Add support for IBM z/OS (#5304)

src/_cffi_src/build_openssl.py

@@ -40,6 +40,9 @@
         # -lpthread required due to usage of pthread an potential
         # existance of a static part containing e.g. pthread_atfork
         # (https://github.com/pyca/cryptography/issues/5084)
+        if sys.platform == 'zos':
+            return ["ssl", "crypto"]
+        else:
             return ["ssl", "crypto", "pthread"]
 
 

src/_cffi_src/openssl/callbacks.py

@@ -20,6 +20,10 @@
 #include <stdlib.h>
 #include <pthread.h>
 #endif
+
+#ifdef __MVS__
+#include <errno.h>
+#endif
 """
 
 TYPES = """
@@ -66,7 +70,19 @@
         perror("Fatal error in callback initialization: " #call);       \
         abort();                                                        \
     }
+#ifdef __MVS__
+/*  When pthread_mutex_init is called more than once on the same mutex,
+    on z/OS this throws an EBUSY error.
+*/
+#define ASSERT_STATUS_INIT(call)                                        \
+    if ((call) != 0 && errno != EBUSY) {                                \
+        perror("Fatal error in callback initialization: " #call);       \
+        abort();                                                        \
+    }
+#else
+#define ASSERT_STATUS_INIT ASSERT_STATUS
+#endif
 static inline void cryptography_mutex_init(Cryptography_mutex *mutex) {
 #if !defined(pthread_mutexattr_default)
 #  define pthread_mutexattr_default ((pthread_mutexattr_t *)NULL)
 #endif
@@ -69,8 +85,8 @@
 static inline void cryptography_mutex_init(Cryptography_mutex *mutex) {
 #if !defined(pthread_mutexattr_default)
 #  define pthread_mutexattr_default ((pthread_mutexattr_t *)NULL)
 #endif
-    ASSERT_STATUS(pthread_mutex_init(mutex, pthread_mutexattr_default));
+    ASSERT_STATUS_INIT(pthread_mutex_init(mutex, pthread_mutexattr_default));
 }
 static inline void cryptography_mutex_lock(Cryptography_mutex *mutex) {
     ASSERT_STATUS(pthread_mutex_lock(mutex));

src/_cffi_src/openssl/src/osrandom_engine.h

@@ -6,4 +6,5 @@
   #include <fcntl.h>
   #include <unistd.h>
    /* for defined(BSD) */
+  #ifndef __MVS__
     #include <sys/param.h>
@@ -9,4 +10,5 @@
     #include <sys/param.h>
+  #endif
 
   #ifdef BSD
     /* for SYS_getentropy */