From 4b9fdc2bce07fa4334ef9f6119b7ef9b279e278e Mon Sep 17 00:00:00 2001
From: Alan Cox <alc@FreeBSD.org>
Date: Sun, 26 May 2002 04:54:56 +0000
Subject: [PATCH]  o Acquire and release Giant around pmap operations in
 vm_fault_unwire()    and vm_map_delete().  Assert GIANT_REQUIRED in
 vm_map_delete()    only if operating on the kernel_object or the kmem_object.
  o Remove GIANT_REQUIRED from vm_map_remove().  o Remove the acquisition and
 release of Giant from munmap().

---
 sys/vm/vm_fault.c | 3 ++-
 sys/vm/vm_map.c   | 7 +++----
 sys/vm/vm_mmap.c  | 2 --
 3 files changed, 5 insertions(+), 7 deletions(-)

diff --git a/sys/vm/vm_fault.c b/sys/vm/vm_fault.c
index 9cfe1cee4bb6..3e0edeb17417 100644
--- a/sys/vm/vm_fault.c
+++ b/sys/vm/vm_fault.c
@@ -979,12 +979,12 @@ vm_fault_unwire(map, start, end)
 	vm_map_t map;
 	vm_offset_t start, end;
 {
-
 	vm_offset_t va, pa;
 	pmap_t pmap;
 
 	pmap = vm_map_pmap(map);
 
+	mtx_lock(&Giant);
 	/*
 	 * Since the pages are wired down, we must be able to get their
 	 * mappings from the physical map system.
@@ -1003,6 +1003,7 @@ vm_fault_unwire(map, start, end)
 	 */
 	pmap_pageable(pmap, start, end, TRUE);
 
+	mtx_unlock(&Giant);
 }
 
 /*
diff --git a/sys/vm/vm_map.c b/sys/vm/vm_map.c
index a746d46317eb..983b3b1801f9 100644
--- a/sys/vm/vm_map.c
+++ b/sys/vm/vm_map.c
@@ -2041,8 +2041,6 @@ vm_map_delete(vm_map_t map, vm_offset_t start, vm_offset_t end)
 	vm_map_entry_t entry;
 	vm_map_entry_t first_entry;
 
-	GIANT_REQUIRED;
-
 	/*
 	 * Find the start of the region, and clip it
 	 */
@@ -2091,8 +2089,10 @@ vm_map_delete(vm_map_t map, vm_offset_t start, vm_offset_t end)
 		offidxend = offidxstart + count;
 
 		if ((object == kernel_object) || (object == kmem_object)) {
+			GIANT_REQUIRED;
 			vm_object_page_remove(object, offidxstart, offidxend, FALSE);
 		} else {
+			mtx_lock(&Giant);
 			pmap_remove(map->pmap, s, e);
 			if (object != NULL &&
 			    object->ref_count != 1 &&
@@ -2108,6 +2108,7 @@ vm_map_delete(vm_map_t map, vm_offset_t start, vm_offset_t end)
 					object->size = offidxstart;
 				}
 			}
+			mtx_unlock(&Giant);
 		}
 
 		/*
@@ -2133,8 +2134,6 @@ vm_map_remove(vm_map_t map, vm_offset_t start, vm_offset_t end)
 {
 	int result, s = 0;
 
-	GIANT_REQUIRED;
-
 	if (map == kmem_map)
 		s = splvm();
 
diff --git a/sys/vm/vm_mmap.c b/sys/vm/vm_mmap.c
index 750ab07f7e27..c0033536212a 100644
--- a/sys/vm/vm_mmap.c
+++ b/sys/vm/vm_mmap.c
@@ -615,9 +615,7 @@ munmap(td, uap)
 		return (EINVAL);
 
 	/* returns nothing but KERN_SUCCESS anyway */
-	mtx_lock(&Giant);
 	(void) vm_map_remove(map, addr, addr + size);
-	mtx_unlock(&Giant);
 	return (0);
 }