Our swap is encrypted by default
(synced with gnupg/patches/patch-util_secmem_c)

Index: src/secmem.c
--- src/secmem.c.orig
+++ src/secmem.c
@@ -36,6 +36,8 @@
 #include <sys/capability.h>
 #endif
 #endif
+#include <sys/sysctl.h>
+#include <uvm/uvm_swap_encrypt.h>
 
 #include "g10lib.h"
 #include "secmem.h"
@@ -279,8 +281,24 @@ mb_get_new (pooldesc_t *pool, memblock_t *block, size_
 static void
 print_warn (void)
 {
-  if (!no_warning)
-    log_info (_("Warning: using insecure memory!\n"));
+	int    mib[3], swapencrypt = 0;
+	size_t len;
+
+	mib[0] = CTL_VM;
+	mib[1] = VM_SWAPENCRYPT;
+	mib[2] = SWPENC_ENABLE;
+
+	len = sizeof(swapencrypt);
+
+	if (sysctl(mib, 3, &swapencrypt, &len, NULL, 0) == -1)
+		log_info("WARNING: Can't receive vm.swapencrypt.enable sysctl value\n");
+
+	if (!no_warning && !swapencrypt)
+	{
+		log_info("WARNING: Using insecure memory!\n");
+		log_info("Please enable swap encryption via"
+			 " 'sysctl vm.swapencrypt.enable=1'.\n");
+	}
 }