#define OPENSSL_SUPPRESS_DEPRECATED
#include <openssl/crypto.h>
+#include <crypto/cryptlib.h>
#include "internal/cryptlib.h"
+#include "internal/rcu.h"
+#include "rcu_internal.h"
#if defined(__sun)
# include <atomic.h>
# define USE_RWLOCK
# endif
+# if defined(__GNUC__) && defined(__ATOMIC_ACQUIRE) && !defined(BROKEN_CLANG_ATOMICS)
+# define ATOMIC_LOAD_N(p,o) __atomic_load_n(p, o)
+# define ATOMIC_STORE_N(p, v, o) __atomic_store_n(p, v, o)
+# define ATOMIC_STORE(p, v, o) __atomic_store(p, v, o)
+# define ATOMIC_EXCHANGE_N(p, v, o) __atomic_exchange_n(p, v, o)
+# define ATOMIC_ADD_FETCH(p, v, o) __atomic_add_fetch(p, v, o)
+# define ATOMIC_FETCH_ADD(p, v, o) __atomic_fetch_add(p, v, o)
+# define ATOMIC_SUB_FETCH(p, v, o) __atomic_sub_fetch(p, v, o)
+# define ATOMIC_AND_FETCH(p, m, o) __atomic_and_fetch(p, m, o)
+# define ATOMIC_OR_FETCH(p, m, o) __atomic_or_fetch(p, m, o)
+#else
+static pthread_mutex_t atomic_sim_lock = PTHREAD_MUTEX_INITIALIZER;
+
+static inline void *fallback_atomic_load_n(void **p)
+{
+ void *ret;
+
+ pthread_mutex_lock(&atomic_sim_lock);
+ ret = *(void **)p;
+ pthread_mutex_unlock(&atomic_sim_lock);
+ return ret;
+}
+
+# define ATOMIC_LOAD_N(p, o) fallback_atomic_load_n((void **)p)
+
+static inline void *fallback_atomic_store_n(void **p, void *v)
+{
+ void *ret;
+
+ pthread_mutex_lock(&atomic_sim_lock);
+ ret = *p;
+ *p = v;
+ pthread_mutex_unlock(&atomic_sim_lock);
+ return ret;
+}
+
+# define ATOMIC_STORE_N(p, v, o) fallback_atomic_store_n((void **)p, (void *)v)
+
+static inline void fallback_atomic_store(void **p, void **v)
+{
+ void *ret;
+
+ pthread_mutex_lock(&atomic_sim_lock);
+ ret = *p;
+ *p = *v;
+ v = ret;
+ pthread_mutex_unlock(&atomic_sim_lock);
+}
+
+# define ATOMIC_STORE(p, v, o) fallback_atomic_store((void **)p, (void **)v)
+
+static inline void *fallback_atomic_exchange_n(void **p, void *v)
+{
+ void *ret;
+
+ pthread_mutex_lock(&atomic_sim_lock);
+ ret = *p;
+ *p = v;
+ pthread_mutex_unlock(&atomic_sim_lock);
+ return ret;
+}
+
+#define ATOMIC_EXCHANGE_N(p, v, o) fallback_atomic_exchange_n((void **)p, (void *)v)
+
+static inline uint64_t fallback_atomic_add_fetch(uint64_t *p, uint64_t v)
+{
+ uint64_t ret;
+
+ pthread_mutex_lock(&atomic_sim_lock);
+ *p += v;
+ ret = *p;
+ pthread_mutex_unlock(&atomic_sim_lock);
+ return ret;
+}
+
+# define ATOMIC_ADD_FETCH(p, v, o) fallback_atomic_add_fetch(p, v)
+
+static inline uint64_t fallback_atomic_fetch_add(uint64_t *p, uint64_t v)
+{
+ uint64_t ret;
+
+ pthread_mutex_lock(&atomic_sim_lock);
+ ret = *p;
+ *p += v;
+ pthread_mutex_unlock(&atomic_sim_lock);
+ return ret;
+}
+
+# define ATOMIC_FETCH_ADD(p, v, o) fallback_atomic_fetch_add(p, v)
+
+static inline uint64_t fallback_atomic_sub_fetch(uint64_t *p, uint64_t v)
+{
+ uint64_t ret;
+
+ pthread_mutex_lock(&atomic_sim_lock);
+ *p -= v;
+ ret = *p;
+ pthread_mutex_unlock(&atomic_sim_lock);
+ return ret;
+}
+
+# define ATOMIC_SUB_FETCH(p, v, o) fallback_atomic_sub_fetch(p, v)
+
+static inline uint64_t fallback_atomic_and_fetch(uint64_t *p, uint64_t m)
+{
+ uint64_t ret;
+
+ pthread_mutex_lock(&atomic_sim_lock);
+ *p &= m;
+ ret = *p;
+ pthread_mutex_unlock(&atomic_sim_lock);
