Index: head/sys/kern/kern_physio.c =================================================================== --- head/sys/kern/kern_physio.c (revision 366730) +++ head/sys/kern/kern_physio.c (revision 366731) @@ -1,229 +1,230 @@ /*- * SPDX-License-Identifier: BSD-4-Clause * * Copyright (c) 1994 John S. Dyson * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice immediately at the beginning of the file, without modification, * this list of conditions, and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Absolutely no warranty of function or purpose is made by the author * John S. Dyson. * 4. Modifications may be freely made to this file if the above conditions * are met. */ #include __FBSDID("$FreeBSD$"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include int physio(struct cdev *dev, struct uio *uio, int ioflag) { struct cdevsw *csw; struct buf *pbuf; struct bio *bp; struct vm_page **pages; - caddr_t sa; + char *base, *sa; u_int iolen, poff; int error, i, npages, maxpages; vm_prot_t prot; csw = dev->si_devsw; npages = 0; sa = NULL; /* check if character device is being destroyed */ if (csw == NULL) return (ENXIO); /* XXX: sanity check */ if(dev->si_iosize_max < PAGE_SIZE) { printf("WARNING: %s si_iosize_max=%d, using DFLTPHYS.\n", devtoname(dev), dev->si_iosize_max); dev->si_iosize_max = DFLTPHYS; } /* * If the driver does not want I/O to be split, that means that we * need to reject any requests that will not fit into one buffer. */ if (dev->si_flags & SI_NOSPLIT && (uio->uio_resid > dev->si_iosize_max || uio->uio_resid > MAXPHYS || uio->uio_iovcnt > 1)) { /* * Tell the user why his I/O was rejected. */ if (uio->uio_resid > dev->si_iosize_max) uprintf("%s: request size=%zd > si_iosize_max=%d; " "cannot split request\n", devtoname(dev), uio->uio_resid, dev->si_iosize_max); if (uio->uio_resid > MAXPHYS) uprintf("%s: request size=%zd > MAXPHYS=%d; " "cannot split request\n", devtoname(dev), uio->uio_resid, MAXPHYS); if (uio->uio_iovcnt > 1) uprintf("%s: request vectors=%d > 1; " "cannot split request\n", devtoname(dev), uio->uio_iovcnt); return (EFBIG); } /* * Keep the process UPAGES from being swapped. Processes swapped * out while holding pbufs, used by swapper, may lead to deadlock. */ PHOLD(curproc); bp = g_alloc_bio(); if (uio->uio_segflg != UIO_USERSPACE) { pbuf = NULL; pages = NULL; } else if ((dev->si_flags & SI_UNMAPPED) && unmapped_buf_allowed) { pbuf = NULL; maxpages = btoc(MIN(uio->uio_resid, MAXPHYS)) + 1; pages = malloc(sizeof(*pages) * maxpages, M_DEVBUF, M_WAITOK); } else { pbuf = uma_zalloc(pbuf_zone, M_WAITOK); sa = pbuf->b_data; maxpages = btoc(MAXPHYS); pages = pbuf->b_pages; } prot = VM_PROT_READ; if (uio->uio_rw == UIO_READ) prot |= VM_PROT_WRITE; /* Less backwards than it looks */ error = 0; for (i = 0; i < uio->uio_iovcnt; i++) { #ifdef RACCT if (racct_enable) { PROC_LOCK(curproc); if (uio->uio_rw == UIO_READ) { racct_add_force(curproc, RACCT_READBPS, uio->uio_iov[i].iov_len); racct_add_force(curproc, RACCT_READIOPS, 1); } else { racct_add_force(curproc, RACCT_WRITEBPS, uio->uio_iov[i].iov_len); racct_add_force(curproc, RACCT_WRITEIOPS, 1); } PROC_UNLOCK(curproc); } #endif /* RACCT */ while (uio->uio_iov[i].iov_len) { g_reset_bio(bp); if (uio->uio_rw == UIO_READ) { bp->bio_cmd = BIO_READ; curthread->td_ru.ru_inblock++; } else { bp->bio_cmd = BIO_WRITE; curthread->td_ru.ru_oublock++; } bp->bio_offset = uio->uio_offset; - bp->bio_data = uio->uio_iov[i].iov_base; + base = uio->uio_iov[i].iov_base; bp->bio_length = uio->uio_iov[i].iov_len; if (bp->bio_length > dev->si_iosize_max) bp->bio_length = dev->si_iosize_max; if (bp->bio_length > MAXPHYS) bp->bio_length = MAXPHYS; /* * Make sure the pbuf can map the request. * The pbuf has kvasize = MAXPHYS, so a request * larger than MAXPHYS - PAGE_SIZE must be * page aligned or it will be fragmented. */ - poff = (vm_offset_t)bp->bio_data & PAGE_MASK; + poff = (vm_offset_t)base & PAGE_MASK; if (pbuf && bp->bio_length + poff > pbuf->b_kvasize) { if (dev->si_flags & SI_NOSPLIT) { uprintf("%s: request ptr %p is not " "on a page boundary; cannot split " "request\n", devtoname(dev), - bp->bio_data); + base); error = EFBIG; goto doerror; } bp->bio_length = pbuf->b_kvasize; if (poff != 0) bp->bio_length -= PAGE_SIZE; } bp->bio_bcount = bp->bio_length; bp->bio_dev = dev; if (pages) { if ((npages = vm_fault_quick_hold_pages( &curproc->p_vmspace->vm_map, - (vm_offset_t)bp->bio_data, bp->bio_length, + (vm_offset_t)base, bp->bio_length, prot, pages, maxpages)) < 0) { error = EFAULT; goto doerror; } if (pbuf && sa) { pmap_qenter((vm_offset_t)sa, pages, npages); bp->bio_data = sa + poff; } else { bp->bio_ma = pages; bp->bio_ma_n = npages; bp->bio_ma_offset = poff; bp->bio_data = unmapped_buf; bp->bio_flags |= BIO_UNMAPPED; } - } + } else + bp->bio_data = base; csw->d_strategy(bp); if (uio->uio_rw == UIO_READ) biowait(bp, "physrd"); else biowait(bp, "physwr"); if (pages) { if (pbuf) pmap_qremove((vm_offset_t)sa, npages); vm_page_unhold_pages(pages, npages); } iolen = bp->bio_length - bp->bio_resid; if (iolen == 0 && !(bp->bio_flags & BIO_ERROR)) goto doerror; /* EOF */ uio->uio_iov[i].iov_len -= iolen; uio->uio_iov[i].iov_base = (char *)uio->uio_iov[i].iov_base + iolen; uio->uio_resid -= iolen; uio->uio_offset += iolen; if (bp->bio_flags & BIO_ERROR) { error = bp->bio_error; goto doerror; } } } doerror: if (pbuf) uma_zfree(pbuf_zone, pbuf); else if (pages) free(pages, M_DEVBUF); g_destroy_bio(bp); PRELE(curproc); return (error); }