Index: generic/src/syscall/copy.c
===================================================================
--- generic/src/syscall/copy.c	(revision e8194664346da297d4362295839ff6b1fb615c0b)
+++ generic/src/syscall/copy.c	(revision e8194664346da297d4362295839ff6b1fb615c0b)
@@ -0,0 +1,125 @@
+/*
+ * Copyright (C) 2006 Jakub Jermar
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ * - The name of the author may not be used to endorse or promote products
+ *   derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/**
+ * @file	copy.c
+ * @brief	Copying between kernel and userspace.
+ *
+ * This file contains sanitized functions for copying data
+ * between kernel and userspace.
+ */
+
+#include <syscall/copy.h>
+#include <proc/thread.h>
+#include <mm/as.h>
+#include <macros.h>
+#include <arch.h>
+#include <errno.h>
+#include <typedefs.h>
+
+/** Copy data from userspace to kernel.
+ *
+ * Provisions are made to return value even after page fault.
+ *
+ * This function can be called only from syscall.
+ *
+ * @param dst Destination kernel address.
+ * @param uspace_src Source userspace address.
+ * @param size Size of the data to be copied.
+ *
+ * @return 0 on success or error code from @ref errno.h.
+ */
+int copy_from_uspace(void *dst, void *uspace_src, size_t size)
+{
+	ipl_t ipl;
+	int rc;
+	
+	ASSERT(THREAD);
+	ASSERT(!THREAD->in_copy_from_uspace);
+	
+	if (!KERNEL_ADDRESS_SPACE_SHADOWED) {
+		if (overlaps((__address) uspace_src, size,
+			KERNEL_ADDRESS_SPACE_START, KERNEL_ADDRESS_SPACE_END-KERNEL_ADDRESS_SPACE_START)) {
+			/*
+			 * The userspace source block conflicts with kernel address space.
+			 */
+			return EPERM;
+		}
+	}
+	
+	ipl = interrupts_disable();
+	THREAD->in_copy_from_uspace = true;
+	
+	rc = memcpy_from_uspace(dst, uspace_src, size);
+
+	THREAD->in_copy_from_uspace = false;
+
+	interrupts_restore(ipl);
+	return !rc ? EPERM : 0;
+}
+
+/** Copy data from kernel to userspace.
+ *
+ * Provisions are made to return value even after page fault.
+ *
+ * This function can be called only from syscall.
+ *
+ * @param uspace_dst Destination userspace address.
+ * @param uspace_src Source kernel address.
+ * @param size Size of the data to be copied.
+ *
+ * @return 0 on success or error code from @ref errno.h.
+ */
+int copy_to_uspace(void *uspace_dst, void *src, size_t size)
+{
+	ipl_t ipl;
+	int rc;
+	
+	ASSERT(THREAD);
+	ASSERT(!THREAD->in_copy_from_uspace);
+	
+	if (!KERNEL_ADDRESS_SPACE_SHADOWED) {
+		if (overlaps((__address) uspace_dst, size,
+			KERNEL_ADDRESS_SPACE_START, KERNEL_ADDRESS_SPACE_END-KERNEL_ADDRESS_SPACE_START)) {
+			/*
+			 * The userspace destination block conflicts with kernel address space.
+			 */
+			return EPERM;
+		}
+	}
+	
+	ipl = interrupts_disable();
+	THREAD->in_copy_from_uspace = true;
+	
+	rc = memcpy_to_uspace(uspace_dst, src, size);
+
+	THREAD->in_copy_from_uspace = false;
+
+	interrupts_restore(ipl);
+	return !rc ? EPERM : 0;
+}