From: Maria Matejka <mq@ucw.cz>
Date: Tue, 27 Jan 2026 08:38:36 +0000 (+0100)
Subject: Debug: Allocate pages scattered to help catching out-of-range bugs
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=refs%2Fheads%2Fmq-debug-alloc-scattered;p=thirdparty%2Fbird.git

Debug: Allocate pages scattered to help catching out-of-range bugs
---

diff --git a/sysdep/unix/alloc.c b/sysdep/unix/alloc.c
index fcf855082..61c62b8f6 100644
--- a/sysdep/unix/alloc.c
+++ b/sysdep/unix/alloc.c
@@ -304,7 +304,12 @@ alloc_page(void)
   ajlog(ptr, NULL, 0, AJT_ALLOC_MMAP);
 
   for (int i=1; i<ALLOC_PAGES_AT_ONCE; i++)
-    free_page(ptr + page_size * i);
+#if DEBUGGING
+    if (i & 1)
+      mprotect(ptr + page_size * i, page_size, PROT_NONE);
+    else
+#endif
+      free_page(ptr + page_size * i);
 
   return ptr;
 #endif