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subr_copy.c revision 1.19
      1  1.19  riastrad /*	$NetBSD: subr_copy.c,v 1.19 2023/05/22 14:07:24 riastradh Exp $	*/
      2   1.1     pooka 
      3   1.1     pooka /*-
      4   1.9   thorpej  * Copyright (c) 1997, 1998, 1999, 2002, 2007, 2008, 2019
      5   1.9   thorpej  *	The NetBSD Foundation, Inc.
      6   1.1     pooka  * All rights reserved.
      7   1.1     pooka  *
      8   1.1     pooka  * This code is derived from software contributed to The NetBSD Foundation
      9   1.1     pooka  * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
     10   1.1     pooka  * NASA Ames Research Center.
     11   1.1     pooka  *
     12   1.1     pooka  * Redistribution and use in source and binary forms, with or without
     13   1.1     pooka  * modification, are permitted provided that the following conditions
     14   1.1     pooka  * are met:
     15   1.1     pooka  * 1. Redistributions of source code must retain the above copyright
     16   1.1     pooka  *    notice, this list of conditions and the following disclaimer.
     17   1.1     pooka  * 2. Redistributions in binary form must reproduce the above copyright
     18   1.1     pooka  *    notice, this list of conditions and the following disclaimer in the
     19   1.1     pooka  *    documentation and/or other materials provided with the distribution.
     20   1.1     pooka  *
     21   1.1     pooka  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     22   1.1     pooka  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     23   1.1     pooka  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     24   1.1     pooka  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     25   1.1     pooka  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     26   1.1     pooka  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     27   1.1     pooka  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     28   1.1     pooka  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     29   1.1     pooka  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     30   1.1     pooka  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     31   1.1     pooka  * POSSIBILITY OF SUCH DAMAGE.
     32   1.1     pooka  */
     33   1.1     pooka 
     34   1.1     pooka /*
     35   1.1     pooka  * Copyright (c) 1982, 1986, 1991, 1993
     36   1.1     pooka  *	The Regents of the University of California.  All rights reserved.
     37   1.1     pooka  * (c) UNIX System Laboratories, Inc.
     38   1.1     pooka  * All or some portions of this file are derived from material licensed
     39   1.1     pooka  * to the University of California by American Telephone and Telegraph
     40   1.1     pooka  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
     41   1.1     pooka  * the permission of UNIX System Laboratories, Inc.
     42   1.1     pooka  *
     43   1.1     pooka  * Copyright (c) 1992, 1993
     44   1.1     pooka  *	The Regents of the University of California.  All rights reserved.
     45   1.1     pooka  *
     46   1.1     pooka  * This software was developed by the Computer Systems Engineering group
     47   1.1     pooka  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
     48   1.1     pooka  * contributed to Berkeley.
     49   1.1     pooka  *
     50   1.1     pooka  * All advertising materials mentioning features or use of this software
     51   1.1     pooka  * must display the following acknowledgement:
     52   1.1     pooka  *	This product includes software developed by the University of
     53   1.1     pooka  *	California, Lawrence Berkeley Laboratory.
     54   1.1     pooka  *
     55   1.1     pooka  * Redistribution and use in source and binary forms, with or without
     56   1.1     pooka  * modification, are permitted provided that the following conditions
     57   1.1     pooka  * are met:
     58   1.1     pooka  * 1. Redistributions of source code must retain the above copyright
     59   1.1     pooka  *    notice, this list of conditions and the following disclaimer.
     60   1.1     pooka  * 2. Redistributions in binary form must reproduce the above copyright
     61   1.1     pooka  *    notice, this list of conditions and the following disclaimer in the
     62   1.1     pooka  *    documentation and/or other materials provided with the distribution.
     63   1.1     pooka  * 3. Neither the name of the University nor the names of its contributors
     64   1.1     pooka  *    may be used to endorse or promote products derived from this software
     65   1.1     pooka  *    without specific prior written permission.
     66   1.1     pooka  *
     67   1.1     pooka  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     68   1.1     pooka  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     69   1.1     pooka  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     70   1.1     pooka  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     71   1.1     pooka  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     72   1.1     pooka  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     73   1.1     pooka  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     74   1.1     pooka  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     75   1.1     pooka  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     76   1.1     pooka  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     77   1.1     pooka  * SUCH DAMAGE.
