From fa69b3d0d1e05cf391ec56c6c81043da61c3c3da Mon Sep 17 00:00:00 2001
From: "Hui, Chunyang" <sanqian.hcy@antfin.com>
Date: Thu, 21 Oct 2021 09:32:13 +0000
Subject: [PATCH] Try reduce vma count on host to prevent panic because of too
 much mprotect

---
 src/libos/src/vm/vm_manager.rs | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/libos/src/vm/vm_manager.rs b/src/libos/src/vm/vm_manager.rs
index 42d138c8..ecaca4b3 100644
--- a/src/libos/src/vm/vm_manager.rs
+++ b/src/libos/src/vm/vm_manager.rs
@@ -783,6 +783,9 @@ impl InternalVMManager {
         // Remove from chunks
         self.chunks.remove(chunk);
 
+        // Mprotect the whole chunk to reduce the usage of vma count of host
+        VMPerms::apply_perms(range, VMPerms::DEFAULT);
+
         // Add range back to freespace manager
         self.free_manager.add_range_back_to_free_manager(range);
         Ok(())