3846a82284
and the equivalent functionality is now provided by sendfile(2) over posix shared memory filedescriptor. Remove the cow member of struct vm_page, and rearrange the remaining members. While there, make hold_count unsigned. Requested and reviewed by: alc Tested by: pho Sponsored by: The FreeBSD Foundation Approved by: re (delphij)
441 lines
10 KiB
C
441 lines
10 KiB
C
/*-
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* Copyright (c) 1982, 1986, 1991, 1993
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* The Regents of the University of California. All rights reserved.
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* (c) UNIX System Laboratories, Inc.
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* All or some portions of this file are derived from material licensed
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* to the University of California by American Telephone and Telegraph
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* Co. or Unix System Laboratories, Inc. and are reproduced herein with
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* the permission of UNIX System Laboratories, Inc.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)kern_subr.c 8.3 (Berkeley) 1/21/94
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/kernel.h>
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#include <sys/limits.h>
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#include <sys/lock.h>
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#include <sys/mman.h>
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#include <sys/proc.h>
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#include <sys/resourcevar.h>
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#include <sys/rwlock.h>
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#include <sys/sched.h>
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#include <sys/sysctl.h>
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#include <sys/vnode.h>
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#include <vm/vm.h>
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#include <vm/vm_param.h>
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#include <vm/vm_extern.h>
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#include <vm/vm_page.h>
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#include <vm/vm_pageout.h>
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#include <vm/vm_map.h>
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SYSCTL_INT(_kern, KERN_IOV_MAX, iov_max, CTLFLAG_RD, NULL, UIO_MAXIOV,
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"Maximum number of elements in an I/O vector; sysconf(_SC_IOV_MAX)");
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static int uiomove_faultflag(void *cp, int n, struct uio *uio, int nofault);
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int
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copyin_nofault(const void *udaddr, void *kaddr, size_t len)
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{
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int error, save;
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save = vm_fault_disable_pagefaults();
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error = copyin(udaddr, kaddr, len);
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vm_fault_enable_pagefaults(save);
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return (error);
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}
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int
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copyout_nofault(const void *kaddr, void *udaddr, size_t len)
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{
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int error, save;
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save = vm_fault_disable_pagefaults();
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error = copyout(kaddr, udaddr, len);
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vm_fault_enable_pagefaults(save);
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return (error);
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}
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#define PHYS_PAGE_COUNT(len) (howmany(len, PAGE_SIZE) + 1)
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int
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physcopyin(void *src, vm_paddr_t dst, size_t len)
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{
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vm_page_t m[PHYS_PAGE_COUNT(len)];
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struct iovec iov[1];
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struct uio uio;
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int i;
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iov[0].iov_base = src;
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iov[0].iov_len = len;
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uio.uio_iov = iov;
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uio.uio_iovcnt = 1;
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uio.uio_offset = 0;
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uio.uio_resid = len;
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uio.uio_segflg = UIO_SYSSPACE;
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uio.uio_rw = UIO_WRITE;
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for (i = 0; i < PHYS_PAGE_COUNT(len); i++, dst += PAGE_SIZE)
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m[i] = PHYS_TO_VM_PAGE(dst);
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return (uiomove_fromphys(m, dst & PAGE_MASK, len, &uio));
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}
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int
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physcopyout(vm_paddr_t src, void *dst, size_t len)
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{
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vm_page_t m[PHYS_PAGE_COUNT(len)];
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struct iovec iov[1];
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struct uio uio;
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int i;
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iov[0].iov_base = dst;
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iov[0].iov_len = len;
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uio.uio_iov = iov;
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uio.uio_iovcnt = 1;
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uio.uio_offset = 0;
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uio.uio_resid = len;
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uio.uio_segflg = UIO_SYSSPACE;
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uio.uio_rw = UIO_READ;
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for (i = 0; i < PHYS_PAGE_COUNT(len); i++, src += PAGE_SIZE)
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m[i] = PHYS_TO_VM_PAGE(src);
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return (uiomove_fromphys(m, src & PAGE_MASK, len, &uio));
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}
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#undef PHYS_PAGE_COUNT
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int
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uiomove(void *cp, int n, struct uio *uio)
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{
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return (uiomove_faultflag(cp, n, uio, 0));
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}
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int
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uiomove_nofault(void *cp, int n, struct uio *uio)
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{
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return (uiomove_faultflag(cp, n, uio, 1));
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}
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static int
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uiomove_faultflag(void *cp, int n, struct uio *uio, int nofault)
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{
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struct thread *td;
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struct iovec *iov;
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size_t cnt;
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int error, newflags, save;
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td = curthread;
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error = 0;
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KASSERT(uio->uio_rw == UIO_READ || uio->uio_rw == UIO_WRITE,
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("uiomove: mode"));
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KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == td,
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("uiomove proc"));
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if (!nofault)
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WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
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"Calling uiomove()");
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/* XXX does it make a sense to set TDP_DEADLKTREAT for UIO_SYSSPACE ? */
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newflags = TDP_DEADLKTREAT;
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if (uio->uio_segflg == UIO_USERSPACE && nofault) {
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/*
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* Fail if a non-spurious page fault occurs.