     78   1.1     pooka  *
     79   1.1     pooka  *	@(#)kern_subr.c	8.4 (Berkeley) 2/14/95
     80   1.1     pooka  */
     81   1.1     pooka 
     82   1.1     pooka #include <sys/cdefs.h>
     83  1.19  riastrad __KERNEL_RCSID(0, "$NetBSD: subr_copy.c,v 1.19 2023/05/22 14:07:24 riastradh Exp $");
     84   1.9   thorpej 
     85   1.9   thorpej #define	__UFETCHSTORE_PRIVATE
     86   1.9   thorpej #define	__UCAS_PRIVATE
     87   1.1     pooka 
     88   1.1     pooka #include <sys/param.h>
     89   1.1     pooka #include <sys/fcntl.h>
     90   1.1     pooka #include <sys/proc.h>
     91   1.1     pooka #include <sys/systm.h>
     92   1.1     pooka 
     93   1.1     pooka #include <uvm/uvm_extern.h>
     94   1.1     pooka 
     95   1.1     pooka void
     96   1.1     pooka uio_setup_sysspace(struct uio *uio)
     97   1.1     pooka {
     98   1.1     pooka 
     99   1.1     pooka 	uio->uio_vmspace = vmspace_kernel();
    100   1.1     pooka }
    101   1.1     pooka 
    102   1.1     pooka int
    103   1.1     pooka uiomove(void *buf, size_t n, struct uio *uio)
    104   1.1     pooka {
    105   1.1     pooka 	struct vmspace *vm = uio->uio_vmspace;
    106   1.1     pooka 	struct iovec *iov;
    107   1.1     pooka 	size_t cnt;
    108   1.1     pooka 	int error = 0;
    109   1.1     pooka 	char *cp = buf;
    110   1.1     pooka 
    111   1.1     pooka 	ASSERT_SLEEPABLE();
    112   1.1     pooka 
    113   1.6  riastrad 	KASSERT(uio->uio_rw == UIO_READ || uio->uio_rw == UIO_WRITE);
    114   1.1     pooka 	while (n > 0 && uio->uio_resid) {
    115  1.18  riastrad 		KASSERT(uio->uio_iovcnt > 0);
    116   1.1     pooka 		iov = uio->uio_iov;
    117   1.1     pooka 		cnt = iov->iov_len;
    118   1.1     pooka 		if (cnt == 0) {
    119  1.18  riastrad 			KASSERT(uio->uio_iovcnt > 1);
    120   1.1     pooka 			uio->uio_iov++;
    121   1.1     pooka 			uio->uio_iovcnt--;
    122   1.1     pooka 			continue;
    123   1.1     pooka 		}
    124   1.1     pooka 		if (cnt > n)
    125   1.1     pooka 			cnt = n;
    126   1.1     pooka 		if (!VMSPACE_IS_KERNEL_P(vm)) {
    127  1.13        ad 			preempt_point();
    128   1.1     pooka 		}
    129   1.1     pooka 
    130   1.1     pooka 		if (uio->uio_rw == UIO_READ) {
    131   1.1     pooka 			error = copyout_vmspace(vm, cp, iov->iov_base,
    132   1.1     pooka 			    cnt);
    133   1.1     pooka 		} else {
    134   1.1     pooka 			error = copyin_vmspace(vm, iov->iov_base, cp,
    135   1.1     pooka 			    cnt);
    136   1.1     pooka 		}
    137   1.1     pooka 		if (error) {
    138   1.1     pooka 			break;
    139   1.1     pooka 		}
    140   1.1     pooka 		iov->iov_base = (char *)iov->iov_base + cnt;
    141   1.1     pooka 		iov->iov_len -= cnt;
    142   1.1     pooka 		uio->uio_resid -= cnt;
    143   1.1     pooka 		uio->uio_offset += cnt;
    144   1.1     pooka 		cp += cnt;
    145   1.1     pooka 		KDASSERT(cnt <= n);
    146   1.1     pooka 		n -= cnt;
    147   1.1     pooka 	}
    148   1.1     pooka 
    149   1.1     pooka 	return (error);
    150   1.1     pooka }
    151   1.1     pooka 
    152   1.1     pooka /*
    153   1.1     pooka  * Wrapper for uiomove() that validates the arguments against a known-good
    154   1.1     pooka  * kernel buffer.
