#include #ifdef DEBUG_SUBSYSTEM #undef DEBUG_SUBSYSTEM #endif #define DEBUG_SUBSYSTEM S_KMEM /* * Memory allocation interfaces */ #ifdef DEBUG_KMEM /* Shim layer memory accounting */ atomic64_t kmem_alloc_used; unsigned long kmem_alloc_max = 0; atomic64_t vmem_alloc_used; unsigned long vmem_alloc_max = 0; int kmem_warning_flag = 1; atomic64_t kmem_cache_alloc_failed; spinlock_t kmem_lock; struct hlist_head kmem_table[KMEM_TABLE_SIZE]; struct list_head kmem_list; spinlock_t vmem_lock; struct hlist_head vmem_table[VMEM_TABLE_SIZE]; struct list_head vmem_list; EXPORT_SYMBOL(kmem_alloc_used); EXPORT_SYMBOL(kmem_alloc_max); EXPORT_SYMBOL(vmem_alloc_used); EXPORT_SYMBOL(vmem_alloc_max); EXPORT_SYMBOL(kmem_warning_flag); EXPORT_SYMBOL(kmem_lock); EXPORT_SYMBOL(kmem_table); EXPORT_SYMBOL(kmem_list); EXPORT_SYMBOL(vmem_lock); EXPORT_SYMBOL(vmem_table); EXPORT_SYMBOL(vmem_list); int kmem_set_warning(int flag) { return (kmem_warning_flag = !!flag); } #else int kmem_set_warning(int flag) { return 0; } #endif EXPORT_SYMBOL(kmem_set_warning); /* * Slab allocation interfaces * * While the linux slab implementation was inspired by solaris they * have made some changes to the API which complicates this shim * layer. For one thing the same symbol names are used with different * arguments for the prototypes. To deal with this we must use the * preprocessor to re-order arguments. Happily for us standard C says, * "Macro's appearing in their own expansion are not reexpanded" so * this does not result in an infinite recursion. Additionally the * function pointers registered by solarias differ from those used * by linux so a lookup and mapping from linux style callback to a * solaris style callback is needed. There is some overhead in this * operation which isn't horibile but it needs to be kept in mind. */ #define KCC_MAGIC 0x7a7a7a7a #define KCC_POISON 0x77 typedef struct kmem_cache_cb { int kcc_magic; struct list_head kcc_list; kmem_cache_t * kcc_cache; kmem_constructor_t kcc_constructor; kmem_destructor_t kcc_destructor; kmem_reclaim_t kcc_reclaim; void * kcc_private; void * kcc_vmp; atomic_t kcc_ref; } kmem_cache_cb_t; static struct rw_semaphore kmem_cache_cb_sem; static struct list_head kmem_cache_cb_list; static struct shrinker *kmem_cache_shrinker; /* Function must be called while holding the kmem_cache_cb_sem * Because kmem_cache_t is an opaque datatype we're forced to * match pointers to identify specific cache entires. */ static kmem_cache_cb_t * kmem_cache_find_cache_cb(kmem_cache_t *cache) { kmem_cache_cb_t *kcc; #ifdef CONFIG_RWSEM_GENERIC_SPINLOCK ASSERT(rwsem_is_locked(&kmem_cache_cb_sem)); #endif list_for_each_entry(kcc, &kmem_cache_cb_list, kcc_list) if (cache == kcc->kcc_cache) return kcc; return NULL; } static kmem_cache_cb_t * kmem_cache_add_cache_cb(kmem_cache_t *cache, kmem_constructor_t constructor, kmem_destructor_t destructor, kmem_reclaim_t reclaim, void *priv, void *vmp) { kmem_cache_cb_t *kcc; kcc = (kmem_cache_cb_t *)kmalloc(sizeof(*kcc), GFP_KERNEL); if (kcc) { kcc->kcc_magic = KCC_MAGIC; kcc->kcc_cache = cache; kcc->kcc_constructor = constructor; kcc->kcc_destructor = destructor; kcc->kcc_reclaim = reclaim; kcc->kcc_private = priv; kcc->kcc_vmp = vmp; atomic_set(&kcc->kcc_ref, 0); down_write(&kmem_cache_cb_sem); list_add(&kcc->kcc_list, &kmem_cache_cb_list); up_write(&kmem_cache_cb_sem); } return kcc; } static void kmem_cache_remove_cache_cb(kmem_cache_cb_t *kcc) { down_write(&kmem_cache_cb_sem); ASSERT(atomic_read(&kcc->kcc_ref) == 0); list_del(&kcc->kcc_list); up_write(&kmem_cache_cb_sem); if (kcc){ memset(kcc, KCC_POISON, sizeof(*kcc)); kfree(kcc); } } static void kmem_cache_generic_constructor(void *ptr, kmem_cache_t *cache, unsigned long flags) { kmem_cache_cb_t *kcc; kmem_constructor_t constructor; void *private; /* Ensure constructor verifies are not passed to the registered * constructors. This may not be safe due to the Solaris constructor * not being aware of how to handle the SLAB_CTOR_VERIFY flag */ if (flags & SLAB_CTOR_VERIFY) return; /* We can be called with interrupts disabled so it is critical that * this function and the registered constructor never sleep. */ while (!down_read_trylock(&kmem_cache_cb_sem)); /* Callback list must be in sync with linux slab caches */ kcc = kmem_cache_find_cache_cb(cache); ASSERT(kcc); ASSERT(kcc->kcc_magic == KCC_MAGIC); atomic_inc(&kcc->kcc_ref); constructor = kcc->kcc_constructor; private = kcc->kcc_private; up_read(&kmem_cache_cb_sem); if (constructor) constructor(ptr, private, (int)flags); atomic_dec(&kcc->kcc_ref); /* Linux constructor has no return code, silently eat it */ } static void kmem_cache_generic_destructor(void *ptr, kmem_cache_t *cache, unsigned long flags) { kmem_cache_cb_t *kcc; kmem_destructor_t destructor; void *private; /* We can be called with interrupts disabled so it is critical that * this function and the registered constructor never sleep. */ while (!down_read_trylock(&kmem_cache_cb_sem)); /* Callback list must be in sync with linux slab caches */ kcc = kmem_cache_find_cache_cb(cache); ASSERT(kcc); ASSERT(kcc->kcc_magic == KCC_MAGIC); atomic_inc(&kcc->kcc_ref); destructor = kcc->kcc_destructor; private = kcc->kcc_private; up_read(&kmem_cache_cb_sem); /* Solaris destructor takes no flags, silently eat them */ if (destructor) destructor(ptr, private); atomic_dec(&kcc->kcc_ref); } /* XXX - Arguments are ignored */ static int kmem_cache_generic_shrinker(int nr_to_scan, unsigned int gfp_mask) { kmem_cache_cb_t *kcc; int total = 0; /* Under linux a shrinker is not tightly coupled with a slab * cache. In fact linux always systematically trys calling all * registered shrinker callbacks until its target reclamation level * is reached. Because of this we only register one shrinker * 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(&kmem_cache_cb_sem); list_for_each_entry(kcc, &kmem_cache_cb_list, kcc_list) { ASSERT(kcc); ASSERT(kcc->kcc_magic == KCC_MAGIC); /* Take a reference on the cache in question. If that * cache is contended simply skip it, it may already be * in the process of a reclaim or the ctor/dtor may be * running in either case it's best to skip it. */ atomic_inc(&kcc->kcc_ref); if (atomic_read(&kcc->kcc_ref) > 1) { atomic_dec(&kcc->kcc_ref); continue; } /* Under linux the desired number and gfp type of objects * is