diff -Nupr open-iscsi-2.0.875~/include/iscsi_err.h open-iscsi-2.0.875/include/iscsi_err.h
--- open-iscsi-2.0.875~/include/iscsi_err.h	2017-09-01 20:05:23.000000000 +0200
+++ open-iscsi-2.0.875/include/iscsi_err.h	2021-01-14 17:17:39.934997544 +0100
@@ -4,7 +4,7 @@
 #ifndef _ISCSI_ERR_
 #define _ISCSI_ERR_
 
-enum {
+enum iscsi_error_list {
 	ISCSI_SUCCESS			= 0,
 	/* Generic error */
 	ISCSI_ERR			= 1,
@@ -71,7 +71,9 @@ enum {
 
 	/* Always last. Indicates end of error code space */
 	ISCSI_MAX_ERR_VAL,
-} iscsi_err;
+};
+
+extern enum iscsi_error_list iscsi_err;
 
 extern void iscsi_err_print_msg(int err);
 extern char *iscsi_err_to_str(int err);
diff -Nupr open-iscsi-2.0.875~/include/iscsi_if.h open-iscsi-2.0.875/include/iscsi_if.h
--- open-iscsi-2.0.875~/include/iscsi_if.h	2017-09-01 20:05:23.000000000 +0200
+++ open-iscsi-2.0.875/include/iscsi_if.h	2021-01-14 17:17:39.934997544 +0100
@@ -341,7 +341,7 @@ struct iscsi_iface_param_info {
 	uint8_t iface_type;	/* IPv4 or IPv6 */
 	uint8_t param_type;	/* iscsi_param_type */
 	uint8_t value[0];	/* length sized value follows */
-} __packed;
+} __attribute__((__packed__));
 
 /*
  * To keep the struct iscsi_uevent size the same for userspace code
diff -Nupr open-iscsi-2.0.875~/iscsiuio/configure.ac open-iscsi-2.0.875/iscsiuio/configure.ac
--- open-iscsi-2.0.875~/iscsiuio/configure.ac	2017-09-01 20:05:23.000000000 +0200
+++ open-iscsi-2.0.875/iscsiuio/configure.ac	2021-01-14 17:17:39.936330877 +0100
@@ -70,7 +70,7 @@ AC_CONFIG_COMMANDS([default],[[
     else
         echo 'char *build_date = "'`date`'";' > src/unix/build_date.c
     fi
-    echo 'char *build_date;'> src/unix/build_date.h
+    echo 'extern char *build_date;'> src/unix/build_date.h
 ]],[[]])
 
 AC_PREFIX_DEFAULT()
diff -Nupr open-iscsi-2.0.875~/iscsiuio/src/uip/uip.h open-iscsi-2.0.875/iscsiuio/src/uip/uip.h
--- open-iscsi-2.0.875~/iscsiuio/src/uip/uip.h	2017-09-01 20:05:23.000000000 +0200
+++ open-iscsi-2.0.875/iscsiuio/src/uip/uip.h	2021-01-14 17:17:39.936330877 +0100
@@ -70,8 +70,8 @@ struct uip_stack;
 typedef u16_t uip_ip4addr_t[2];
 typedef u16_t uip_ip6addr_t[8];
 
-const uip_ip6addr_t all_zeroes_addr6;
-const uip_ip4addr_t all_zeroes_addr4;
+extern const uip_ip6addr_t all_zeroes_addr6;
+extern const uip_ip4addr_t all_zeroes_addr4;
 
 #define ETH_BUF(buf) ((struct uip_eth_hdr *)buf)
 #define VLAN_ETH_BUF(buf) ((struct uip_vlan_eth_hdr *)buf)
diff -Nupr open-iscsi-2.0.875~/usr/log.c open-iscsi-2.0.875/usr/log.c
--- open-iscsi-2.0.875~/usr/log.c	2017-09-01 20:05:23.000000000 +0200
+++ open-iscsi-2.0.875/usr/log.c	2021-01-14 17:17:39.934997544 +0100
@@ -33,6 +33,7 @@
 
 char *log_name;
 int log_level = 0;
+struct logarea *la = NULL;
 
 static int log_stop_daemon = 0;
 static void (*log_func)(int prio, void *priv, const char *fmt, va_list ap);
diff -Nupr open-iscsi-2.0.875~/usr/log.h open-iscsi-2.0.875/usr/log.h
--- open-iscsi-2.0.875~/usr/log.h	2017-09-01 20:05:23.000000000 +0200
+++ open-iscsi-2.0.875/usr/log.h	2021-01-14 17:17:39.936330877 +0100
@@ -64,7 +64,7 @@ struct logarea {
 	union semun semarg;
 };
 
-struct logarea *la;
+extern struct logarea *la;
 
 extern int log_init(char *program_name, int size,
 	void (*func)(int prio, void *priv, const char *fmt, va_list ap),