    155   1.1     pooka  */
    156   1.1     pooka int
    157   1.1     pooka uiomove_frombuf(void *buf, size_t buflen, struct uio *uio)
    158   1.1     pooka {
    159   1.1     pooka 	size_t offset;
    160   1.1     pooka 
    161   1.1     pooka 	if (uio->uio_offset < 0 || /* uio->uio_resid < 0 || */
    162   1.1     pooka 	    (offset = uio->uio_offset) != uio->uio_offset)
    163   1.1     pooka 		return (EINVAL);
    164   1.1     pooka 	if (offset >= buflen)
    165   1.1     pooka 		return (0);
    166   1.1     pooka 	return (uiomove((char *)buf + offset, buflen - offset, uio));
    167   1.1     pooka }
    168   1.1     pooka 
    169  1.19  riastrad int
    170  1.19  riastrad uiopeek(void *buf, size_t n, struct uio *uio)
    171  1.19  riastrad {
    172  1.19  riastrad 	struct vmspace *vm = uio->uio_vmspace;
    173  1.19  riastrad 	struct iovec *iov;
    174  1.19  riastrad 	size_t cnt;
    175  1.19  riastrad 	int error = 0;
    176  1.19  riastrad 	char *cp = buf;
    177  1.19  riastrad 	size_t resid = uio->uio_resid;
    178  1.19  riastrad 	int iovcnt = uio->uio_iovcnt;
    179  1.19  riastrad 	char *base;
    180  1.19  riastrad 	size_t len;
    181  1.19  riastrad 
    182  1.19  riastrad 	KASSERT(uio->uio_rw == UIO_READ || uio->uio_rw == UIO_WRITE);
    183  1.19  riastrad 
    184  1.19  riastrad 	if (n == 0 || resid == 0)
    185  1.19  riastrad 		return 0;
    186  1.19  riastrad 	iov = uio->uio_iov;
    187  1.19  riastrad 	base = iov->iov_base;
    188  1.19  riastrad 	len = iov->iov_len;
    189  1.19  riastrad 
    190  1.19  riastrad 	while (n > 0 && resid > 0) {
    191  1.19  riastrad 		KASSERT(iovcnt > 0);
    192  1.19  riastrad 		cnt = len;
    193  1.19  riastrad 		if (cnt == 0) {
    194  1.19  riastrad 			KASSERT(iovcnt > 1);
    195  1.19  riastrad 			iov++;
    196  1.19  riastrad 			iovcnt--;
    197  1.19  riastrad 			base = iov->iov_base;
    198  1.19  riastrad 			len = iov->iov_len;
    199  1.19  riastrad 			continue;
    200  1.19  riastrad 		}
    201  1.19  riastrad 		if (cnt > n)
    202  1.19  riastrad 			cnt = n;
    203  1.19  riastrad 		if (!VMSPACE_IS_KERNEL_P(vm)) {
    204  1.19  riastrad 			preempt_point();
    205  1.19  riastrad 		}
    206  1.19  riastrad 
    207  1.19  riastrad 		if (uio->uio_rw == UIO_READ) {
    208  1.19  riastrad 			error = copyout_vmspace(vm, cp, base, cnt);
    209  1.19  riastrad 		} else {
    210  1.19  riastrad 			error = copyin_vmspace(vm, base, cp, cnt);
    211  1.19  riastrad 		}
    212  1.19  riastrad 		if (error) {
    213  1.19  riastrad 			break;
    214  1.19  riastrad 		}
    215  1.19  riastrad 		base += cnt;
    216  1.19  riastrad 		len -= cnt;
    217  1.19  riastrad 		resid -= cnt;
    218  1.19  riastrad 		cp += cnt;
    219  1.19  riastrad 		KDASSERT(cnt <= n);
    220  1.19  riastrad 		n -= cnt;
    221  1.19  riastrad 	}
    222  1.19  riastrad 
    223  1.19  riastrad 	return error;
    224  1.19  riastrad }
    225  1.19  riastrad 
    226  1.19  riastrad void
    227  1.19  riastrad uioskip(size_t n, struct uio *uio)
    228  1.19  riastrad {
    229  1.19  riastrad 	struct iovec *iov;
    230  1.19  riastrad 	size_t cnt;
    231  1.19  riastrad 
    232  1.19  riastrad 	KASSERTMSG(n <= uio->uio_resid, "n=%zu resid=%zu", n, uio->uio_resid);
    233  1.19  riastrad 
    234  1.19  riastrad 	KASSERT(uio->uio_rw == UIO_READ || uio->uio_rw == UIO_WRITE);
    235  1.19  riastrad 	while (n > 0 && uio->uio_resid) {
    236  1.19  riastrad 		KASSERT(uio->uio_iovcnt > 0);
    237  1.19  riastrad 		iov = uio->uio_iov;
    238  1.19  riastrad 		cnt = iov->iov_len;
    239  1.19  riastrad 		if (cnt == 0) {
    240  1.19  riastrad 			KASSERT(uio->uio_iovcnt > 1);
    241  1.19  riastrad 			uio->uio_iov++;
    242  1.19  riastrad 			uio->uio_iovcnt--;
    243  1.19  riastrad 			continue;
    244  1.19  riastrad 		}
    245  1.19  riastrad 		if (cnt > n)
    246  1.19  riastrad 			cnt = n;
    247  1.19  riastrad 		iov->iov_base = (char *)iov->iov_base + cnt;
    248  1.19  riastrad 		iov->iov_len -= cnt;
    249  1.19  riastrad 		uio->uio_resid -= cnt;
    250  1.19  riastrad 		uio->uio_offset += cnt;
    251  1.19  riastrad 		KDASSERT(cnt <= n);
    252  1.19  riastrad 		n -= cnt;
    253  1.19  riastrad 	}
    254  1.19  riastrad }
    255  1.19  riastrad 
    256   1.1     pooka /*
    257   1.1     pooka  * Give next character to user as result of read.
