* Reserved areas would also be created in existing reserved areas in case the

space was becoming tight. This actually fixes #4778.
* Fixed overflow problem in find_reserved_area().
* Cleaned up the test app, added license.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@33597 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/system/kernel/vm/vm.cpp

@@ -1022,8 +1022,8 @@ find_reserved_area(vm_address_space* addressSpace, addr_t start,
 	next = addressSpace->areas;
 	while (next != NULL) {
 		if (next->base <= start
-			&& next->base + next->size > start + (size - 1)) {
+			&& next->base + (next->size - 1) >= start + (size - 1)) {
-			// this area covers the requested range
+			// This area covers the requested range
 			if (next->id != RESERVED_AREA_ID) {
 				// but it's not reserved space, it's a real area
 				return B_BAD_VALUE;
@@ -1039,7 +1039,7 @@ find_reserved_area(vm_address_space* addressSpace, addr_t start,
 	if (next == NULL)
 		return B_ENTRY_NOT_FOUND;
 
-	// now we have to transfer the requested part of the reserved
+	// Now we have to transfer the requested part of the reserved
 	// range to the new area - and remove, resize or split the old
 	// reserved area.
 
@@ -1126,7 +1126,7 @@ find_and_insert_area_slot(vm_address_space* addressSpace, addr_t start,
 		|| start + (size - 1) > end)
 		return B_BAD_ADDRESS;
 
-	if (addressSpec == B_EXACT_ADDRESS) {
+	if (addressSpec == B_EXACT_ADDRESS && area->id != RESERVED_AREA_ID) {
 		// search for a reserved area
 		status_t status = find_reserved_area(addressSpace, start, size, area);
 		if (status == B_OK || status == B_BAD_VALUE)
@@ -1206,7 +1206,7 @@ second_chance:
 				foundSpot = true;
 				area->base = alignedBase;
 				break;
-			} else {
+			} else if (area->id != RESERVED_AREA_ID) {
 				// We didn't find a free spot - if there are any reserved areas,
 				// we can now test those for free space
 				// TODO: it would make sense to start with the biggest of them

src/tests/system/kernel/reserved_areas_test.cpp

@@ -1,3 +1,9 @@
+/*
+ * Copyright 2009, Axel Dörfler, axeld@pinc-software.de.
+ * Distributed under the terms of the MIT License.
+ */
+
+
 //!	Test application that reproduces bug #4778.
 
 
@@ -43,18 +49,17 @@ area_creator(void*)
 			base = (void*)0x60000000;
 			status = _kern_reserve_address_range((addr_t*)&base, B_BASE_ADDRESS,
 				128 * 1024 * 1024);
-			if (status != B_OK)
-				snooze(10000000LL);
 			addressSpec = status == B_OK ? B_EXACT_ADDRESS : B_BASE_ADDRESS;
-printf("\naddress spec = %lx, base %p (status %s)\n", addressSpec, base, strerror(status));
+			printf("\naddress spec = %lx, base %p (status %s)\n", addressSpec,
+				base, strerror(status));
 		}
 
 		area_id area = create_area(readOnly ? "read-only memory" : "r/w memory",
 			&base, addressSpec, B_PAGE_SIZE * 4, B_NO_LOCK,
 			B_READ_AREA | (readOnly ? 0 : B_WRITE_AREA));
 		if (area >= 0) {
-printf("new %s area %ld at %p\n", readOnly ? "read-only" : "r/w", area, base);
+			printf("new %s area %ld at %p\n", readOnly ? "read-only" : "r/w",
-//			putchar('#');
+				area, base);
 		} else
 			break;