From 0eea1cf72fde6668c1addc8e9e685083db9cf3d6 Mon Sep 17 00:00:00 2001
From: "Randall S. Becker" <randall.becker@nexbridge.ca>
Date: Tue, 7 Oct 2025 00:02:42 +0100
Subject: [PATCH] Fixes for NonStop builds on 3.5 to handle OS platform header
 file changes.

This changes handles the introduction of _POSIX_VERSION into the NonStop x86
header files that tricks OpenSSL into thinking that ucontext.h is available.

Fixes #28498

Signed-off-by: Randall S. Becker <randall.becker@nexbridge.ca>
---
 Configurations/50-nonstop.conf  |  2 ++
 NOTES-NONSTOP.md                | 12 ++++++++++--
 crypto/async/arch/async_posix.h |  9 +++++++--
 3 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/Configurations/50-nonstop.conf b/Configurations/50-nonstop.conf
index a68f200856..24ab6009fc 100644
--- a/Configurations/50-nonstop.conf
+++ b/Configurations/50-nonstop.conf
@@ -168,6 +168,7 @@
     # Build models
     'nonstop-model-put' => {
         template         => 1,
+        disable          => ['secure-memory'],
         defines          => ['_PUT_MODEL_',
                              '_REENTRANT', '_THREAD_SUPPORT_FUNCTIONS'],
         ex_libs          => '-lput',
@@ -177,6 +178,7 @@
     # Build models
     'nonstop-model-klt' => {
         template         => 1,
+        disable          => ['secure-memory'],
         defines          => ['_KLT_MODEL_',
                              '_REENTRANT', '_THREAD_SUPPORT_FUNCTIONS'],
         ex_libs          => '-lklt',
diff --git a/NOTES-NONSTOP.md b/NOTES-NONSTOP.md
index 30deed20b8..a2d485132d 100644
--- a/NOTES-NONSTOP.md
+++ b/NOTES-NONSTOP.md
@@ -37,8 +37,7 @@ for each on the TNS/X (L-Series) platform:
 The KLT threading model is a newly released model on NonStop. It implements
 kernel-level threading. KLT provides much closer threading to what OpenSSL
 uses for Linux-like threading models. KLT continues to use the pthread library
-API. There is no supported 32-bit or Guardian builds for KLT. Note: KLT is
-not currently available but is planned for post-2024.
+API. There is no supported 32-bit or Guardian builds for KLT.
 
 The SPT threading model is no longer supported as of OpenSSL 3.2.
 
@@ -53,6 +52,9 @@ instead of `nsx` in the set above.
 You cannot build for TNS/E for FIPS, so you must specify the `no-fips`
 option to `./Configure`.
 
+TNS/E has moved to a limited support state, so fixes for this platform will not
+be guaranteed in future.
+
 Linking and Loading Considerations
 ----------------------------------
 
@@ -73,6 +75,12 @@ for NonStop builds. If you need to have `atexit()` functionality, set
 register `OPENSSL_cleanup()` automatically. Preferably, you can explicitly call
 `OPENSSL_cleanup()` from your application.
 
+Secure Memory
+-------------
+
+The mechanism used by OpenSSL for secure memory is not supported on NonStop.
+Use the `no-secure-memory` option when running `Configure`.
+
 About Prefix and OpenSSLDir
 ---------------------------
 
diff --git a/crypto/async/arch/async_posix.h b/crypto/async/arch/async_posix.h
index ceb86e24bf..6dec71d6ec 100644
--- a/crypto/async/arch/async_posix.h
+++ b/crypto/async/arch/async_posix.h
@@ -13,7 +13,8 @@
 
 #if defined(OPENSSL_SYS_UNIX) \
     && defined(OPENSSL_THREADS) && !defined(OPENSSL_NO_ASYNC) \
-    && !defined(__ANDROID__) && !defined(__OpenBSD__)
+    && !defined(__ANDROID__) && !defined(__OpenBSD__) \
+    && !defined(OPENSSL_SYS_TANDEM)
 
 # include <unistd.h>
 
@@ -48,7 +49,11 @@
  */
 #   define USE_SWAPCONTEXT
 #  endif
-#  include <ucontext.h>
+#  if defined (OPENSSL_SYS_TANDEM)
+#   include <tdmsig.h>
+#  else
+#   include <ucontext.h>
+#  endif
 #  ifndef USE_SWAPCONTEXT
 #   include <setjmp.h>
 #  endif