    258   1.1     pooka  */
    259   1.1     pooka int
    260   1.1     pooka ureadc(int c, struct uio *uio)
    261   1.1     pooka {
    262   1.1     pooka 	struct iovec *iov;
    263   1.1     pooka 
    264   1.1     pooka 	if (uio->uio_resid <= 0)
    265   1.1     pooka 		panic("ureadc: non-positive resid");
    266   1.1     pooka again:
    267   1.1     pooka 	if (uio->uio_iovcnt <= 0)
    268   1.1     pooka 		panic("ureadc: non-positive iovcnt");
    269   1.1     pooka 	iov = uio->uio_iov;
    270   1.1     pooka 	if (iov->iov_len <= 0) {
    271   1.1     pooka 		uio->uio_iovcnt--;
    272   1.1     pooka 		uio->uio_iov++;
    273   1.1     pooka 		goto again;
    274   1.1     pooka 	}
    275   1.1     pooka 	if (!VMSPACE_IS_KERNEL_P(uio->uio_vmspace)) {
    276   1.9   thorpej 		int error;
    277   1.9   thorpej 		if ((error = ustore_char(iov->iov_base, c)) != 0)
    278   1.9   thorpej 			return (error);
    279   1.1     pooka 	} else {
    280   1.1     pooka 		*(char *)iov->iov_base = c;
    281   1.1     pooka 	}
    282   1.1     pooka 	iov->iov_base = (char *)iov->iov_base + 1;
    283   1.1     pooka 	iov->iov_len--;
    284   1.1     pooka 	uio->uio_resid--;
    285   1.1     pooka 	uio->uio_offset++;
    286   1.1     pooka 	return (0);
    287   1.1     pooka }
    288   1.1     pooka 
    289   1.1     pooka /*
    290   1.1     pooka  * Like copyin(), but operates on an arbitrary vmspace.
    291   1.1     pooka  */
    292   1.1     pooka int
    293   1.1     pooka copyin_vmspace(struct vmspace *vm, const void *uaddr, void *kaddr, size_t len)
    294   1.1     pooka {
    295   1.1     pooka 	struct iovec iov;
    296   1.1     pooka 	struct uio uio;
    297   1.1     pooka 	int error;
    298   1.1     pooka 
    299   1.1     pooka 	if (len == 0)
    300   1.1     pooka 		return (0);
    301   1.1     pooka 
    302   1.3  riastrad 	if (VMSPACE_IS_KERNEL_P(vm)) {
    303   1.3  riastrad 		return kcopy(uaddr, kaddr, len);
    304   1.3  riastrad 	}
    305   1.2  riastrad 	if (__predict_true(vm == curproc->p_vmspace)) {
    306   1.2  riastrad 		return copyin(uaddr, kaddr, len);
    307   1.2  riastrad 	}
    308   1.1     pooka 
    309   1.1     pooka 	iov.iov_base = kaddr;
    310   1.1     pooka 	iov.iov_len = len;
    311   1.1     pooka 	uio.uio_iov = &iov;
    312   1.1     pooka 	uio.uio_iovcnt = 1;
    313   1.1     pooka 	uio.uio_offset = (off_t)(uintptr_t)uaddr;
    314   1.1     pooka 	uio.uio_resid = len;
    315   1.1     pooka 	uio.uio_rw = UIO_READ;
    316   1.1     pooka 	UIO_SETUP_SYSSPACE(&uio);
    317   1.7  christos 	error = uvm_io(&vm->vm_map, &uio, 0);
    318   1.1     pooka 
    319   1.1     pooka 	return (error);
    320   1.1     pooka }
    321   1.1     pooka 
    322   1.1     pooka /*
    323   1.1     pooka  * Like copyout(), but operates on an arbitrary vmspace.