+ return ret;
+}
+
+# define ATOMIC_AND_FETCH(p, v, o) fallback_atomic_and_fetch(p, v)
+
+static inline uint64_t fallback_atomic_or_fetch(uint64_t *p, uint64_t m)
+{
+ uint64_t ret;
+
+ pthread_mutex_lock(&atomic_sim_lock);
+ *p |= m;
+ ret = *p;
+ pthread_mutex_unlock(&atomic_sim_lock);
+ return ret;
+}
+
+# define ATOMIC_OR_FETCH(p, v, o) fallback_atomic_or_fetch(p, v)
+#endif
+
+static CRYPTO_THREAD_LOCAL rcu_thr_key;
+
+/*
+ * users is broken up into 2 parts
+ * bits 0-15 current readers
+ * bit 32-63 - ID
+ */
+# define READER_SHIFT 0
+# define ID_SHIFT 32
+# define READER_SIZE 16
+# define ID_SIZE 32
+
+# define READER_MASK (((uint64_t)1 << READER_SIZE) - 1)
+# define ID_MASK (((uint64_t)1 << ID_SIZE) - 1)
+# define READER_COUNT(x) (((uint64_t)(x) >> READER_SHIFT) & READER_MASK)
+# define ID_VAL(x) (((uint64_t)(x) >> ID_SHIFT) & ID_MASK)
+# define VAL_READER ((uint64_t)1 << READER_SHIFT)
+# define VAL_ID(x) ((uint64_t)x << ID_SHIFT)
+
+/*
+ * This is the core of an rcu lock. It tracks the readers and writers for the
+ * current quiescence point for a given lock. Users is the 64 bit value that
+ * stores the READERS/ID as defined above
+ *
+ */
+struct rcu_qp {
+ uint64_t users;
+};
+
+struct thread_qp {
+ struct rcu_qp *qp;
+ unsigned int depth;
+ CRYPTO_RCU_LOCK *lock;
+};
+
+#define MAX_QPS 10
+/*
+ * This is the per thread tracking data
+ * that is assigned to each thread participating
+ * in an rcu qp
+ *
+ * qp points to the qp that it last acquired
+ *
+ */
+struct rcu_thr_data {
+ struct thread_qp thread_qps[MAX_QPS];
+};
+
+/*
+ * This is the internal version of a CRYPTO_RCU_LOCK
+ * it is cast from CRYPTO_RCU_LOCK
+ */
+struct rcu_lock_st {
+ /* Callbacks to call for next ossl_synchronize_rcu */
+ struct rcu_cb_item *cb_items;
+
+ /* rcu generation counter for in-order retirement */
+ uint32_t id_ctr;
+
+ /* Array of quiescent points for synchronization */
+ struct rcu_qp *qp_group;
+
+ /* Number of elements in qp_group array */
+ size_t group_count;
+
+ /* Index of the current qp in the qp_group array */
+ uint64_t reader_idx;
+
+ /* value of the next id_ctr value to be retired */
+ uint32_t next_to_retire;
+
+ /* index of the next free rcu_qp in the qp_group */
+ uint64_t current_alloc_idx;
+
+ /* number of qp's in qp_group array currently being retired */
+ uint32_t writers_alloced;
+
+ /* lock protecting write side operations */
+ pthread_mutex_t write_lock;
+
+ /* lock protecting updates to writers_alloced/current_alloc_idx */
+ pthread_mutex_t alloc_lock;
+
+ /* signal to wake threads waiting on alloc_lock */
+ pthread_cond_t alloc_signal;
+
+ /* lock to enforce in-order retirement */
+ pthread_mutex_t prior_lock;
+
+ /* signal to wake threads waiting on prior_lock */
+ pthread_cond_t prior_signal;
+};
+
+/*
+ * Called on thread exit to free the pthread key
+ * associated with this thread, if any
+ */
+static void free_rcu_thr_data(void *ptr)
+{
+ struct rcu_thr_data *data =
+ (struct rcu_thr_data *)CRYPTO_THREAD_get_local(&rcu_thr_key);
+
+ OPENSSL_free(data);
+ CRYPTO_THREAD_set_local(&rcu_thr_key, NULL);
+}
+
+static void ossl_rcu_init(void)
+{
+ CRYPTO_THREAD_init_local(&rcu_thr_key, NULL);
