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/kernel.h> 40 #include <sys/lock.h> 41 #include <sys/mutex.h> 42 #include <sys/proc.h> 43 #include <sys/systm.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/vmparam.h> 51 52 /* 53 * Implement uiomove(9) from physical memory using sf_bufs to 54 * avoid the creation and destruction of ephemeral mappings. 55 */ 56 int 57 uiomove_fromphys(vm_page_t ma[], vm_offset_t offset, int n, struct uio *uio) 58 { 59 struct thread *td = curthread; 60 struct iovec *iov; 61 void *cp; 62 vm_offset_t page_offset; 63 size_t cnt; 64 int error = 0; 65 int save = 0; 66 struct sf_buf *sf; 67 68 KASSERT(uio->uio_rw == UIO_READ || uio->uio_rw == UIO_WRITE, 69 ("uiomove_fromphys: mode")); 70 KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread, 71 ("uiomove_fromphys proc")); 72 KASSERT(uio->uio_resid >= 0, 73 ("%s: uio %p resid underflow", __func__, uio)); 74 75 save = td->td_pflags & TDP_DEADLKTREAT; 76 td->td_pflags |= TDP_DEADLKTREAT; 77 while (n > 0 && uio->uio_resid) { 78 KASSERT(uio->uio_iovcnt > 0, 79 ("%s: uio %p iovcnt underflow", __func__, uio)); 80 81 iov = uio->uio_iov; 82 cnt = iov->iov_len; 83 if (cnt == 0) { 84 uio->uio_iov++; 85 uio->uio_iovcnt--; 86 continue; 87 } 88 if (cnt > n) 89 cnt = n; 90 page_offset = offset & PAGE_MASK; 91 cnt = min(cnt, PAGE_SIZE - page_offset); 92 sf = sf_buf_alloc(ma[offset >> PAGE_SHIFT], 0); 93 cp = (char*)sf_buf_kva(sf) + page_offset; 94 switch (uio->uio_segflg) { 95 case UIO_USERSPACE: 96 maybe_yield(); 97 if (uio->uio_rw == UIO_READ) 98 error = copyout(cp, iov->iov_base, cnt); 99 else 100 error = copyin(iov->iov_base, cp, cnt); 101 if (error) { 102 sf_buf_free(sf); 103 goto out; 104 } 105 break; 106 case UIO_SYSSPACE: 107 if (uio->uio_rw == UIO_READ) 108 bcopy(cp, iov->iov_base, cnt); 109 else 110 bcopy(iov->iov_base, cp, cnt); 111 break; 112 case UIO_NOCOPY: 113 break; 114 } 115 sf_buf_free(sf); 116 iov->iov_base = (char *)iov->iov_base + cnt; 117 iov->iov_len -= cnt; 118 uio->uio_resid -= cnt; 119 uio->uio_offset += cnt; 120 offset += cnt; 121 n -= cnt; 122 } 123 out: 124 if (save == 0) 125 td->td_pflags &= ~TDP_DEADLKTREAT; 126 return (error); 127 } 128