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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");
#if defined(__GNUC__) || defined(__clang__)
OPENSSL_STATIC_ASSERT(alignof(CRYPTO_MUTEX) >= alignof(pthread_rwlock_t),
"CRYPTO_MUTEX has insufficient alignment");
#endif
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