path: root/crypto/threads_pthread.c

/*
 * Copyright 2016-2022 The OpenSSL Project Authors. All Rights Reserved.
 *
 * Licensed under the Apache License 2.0 (the "License").  You may not use
 * this file except in compliance with the License.  You can obtain a copy
 * in the file LICENSE in the source distribution or at
 * https://www.openssl.org/source/license.html
 */

/* We need to use the OPENSSL_fork_*() deprecated APIs */
#define OPENSSL_SUPPRESS_DEPRECATED

#include <openssl/crypto.h>
#include "internal/cryptlib.h"

#if defined(__sun)
# include <atomic.h>
#endif

#if defined(__apple_build_version__) && __apple_build_version__ < 6000000
/*
 * OS/X 10.7 and 10.8 had a weird version of clang which has __ATOMIC_ACQUIRE and
 * __ATOMIC_ACQ_REL but which expects only one parameter for __atomic_is_lock_free()
 * rather than two which has signature __atomic_is_lock_free(sizeof(_Atomic(T))).
 * All of this makes impossible to use __atomic_is_lock_free here.
 *
 * See: https://github.com/llvm/llvm-project/commit/a4c2602b714e6c6edb98164550a5ae829b2de760
 */
#define BROKEN_CLANG_ATOMICS
#endif

#if defined(OPENSSL_THREADS) && !defined(CRYPTO_TDEBUG) && !defined(OPENSSL_SYS_WINDOWS)

# if defined(OPENSSL_SYS_UNIX)
#  include <sys/types.h>
#  include <unistd.h>
#endif

# include <assert.h>

# ifdef PTHREAD_RWLOCK_INITIALIZER
#  define USE_RWLOCK
# endif

CRYPTO_RWLOCK *CRYPTO_THREAD_lock_new(void)
{
# ifdef USE_RWLOCK
    CRYPTO_RWLOCK *lock;

    if ((lock = CRYPTO_zalloc(sizeof(pthread_rwlock_t), NULL, 0)) == NULL)
        /* Don't set error, to avoid recursion blowup. */
        return NULL;

    if (pthread_rwlock_init(lock, NULL) != 0) {
        OPENSSL_free(lock);
        return NULL;
    }
# else
    pthread_mutexattr_t attr;
    CRYPTO_RWLOCK *lock;

    if ((lock = CRYPTO_zalloc(sizeof(pthread_mutex_t), NULL, 0)) == NULL)
        /* Don't set error, to avoid recursion blowup. */
        return NULL;

    /*
     * We don't use recursive mutexes, but try to catch errors if we do.
     */
    pthread_mutexattr_init(&attr);
#  if !defined (__TANDEM) && !defined (_SPT_MODEL_)
#   if !defined(NDEBUG) && !defined(OPENSSL_NO_MUTEX_ERRORCHECK)
    pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_ERRORCHECK);
#   else
    pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_NORMAL);
#   endif
#  else
    /* The SPT Thread Library does not define MUTEX attributes. */
#  endif

    if (pthread_mutex_init(lock, &attr) != 0) {
        pthread_mutexattr_destroy(&attr);
        OPENSSL_free(lock);
        return NULL;
    }

    pthread_mutexattr_destroy(&attr);
# endif

    return lock;
}

__owur int CRYPTO_THREAD_read_lock(CRYPTO_RWLOCK *lock)
{
# ifdef USE_RWLOCK
    if (pthread_rwlock_rdlock(lock) != 0)
        return 0;
# else
    if (pthread_mutex_lock(lock) != 0) {
        assert(errno != EDEADLK && errno != EBUSY);
        return 0;
    }
# endif

    return 1;
}

__owur int CRYPTO_THREAD_write_lock(CRYPTO_RWLOCK *lock)
{
# ifdef USE_RWLOCK
    if (pthread_rwlock_wrlock(lock) != 0)
        return 0;
# else
    if (pthread_mutex_lock(lock) != 0) {
        assert(errno != EDEADLK && errno != EBUSY);
        return 0;
    }
# endif

    return 1;
}

int CRYPTO_THREAD_unlock(CRYPTO_RWLOCK *lock)
{
# ifdef USE_RWLOCK
    if (pthread_rwlock_unlock(lock) != 0)
        return 0;
# else
    if (pthread_mutex_unlock(lock) != 0) {
        assert(errno != EPERM);
        return 0;
    }
# endif

    return 1;
}

void CRYPTO_THREAD_lock_free(CRYPTO_RWLOCK *lock)
{
    if (lock == NULL)
        return;

