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- /* Copyright (c) 2015, Google Inc.
- *
- * Permission to use, copy, modify, and/or distribute this software for any
- * purpose with or without fee is hereby granted, provided that the above
- * copyright notice and this permission notice appear in all copies.
- *
- * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
- * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
- * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
- * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
- * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
- * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
-
- #include "internal.h"
-
- #if defined(OPENSSL_PTHREADS)
-
- #include <pthread.h>
- #include <stdlib.h>
- #include <string.h>
-
- #include <openssl/mem.h>
- #include <openssl/type_check.h>
-
-
- OPENSSL_STATIC_ASSERT(sizeof(CRYPTO_MUTEX) >= sizeof(pthread_rwlock_t),
- "CRYPTO_MUTEX is too small");
-
- void CRYPTO_MUTEX_init(CRYPTO_MUTEX *lock) {
- if (pthread_rwlock_init((pthread_rwlock_t *) lock, NULL) != 0) {
- abort();
- }
- }
-
- void CRYPTO_MUTEX_lock_read(CRYPTO_MUTEX *lock) {
- if (pthread_rwlock_rdlock((pthread_rwlock_t *) lock) != 0) {
- abort();
- }
- }
-
- void CRYPTO_MUTEX_lock_write(CRYPTO_MUTEX *lock) {
- if (pthread_rwlock_wrlock((pthread_rwlock_t *) lock) != 0) {
- abort();
- }
- }
-
- void CRYPTO_MUTEX_unlock_read(CRYPTO_MUTEX *lock) {
- if (pthread_rwlock_unlock((pthread_rwlock_t *) lock) != 0) {
- abort();
- }
- }
-
- void CRYPTO_MUTEX_unlock_write(CRYPTO_MUTEX *lock) {
- if (pthread_rwlock_unlock((pthread_rwlock_t *) lock) != 0) {
- abort();
- }
- }
-
- void CRYPTO_MUTEX_cleanup(CRYPTO_MUTEX *lock) {
- pthread_rwlock_destroy((pthread_rwlock_t *) lock);
- }
-
- void CRYPTO_STATIC_MUTEX_lock_read(struct CRYPTO_STATIC_MUTEX *lock) {
- if (pthread_rwlock_rdlock(&lock->lock) != 0) {
- abort();
- }
- }
-
- void CRYPTO_STATIC_MUTEX_lock_write(struct CRYPTO_STATIC_MUTEX *lock) {
- if (pthread_rwlock_wrlock(&lock->lock) != 0) {
- abort();
- }
- }
-
- void CRYPTO_STATIC_MUTEX_unlock_read(struct CRYPTO_STATIC_MUTEX *lock) {
- if (pthread_rwlock_unlock(&lock->lock) != 0) {
- abort();
- }
- }
-
- void CRYPTO_STATIC_MUTEX_unlock_write(struct CRYPTO_STATIC_MUTEX *lock) {
- if (pthread_rwlock_unlock(&lock->lock) != 0) {
- abort();
- }
- }
-
- void CRYPTO_once(CRYPTO_once_t *once, void (*init)(void)) {
- if (pthread_once(once, init) != 0) {
- abort();
- }
- }
-
- static pthread_mutex_t g_destructors_lock = PTHREAD_MUTEX_INITIALIZER;
- static thread_local_destructor_t g_destructors[NUM_OPENSSL_THREAD_LOCALS];
-
- // thread_local_destructor is called when a thread exits. It releases thread
- // local data for that thread only.
- static void thread_local_destructor(void *arg) {
- if (arg == NULL) {
- return;
- }
-
- thread_local_destructor_t destructors[NUM_OPENSSL_THREAD_LOCALS];
- if (pthread_mutex_lock(&g_destructors_lock) != 0) {
- return;
- }
- OPENSSL_memcpy(destructors, g_destructors, sizeof(destructors));
- pthread_mutex_unlock(&g_destructors_lock);
-
- unsigned i;
- void **pointers = arg;
- for (i = 0; i < NUM_OPENSSL_THREAD_LOCALS; i++) {
- if (destructors[i] != NULL) {
- destructors[i](pointers[i]);
- }
- }
-
- OPENSSL_free(pointers);
- }
-
- static pthread_once_t g_thread_local_init_once = PTHREAD_ONCE_INIT;
- static pthread_key_t g_thread_local_key;
- static int g_thread_local_key_created = 0;
-
- // OPENSSL_DANGEROUS_RELEASE_PTHREAD_KEY can be defined to cause
- // |pthread_key_delete| to be called in a destructor function. This can be
- // useful for programs that dlclose BoringSSL.
- //
- // Note that dlclose()ing BoringSSL is not supported and will leak memory:
- // thread-local values will be leaked as well as anything initialised via a
- // once. The |pthread_key_t| is destroyed because they run out very quickly,
- // while the other leaks are slow, and this allows code that happens to use
- // dlclose() despite all the problems to continue functioning.
- //
- // This is marked "dangerous" because it can cause multi-threaded processes to
- // crash (even if they don't use dlclose): if the destructor runs while other
- // threads are still executing then they may end up using an invalid key to
- // access thread-local variables.
- //
- // This may be removed after February 2020.
- #if defined(OPENSSL_DANGEROUS_RELEASE_PTHREAD_KEY) && \
- (defined(__GNUC__) || defined(__clang__))
- // thread_key_destructor is called when the library is unloaded with dlclose.
- static void thread_key_destructor(void) __attribute__((destructor, unused));
- static void thread_key_destructor(void) {
- if (g_thread_local_key_created) {
- g_thread_local_key_created = 0;
- pthread_key_delete(g_thread_local_key);
- }
- }
- #endif
-
- static void thread_local_init(void) {
- g_thread_local_key_created =
- pthread_key_create(&g_thread_local_key, thread_local_destructor) == 0;
- }
-
- void *CRYPTO_get_thread_local(thread_local_data_t index) {
- CRYPTO_once(&g_thread_local_init_once, thread_local_init);
- if (!g_thread_local_key_created) {
- return NULL;
- }
-
- void **pointers = pthread_getspecific(g_thread_local_key);
- if (pointers == NULL) {
- return NULL;
- }
- return pointers[index];
- }
-
- int CRYPTO_set_thread_local(thread_local_data_t index, void *value,
- thread_local_destructor_t destructor) {
- CRYPTO_once(&g_thread_local_init_once, thread_local_init);
- if (!g_thread_local_key_created) {
- destructor(value);
- return 0;
- }
-
- void **pointers = pthread_getspecific(g_thread_local_key);
- if (pointers == NULL) {
- pointers = OPENSSL_malloc(sizeof(void *) * NUM_OPENSSL_THREAD_LOCALS);
- if (pointers == NULL) {
- destructor(value);
- return 0;
- }
- OPENSSL_memset(pointers, 0, sizeof(void *) * NUM_OPENSSL_THREAD_LOCALS);
- if (pthread_setspecific(g_thread_local_key, pointers) != 0) {
- OPENSSL_free(pointers);
- destructor(value);
- return 0;
- }
- }
-
- if (pthread_mutex_lock(&g_destructors_lock) != 0) {
- destructor(value);
- return 0;
- }
- g_destructors[index] = destructor;
- pthread_mutex_unlock(&g_destructors_lock);
-
- pointers[index] = value;
- return 1;
- }
-
- #endif // OPENSSL_PTHREADS
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