# define USE_RWLOCK
# endif
-# if defined(__GNUC__) && defined(__ATOMIC_ACQUIRE) && !defined(BROKEN_CLANG_ATOMICS)
+/*
+ * For all GNU/clang atomic builtins, we also need fallbacks, to cover all
+ * other compilers.
+
+ * Unfortunately, we can't do that with some "generic type", because there's no
+ * guarantee that the chosen generic type is large enough to cover all cases.
+ * Therefore, we implement fallbacks for each applicable type, with composed
+ * names that include the type they handle.
+ *
+ * (an anecdote: we previously tried to use |void *| as the generic type, with
+ * the thought that the pointer itself is the largest type. However, this is
+ * not true on 32-bit pointer platforms, as a |uint64_t| is twice as large)
+ *
+ * All applicable ATOMIC_ macros take the intended type as first parameter, so
+ * they can map to the correct fallback function. In the GNU/clang case, that
+ * parameter is simply ignored.
+ */
+
+/*
+ * Internal types used with the ATOMIC_ macros, to make it possible to compose
+ * fallback function names.
+ */
+typedef void *pvoid;
+typedef struct rcu_cb_item *prcu_cb_item;
+
+# if defined(__GNUC__) && defined(__ATOMIC_ACQUIRE) && !defined(BROKEN_CLANG_ATOMICS) \
+ && !defined(USE_ATOMIC_FALLBACKS)
# if defined(__APPLE__) && defined(__clang__) && defined(__aarch64__)
/*
- * Apple M1 virtualized cpu seems to have some problem using the ldapr instruction
- * (see https://github.com/openssl/openssl/pull/23974)
+ * For pointers, Apple M1 virtualized cpu seems to have some problem using the
+ * ldapr instruction (see https://github.com/openssl/openssl/pull/23974)
* When using the native apple clang compiler, this instruction is emitted for
* atomic loads, which is bad. So, if
* 1) We are building on a target that defines __APPLE__ AND
* function to issue the ldar instruction instead, which procuces the proper
* sequencing guarantees
*/
-static inline void *apple_atomic_load_n(void **p)
+static inline void *apple_atomic_load_n_pvoid(void **p,
+ ossl_unused int memorder)
{
void *ret;
return ret;
}
-# define ATOMIC_LOAD_N(p, o) apple_atomic_load_n((void **)p)
+/* For uint64_t, we should be fine, though */
+# define apple_atomic_load_n_uint64_t(p, o) __atomic_load_n(p, o)
+
+# define ATOMIC_LOAD_N(t, p, o) apple_atomic_load_n_##t(p, o)
# else
-# define ATOMIC_LOAD_N(p,o) __atomic_load_n(p, o)
+# define ATOMIC_LOAD_N(t, p, o) __atomic_load_n(p, o)
# endif
-# 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_STORE_N(t, p, v, o) __atomic_store_n(p, v, o)
+# define ATOMIC_STORE(t, p, v, o) __atomic_store(p, v, o)
+# define ATOMIC_EXCHANGE_N(t, 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)
# 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 IMPL_fallback_atomic_load_n(t) \
+ static inline t fallback_atomic_load_n_##t(t *p) \
+ { \
+ t ret; \
+ \
+ pthread_mutex_lock(&atomic_sim_lock); \
+ ret = *p; \
+ pthread_mutex_unlock(&atomic_sim_lock); \
+ return ret; \
+ }
+IMPL_fallback_atomic_load_n(uint64_t)
+IMPL_fallback_atomic_load_n(pvoid)
+
+# define ATOMIC_LOAD_N(t, p, o) fallback_atomic_load_n_##t(p)
+
+# define IMPL_fallback_atomic_store_n(t) \
+ static inline t fallback_atomic_store_n_##t(t *p, t v) \
+ { \
+ t ret; \
