Add private get_memory_properties() syscall which allows one to retrieve the

address protection bits as well as the wiring flags for an arbitrary address
in a team's address space. Will be used in the debugger for the purposes
of the memory inspector/editor, in order to determine whether it can in fact
allow editing for the currently inspected address range.



git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@42129 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/libroot/memory_private.h

@@ -0,0 +1,21 @@
+/*
+ * Copyright 2011, Rene Gollent, rene@gollent.com.
+ * Distributed under the terms of the MIT License.
+ */
+#ifndef _LIBROOT_MEMORY_PRIVATE_H
+#define _LIBROOT_MEMORY_PRIVATE_H
+
+#include <OS.h>
+
+#include <sys/cdefs.h>
+
+
+__BEGIN_DECLS
+
+status_t get_memory_properties(team_id teamID, const void* address,
+	uint32* _protected, uint32* _lock);
+
+__END_DECLS
+
+
+#endif	// _LIBROOT_MEMORY_PRIVATE_H

headers/private/system/syscalls.h

@@ -435,6 +435,11 @@ extern status_t		_kern_sync_memory(void *address, size_t size, int flags);
 extern status_t		_kern_memory_advice(void *address, size_t size,
 						uint32 advice);
 
+extern status_t		_kern_get_memory_properties(team_id teamID, 
+						const void *address,
+						uint32* _protected, 
+						uint32* _lock);
+
 /* kernel port functions */
 extern port_id		_kern_create_port(int32 queue_length, const char *name);
 extern status_t		_kern_close_port(port_id id);

src/system/kernel/vm/vm.cpp

@@ -6303,6 +6303,41 @@ _user_memory_advice(void* address, size_t size, uint32 advice)
 }
 
 
+status_t
+_user_get_memory_properties(team_id teamID, const void* address,
+	uint32* _protected, uint32* _lock)
+{
+	if (!IS_USER_ADDRESS(_protected) || !IS_USER_ADDRESS(_lock))
+		return B_BAD_ADDRESS;
+
+	AddressSpaceReadLocker locker;
+	status_t error = locker.SetTo(teamID);
+	if (error != B_OK)
+		return error;
+
+	VMArea* area = locker.AddressSpace()->LookupArea((addr_t)address);
+	if (area == NULL)
+		return B_NO_MEMORY;
+
+
+	uint32 protection = area->protection;
+	if (area->page_protections != NULL)
+		protection = get_area_page_protection(area, (addr_t)address);
+
+	uint32 wiring = area->wiring;
+
+	locker.Unlock();
+
+	error = user_memcpy(_protected, &protection, sizeof(protection));
+	if (error != B_OK)
+		return error;
+
+	error = user_memcpy(_lock, &wiring, sizeof(wiring));
+
+	return error;
+}
+
+
 // #pragma mark -- compatibility
 
 

src/system/libroot/os/Jamfile

@@ -20,6 +20,7 @@ MergeObject os_main.o :
 	fs_query.cpp
 	fs_volume.c
 	image.cpp
+	memory.cpp
 	parsedate.cpp
 	port.c
 	scheduler.c

src/system/libroot/os/memory.cpp

@@ -0,0 +1,17 @@
+/*
+ * Copyright 2011, Rene Gollent, rene@gollent.com.
+ * Distributed under the terms of the MIT License.
+ */
+#include <memory_private.h>
+
+#include <OS.h>
+
+#include <syscalls.h>
+
+
+status_t
+get_memory_properties(team_id teamID, const void* address, uint32* _protected,
+	 uint32* _lock)
+{
+	return _kern_get_memory_properties(teamID, address, _protected, _lock);
+}