/*
* 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.
*/
/** @addtogroup kernel_generic
* @{
*/
/**
* @file
* @brief Copying between kernel and userspace.
*
* This file contains sanitized functions for copying data
* between kernel and userspace.
*/
#include <assert.h>
#include <syscall/copy.h>
#include <proc/thread.h>
#include <mm/as.h>
#include <macros.h>
#include <arch.h>
#include <errno.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 EOK on success or an error code from @ref errno.h.
*/
errno_t copy_from_uspace(void *dst, uspace_addr_t uspace_src, size_t size)
{
ipl_t ipl;
errno_t rc;
assert(THREAD);
assert(!THREAD->in_copy_from_uspace);
if (!KERNEL_ADDRESS_SPACE_SHADOWED) {
if (overlaps(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;
}
}
#ifdef ADDRESS_SPACE_HOLE_START
/*
* Check whether the address is outside the address space hole.
*/
if (overlaps(uspace_src, size, ADDRESS_SPACE_HOLE_START,
ADDRESS_SPACE_HOLE_END - ADDRESS_SPACE_HOLE_START))
return EPERM;
#endif
ipl = interrupts_disable();
THREAD->in_copy_from_uspace = true;
rc = !memcpy_from_uspace(dst, uspace_src, size) ? EPERM : EOK;
THREAD->in_copy_from_uspace = false;
interrupts_restore(ipl);
return rc;
}
/** 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 src Source kernel address.
* @param size Size of the data to be copied.
*
* @return 0 on success or an error code from @ref errno.h.
*/
errno_t copy_to_uspace(uspace_addr_t uspace_dst, const void *src, size_t size)
{
ipl_t ipl;
errno_t rc;
assert(THREAD);
assert(!THREAD->in_copy_to_uspace);
if (!KERNEL_ADDRESS_SPACE_SHADOWED) {
if (overlaps(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;
}
}
#ifdef ADDRESS_SPACE_HOLE_START
/*
* Check whether the address is outside the address space hole.
*/
if (overlaps(uspace_dst, size, ADDRESS_SPACE_HOLE_START,
ADDRESS_SPACE_HOLE_END - ADDRESS_SPACE_HOLE_START))
return EPERM;
#endif
ipl = interrupts_disable();
THREAD->in_copy_to_uspace = true;
rc = !memcpy_to_uspace(uspace_dst, src, size) ? EPERM : EOK;
THREAD->in_copy_to_uspace = false;
interrupts_restore(ipl);
return rc;
}
/** @}
*/