passed to the reclaiming function as a sugested reclaim * target. I do not pass these args on because reclaim * policy is entirely up to the owner under solaris. We only * pass on the pre-registered private data. */ if (kcc->kcc_reclaim) kcc->kcc_reclaim(kcc->kcc_private); atomic_dec(&kcc->kcc_ref); total += 1; } /* Under linux we should return the remaining number of entires in * the cache. Unfortunately, I don't see an easy way to safely * emulate this behavior so I'm returning one entry per cache which * was registered with the generic shrinker. This should fake out * the linux VM when it attempts to shrink caches. */ up_read(&kmem_cache_cb_sem); return total; } /* Ensure the __kmem_cache_create/__kmem_cache_destroy macros are * removed here to prevent a recursive substitution, we want to call * the native linux version. */ #undef kmem_cache_create #undef kmem_cache_destroy #undef kmem_cache_alloc kmem_cache_t * __kmem_cache_create(char *name, size_t size, size_t align, kmem_constructor_t constructor, kmem_destructor_t destructor, kmem_reclaim_t reclaim, void *priv, void *vmp, int flags) { kmem_cache_t *cache; kmem_cache_cb_t *kcc; int shrinker_flag = 0; char *cache_name; ENTRY; /* XXX: - Option currently unsupported by shim layer */ ASSERT(!vmp); cache_name = kzalloc(strlen(name) + 1, GFP_KERNEL); if (cache_name == NULL) RETURN(NULL); strcpy(cache_name, name); cache = kmem_cache_create(cache_name, size, align, flags, kmem_cache_generic_constructor, kmem_cache_generic_destructor); if (cache == NULL) RETURN(NULL); /* Register shared shrinker function on initial cache create */ down_read(&kmem_cache_cb_sem); if (list_empty(&kmem_cache_cb_list)) { kmem_cache_shrinker = set_shrinker(KMC_DEFAULT_SEEKS, kmem_cache_generic_shrinker); if (kmem_cache_shrinker == NULL) { kmem_cache_destroy(cache); up_read(&kmem_cache_cb_sem); RETURN(NULL); } } up_read(&kmem_cache_cb_sem); kcc = kmem_cache_add_cache_cb(cache, constructor, destructor, reclaim, priv, vmp); if (kcc == NULL) { if (shrinker_flag) /* New shrinker registered must be removed */ remove_shrinker(kmem_cache_shrinker); kmem_cache_destroy(cache); RETURN(NULL); } RETURN(cache); } EXPORT_SYMBOL(__kmem_cache_create); /* Return code provided despite Solaris's void return. There should be no * harm here since the Solaris versions will ignore it anyway. */ int __kmem_cache_destroy(kmem_cache_t *cache) { kmem_cache_cb_t *kcc; char *name; int rc; ENTRY; down_read(&kmem_cache_cb_sem); kcc = kmem_cache_find_cache_cb(cache); if (kcc == NULL) { up_read(&kmem_cache_cb_sem); RETURN(-EINVAL); } atomic_inc(&kcc->kcc_ref); up_read(&kmem_cache_cb_sem); name = (char *)kmem_cache_name(cache); rc = kmem_cache_destroy(cache); atomic_dec(&kcc->kcc_ref); kmem_cache_remove_cache_cb(kcc); kfree(name); /* Unregister generic shrinker on removal of all caches */ down_read(&kmem_cache_cb_sem); if (list_empty(&kmem_cache_cb_list)) remove_shrinker(kmem_cache_shrinker); up_read(&kmem_cache_cb_sem); RETURN(rc); } EXPORT_SYMBOL(__kmem_cache_destroy); /* Under Solaris if the KM_SLEEP flag is passed we absolutely must * sleep until we are allocated the memory. Under Linux you can still * get a memory