From 049ff6c39c73edd3709c05bd0e46184320471358 Mon Sep 17 00:00:00 2001
From: Zhiguang Liu <zhiguang.liu@intel.com>
Date: Fri, 1 Mar 2024 11:01:32 +0800
Subject: StandaloneMmPkg: Support to unregister MMI handler inside MMI handler

To support unregister MMI handler inside MMI handler itself,
get next node before MMI handler is executed, since LIST_ENTRY that
Link points to may be freed if unregister MMI handler in MMI handler
itself.

Cc: Liming Gao <gaoliming@byosoft.com.cn>
Cc: Jiaxin Wu <jiaxin.wu@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Sami Mujawar <sami.mujawar@arm.com>
Signed-off-by: Zhiguang Liu <zhiguang.liu@intel.com>
Message-Id: <20240301030133.628-4-zhiguang.liu@intel.com>
---
 StandaloneMmPkg/Core/Mmi.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/StandaloneMmPkg/Core/Mmi.c b/StandaloneMmPkg/Core/Mmi.c
index 0de6fd17fc..c1a1d76e85 100644
--- a/StandaloneMmPkg/Core/Mmi.c
+++ b/StandaloneMmPkg/Core/Mmi.c
@@ -154,9 +154,14 @@ MmiManage (
     Head = &MmiEntry->MmiHandlers;
   }
 
-  for (Link = Head->ForwardLink; Link != Head; Link = Link->ForwardLink) {
+  for (Link = Head->ForwardLink; Link != Head;) {
     MmiHandler = CR (Link, MMI_HANDLER, Link, MMI_HANDLER_SIGNATURE);
-
+    //
+    // To support unregister MMI handler inside MMI handler itself,
+    // get next node before handler is executed, since LIST_ENTRY that
+    // Link points to may be freed if unregister MMI handler.
+    //
+    Link   = Link->ForwardLink;
     Status = MmiHandler->Handler (
                            (EFI_HANDLE)MmiHandler,
                            Context,
-- 
cgit