From e7bbea38d981582adb68f002d1abf784b0ea7047 Mon Sep 17 00:00:00 2001
From: alc <alc@FreeBSD.org>
Date: Sun, 12 May 2002 05:22:56 +0000
Subject:  o Acquire and release Giant in vm_object_reference() and   
 vm_object_deallocate(), replacing the assertion GIANT_REQUIRED.  o Remove
 GIANT_REQUIRED from vm_map_protect() and vm_map_simplify_entry().  o Acquire
 and release Giant around vm_map_protect()'s call to pmap_protect().

Altogether, these changes eliminate the need for mprotect() to acquire
and release Giant.
---
 sys/vm/vm_map.c    |  5 ++---
 sys/vm/vm_object.c | 15 +++++++--------
 2 files changed, 9 insertions(+), 11 deletions(-)

(limited to 'sys')

diff --git a/sys/vm/vm_map.c b/sys/vm/vm_map.c
index 5cb8f98..fb690e9 100644
--- a/sys/vm/vm_map.c
+++ b/sys/vm/vm_map.c
@@ -938,8 +938,6 @@ vm_map_simplify_entry(vm_map_t map, vm_map_entry_t entry)
 	vm_map_entry_t next, prev;
 	vm_size_t prevsize, esize;
 
-	GIANT_REQUIRED;
-
 	if (entry->eflags & MAP_ENTRY_IS_SUB_MAP)
 		return;
 
@@ -1187,7 +1185,6 @@ vm_map_protect(vm_map_t map, vm_offset_t start, vm_offset_t end,
 	vm_map_entry_t current;
 	vm_map_entry_t entry;
 
-	GIANT_REQUIRED;
 	vm_map_lock(map);
 
 	VM_MAP_RANGE_CHECK(map, start, end);
@@ -1237,12 +1234,14 @@ vm_map_protect(vm_map_t map, vm_offset_t start, vm_offset_t end,
 		 * here -- CHECK THIS XXX
 		 */
 		if (current->protection != old_prot) {
+			mtx_lock(&Giant);
 #define MASK(entry)	(((entry)->eflags & MAP_ENTRY_COW) ? ~VM_PROT_WRITE : \
 							VM_PROT_ALL)
 			pmap_protect(map->pmap, current->start,
 			    current->end,
 			    current->protection & MASK(current));
 #undef	MASK
+			mtx_unlock(&Giant);
 		}
 		vm_map_simplify_entry(map, current);
 		current = current->next;
diff --git a/sys/vm/vm_object.c b/sys/vm/vm_object.c
index 352ad2f..0db982e 100644
--- a/sys/vm/vm_object.c
+++ b/sys/vm/vm_object.c
@@ -360,11 +360,10 @@ vm_object_allocate(objtype_t type, vm_size_t size)
 void
 vm_object_reference(vm_object_t object)
 {
-	GIANT_REQUIRED;
-
 	if (object == NULL)
 		return;
 
+	mtx_lock(&Giant);
 #if 0
 	/* object can be re-referenced during final cleaning */
 	KASSERT(!(object->flags & OBJ_DEAD),
@@ -377,6 +376,7 @@ vm_object_reference(vm_object_t object)
 			printf("vm_object_reference: delay in getting object\n");
 		}
 	}
+	mtx_unlock(&Giant);
 }
 
 /*
@@ -427,12 +427,12 @@ vm_object_deallocate(vm_object_t object)
 {
 	vm_object_t temp;
 
-	GIANT_REQUIRED;
-
+	mtx_lock(&Giant);
 	while (object != NULL) {
 
 		if (object->type == OBJT_VNODE) {
 			vm_object_vndeallocate(object);
+			mtx_unlock(&Giant);
 			return;
 		}
 
@@ -447,6 +447,7 @@ vm_object_deallocate(vm_object_t object)
 		 */
 		object->ref_count--;
 		if (object->ref_count > 1) {
+			mtx_unlock(&Giant);
 			return;
 		} else if (object->ref_count == 1) {
 			if (object->shadow_count == 0) {
@@ -487,13 +488,10 @@ vm_object_deallocate(vm_object_t object)
 					continue;
 				}
 			}
-
+			mtx_unlock(&Giant);
 			return;
-
 		}
-
 doterm:
-
 		temp = object->backing_object;
 		if (temp) {
 			TAILQ_REMOVE(&temp->shadow_head, object, shadow_list);
@@ -514,6 +512,7 @@ doterm:
 			vm_object_terminate(object);
 		object = temp;
 	}
+	mtx_unlock(&Giant);
 }
 
 /*
-- 
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