From 8997ce47bda0a667ee41e49bdb2131bdedd9ef25 Mon Sep 17 00:00:00 2001
From: Otto Moerbeek <otto.moerbeek@open-xchange.com>
Date: Tue, 28 Mar 2023 14:00:03 +0200
Subject: [PATCH] Unbreak FreeBSD mthread stack allocation

On FreeBSD, MAP_STACK has a completely different meaning compared to
OpenBSD. So only use MAP_STACK on OpenBSD.
---
 pdns/recursordist/lazy_allocator.hh | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/pdns/recursordist/lazy_allocator.hh b/pdns/recursordist/lazy_allocator.hh
index 720fd4f5ee..39665b6ad2 100644
--- a/pdns/recursordist/lazy_allocator.hh
+++ b/pdns/recursordist/lazy_allocator.hh
@@ -28,8 +28,10 @@
 #include <unistd.h>
 
 // On OpenBSD mem used as stack should be marked MAP_STACK
-#if !defined(MAP_STACK)
-#define MAP_STACK 0
+#ifdef __OpenBSD__
+#define PDNS_MAP_STACK MAP_STACK
+#else
+#define PDNS_MAP_STACK 0
 #endif
 
 template <typename T>
@@ -88,7 +90,7 @@ struct lazy_allocator
 #else
     const int protection = PROT_NONE;
 #endif
-    void* p = mmap(nullptr, allocatedSize, protection, MAP_PRIVATE | MAP_ANON | MAP_STACK, -1, 0);
+    void* p = mmap(nullptr, allocatedSize, protection, MAP_PRIVATE | MAP_ANON | PDNS_MAP_STACK, -1, 0);
     if (p == MAP_FAILED) {
       throw std::bad_alloc();
     }
-- 
2.47.2