC);
down_write(&spl_kmem_cache_sem);
list_del_init(&skc->skc_list);
up_write(&spl_kmem_cache_sem);
spl_magazine_destroy(skc);
spin_lock(&skc->skc_lock);
@ -505,7 +507,7 @@ spl_kmem_cache_destroy(spl_kmem_cache_t *skc)
ASSERTF(skc->skc_hash_count == 0, "skc->skc_hash_count=%d\n",
skc->skc_hash_count);
list_for_each_entry_safe(sks, m, &skc->skc_partial_list, sks_list)
list_for_each_entry_safe(sks, m, &skc->skc_partial_list, sks_list)
spl_slab_free(sks);
kmem_free(skc->skc_hash, skc->skc_hash_size);
@ -530,19 +532,20 @@ spl_hash_ptr(void *ptr, unsigned int bits)
static spl_kmem_obj_t *
spl_hash_obj(spl_kmem_cache_t *skc, void *obj)
{
struct hlist_node *node;
struct hlist_node *node;
spl_kmem_obj_t *sko = NULL;
unsigned long key = spl_hash_ptr(obj, skc->skc_hash_bits);
int i = 0;
ASSERT(skc->skc_magic == SKC_MAGIC);
ASSERT(spin_is_locked(&skc->skc_lock));
hlist_for_each_entry(sko, node, &skc->skc_hash[key], sko_hlist) {
hlist_for_each_entry(sko, node, &skc->skc_hash[key], sko_hlist) {
if (unlikely((++i) > skc->skc_hash_depth))
skc->skc_hash_depth = i;
if (sko->sko_addr == obj) {
if (sko->sko_addr == obj) {
ASSERT(sko->sko_magic == SKO_MAGIC);
RETURN(sko);
}
@ -557,6 +560,8 @@ spl_cache_obj(spl_kmem_cache_t *skc, spl_kmem_slab_t *sks)
spl_kmem_obj_t *sko;
unsigned long key;
ASSERT(skc->skc_magic == SKC_MAGIC);
ASSERT(sks->sks_magic == SKS_MAGIC);
ASSERT(spin_is_locked(&skc->skc_lock));
sko = list_entry((&sks->sks_free_list)->next,spl_kmem_obj_t,sko_list);
@ -596,12 +601,14 @@ spl_cache_obj(spl_kmem_cache_t *skc, spl_kmem_slab_t *sks)
static spl_kmem_slab_t *
spl_cache_grow(spl_kmem_cache_t *skc, int flags)
{
spl_kmem_slab_t *sks;
spl_kmem_slab_t *sks;
spl_kmem_obj_t *sko;
ENTRY;
if (flags & __GFP_WAIT) {
flags |= __GFP_NOFAIL;
ASSERT(skc->skc_magic == SKC_MAGIC);
if (flags & __GFP_WAIT) {
// flags |= __GFP_NOFAIL; /* XXX: Solaris assumes this */
might_sleep();
local_irq_enable();
}
@ -622,7 +629,7 @@ spl_cache_grow(spl_kmem_cache_t *skc, int flags)
skc->skc_ctor(sko->sko_addr, skc->skc_private, flags);
}
if (flags & __GFP_WAIT)
if (flags & __GFP_WAIT)
local_irq_disable();
/* Link the new empty slab in to the end of skc_partial_list */
@ -638,11 +645,15 @@ spl_cache_grow(spl_kmem_cache_t *skc, int flags)
static int
spl_cache_refill(spl_kmem_cache_t *skc, spl_kmem_magazine_t *skm, int flags)
{
spl_kmem_slab_t *sks;
int refill = skm->skm_refill;
spl_kmem_slab_t *sks;
int rc = 0, refill;
ENTRY;
ASSERT(skc->skc_magic == SKC_MAGIC);
ASSERT(skm->skm_magic == SKM_MAGIC);
/* XXX: Check for refill bouncing by age perhaps */
refill = MIN(skm->skm_refill, skm->skm_size - skm->skm_avail);
spin_lock(&skc->skc_lock);
while (refill > 0) {
@ -651,11 +662,16 @@ spl_cache_refill(spl_kmem_cache_t *skc, spl_kmem_magazine_t *skm, int flags)
spin_unlock(&skc->skc_lock);
sks = spl_cache_grow(skc, flags);
if (!sks)
GOTO(out, refill);
GOTO(out, rc);
/* Rescheduled to different CPU skm is not local */
if (skm != skc->skc_mag[smp_processor_id()])
GOTO(out, refill);
GOTO(out, rc);
/* Potentially rescheduled to the same CPU but
* allocations may have occured from this CPU while
* we were sleeping so recalculate max refill. */
refill = MIN(refill, skm->skm_size - skm->skm_avail);
spin_lock(&skc->skc_lock);
continue;
@ -669,10 +685,12 @@ spl_cache_refill(spl_kmem_cache_t *skc, spl_kmem_magazine_t *skm, int flags)
ASSERT(!list_empty(&sks->sks_free_list));
/* Consume as many objects as needed to refill the requested
* cache. We must be careful to lock here because our local
* magazine may not be local anymore due to spl_cache_grow. */
while ((sks->sks_ref < sks->sks_objs) && (refill-- > 0))