+}
+
+/* Read side acquisition of the current qp */
+static struct rcu_qp *get_hold_current_qp(struct rcu_lock_st *lock)
+{
+ uint64_t qp_idx;
+
+ /* get the current qp index */
+ for (;;) {
+ /*
+ * Notes on use of __ATOMIC_ACQUIRE
+ * We need to ensure the following:
+ * 1) That subsequent operations aren't optimized by hoisting them above
+ * this operation. Specifically, we don't want the below re-load of
+ * qp_idx to get optimized away
+ * 2) We want to ensure that any updating of reader_idx on the write side
+ * of the lock is flushed from a local cpu cache so that we see any
+ * updates prior to the load. This is a non-issue on cache coherent
+ * systems like x86, but is relevant on other arches
+ * Note: This applies to the reload below as well
+ */
+ qp_idx = (uint64_t)ATOMIC_LOAD_N(&lock->reader_idx, __ATOMIC_ACQUIRE);
+
+ /*
+ * Notes of use of __ATOMIC_RELEASE
+ * This counter is only read by the write side of the lock, and so we
+ * specify __ATOMIC_RELEASE here to ensure that the write side of the
+ * lock see this during the spin loop read of users, as it waits for the
+ * reader count to approach zero
+ */
+ ATOMIC_ADD_FETCH(&lock->qp_group[qp_idx].users, VAL_READER,
+ __ATOMIC_RELEASE);
+
+ /* if the idx hasn't changed, we're good, else try again */
+ if (qp_idx == (uint64_t)ATOMIC_LOAD_N(&lock->reader_idx, __ATOMIC_ACQUIRE))
+ break;
+
+ /*
+ * Notes on use of __ATOMIC_RELEASE
+ * As with the add above, we want to ensure that this decrement is
+ * seen by the write side of the lock as soon as it happens to prevent
+ * undue spinning waiting for write side completion
+ */
+ ATOMIC_SUB_FETCH(&lock->qp_group[qp_idx].users, VAL_READER,
+ __ATOMIC_RELEASE);
+ }
+
+ return &lock->qp_group[qp_idx];
+}
+
+void ossl_rcu_read_lock(CRYPTO_RCU_LOCK *lock)
+{
+ struct rcu_thr_data *data;
+ int i, available_qp = -1;
+
+ /*
+ * we're going to access current_qp here so ask the
+ * processor to fetch it
+ */
+ data = CRYPTO_THREAD_get_local(&rcu_thr_key);
+
+ if (data == NULL) {
+ data = OPENSSL_zalloc(sizeof(*data));
+ OPENSSL_assert(data != NULL);
+ CRYPTO_THREAD_set_local(&rcu_thr_key, data);
+ ossl_init_thread_start(NULL, NULL, free_rcu_thr_data);
+ }
+
+ for (i = 0; i < MAX_QPS; i++) {
+ if (data->thread_qps[i].qp == NULL && available_qp == -1)
+ available_qp = i;
+ /* If we have a hold on this lock already, we're good */
+ if (data->thread_qps[i].lock == lock) {
+ data->thread_qps[i].depth++;
+ return;
+ }
+ }
+
+ /*
+ * if we get here, then we don't have a hold on this lock yet
+ */
+ assert(available_qp != -1);
+
+ data->thread_qps[available_qp].qp = get_hold_current_qp(lock);
+ data->thread_qps[available_qp].depth = 1;
+ data->thread_qps[available_qp].lock = lock;
+}
+
+void ossl_rcu_read_unlock(CRYPTO_RCU_LOCK *lock)
+{
+ int i;
+ struct rcu_thr_data *data = CRYPTO_THREAD_get_local(&rcu_thr_key);
+ uint64_t ret;
+
+ assert(data != NULL);
+
+ for (i = 0; i < MAX_QPS; i++) {
+ if (data->thread_qps[i].lock == lock) {
+ /*
+ * As with read side acquisition, we use __ATOMIC_RELEASE here
+ * to ensure that the decrement is published immediately
+ * to any write side waiters
