Fix seeding from random device w/o getrandom syscall
[openssl.git] / crypto / threads_pthread.c
index 9f4ae76..5a59779 100644 (file)
@@ -1,5 +1,5 @@
 /*
- * Copyright 2016 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 2016-2018 The OpenSSL Project Authors. All Rights Reserved.
  *
  * Licensed under the OpenSSL license (the "License").  You may not use
  * this file except in compliance with the License.  You can obtain a copy
@@ -8,43 +8,87 @@
  */
 
 #include <openssl/crypto.h>
+#include "internal/cryptlib.h"
 
 #if defined(OPENSSL_THREADS) && !defined(CRYPTO_TDEBUG) && !defined(OPENSSL_SYS_WINDOWS)
 
+# ifdef PTHREAD_RWLOCK_INITIALIZER
+#  define USE_RWLOCK
+# endif
+
 CRYPTO_RWLOCK *CRYPTO_THREAD_lock_new(void)
 {
-    CRYPTO_RWLOCK *lock = OPENSSL_zalloc(sizeof(pthread_rwlock_t));
-    if (lock == NULL)
+# ifdef USE_RWLOCK
+    CRYPTO_RWLOCK *lock;
+
+    if ((lock = OPENSSL_zalloc(sizeof(pthread_rwlock_t))) == 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 = OPENSSL_zalloc(sizeof(pthread_mutex_t))) == NULL) {
+        /* Don't set error, to avoid recursion blowup. */
+        return NULL;
+    }
+
+    pthread_mutexattr_init(&attr);
+    pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
+
+    if (pthread_mutex_init(lock, &attr) != 0) {
+        pthread_mutexattr_destroy(&attr);
+        OPENSSL_free(lock);
+        return NULL;
+    }
+
+    pthread_mutexattr_destroy(&attr);
+# endif
 
     return lock;
 }
 
 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)
+        return 0;
+# endif
 
     return 1;
 }
 
 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)
+        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)
+        return 0;
+# endif
 
     return 1;
 }
@@ -54,7 +98,11 @@ 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;
@@ -110,8 +158,11 @@ int CRYPTO_THREAD_compare_id(CRYPTO_THREAD_ID a, CRYPTO_THREAD_ID b)
 int CRYPTO_atomic_add(int *val, int amount, int *ret, CRYPTO_RWLOCK *lock)
 {
 # if defined(__GNUC__) && defined(__ATOMIC_ACQ_REL)
-    *ret = __atomic_add_fetch(val, amount, __ATOMIC_ACQ_REL);
-# else
+    if (__atomic_is_lock_free(sizeof(*val), val)) {
+        *ret = __atomic_add_fetch(val, amount, __ATOMIC_ACQ_REL);
+        return 1;
+    }
+# endif
     if (!CRYPTO_THREAD_write_lock(lock))
         return 0;
 
@@ -120,9 +171,26 @@ int CRYPTO_atomic_add(int *val, int amount, int *ret, CRYPTO_RWLOCK *lock)
 
     if (!CRYPTO_THREAD_unlock(lock))
         return 0;
-# endif
 
     return 1;
 }
 
+# ifdef OPENSSL_SYS_UNIX
+static pthread_once_t fork_once_control = PTHREAD_ONCE_INIT;
+
+static void fork_once_func(void)
+{
+    pthread_atfork(OPENSSL_fork_prepare,
+                   OPENSSL_fork_parent, OPENSSL_fork_child);
+}
+# endif
+
+int openssl_init_fork_handlers(void)
+{
+# ifdef OPENSSL_SYS_UNIX
+    if (pthread_once(&fork_once_control, fork_once_func) == 0)
+        return 1;
+# endif
+    return 0;
+}
 #endif