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 * @(#)kern_subr.c 8.3 (Berkeley) 1/21/94 38 */ 39 40 #include <sys/cdefs.h> 41 __FBSDID("$FreeBSD$"); 42 43 #include <sys/param.h> 44 #include <sys/systm.h> 45 #include <sys/kernel.h> 46 #include <sys/lock.h> 47 #include <sys/mutex.h> 48 #include <sys/proc.h> 49 #include <sys/uio.h> 50 #include <sys/sf_buf.h> 51 52 #include <vm/vm.h> 53 #include <vm/vm_page.h> 54 55 #include <machine/cpu.h> 56 #include <machine/vmparam.h> 57 #include <machine/md_var.h> 58 59 /* 60 * Implement uiomove(9) from physical memory using sf_bufs to 61 * avoid the creation and destruction of ephemeral mappings. 62 */ 63 int 64 uiomove_fromphys(vm_page_t ma[], vm_offset_t offset, int n, struct uio *uio) 65 { 66 struct thread *td = curthread; 67 struct iovec *iov; 68 void *cp; 69 vm_offset_t page_offset; 70 vm_page_t m; 71 size_t cnt; 72 int error = 0; 73 int save = 0; 74 struct sf_buf *sf; 75 76 KASSERT(uio->uio_rw == UIO_READ || uio->uio_rw == UIO_WRITE, 77 ("uiomove_fromphys: mode")); 78 KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread, 79 ("uiomove_fromphys proc")); 80 81 save = td->td_pflags & TDP_DEADLKTREAT; 82 td->td_pflags |= TDP_DEADLKTREAT; 83 while (n > 0 && uio->uio_resid) { 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 if (uio->uio_rw == UIO_READ) 104 error = copyout(cp, iov->iov_base, cnt); 105 else 106 error = copyin(iov->iov_base, cp, cnt); 107 if (error) { 108 sf_buf_free(sf); 109 goto out; 110 } 111 break; 112 case UIO_SYSSPACE: 113 if (uio->uio_rw == UIO_READ) 114 bcopy(cp, iov->iov_base, cnt); 115 else 116 bcopy(iov->iov_base, cp, cnt); 117 break; 118 case UIO_NOCOPY: 119 break; 120 } 121 sf_buf_free(sf); 122 iov->iov_base = (char *)iov->iov_base + cnt; 123 iov->iov_len -= cnt; 124 uio->uio_resid -= cnt; 125 uio->uio_offset += cnt; 126 offset += cnt; 127 n -= cnt; 128 } 129 out: 130 if (save == 0) 131 td->td_pflags &= ~TDP_DEADLKTREAT; 132 return (error); 133 } 134