| /* |
| * CDDL HEADER START |
| * |
| * The contents of this file are subject to the terms of the |
| * Common Development and Distribution License (the "License"). |
| * You may not use this file except in compliance with the License. |
| * |
| * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE |
| * or http://www.opensolaris.org/os/licensing. |
| * See the License for the specific language governing permissions |
| * and limitations under the License. |
| * |
| * When distributing Covered Code, include this CDDL HEADER in each |
| * file and include the License file at usr/src/OPENSOLARIS.LICENSE. |
| * If applicable, add the following below this CDDL HEADER, with the |
| * fields enclosed by brackets "[]" replaced with your own identifying |
| * information: Portions Copyright [yyyy] [name of copyright owner] |
| * |
| * CDDL HEADER END |
| */ |
| /* |
| * Copyright 2009 Sun Microsystems, Inc. All rights reserved. |
| * Use is subject to license terms. |
| */ |
| |
| /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */ |
| /* All Rights Reserved */ |
| |
| /* |
| * University Copyright- Copyright (c) 1982, 1986, 1988 |
| * The Regents of the University of California |
| * All Rights Reserved |
| * |
| * University Acknowledgment- Portions of this document are derived from |
| * software developed by the University of California, Berkeley, and its |
| * contributors. |
| */ |
| /* |
| * Copyright (c) 2015 by Chunwei Chen. All rights reserved. |
| */ |
| |
| /* |
| * The uio support from OpenSolaris has been added as a short term |
| * work around. The hope is to adopt native Linux type and drop the |
| * use of uio's entirely. Under Linux they only add overhead and |
| * when possible we want to use native APIs for the ZPL layer. |
| */ |
| #ifdef _KERNEL |
| |
| #include <sys/types.h> |
| #include <sys/uio_impl.h> |
| #include <sys/sysmacros.h> |
| #include <sys/strings.h> |
| #include <linux/kmap_compat.h> |
| #include <linux/uaccess.h> |
| |
| /* |
| * Move "n" bytes at byte address "p"; "rw" indicates the direction |
| * of the move, and the I/O parameters are provided in "uio", which is |
| * update to reflect the data which was moved. Returns 0 on success or |
| * a non-zero errno on failure. |
| */ |
| static int |
| uiomove_iov(void *p, size_t n, enum uio_rw rw, struct uio *uio) |
| { |
| const struct iovec *iov = uio->uio_iov; |
| size_t skip = uio->uio_skip; |
| ulong_t cnt; |
| |
| while (n && uio->uio_resid) { |
| cnt = MIN(iov->iov_len - skip, n); |
| switch (uio->uio_segflg) { |
| case UIO_USERSPACE: |
| case UIO_USERISPACE: |
| /* |
| * p = kernel data pointer |
| * iov->iov_base = user data pointer |
| */ |
| if (rw == UIO_READ) { |
| if (copy_to_user(iov->iov_base+skip, p, cnt)) |
| return (EFAULT); |
| } else { |
| unsigned long b_left = 0; |
| if (uio->uio_fault_disable) { |
| if (!zfs_access_ok(VERIFY_READ, |
| (iov->iov_base + skip), cnt)) { |
| return (EFAULT); |
| } |
| pagefault_disable(); |
| b_left = |
| __copy_from_user_inatomic(p, |
| (iov->iov_base + skip), cnt); |
| pagefault_enable(); |
| } else { |
| b_left = |
| copy_from_user(p, |
| (iov->iov_base + skip), cnt); |
| } |
| if (b_left > 0) { |
| unsigned long c_bytes = |
| cnt - b_left; |
| uio->uio_skip += c_bytes; |
| ASSERT3U(uio->uio_skip, <, |
| iov->iov_len); |
| uio->uio_resid -= c_bytes; |
| uio->uio_loffset += c_bytes; |
| return (EFAULT); |
| } |
| } |
| break; |
| case UIO_SYSSPACE: |
| if (rw == UIO_READ) |
| bcopy(p, iov->iov_base + skip, cnt); |
| else |
| bcopy(iov->iov_base + skip, p, cnt); |
| break; |
| default: |
| ASSERT(0); |
| } |
| skip += cnt; |
| if (skip == iov->iov_len) { |
| skip = 0; |
| uio->uio_iov = (++iov); |
| uio->uio_iovcnt--; |
| } |
| uio->uio_skip = skip; |