* cache. We must also be careful not to overfill it. */
while (sks->sks_ref < sks->sks_objs && refill-- > 0 && ++rc) {
ASSERT(skm->skm_avail < skm->skm_size);
ASSERT(rc < skm->skm_size);
skm->skm_objs[skm->skm_avail++]=spl_cache_obj(skc,sks);
}
/* Move slab to skc_complete_list when full */
if (sks->sks_ref == sks->sks_objs) {
@ -684,16 +702,17 @@ spl_cache_refill(spl_kmem_cache_t *skc, spl_kmem_magazine_t *skm, int flags)
spin_unlock(&skc->skc_lock);
out:
/* Returns the number of entries added to cache */
RETURN(skm->skm_refill - refill);
RETURN(rc);
}
static void
spl_cache_shrink(spl_kmem_cache_t *skc, void *obj)
{
spl_kmem_slab_t *sks = NULL;
spl_kmem_slab_t *sks = NULL;
spl_kmem_obj_t *sko = NULL;
ENTRY;
ASSERT(skc->skc_magic == SKC_MAGIC);
ASSERT(spin_is_locked(&skc->skc_lock));
sko = spl_hash_obj(skc, obj);
@ -738,14 +757,16 @@ spl_cache_flush(spl_kmem_cache_t *skc, spl_kmem_magazine_t *skm, int flush)
int i, count = MIN(flush, skm->skm_avail);
ENTRY;
ASSERT(skc->skc_magic == SKC_MAGIC);
ASSERT(skm->skm_magic == SKM_MAGIC);
spin_lock(&skc->skc_lock);
for (i = 0; i < count; i++)
spl_cache_shrink(skc, skm->skm_objs[i]);
__spl_slab_reclaim(skc);
skm->skm_avail -= count;
memmove(skm->skm_objs, &(skm->skm_objs[count]),
// __spl_slab_reclaim(skc);
skm->skm_avail -= count;
memmove(skm->skm_objs, &(skm->skm_objs[count]),
sizeof(void *) * skm->skm_avail);
spin_unlock(&skc->skc_lock);
@ -759,9 +780,11 @@ spl_kmem_cache_alloc(spl_kmem_cache_t *skc, int flags)
spl_kmem_magazine_t *skm;
unsigned long irq_flags;
void *obj = NULL;
int id;
ENTRY;
ASSERT(flags & KM_SLEEP);
ASSERT(skc->skc_magic == SKC_MAGIC);
ASSERT(flags & KM_SLEEP); /* XXX: KM_NOSLEEP not yet supported */
local_irq_save(irq_flags);
restart:
@ -769,7 +792,12 @@ spl_kmem_cache_alloc(spl_kmem_cache_t *skc, int flags)
* in the restart case we must be careful to reaquire
* the local magazine since this may have changed
* when we need to grow the cache. */
id = smp_processor_id();
ASSERTF(id < 4, "cache=%p smp_processor_id=%d\n", skc, id);
skm = skc->skc_mag[smp_processor_id()];
ASSERTF(skm->skm_magic == SKM_MAGIC, "%x != %x: %s/%p/%p %x/%x/%x\n",
skm->skm_magic, SKM_MAGIC, skc->skc_name, skc, skm,
skm->skm_size, skm->skm_refill, skm->skm_avail);
if (likely(skm->skm_avail)) {
/* Object available in CPU cache, use it */
@ -798,6 +826,7 @@ spl_kmem_cache_free(spl_kmem_cache_t *skc, void *obj)
unsigned long flags;
ENTRY;
ASSERT(skc->skc_magic == SKC_MAGIC);
local_irq_save(flags);
/* Safe to update per-cpu structure without lock, but
@ -805,10 +834,12 @@ spl_kmem_cache_free(spl_kmem_cache_t *skc, void *obj)
* it is entirely possible to allocate an object from one
* CPU cache and return it to another. */
skm = skc->skc_mag[smp_processor_id()];
ASSERT(skm->skm_magic == SKM_MAGIC);
/* Per-CPU cache full, flush it to make space */
if (unlikely(skm->skm_avail >= skm->skm_size))
(void)spl_cache_flush(skc, skm, skm->skm_refill);
(void)spl_cache_flush(skc, skm, 1);
/* Available space in cache, use it */
skm->skm_objs[skm->skm_avail++] = obj;
@ -822,7 +853,7 @@ EXPORT_SYMBOL(spl_kmem_cache_free);
static int
spl_kmem_cache_generic_shrinker(int nr_to_scan, unsigned int gfp_mask)
{
spl_kmem_cache_t *skc;
spl_kmem_cache_t *skc;
/* Under linux a shrinker is not tightly coupled with a slab
* cache. In fact linux always systematically trys calling all
@ -831,12 +862,12 @@ spl_kmem_cache_generic_shrinker(int nr_to_scan, unsigned int gfp_mask)
* function in the shim layer for all slab caches. And we always
* attempt to shrink all caches when this generic shrinker is called.
