/*
* Copyright (c) 2016 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_ipc
* @{
*/
/** @file
*/
#include <ipc/sysipc_ops.h>
#include <ipc/ipc.h>
#include <mm/as.h>
#include <mm/page.h>
#include <genarch/mm/page_pt.h>
#include <genarch/mm/page_ht.h>
#include <mm/frame.h>
#include <proc/task.h>
#include <abi/errno.h>
#include <arch.h>
static errno_t pagein_request_preprocess(call_t *call, phone_t *phone)
{
/*
* Allow only requests from numerically higher task IDs to
* numerically lower task IDs to prevent deadlock in
* pagein_answer_preprocess() that could happen if two tasks
* wanted to be each other's pager.
*/
if (TASK->taskid <= phone->callee->task->taskid)
return ENOTSUP;
else
return EOK;
}
static errno_t pagein_answer_preprocess(call_t *answer, ipc_data_t *olddata)
{
/*
* We only do the special handling below if the call was initiated by
* the kernel. Otherwise a malicious task could use this mechanism to
* hold memory frames forever.
*/
if (!answer->priv)
return EOK;
if (!ipc_get_retval(&answer->data)) {
pte_t pte;
uintptr_t frame;
page_table_lock(AS, true);
bool found = page_mapping_find(AS, ipc_get_arg1(&answer->data),
false, &pte);
if (found & PTE_PRESENT(&pte)) {
frame = PTE_GET_FRAME(&pte);
pfn_t pfn = ADDR2PFN(frame);
if (find_zone(pfn, 1, 0) != (size_t) -1) {
/*
* The frame is in physical memory managed by
* the frame allocator.
*/
frame_reference_add(ADDR2PFN(frame));
}
ipc_set_arg1(&answer->data, frame);
} else {
ipc_set_retval(&answer->data, ENOENT);
}
page_table_unlock(AS, true);
}
return EOK;
}
sysipc_ops_t ipc_m_page_in_ops = {
.request_preprocess = pagein_request_preprocess,
.request_forget = null_request_forget,
.request_process = null_request_process,
.answer_cleanup = null_answer_cleanup,
.answer_preprocess = pagein_answer_preprocess,
.answer_process = null_answer_process,
};
/** @}
*/