    324   1.1     pooka  */
    325   1.1     pooka int
    326   1.1     pooka copyout_vmspace(struct vmspace *vm, const void *kaddr, void *uaddr, size_t len)
    327   1.1     pooka {
    328   1.1     pooka 	struct iovec iov;
    329   1.1     pooka 	struct uio uio;
    330   1.1     pooka 	int error;
    331   1.1     pooka 
    332   1.1     pooka 	if (len == 0)
    333   1.1     pooka 		return (0);
    334   1.1     pooka 
    335   1.3  riastrad 	if (VMSPACE_IS_KERNEL_P(vm)) {
    336   1.3  riastrad 		return kcopy(kaddr, uaddr, len);
    337   1.3  riastrad 	}
    338   1.2  riastrad 	if (__predict_true(vm == curproc->p_vmspace)) {
    339   1.2  riastrad 		return copyout(kaddr, uaddr, len);
    340   1.2  riastrad 	}
    341   1.1     pooka 
    342   1.1     pooka 	iov.iov_base = __UNCONST(kaddr); /* XXXUNCONST cast away const */
    343   1.1     pooka 	iov.iov_len = len;
    344   1.1     pooka 	uio.uio_iov = &iov;
    345   1.1     pooka 	uio.uio_iovcnt = 1;
    346   1.1     pooka 	uio.uio_offset = (off_t)(uintptr_t)uaddr;
    347   1.1     pooka 	uio.uio_resid = len;
    348   1.1     pooka 	uio.uio_rw = UIO_WRITE;
    349   1.1     pooka 	UIO_SETUP_SYSSPACE(&uio);
    350   1.7  christos 	error = uvm_io(&vm->vm_map, &uio, 0);
    351   1.1     pooka 
    352   1.1     pooka 	return (error);
    353   1.1     pooka }
    354   1.1     pooka 
    355   1.1     pooka /*
    356   1.1     pooka  * Like copyin(), but operates on an arbitrary process.
    357   1.1     pooka  */
    358   1.1     pooka int
    359   1.1     pooka copyin_proc(struct proc *p, const void *uaddr, void *kaddr, size_t len)
    360   1.1     pooka {
    361   1.1     pooka 	struct vmspace *vm;
    362   1.1     pooka 	int error;
    363   1.1     pooka 
    364   1.1     pooka 	error = proc_vmspace_getref(p, &vm);
    365   1.1     pooka 	if (error) {
    366   1.1     pooka 		return error;
    367   1.1     pooka 	}
    368   1.1     pooka 	error = copyin_vmspace(vm, uaddr, kaddr, len);
    369   1.1     pooka 	uvmspace_free(vm);
    370   1.1     pooka 
    371   1.1     pooka 	return error;
    372   1.1     pooka }
    373   1.1     pooka 
    374   1.1     pooka /*
    375   1.1     pooka  * Like copyout(), but operates on an arbitrary process.
    376   1.1     pooka  */
    377   1.1     pooka int
    378   1.1     pooka copyout_proc(struct proc *p, const void *kaddr, void *uaddr, size_t len)
    379   1.1     pooka {
    380   1.1     pooka 	struct vmspace *vm;
    381   1.1     pooka 	int error;
    382   1.1     pooka 
    383   1.1     pooka 	error = proc_vmspace_getref(p, &vm);
    384   1.1     pooka 	if (error) {
    385   1.1     pooka 		return error;
    386   1.1     pooka 	}
    387   1.1     pooka 	error = copyout_vmspace(vm, kaddr, uaddr, len);
    388   1.1     pooka 	uvmspace_free(vm);
    389   1.1     pooka 
    390   1.1     pooka 	return error;
    391   1.1     pooka }
    392   1.1     pooka 
    393   1.1     pooka /*
    394   1.8       chs  * Like copyin(), but operates on an arbitrary pid.