+ */
+ data->thread_qps[i].depth--;
+ if (data->thread_qps[i].depth == 0) {
+ ret = ATOMIC_SUB_FETCH(&data->thread_qps[i].qp->users, VAL_READER,
+ __ATOMIC_RELEASE);
+ OPENSSL_assert(ret != UINT64_MAX);
+ data->thread_qps[i].qp = NULL;
+ data->thread_qps[i].lock = NULL;
+ }
+ return;
+ }
+ }
+ /*
+ * if we get here, we're trying to unlock a lock that we never acquired
+ * thats fatal
+ */
+ assert(0);
+}
+
+/*
+ * Write side allocation routine to get the current qp
+ * and replace it with a new one
+ */
+static struct rcu_qp *update_qp(CRYPTO_RCU_LOCK *lock)
+{
+ uint64_t new_id;
+ uint64_t current_idx;
+
+ pthread_mutex_lock(&lock->alloc_lock);
+
+ /*
+ * we need at least one qp to be available with one
+ * left over, so that readers can start working on
+ * one that isn't yet being waited on
+ */
+ while (lock->group_count - lock->writers_alloced < 2)
+ /* we have to wait for one to be free */
+ pthread_cond_wait(&lock->alloc_signal, &lock->alloc_lock);
+
+ current_idx = lock->current_alloc_idx;
+
+ /* Allocate the qp */
+ lock->writers_alloced++;
+
+ /* increment the allocation index */
+ lock->current_alloc_idx =
+ (lock->current_alloc_idx + 1) % lock->group_count;
+
+ /* get and insert a new id */
+ new_id = lock->id_ctr;
+ lock->id_ctr++;
+
+ new_id = VAL_ID(new_id);
+ /*
+ * Even though we are under a write side lock here
+ * We need to use atomic instructions to ensure that the results
+ * of this update are published to the read side prior to updating the
+ * reader idx below
+ */
+ ATOMIC_AND_FETCH(&lock->qp_group[current_idx].users, ID_MASK,
+ __ATOMIC_RELEASE);
+ ATOMIC_OR_FETCH(&lock->qp_group[current_idx].users, new_id,
+ __ATOMIC_RELEASE);
+
+ /*
+ * update the reader index to be the prior qp
+ * Note the use of __ATOMIC_RELEASE here is based on the corresponding use
+ * of __ATOMIC_ACQUIRE in get_hold_current_qp, as we wan't any publication
+ * of this value to be seen on the read side immediately after it happens
+ */
+ ATOMIC_STORE_N(&lock->reader_idx, lock->current_alloc_idx,
+ __ATOMIC_RELEASE);
+
+ /* wake up any waiters */
+ pthread_cond_signal(&lock->alloc_signal);
+ pthread_mutex_unlock(&lock->alloc_lock);
+ return &lock->qp_group[current_idx];
+}
+
+static void retire_qp(CRYPTO_RCU_LOCK *lock, struct rcu_qp *qp)
+{
+ pthread_mutex_lock(&lock->alloc_lock);
+ lock->writers_alloced--;
+ pthread_cond_signal(&lock->alloc_signal);
+ pthread_mutex_unlock(&lock->alloc_lock);
+}
+
+static struct rcu_qp *allocate_new_qp_group(CRYPTO_RCU_LOCK *lock,
+ int count)
+{
+ struct rcu_qp *new =
+ OPENSSL_zalloc(sizeof(*new) * count);
+
+ lock->group_count = count;
+ return new;
+}
+
+void ossl_rcu_write_lock(CRYPTO_RCU_LOCK *lock)
+{
+ pthread_mutex_lock(&lock->write_lock);
+}
+
+void ossl_rcu_write_unlock(CRYPTO_RCU_LOCK *lock)
+{
+ pthread_mutex_unlock(&lock->write_lock);
+}
+
+void ossl_synchronize_rcu(CRYPTO_RCU_LOCK *lock)
+{
+ struct rcu_qp *qp;
+ uint64_t count;
+ struct rcu_cb_item *cb_items, *tmpcb;
+
+ /*
+ * __ATOMIC_ACQ_REL is used here to ensure that we get any prior published
+ * writes before we read, and publish our write immediately
+ */
+ cb_items = ATOMIC_EXCHANGE_N(&lock->cb_items, NULL, __ATOMIC_ACQ_REL);