*/
down_read(&spl_kmem_cache_sem);
down_read(&spl_kmem_cache_sem);
list_for_each_entry(skc, &spl_kmem_cache_list, skc_list)
list_for_each_entry(skc, &spl_kmem_cache_list, skc_list)
spl_kmem_cache_reap_now(skc);
up_read(&spl_kmem_cache_sem);
up_read(&spl_kmem_cache_sem);
/* XXX: Under linux we should return the remaining number of
* entries in the cache. We should do this as well.
@ -850,7 +881,8 @@ spl_kmem_cache_reap_now(spl_kmem_cache_t *skc)
spl_kmem_magazine_t *skm;
int i;
ENTRY;
ASSERT(skc && skc->skc_magic == SKC_MAGIC);
ASSERT(skc->skc_magic == SKC_MAGIC);
if (skc->skc_reclaim)
skc->skc_reclaim(skc->skc_private);
@ -879,8 +911,8 @@ EXPORT_SYMBOL(spl_kmem_reap);
int
spl_kmem_init(void)
{
int rc = 0;
ENTRY;
int rc = 0;
ENTRY;
init_rwsem(&spl_kmem_cache_sem);
INIT_LIST_HEAD(&spl_kmem_cache_list);
@ -944,28 +976,27 @@ spl_kmem_init(void)
static char *
spl_sprintf_addr(kmem_debug_t *kd, char *str, int len, int min)
{
int size = ((len - 1) < kd->kd_size) ? (len - 1) : kd->kd_size;
int size = ((len - 1) < kd->kd_size) ? (len - 1) : kd->kd_size;
int i, flag = 1;
ASSERT(str != NULL && len >= 17);
memset(str, 0, len);
memset(str, 0, len);
/* Check for a fully printable string, and while we are at
* it place the printable characters in the passed buffer. */
for (i = 0; i < size; i++) {
str[i] = ((char *)(kd->kd_addr))[i];
if (isprint(str[i])) {
continue;
} else {
/* Minimum number of printable characters found
* to make it worthwhile to print this as ascii. */
if (i > min)
break;
flag = 0;
break;
}
str[i] = ((char *)(kd->kd_addr))[i];
if (isprint(str[i])) {
continue;
} else {
/* Minimum number of printable characters found
* to make it worthwhile to print this as ascii. */
if (i > min)
break;
flag = 0;
break;
}
}
if (!flag) {
@ -1038,8 +1069,8 @@ spl_kmem_fini(void)
unregister_shrinker(&spl_kmem_cache_shrinker);
#endif
(void)kmem_cache_destroy(spl_obj_cache);
(void)kmem_cache_destroy(spl_slab_cache);
(void)kmem_cache_destroy(spl_obj_cache);
(void)kmem_cache_destroy(spl_slab_cache);
EXIT;
}

3
modules/splat/splat-kmem.c
View File

@ -553,9 +553,10 @@ splat_kmem_test8_thread(void *arg)
kcp->kcp_threads--;
if (!kcp->kcp_rc)
kcp->kcp_rc = rc;
spin_unlock(&kcp->kcp_lock);
wake_up(&kcp->kcp_waitq);
spin_unlock(&kcp->kcp_lock);
thread_exit();
}