1 /*- 2 * Copyright (c) 2004 Alan L. Cox <alc@cs.rice.edu> 3 * Copyright (c) 1982, 1986, 1991, 1993 4 * The Regents of the University of California. All rights reserved. 5 * (c) UNIX System Laboratories, Inc. 6 * All or some portions of this file are derived from material licensed 7 * to the University of California by American Telephone and Telegraph 8 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 9 * the permission of UNIX System Laboratories, Inc. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * @(#)kern_subr.c 8.3 (Berkeley) 1/21/94 36 */ 37 38 #include <sys/cdefs.h> 39 __FBSDID("$FreeBSD$"); 40 41 #include <sys/param.h> 42 #include <sys/kernel.h> 43 #include <sys/lock.h> 44 #include <sys/mutex.h> 45 #include <sys/proc.h> 46 #include <sys/systm.h> 47 #include <sys/uio.h> 48 #include <sys/sf_buf.h> 49 50 #include <vm/vm.h> 51 #include <vm/vm_page.h> 52 53 #include <machine/vmparam.h> 54 55 /* 56 * Implement uiomove(9) from physical memory using sf_bufs to 57 * avoid the creation and destruction of ephemeral mappings. 58 */ 59 int 60 uiomove_fromphys(vm_page_t ma[], vm_offset_t offset, int n, struct uio *uio) 61 { 62 struct thread *td = curthread; 63 struct iovec *iov; 64 void *cp; 65 vm_offset_t page_offset; 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 save = td->td_pflags & TDP_DEADLKTREAT; 76 td->td_pflags |= TDP_DEADLKTREAT; 77 while (n > 0 && uio->uio_resid) { 78 iov = uio->uio_iov; 79 cnt = iov->iov_len; 80 if (cnt == 0) { 81 uio->uio_iov++; 82 uio->uio_iovcnt--; 83 continue; 84 } 85 if (cnt > n) 86 cnt = n; 87 page_offset = offset & PAGE_MASK; 88 cnt = min(cnt, PAGE_SIZE - page_offset); 89 sf = sf_buf_alloc(ma[offset >> PAGE_SHIFT], 0); 90 cp = (char*)sf_buf_kva(sf) + page_offset; 91 switch (uio->uio_segflg) { 92 case UIO_USERSPACE: 93 maybe_yield(); 94 if (uio->uio_rw == UIO_READ) 95 error = copyout(cp, iov->iov_base, cnt); 96 else 97 error = copyin(iov->iov_base, cp, cnt); 98 if (error) { 99 sf_buf_free(sf); 100 goto out; 101 } 102 break; 103 case UIO_SYSSPACE: 104 if (uio->uio_rw == UIO_READ) 105 bcopy(cp, iov->iov_base, cnt); 106 else 107 bcopy(iov->iov_base, cp, cnt); 108 break; 109 case UIO_NOCOPY: 110 break; 111 } 112 sf_buf_free(sf); 113 iov->iov_base = (char *)iov->iov_base + cnt; 114 iov->iov_len -= cnt; 115 uio->uio_resid -= cnt; 116 uio->uio_offset += cnt; 117 offset += cnt; 118 n -= cnt; 119 } 120 out: 121 if (save == 0) 122 td->td_pflags &= ~TDP_DEADLKTREAT; 123 return (error); 124 } 125