From 1c2d20a1d06c6def7d655f60761f708703ae2050 Mon Sep 17 00:00:00 2001
From: Mark Johnston <markj@FreeBSD.org>
Date: Mon, 10 Apr 2017 20:57:16 +0000
Subject: [PATCH] Consistently use for-loops in vm_map_protect().

No functional change.

Reviewed by:	kib
MFC after:	1 week
Sponsored by:	Dell EMC Isilon
X-Differential Revision:	https://reviews.freebsd.org/D10349
---
 sys/vm/vm_map.c | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/sys/vm/vm_map.c b/sys/vm/vm_map.c
index 46213feadf04..220d2868e712 100644
--- a/sys/vm/vm_map.c
+++ b/sys/vm/vm_map.c
@@ -1976,8 +1976,8 @@ vm_map_protect(vm_map_t map, vm_offset_t start, vm_offset_t end,
 	/*
 	 * Make a first pass to check for protection violations.
 	 */
-	current = entry;
-	while ((current != &map->header) && (current->start < end)) {
+	for (current = entry; current != &map->header && current->start < end;
+	    current = current->next) {
 		if (current->eflags & MAP_ENTRY_IS_SUB_MAP) {
 			vm_map_unlock(map);
 			return (KERN_INVALID_ARGUMENT);
@@ -1986,17 +1986,15 @@ vm_map_protect(vm_map_t map, vm_offset_t start, vm_offset_t end,
 			vm_map_unlock(map);
 			return (KERN_PROTECTION_FAILURE);
 		}
-		current = current->next;
 	}
 
-
 	/*
 	 * Do an accounting pass for private read-only mappings that
 	 * now will do cow due to allowed write (e.g. debugger sets
 	 * breakpoint on text segment)
 	 */
-	for (current = entry; (current != &map->header) &&
-	     (current->start < end); current = current->next) {
+	for (current = entry; current != &map->header && current->start < end;
+	    current = current->next) {
 
 		vm_map_clip_end(map, current, end);
 
@@ -2049,8 +2047,8 @@ vm_map_protect(vm_map_t map, vm_offset_t start, vm_offset_t end,
 	 * Go back and fix up protections. [Note that clipping is not
 	 * necessary the second time.]
 	 */
-	current = entry;
-	while ((current != &map->header) && (current->start < end)) {
+	for (current = entry; current != &map->header && current->start < end;
+	    current = current->next) {
 		old_prot = current->protection;
 
 		if (set_max)
@@ -2084,7 +2082,6 @@ vm_map_protect(vm_map_t map, vm_offset_t start, vm_offset_t end,
 #undef	MASK
 		}
 		vm_map_simplify_entry(map, current);
-		current = current->next;
 	}
 	vm_map_unlock(map);
 	return (KERN_SUCCESS);