    395   1.8       chs  */
    396   1.8       chs int
    397   1.8       chs copyin_pid(pid_t pid, const void *uaddr, void *kaddr, size_t len)
    398   1.8       chs {
    399   1.8       chs 	struct proc *p;
    400   1.8       chs 	struct vmspace *vm;
    401   1.8       chs 	int error;
    402   1.8       chs 
    403  1.14        ad 	mutex_enter(&proc_lock);
    404   1.8       chs 	p = proc_find(pid);
    405   1.8       chs 	if (p == NULL) {
    406  1.14        ad 		mutex_exit(&proc_lock);
    407   1.8       chs 		return ESRCH;
    408   1.8       chs 	}
    409   1.8       chs 	mutex_enter(p->p_lock);
    410  1.12       chs 	error = proc_vmspace_getref(p, &vm);
    411   1.8       chs 	mutex_exit(p->p_lock);
    412  1.14        ad 	mutex_exit(&proc_lock);
    413   1.8       chs 
    414  1.12       chs 	if (error == 0) {
    415  1.12       chs 		error = copyin_vmspace(vm, uaddr, kaddr, len);
    416  1.12       chs 		uvmspace_free(vm);
    417  1.12       chs 	}
    418   1.8       chs 	return error;
    419   1.8       chs }
    420   1.8       chs 
    421   1.8       chs /*
    422   1.1     pooka  * Like copyin(), except it operates on kernel addresses when the FKIOCTL
    423   1.1     pooka  * flag is passed in `ioctlflags' from the ioctl call.
    424   1.1     pooka  */
    425   1.1     pooka int
    426   1.1     pooka ioctl_copyin(int ioctlflags, const void *src, void *dst, size_t len)
    427   1.1     pooka {
    428   1.1     pooka 	if (ioctlflags & FKIOCTL)
    429   1.1     pooka 		return kcopy(src, dst, len);
    430   1.1     pooka 	return copyin(src, dst, len);
    431   1.1     pooka }
    432   1.1     pooka 
    433   1.1     pooka /*
    434   1.1     pooka  * Like copyout(), except it operates on kernel addresses when the FKIOCTL
    435   1.1     pooka  * flag is passed in `ioctlflags' from the ioctl call.
    436   1.1     pooka  */
    437   1.1     pooka int
    438   1.1     pooka ioctl_copyout(int ioctlflags, const void *src, void *dst, size_t len)
    439   1.1     pooka {
    440   1.1     pooka 	if (ioctlflags & FKIOCTL)
    441   1.1     pooka 		return kcopy(src, dst, len);
    442   1.1     pooka 	return copyout(src, dst, len);
    443   1.1     pooka }
    444   1.9   thorpej 
    445   1.9   thorpej /*
    446   1.9   thorpej  * User-space CAS / fetch / store
    447   1.9   thorpej  */
    448   1.9   thorpej 
    449   1.9   thorpej #ifdef __NO_STRICT_ALIGNMENT
    450   1.9   thorpej #define	CHECK_ALIGNMENT(x)	__nothing
    451   1.9   thorpej #else /* ! __NO_STRICT_ALIGNMENT */
    452   1.9   thorpej static bool
    453   1.9   thorpej ufetchstore_aligned(uintptr_t uaddr, size_t size)
    454   1.9   thorpej {
    455   1.9   thorpej 	return (uaddr & (size - 1)) == 0;
    456   1.9   thorpej }
    457   1.9   thorpej 
    458   1.9   thorpej #define	CHECK_ALIGNMENT()						\
    459   1.9   thorpej do {									\
    460   1.9   thorpej 	if (!ufetchstore_aligned((uintptr_t)uaddr, sizeof(*uaddr)))	\
    461   1.9   thorpej 		return EFAULT;						\
    462   1.9   thorpej } while (/*CONSTCOND*/0)
    463   1.9   thorpej #endif /* __NO_STRICT_ALIGNMENT */
    464   1.9   thorpej 
    465  1.10   thorpej /*
    466  1.10   thorpej  * __HAVE_UCAS_FULL platforms provide _ucas_32() and _ucas_64() themselves.
    467  1.10   thorpej  * _RUMPKERNEL also provides it's own _ucas_32() and _ucas_64().
    468  1.10   thorpej  *
    469  1.10   thorpej  * In all other cases, we provide generic implementations that work on
    470  1.10   thorpej  * all platforms.
