/* * 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, }; /** @} */