From 5c3c2a9bacf75831716bbe028f84d9f1cd4dad74 Mon Sep 17 00:00:00 2001
From: Andreas Kling <awesomekling@gmail.com>
Date: Fri, 10 Jan 2020 19:24:01 +0100
Subject: [PATCH] Kernel: Copy Region's "is_mmap" flag when cloning regions for
 fork()

Otherwise child processes will not be allowed to munmap(), madvise(),
etc. on the cloned regions!
---
 Kernel/VM/Region.cpp | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/Kernel/VM/Region.cpp b/Kernel/VM/Region.cpp
index 5a0917d44c..244103a4f2 100644
--- a/Kernel/VM/Region.cpp
+++ b/Kernel/VM/Region.cpp
@@ -65,7 +65,9 @@ NonnullOwnPtr<Region> Region::clone()
             vaddr().get());
 #endif
         // Create a new region backed by the same VMObject.
-        return Region::create_user_accessible(m_range, m_vmobject, m_offset_in_vmobject, m_name, m_access);
+        auto region = Region::create_user_accessible(m_range, m_vmobject, m_offset_in_vmobject, m_name, m_access);
+        region->set_mmap(m_mmap);
+        return region;
     }
 
 #ifdef MM_DEBUG
@@ -87,6 +89,7 @@ NonnullOwnPtr<Region> Region::clone()
         ASSERT(vmobject().is_anonymous());
         clone_region->set_stack(true);
     }
+    clone_region->set_mmap(m_mmap);
     return clone_region;
 }