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*/
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newflags |= TDP_NOFAULTING | TDP_RESETSPUR;
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}
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save = curthread_pflags_set(newflags);
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while (n > 0 && uio->uio_resid) {
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iov = uio->uio_iov;
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cnt = iov->iov_len;
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if (cnt == 0) {
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uio->uio_iov++;
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uio->uio_iovcnt--;
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continue;
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}
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if (cnt > n)
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cnt = n;
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switch (uio->uio_segflg) {
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case UIO_USERSPACE:
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maybe_yield();
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if (uio->uio_rw == UIO_READ)
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error = copyout(cp, iov->iov_base, cnt);
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else
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error = copyin(iov->iov_base, cp, cnt);
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if (error)
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goto out;
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break;
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case UIO_SYSSPACE:
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if (uio->uio_rw == UIO_READ)
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bcopy(cp, iov->iov_base, cnt);
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else
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bcopy(iov->iov_base, cp, cnt);
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break;
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case UIO_NOCOPY:
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break;
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}
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iov->iov_base = (char *)iov->iov_base + cnt;
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iov->iov_len -= cnt;
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uio->uio_resid -= cnt;
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uio->uio_offset += cnt;
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cp = (char *)cp + cnt;
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n -= cnt;
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}
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out:
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curthread_pflags_restore(save);
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return (error);
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}
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/*
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* Wrapper for uiomove() that validates the arguments against a known-good
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* kernel buffer. Currently, uiomove accepts a signed (n) argument, which
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* is almost definitely a bad thing, so we catch that here as well. We
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* return a runtime failure, but it might be desirable to generate a runtime
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* assertion failure instead.
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*/
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int
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uiomove_frombuf(void *buf, int buflen, struct uio *uio)
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{
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size_t offset, n;
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if (uio->uio_offset < 0 || uio->uio_resid < 0 ||
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(offset = uio->uio_offset) != uio->uio_offset)
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return (EINVAL);
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if (buflen <= 0 || offset >= buflen)
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return (0);
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if ((n = buflen - offset) > IOSIZE_MAX)
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return (EINVAL);
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return (uiomove((char *)buf + offset, n, uio));
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}
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/*
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* Give next character to user as result of read.
