1/*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 2004 Alan L. Cox <alc@cs.rice.edu> 5 * Copyright (c) 1982, 1986, 1991, 1993 6 * The Regents of the University of California. All rights reserved. 7 * (c) UNIX System Laboratories, Inc. 8 * All or some portions of this file are derived from material licensed 9 * to the University of California by American Telephone and Telegraph 10 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 11 * the permission of UNIX System Laboratories, Inc. 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 3. Neither the name of the University nor the names of its contributors 22 * may be used to endorse or promote products derived from this software 23 * without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35 * SUCH DAMAGE. 36 */ 37 38#include <sys/param.h> 39#include <sys/systm.h> 40#include <sys/kernel.h> 41#include <sys/lock.h> 42#include <sys/mutex.h> 43#include <sys/proc.h> 44#include <sys/uio.h> 45#include <sys/sf_buf.h> 46 47#include <vm/vm.h> 48#include <vm/vm_page.h> 49 50#include <machine/cpu.h> 51#include <machine/vmparam.h> 52#include <machine/md_var.h> 53 54/* 55 * Implement uiomove(9) from physical memory using sf_bufs to 56 * avoid the creation and destruction of ephemeral mappings. 57 */ 58int 59uiomove_fromphys(vm_page_t ma[], vm_offset_t offset, int n, struct uio *uio) 60{ 61 struct thread *td = curthread; 62 struct iovec *iov; 63 void *cp; 64 vm_offset_t page_offset; 65 vm_page_t m; 66 size_t cnt; 67 int error = 0; 68 int save = 0; 69 struct sf_buf *sf; 70 71 KASSERT(uio->uio_rw == UIO_READ || uio->uio_rw == UIO_WRITE, 72 ("uiomove_fromphys: mode")); 73 KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread, 74 ("uiomove_fromphys proc")); 75 KASSERT(uio->uio_resid >= 0, 76 ("%s: uio %p resid underflow", __func__, uio)); 77 78 save = td->td_pflags & TDP_DEADLKTREAT; 79 td->td_pflags |= TDP_DEADLKTREAT; 80 while (n > 0 && uio->uio_resid) { 81 KASSERT(uio->uio_iovcnt > 0, 82 ("%s: uio %p iovcnt underflow", __func__, uio)); 83 84 iov = uio->uio_iov; 85 cnt = iov->iov_len; 86 if (cnt == 0) { 87 uio->uio_iov++; 88 uio->uio_iovcnt--; 89 continue; 90 } 91 if (cnt > n) 92 cnt = n; 93 page_offset = offset & PAGE_MASK; 94 cnt = min(cnt, PAGE_SIZE - page_offset); 95 96 m = ma[offset >> PAGE_SHIFT]; 97 sf = sf_buf_alloc(m, 0); 98 cp = (char*)sf_buf_kva(sf) + page_offset; 99 100 switch (uio->uio_segflg) { 101 case UIO_USERSPACE: 102 maybe_yield(); 103 switch (uio->uio_rw) { 104 case UIO_READ: 105 error = copyout(cp, iov->iov_base, cnt); 106 break; 107 case UIO_WRITE: 108 error = copyin(iov->iov_base, cp, cnt); 109 break; 110 } 111 if (error) { 112 sf_buf_free(sf); 113 goto out; 114 } 115 break; 116 case UIO_SYSSPACE: 117 switch (uio->uio_rw) { 118 case UIO_READ: 119 bcopy(cp, iov->iov_base, cnt); 120 break; 121 case UIO_WRITE: 122 bcopy(iov->iov_base, cp, cnt); 123 break; 124 } 125 break; 126 case UIO_NOCOPY: 127 break; 128 } 129 sf_buf_free(sf); 130 iov->iov_base = (char *)iov->iov_base + cnt; 131 iov->iov_len -= cnt; 132 uio->uio_resid -= cnt; 133 uio->uio_offset += cnt; 134 offset += cnt; 135 n -= cnt; 136 } 137out: 138 if (save == 0) 139 td->td_pflags &= ~TDP_DEADLKTREAT; 140 return (error); 141} 142