+
+ qp = update_qp(lock);
+
+ /*
+ * wait for the reader count to reach zero
+ * Note the use of __ATOMIC_ACQUIRE here to ensure that any
+ * prior __ATOMIC_RELEASE write operation in get_hold_current_qp
+ * is visible prior to our read
+ */
+ do {
+ count = (uint64_t)ATOMIC_LOAD_N(&qp->users, __ATOMIC_ACQUIRE);
+ } while (READER_COUNT(count) != 0);
+
+ /* retire in order */
+ pthread_mutex_lock(&lock->prior_lock);
+ while (lock->next_to_retire != ID_VAL(count))
+ pthread_cond_wait(&lock->prior_signal, &lock->prior_lock);
+ lock->next_to_retire++;
+ pthread_cond_broadcast(&lock->prior_signal);
+ pthread_mutex_unlock(&lock->prior_lock);
+
+ retire_qp(lock, qp);
+
+ /* handle any callbacks that we have */
+ while (cb_items != NULL) {
+ tmpcb = cb_items;
+ cb_items = cb_items->next;
+ tmpcb->fn(tmpcb->data);
+ OPENSSL_free(tmpcb);
+ }
+}
+
+int ossl_rcu_call(CRYPTO_RCU_LOCK *lock, rcu_cb_fn cb, void *data)
+{
+ struct rcu_cb_item *new =
+ OPENSSL_zalloc(sizeof(*new));
+
+ if (new == NULL)
+ return 0;
+
+ new->data = data;
+ new->fn = cb;
+ /*
+ * Use __ATOMIC_ACQ_REL here to indicate that any prior writes to this
+ * list are visible to us prior to reading, and publish the new value
+ * immediately
+ */
+ new->next = ATOMIC_EXCHANGE_N(&lock->cb_items, new, __ATOMIC_ACQ_REL);
+
+ return 1;
+}
+
+void *ossl_rcu_uptr_deref(void **p)
+{
+ return (void *)ATOMIC_LOAD_N(p, __ATOMIC_ACQUIRE);
+}
+
+void ossl_rcu_assign_uptr(void **p, void **v)
+{
+ ATOMIC_STORE(p, v, __ATOMIC_RELEASE);
+}
+
+static CRYPTO_ONCE rcu_init_once = CRYPTO_ONCE_STATIC_INIT;
+
+CRYPTO_RCU_LOCK *ossl_rcu_lock_new(int num_writers)
+{
+ struct rcu_lock_st *new;
+
+ if (!CRYPTO_THREAD_run_once(&rcu_init_once, ossl_rcu_init))
+ return NULL;
+
+ if (num_writers < 1)
+ num_writers = 1;
+
+ new = OPENSSL_zalloc(sizeof(*new));
+ if (new == NULL)
+ return NULL;
+
+ pthread_mutex_init(&new->write_lock, NULL);
+ pthread_mutex_init(&new->prior_lock, NULL);
+ pthread_mutex_init(&new->alloc_lock, NULL);
+ pthread_cond_init(&new->prior_signal, NULL);
+ pthread_cond_init(&new->alloc_signal, NULL);
+ new->qp_group = allocate_new_qp_group(new, num_writers + 1);
+ if (new->qp_group == NULL) {
+ OPENSSL_free(new);
+ new = NULL;
+ }
+ return new;
+}
+
+void ossl_rcu_lock_free(CRYPTO_RCU_LOCK *lock)
+{
+ struct rcu_lock_st *rlock = (struct rcu_lock_st *)lock;
+
+ if (lock == NULL)
+ return;
+
+ /* make sure we're synchronized */
+ ossl_synchronize_rcu(rlock);
+
+ OPENSSL_free(rlock->qp_group);
+ /* There should only be a single qp left now */
+ OPENSSL_free(rlock);
+}
+
CRYPTO_RWLOCK *CRYPTO_THREAD_lock_new(void)
{
# ifdef USE_RWLOCK
CRYPTO_RWLOCK *lock;
- if ((lock = CRYPTO_zalloc(sizeof(pthread_rwlock_t), NULL, 0)) == NULL)
+ if ((lock = OPENSSL_zalloc(sizeof(pthread_rwlock_t))) == NULL)
/* Don't set error, to avoid recursion blowup. */
return NULL;
pthread_mutexattr_t attr;
CRYPTO_RWLOCK *lock;
- if ((lock = CRYPTO_zalloc(sizeof(pthread_mutex_t), NULL, 0)) == NULL)
+ if ((lock = OPENSSL_zalloc(sizeof(pthread_mutex_t))) == NULL)
/* Don't set error, to avoid recursion blowup. */
return NULL;
projects / openssl.git / blobdiff