# ifdef USE_RWLOCK
    pthread_rwlock_destroy(lock);
# else
    pthread_mutex_destroy(lock);
# endif
    OPENSSL_free(lock);

    return;
}

int CRYPTO_THREAD_run_once(CRYPTO_ONCE *once, void (*init)(void))
{
    if (pthread_once(once, init) != 0)
        return 0;

    return 1;
}

int CRYPTO_THREAD_init_local(CRYPTO_THREAD_LOCAL *key, void (*cleanup)(void *))
{
    if (pthread_key_create(key, cleanup) != 0)
        return 0;

    return 1;
}

void *CRYPTO_THREAD_get_local(CRYPTO_THREAD_LOCAL *key)
{
    return pthread_getspecific(*key);
}

int CRYPTO_THREAD_set_local(CRYPTO_THREAD_LOCAL *key, void *val)
{
    if (pthread_setspecific(*key, val) != 0)
        return 0;

    return 1;
}

int CRYPTO_THREAD_cleanup_local(CRYPTO_THREAD_LOCAL *key)
{
    if (pthread_key_delete(*key) != 0)
        return 0;

    return 1;
}

CRYPTO_THREAD_ID CRYPTO_THREAD_get_current_id(void)
{
    return pthread_self();
}

int CRYPTO_THREAD_compare_id(CRYPTO_THREAD_ID a, CRYPTO_THREAD_ID b)
{
    return pthread_equal(a, b);
}

int CRYPTO_atomic_add(int *val, int amount, int *ret, CRYPTO_RWLOCK *lock)
{
# if defined(__GNUC__) && defined(__ATOMIC_ACQ_REL) && !defined(BROKEN_CLANG_ATOMICS)
    if (__atomic_is_lock_free(sizeof(*val), val)) {
        *ret = __atomic_add_fetch(val, amount, __ATOMIC_ACQ_REL);
        return 1;
    }
# elif defined(__sun) && (defined(__SunOS_5_10) || defined(__SunOS_5_11))
    /* This will work for all future Solaris versions. */
    if (ret != NULL) {
        *ret = atomic_add_int_nv((volatile unsigned int *)val, amount);
        return 1;
    }
# endif
    if (lock == NULL || !CRYPTO_THREAD_write_lock(lock))
        return 0;

    *val += amount;
    *ret  = *val;

    if (!CRYPTO_THREAD_unlock(lock))
        return 0;

    return 1;
}

int CRYPTO_atomic_or(uint64_t *val, uint64_t op, uint64_t *ret,
                     CRYPTO_RWLOCK *lock)
{
# if defined(__GNUC__) && defined(__ATOMIC_ACQ_REL) && !defined(BROKEN_CLANG_ATOMICS)
    if (__atomic_is_lock_free(sizeof(*val), val)) {
        *ret = __atomic_or_fetch(val, op, __ATOMIC_ACQ_REL);
        return 1;
    }
# elif defined(__sun) && (defined(__SunOS_5_10) || defined(__SunOS_5_11))
    /* This will work for all future Solaris versions. */
    if (ret != NULL) {
        *ret = atomic_or_64_nv(val, op);
        return 1;
    }
# endif
    if (lock == NULL || !CRYPTO_THREAD_write_lock(lock))
        return 0;
    *val |= op;
    *ret  = *val;

    if (!CRYPTO_THREAD_unlock(lock))
        return 0;

    return 1;
}

int CRYPTO_atomic_load(uint64_t *val, uint64_t *ret, CRYPTO_RWLOCK *lock)
{
# if defined(__GNUC__) && defined(__ATOMIC_ACQUIRE) && !defined(BROKEN_CLANG_ATOMICS)
    if (__atomic_is_lock_free(sizeof(*val), val)) {
        __atomic_load(val, ret, __ATOMIC_ACQUIRE);
        return 1;
    }
# elif defined(__sun) && (defined(__SunOS_5_10) || defined(__SunOS_5_11))
    /* This will work for all future Solaris versions. */
    if (ret != NULL) {
        *ret = atomic_or_64_nv(val, 0);
        return 1;
    }
# endif
    if (lock == NULL || !CRYPTO_THREAD_read_lock(lock))
        return 0;
    *ret  = *val;
    if (!CRYPTO_THREAD_unlock(lock))
        return 0;

    return 1;
}
# ifndef FIPS_MODULE
int openssl_init_fork_handlers(void)
{
    return 1;
}
# endif /* FIPS_MODULE */

int openssl_get_fork_id(void)
{
    return getpid();
}
#endif