    471  1.10   thorpej  */
    472  1.10   thorpej 
    473  1.10   thorpej #if !defined(__HAVE_UCAS_FULL) && !defined(_RUMPKERNEL)
    474   1.9   thorpej #if !defined(__HAVE_UCAS_MP) && defined(MULTIPROCESSOR)
    475   1.9   thorpej #include <sys/atomic.h>
    476   1.9   thorpej #include <sys/cpu.h>
    477   1.9   thorpej #include <sys/once.h>
    478   1.9   thorpej #include <sys/mutex.h>
    479   1.9   thorpej #include <sys/ipi.h>
    480   1.9   thorpej 
    481   1.9   thorpej static int ucas_critical_splcookie;
    482   1.9   thorpej static volatile u_int ucas_critical_pausing_cpus;
    483   1.9   thorpej static u_int ucas_critical_ipi;
    484   1.9   thorpej static ONCE_DECL(ucas_critical_init_once)
    485   1.9   thorpej 
    486   1.9   thorpej static void
    487   1.9   thorpej ucas_critical_cpu_gate(void *arg __unused)
    488   1.9   thorpej {
    489   1.9   thorpej 	int count = SPINLOCK_BACKOFF_MIN;
    490   1.9   thorpej 
    491  1.15  riastrad 	KASSERT(atomic_load_relaxed(&ucas_critical_pausing_cpus) > 0);
    492  1.15  riastrad 
    493  1.15  riastrad 	/*
    494  1.15  riastrad 	 * Notify ucas_critical_wait that we have stopped.  Using
    495  1.15  riastrad 	 * store-release ensures all our memory operations up to the
    496  1.15  riastrad 	 * IPI happen before the ucas -- no buffered stores on our end
    497  1.15  riastrad 	 * can clobber it later on, for instance.
    498  1.15  riastrad 	 *
    499  1.15  riastrad 	 * Matches atomic_load_acquire in ucas_critical_wait -- turns
    500  1.15  riastrad 	 * the following atomic_dec_uint into a store-release.
    501  1.15  riastrad 	 */
    502  1.16  riastrad 	membar_release();
    503   1.9   thorpej 	atomic_dec_uint(&ucas_critical_pausing_cpus);
    504  1.15  riastrad 
    505  1.15  riastrad 	/*
    506  1.15  riastrad 	 * Wait for ucas_critical_exit to reopen the gate and let us
    507  1.15  riastrad 	 * proceed.  Using a load-acquire ensures the ucas happens
    508  1.15  riastrad 	 * before any of our memory operations when we return from the
    509  1.15  riastrad 	 * IPI and proceed -- we won't observe any stale cached value
    510  1.15  riastrad 	 * that the ucas overwrote, for instance.
    511  1.15  riastrad 	 *
    512  1.15  riastrad 	 * Matches atomic_store_release in ucas_critical_exit.
    513  1.15  riastrad 	 */
    514  1.15  riastrad 	while (atomic_load_acquire(&ucas_critical_pausing_cpus) != (u_int)-1) {
    515   1.9   thorpej 		SPINLOCK_BACKOFF(count);
    516   1.9   thorpej 	}
    517   1.9   thorpej }
    518   1.9   thorpej 
    519   1.9   thorpej static int
    520   1.9   thorpej ucas_critical_init(void)
    521   1.9   thorpej {
    522  1.15  riastrad 
    523   1.9   thorpej 	ucas_critical_ipi = ipi_register(ucas_critical_cpu_gate, NULL);
    524   1.9   thorpej 	return 0;
    525   1.9   thorpej }
    526   1.9   thorpej 
    527   1.9   thorpej static void
    528   1.9   thorpej ucas_critical_wait(void)
    529   1.9   thorpej {
    530   1.9   thorpej 	int count = SPINLOCK_BACKOFF_MIN;
    531   1.9   thorpej 
    532  1.15  riastrad 	/*
    533  1.15  riastrad 	 * Wait for all CPUs to stop at the gate.  Using a load-acquire
    534  1.15  riastrad 	 * ensures all memory operations before they stop at the gate
    535  1.15  riastrad 	 * happen before the ucas -- no buffered stores in other CPUs
    536  1.15  riastrad 	 * can clobber it later on, for instance.
    537  1.15  riastrad 	 *
    538  1.16  riastrad 	 * Matches membar_release/atomic_dec_uint (store-release) in
    539  1.15  riastrad 	 * ucas_critical_cpu_gate.
    540  1.15  riastrad 	 */
    541  1.15  riastrad 	while (atomic_load_acquire(&ucas_critical_pausing_cpus) > 0) {
    542   1.9   thorpej 		SPINLOCK_BACKOFF(count);
    543   1.9   thorpej 	}
    544   1.9   thorpej }
    545   1.9   thorpej #endif /* ! __HAVE_UCAS_MP && MULTIPROCESSOR */
    546   1.9   thorpej 
    547   1.9   thorpej static inline void
    548   1.9   thorpej ucas_critical_enter(lwp_t * const l)
    549   1.9   thorpej {
    550   1.9   thorpej 
    551   1.9   thorpej #if !defined(__HAVE_UCAS_MP) && defined(MULTIPROCESSOR)
    552   1.9   thorpej 	if (ncpu > 1) {
    553   1.9   thorpej 		RUN_ONCE(&ucas_critical_init_once, ucas_critical_init);
    554   1.9   thorpej 
    555   1.9   thorpej 		/*
    556   1.9   thorpej 		 * Acquire the mutex first, then go to splhigh() and
    557   1.9   thorpej 		 * broadcast the IPI to lock all of the other CPUs
    558   1.9   thorpej 		 * behind the gate.