allocation failure, so I'm forced to keep requesting * the memory even if the system is under substantial memory pressure * of fragmentation prevents the allocation from succeeded. This is * not the correct fix, or even a good one. But it will do for now. */ void * __kmem_cache_alloc(kmem_cache_t *cache, gfp_t flags) { void *rc; ENTRY; restart: rc = kmem_cache_alloc(cache, flags); if ((rc == NULL) && (flags & KM_SLEEP)) { atomic64_inc(&kmem_cache_alloc_failed); GOTO(restart, rc); } RETURN(rc); } EXPORT_SYMBOL(__kmem_cache_alloc); void __kmem_reap(void) { ENTRY; /* Since there's no easy hook in to linux to force all the registered * shrinkers to run we just run the ones registered for this shim */ kmem_cache_generic_shrinker(KMC_REAP_CHUNK, GFP_KERNEL); EXIT; } EXPORT_SYMBOL(__kmem_reap); int kmem_init(void) { ENTRY; init_rwsem(&kmem_cache_cb_sem); INIT_LIST_HEAD(&kmem_cache_cb_list); #ifdef DEBUG_KMEM { int i; atomic64_set(&kmem_alloc_used, 0); atomic64_set(&vmem_alloc_used, 0); spin_lock_init(&kmem_lock); INIT_LIST_HEAD(&kmem_list); for (i = 0; i < KMEM_TABLE_SIZE; i++) INIT_HLIST_HEAD(&kmem_table[i]); spin_lock_init(&vmem_lock); INIT_LIST_HEAD(&vmem_list); for (i = 0; i < VMEM_TABLE_SIZE; i++) INIT_HLIST_HEAD(&vmem_table[i]); atomic64_set(&kmem_cache_alloc_failed, 0); } #endif RETURN(0); } static char *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 i, flag = 1; ASSERT(str != NULL && len >= 17); 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; } } if (!flag) { sprintf(str, "%02x%02x%02x%02x%02x%02x%02x%02x", *((uint8_t *)kd->kd_addr), *((uint8_t *)kd->kd_addr + 2), *((uint8_t *)kd->kd_addr + 4), *((uint8_t *)kd->kd_addr + 6), *((uint8_t *)kd->kd_addr + 8), *((uint8_t *)kd->kd_addr + 10), *((uint8_t *)kd->kd_addr + 12), *((uint8_t *)kd->kd_addr + 14)); } return str; } void kmem_fini(void) { ENTRY; #ifdef DEBUG_KMEM { unsigned long flags; kmem_debug_t *kd; char str[17]; /* Display all unreclaimed memory addresses, including the * allocation size and the first few bytes of what's located * at that address to aid in debugging. Performance is not * a serious concern here since it is module unload time. */ if (atomic64_read(&kmem_alloc_used) != 0) CWARN("kmem leaked %ld/%ld bytes\n", atomic_read(&kmem_alloc_used), kmem_alloc_max); spin_lock_irqsave(&kmem_lock, flags); if (!list_empty(&kmem_list)) CDEBUG(D_WARNING, "%-16s %-5s %-16s %s:%s\n", "address", "size", "data", "func", "line"); list_for_each_entry(kd, &kmem_list, kd_list) CDEBUG(D_WARNING, "%p %-5d %-16s %s:%d\n", kd->kd_addr, kd->kd_size, sprintf_addr(kd, str, 17, 8), kd->kd_func, kd->kd_line); spin_unlock_irqrestore(&kmem_lock, flags); if (atomic64_read(&vmem_alloc_used) != 0) CWARN("vmem leaked %ld/%ld bytes\n", atomic_read(&vmem_alloc_used), vmem_alloc_max); spin_lock_irqsave(&vmem_lock, flags); if (!list_empty(&vmem_list)) CDEBUG(D_WARNING, "%-16s %-5s %-16s %s:%s\n", "address", "size", "data", "func", "line"); list_for_each_entry(kd, &vmem_list, kd_list) CDEBUG(D_WARNING, "%p %-5d %-16s %s:%d\n", kd->kd_addr, kd->kd_size, sprintf_addr(kd, str, 17, 8), kd->kd_func, kd->kd_line); spin_unlock_irqrestore(&vmem_lock, flags); } #endif EXIT; }