| uio->uio_resid -= cnt; |
| uio->uio_loffset += cnt; |
| p = (caddr_t)p + cnt; |
| n -= cnt; |
| } |
| return (0); |
| } |
| |
| static int |
| uiomove_bvec(void *p, size_t n, enum uio_rw rw, struct uio *uio) |
| { |
| const struct bio_vec *bv = uio->uio_bvec; |
| size_t skip = uio->uio_skip; |
| ulong_t cnt; |
| |
| while (n && uio->uio_resid) { |
| void *paddr; |
| cnt = MIN(bv->bv_len - skip, n); |
| |
| paddr = zfs_kmap_atomic(bv->bv_page, KM_USER1); |
| if (rw == UIO_READ) |
| bcopy(p, paddr + bv->bv_offset + skip, cnt); |
| else |
| bcopy(paddr + bv->bv_offset + skip, p, cnt); |
| zfs_kunmap_atomic(paddr, KM_USER1); |
| |
| skip += cnt; |
| if (skip == bv->bv_len) { |
| skip = 0; |
| uio->uio_bvec = (++bv); |
| uio->uio_iovcnt--; |
| } |
| uio->uio_skip = skip; |
| uio->uio_resid -= cnt; |
| uio->uio_loffset += cnt; |
| p = (caddr_t)p + cnt; |
| n -= cnt; |
| } |
| return (0); |
| } |
| |
| int |
| uiomove(void *p, size_t n, enum uio_rw rw, struct uio *uio) |
| { |
| if (uio->uio_segflg != UIO_BVEC) |
| return (uiomove_iov(p, n, rw, uio)); |
| else |
| return (uiomove_bvec(p, n, rw, uio)); |
| } |
| EXPORT_SYMBOL(uiomove); |
| |
| #define fuword8(uptr, vptr) get_user((*vptr), (uptr)) |
| |
| /* |
| * Fault in the pages of the first n bytes specified by the uio structure. |
| * 1 byte in each page is touched and the uio struct is unmodified. Any |
| * error will terminate the process as this is only a best attempt to get |
| * the pages resident. |
| */ |
| int |
| uio_prefaultpages(ssize_t n, struct uio *uio) |
| { |
| const struct iovec *iov; |
| ulong_t cnt, incr; |
| caddr_t p; |
| uint8_t tmp; |
| int iovcnt; |
| size_t skip; |
| |
| /* no need to fault in kernel pages */ |
| switch (uio->uio_segflg) { |
| case UIO_SYSSPACE: |
| case UIO_BVEC: |
| return (0); |
| case UIO_USERSPACE: |
| case UIO_USERISPACE: |
| break; |
| default: |
| ASSERT(0); |
| } |
| |
| iov = uio->uio_iov; |
| iovcnt = uio->uio_iovcnt; |
| skip = uio->uio_skip; |
| |
| for (; n > 0 && iovcnt > 0; iov++, iovcnt--, skip = 0) { |
| cnt = MIN(iov->iov_len - skip, n); |
| /* empty iov */ |
| if (cnt == 0) |
| continue; |
| n -= cnt; |
| /* |
| * touch each page in this segment. |
| */ |
| p = iov->iov_base + skip; |
| while (cnt) { |
| if (fuword8((uint8_t *)p, &tmp)) |
| return (EFAULT); |
| incr = MIN(cnt, PAGESIZE); |
| p += incr; |
| cnt -= incr; |
| } |
| /* |
| * touch the last byte in case it straddles a page. |
| */ |
| p--; |
| if (fuword8((uint8_t *)p, &tmp)) |
| return (EFAULT); |
| } |
| |
| return (0); |
| } |
| EXPORT_SYMBOL(uio_prefaultpages); |
| |
| /* |
| * same as uiomove() but doesn't modify uio structure. |
| * return in cbytes how many bytes were copied. |
| */ |
| int |
| uiocopy(void *p, size_t n, enum uio_rw rw, struct uio *uio, size_t *cbytes) |
| { |
| struct uio uio_copy; |
| int ret; |
| |
| bcopy(uio, &uio_copy, sizeof (struct uio)); |
| ret = uiomove(p, n, rw, &uio_copy); |
| *cbytes = uio->uio_resid - uio_copy.uio_resid; |
| return (ret); |
| } |
| EXPORT_SYMBOL(uiocopy); |
| |
| /* |
| * Drop the next n chars out of *uiop. |
| */ |
| void |
| uioskip(uio_t *uiop, size_t n) |
| { |
| if (n > uiop->uio_resid) |
| return; |
| |
| uiop->uio_skip += n; |
| if (uiop->uio_segflg != UIO_BVEC) { |
| while (uiop->uio_iovcnt && |
| uiop->uio_skip >= uiop->uio_iov->iov_len) { |
| uiop->uio_skip -= uiop->uio_iov->iov_len; |
| uiop->uio_iov++; |
| uiop->uio_iovcnt--; |
| } |
| } else { |
| while (uiop->uio_iovcnt && |
| uiop->uio_skip >= uiop->uio_bvec->bv_len) { |
| uiop->uio_skip -= uiop->uio_bvec->bv_len; |
| uiop->uio_bvec++; |
| uiop->uio_iovcnt--; |
| } |
| } |
| uiop->uio_loffset += n; |
| uiop->uio_resid -= n; |
| } |
| EXPORT_SYMBOL(uioskip); |
| #endif /* _KERNEL */ |