+ \
+ pthread_mutex_lock(&atomic_sim_lock); \
+ ret = *p; \
+ *p = v; \
+ pthread_mutex_unlock(&atomic_sim_lock); \
+ return ret; \
+ }
+IMPL_fallback_atomic_store_n(uint64_t)
-# define ATOMIC_STORE(p, v, o) fallback_atomic_store((void **)p, (void **)v)
+# define ATOMIC_STORE_N(t, p, v, o) fallback_atomic_store_n_##t(p, v)
-static inline void *fallback_atomic_exchange_n(void **p, void *v)
-{
- void *ret;
+# define IMPL_fallback_atomic_store(t) \
+ static inline void fallback_atomic_store_##t(t *p, t *v) \
+ { \
+ pthread_mutex_lock(&atomic_sim_lock); \
+ *p = *v; \
+ pthread_mutex_unlock(&atomic_sim_lock); \
+ }
+IMPL_fallback_atomic_store(uint64_t)
+IMPL_fallback_atomic_store(pvoid)
+
+# define ATOMIC_STORE(t, p, v, o) fallback_atomic_store_##t(p, v)
+
+# define IMPL_fallback_atomic_exchange_n(t) \
+ static inline t fallback_atomic_exchange_n_##t(t *p, t v) \
+ { \
+ t ret; \
+ \
+ pthread_mutex_lock(&atomic_sim_lock); \
+ ret = *p; \
+ *p = v; \
+ pthread_mutex_unlock(&atomic_sim_lock); \
+ return ret; \
+ }
+IMPL_fallback_atomic_exchange_n(uint64_t)
+IMPL_fallback_atomic_exchange_n(prcu_cb_item)
- pthread_mutex_lock(&atomic_sim_lock);
- ret = *p;
- *p = v;
- pthread_mutex_unlock(&atomic_sim_lock);
- return ret;
-}
+# define ATOMIC_EXCHANGE_N(t, p, v, o) fallback_atomic_exchange_n_##t(p, v)
-# define ATOMIC_EXCHANGE_N(p, v, o) fallback_atomic_exchange_n((void **)p, (void *)v)
+/*
+ * The fallbacks that follow don't need any per type implementation, as
+ * they are designed for uint64_t only. If there comes a time when multiple
+ * types need to be covered, it's relatively easy to refactor them the same
+ * way as the fallbacks above.
+ */
static inline uint64_t fallback_atomic_add_fetch(uint64_t *p, uint64_t v)
{
* 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);
+ qp_idx = ATOMIC_LOAD_N(uint64_t, &lock->reader_idx, __ATOMIC_ACQUIRE);
/*
* Notes of use of __ATOMIC_RELEASE
__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))
+ if (qp_idx == ATOMIC_LOAD_N(uint64_t, &lock->reader_idx, __ATOMIC_ACQUIRE))
break;
/*
* of __ATOMIC_ACQUIRE in get_hold_current_qp, as we want 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_STORE_N(uint64_t, &lock->reader_idx, lock->current_alloc_idx,
__ATOMIC_RELEASE);
/* wake up any waiters */
* __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);
+ cb_items = ATOMIC_EXCHANGE_N(prcu_cb_item, &lock->cb_items, NULL,
+ __ATOMIC_ACQ_REL);
qp = update_qp(lock);
* is visible prior to our read
*/
do {
- count = (uint64_t)ATOMIC_LOAD_N(&qp->users, __ATOMIC_ACQUIRE);
+ count = ATOMIC_LOAD_N(uint64_t, &qp->users, __ATOMIC_ACQUIRE);
} while (READER_COUNT(count) != 0);
/* retire in order */
* 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);
+ new->next = ATOMIC_EXCHANGE_N(prcu_cb_item, &lock->cb_items, new,
+ __ATOMIC_ACQ_REL);
return 1;
}
void *ossl_rcu_uptr_deref(void **p)
{
- return (void *)ATOMIC_LOAD_N(p, __ATOMIC_ACQUIRE);
+ return ATOMIC_LOAD_N(pvoid, p, __ATOMIC_ACQUIRE);
}
void ossl_rcu_assign_uptr(void **p, void **v)
{
- ATOMIC_STORE(p, v, __ATOMIC_RELEASE);
+ ATOMIC_STORE(pvoid, p, v, __ATOMIC_RELEASE);
}
static CRYPTO_ONCE rcu_init_once = CRYPTO_ONCE_STATIC_INIT;
projects / openssl.git / commitdiff