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*/
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int
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ureadc(int c, struct uio *uio)
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{
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struct iovec *iov;
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char *iov_base;
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WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
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"Calling ureadc()");
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again:
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if (uio->uio_iovcnt == 0 || uio->uio_resid == 0)
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panic("ureadc");
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iov = uio->uio_iov;
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if (iov->iov_len == 0) {
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uio->uio_iovcnt--;
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uio->uio_iov++;
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goto again;
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}
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switch (uio->uio_segflg) {
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case UIO_USERSPACE:
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if (subyte(iov->iov_base, c) < 0)
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return (EFAULT);
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break;
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case UIO_SYSSPACE:
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iov_base = iov->iov_base;
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*iov_base = c;
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break;
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case UIO_NOCOPY:
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break;
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}
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iov->iov_base = (char *)iov->iov_base + 1;
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iov->iov_len--;
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uio->uio_resid--;
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uio->uio_offset++;
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return (0);
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}
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int
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copyinfrom(const void * __restrict src, void * __restrict dst, size_t len,
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int seg)
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{
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int error = 0;
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switch (seg) {
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case UIO_USERSPACE:
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error = copyin(src, dst, len);
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break;
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case UIO_SYSSPACE:
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bcopy(src, dst, len);
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break;
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default:
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panic("copyinfrom: bad seg %d\n", seg);
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}
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return (error);
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}
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int
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copyinstrfrom(const void * __restrict src, void * __restrict dst, size_t len,
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size_t * __restrict copied, int seg)
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{
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int error = 0;
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switch (seg) {
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case UIO_USERSPACE:
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error = copyinstr(src, dst, len, copied);
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break;
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case UIO_SYSSPACE:
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error = copystr(src, dst, len, copied);
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break;
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default:
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panic("copyinstrfrom: bad seg %d\n", seg);
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}
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return (error);
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}
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int
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copyiniov(const struct iovec *iovp, u_int iovcnt, struct iovec **iov, int error)
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{
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u_int iovlen;
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*iov = NULL;
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if (iovcnt > UIO_MAXIOV)
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return (error);
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iovlen = iovcnt * sizeof (struct iovec);
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*iov = malloc(iovlen, M_IOV, M_WAITOK);
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error = copyin(iovp, *iov, iovlen);
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if (error) {
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free(*iov, M_IOV);
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*iov = NULL;
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}
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return (error);
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}
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int
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copyinuio(const struct iovec *iovp, u_int iovcnt, struct uio **uiop)
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{
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struct iovec *iov;
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struct uio *uio;
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u_int iovlen;
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int error, i;
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*uiop = NULL;
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if (iovcnt > UIO_MAXIOV)
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return (EINVAL);
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iovlen = iovcnt * sizeof (struct iovec);
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uio = malloc(iovlen + sizeof *uio, M_IOV, M_WAITOK);
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iov = (struct iovec *)(uio + 1);
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error = copyin(iovp, iov, iovlen);
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if (error) {
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free(uio, M_IOV);
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return (error);
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}
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uio->uio_iov = iov;
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uio->uio_iovcnt = iovcnt;
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uio->uio_segflg = UIO_USERSPACE;
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uio->uio_offset = -1;
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uio->uio_resid = 0;
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for (i = 0; i < iovcnt; i++) {
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if (iov->iov_len > IOSIZE_MAX - uio->uio_resid) {
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free(uio, M_IOV);
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return (EINVAL);
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}
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uio->uio_resid += iov->iov_len;
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iov++;
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}
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*uiop = uio;
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return (0);
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}
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struct uio *
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cloneuio(struct uio *uiop)
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{
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struct uio *uio;
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int iovlen;
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iovlen = uiop->uio_iovcnt * sizeof (struct iovec);
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uio = malloc(iovlen + sizeof *uio, M_IOV, M_WAITOK);
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*uio = *uiop;
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uio->uio_iov = (struct iovec *)(uio + 1);
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bcopy(uiop->uio_iov, uio->uio_iov, iovlen);
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return (uio);
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}
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/*
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* Map some anonymous memory in user space of size sz, rounded up to the page
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* boundary.
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*/
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int
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copyout_map(struct thread *td, vm_offset_t *addr, size_t sz)
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{
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struct vmspace *vms;
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int error;
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vm_size_t size;
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vms = td->td_proc->p_vmspace;
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/*
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* Map somewhere after heap in process memory.
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*/
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PROC_LOCK(td->td_proc);
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*addr = round_page((vm_offset_t)vms->vm_daddr +
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lim_max(td->td_proc, RLIMIT_DATA));
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PROC_UNLOCK(td->td_proc);
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/* round size up to page boundry */
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size = (vm_size_t)round_page(sz);
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error = vm_mmap(&vms->vm_map, addr, size, PROT_READ | PROT_WRITE,
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VM_PROT_ALL, MAP_PRIVATE | MAP_ANON, OBJT_DEFAULT, NULL, 0);
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return (error);
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}
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/*
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* Unmap memory in user space.
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*/
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int
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copyout_unmap(struct thread *td, vm_offset_t addr, size_t sz)
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{
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vm_map_t map;
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vm_size_t size;
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if (sz == 0)
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return (0);
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map = &td->td_proc->p_vmspace->vm_map;
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size = (vm_size_t)round_page(sz);
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if (vm_map_remove(map, addr, addr + size) != KERN_SUCCESS)
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return (EINVAL);
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return (0);
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}
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