    559   1.9   thorpej 		 *
    560   1.9   thorpej 		 * N.B. Going to splhigh() implicitly disables preemption,
    561   1.9   thorpej 		 * so there's no need to do it explicitly.
    562   1.9   thorpej 		 */
    563   1.9   thorpej 		mutex_enter(&cpu_lock);
    564   1.9   thorpej 		ucas_critical_splcookie = splhigh();
    565   1.9   thorpej 		ucas_critical_pausing_cpus = ncpu - 1;
    566   1.9   thorpej 		ipi_trigger_broadcast(ucas_critical_ipi, true);
    567   1.9   thorpej 		ucas_critical_wait();
    568   1.9   thorpej 		return;
    569   1.9   thorpej 	}
    570   1.9   thorpej #endif /* ! __HAVE_UCAS_MP && MULTIPROCESSOR */
    571   1.9   thorpej 
    572   1.9   thorpej 	KPREEMPT_DISABLE(l);
    573   1.9   thorpej }
    574   1.9   thorpej 
    575   1.9   thorpej static inline void
    576   1.9   thorpej ucas_critical_exit(lwp_t * const l)
    577   1.9   thorpej {
    578   1.9   thorpej 
    579   1.9   thorpej #if !defined(__HAVE_UCAS_MP) && defined(MULTIPROCESSOR)
    580   1.9   thorpej 	if (ncpu > 1) {
    581  1.15  riastrad 		/*
    582  1.15  riastrad 		 * Open the gate and notify all CPUs in
    583  1.15  riastrad 		 * ucas_critical_cpu_gate that they can now proceed.
    584  1.15  riastrad 		 * Using a store-release ensures the ucas happens
    585  1.15  riastrad 		 * before any memory operations they issue after the
    586  1.15  riastrad 		 * IPI -- they won't observe any stale cache of the
    587  1.15  riastrad 		 * target word, for instance.
    588  1.15  riastrad 		 *
    589  1.15  riastrad 		 * Matches atomic_load_acquire in ucas_critical_cpu_gate.
    590  1.15  riastrad 		 */
    591  1.15  riastrad 		atomic_store_release(&ucas_critical_pausing_cpus, (u_int)-1);
    592   1.9   thorpej 		splx(ucas_critical_splcookie);
    593   1.9   thorpej 		mutex_exit(&cpu_lock);
    594   1.9   thorpej 		return;
    595   1.9   thorpej 	}
    596   1.9   thorpej #endif /* ! __HAVE_UCAS_MP && MULTIPROCESSOR */
    597   1.9   thorpej 
    598   1.9   thorpej 	KPREEMPT_ENABLE(l);
    599   1.9   thorpej }
    600   1.9   thorpej 
    601   1.9   thorpej int
    602   1.9   thorpej _ucas_32(volatile uint32_t *uaddr, uint32_t old, uint32_t new, uint32_t *ret)
    603   1.9   thorpej {
    604   1.9   thorpej 	lwp_t * const l = curlwp;
    605   1.9   thorpej 	uint32_t *uva = ((void *)(uintptr_t)uaddr);
    606   1.9   thorpej 	int error;
    607   1.9   thorpej 
    608   1.9   thorpej 	/*
    609   1.9   thorpej 	 * Wire the user address down to avoid taking a page fault during
    610   1.9   thorpej 	 * the critical section.
    611   1.9   thorpej 	 */
    612   1.9   thorpej 	error = uvm_vslock(l->l_proc->p_vmspace, uva, sizeof(*uaddr),
    613   1.9   thorpej 			   VM_PROT_READ | VM_PROT_WRITE);
    614   1.9   thorpej 	if (error)
    615   1.9   thorpej 		return error;
    616   1.9   thorpej 
    617   1.9   thorpej 	ucas_critical_enter(l);
    618   1.9   thorpej 	error = _ufetch_32(uva, ret);
    619   1.9   thorpej 	if (error == 0 && *ret == old) {
    620   1.9   thorpej 		error = _ustore_32(uva, new);
    621   1.9   thorpej 	}
    622   1.9   thorpej 	ucas_critical_exit(l);
    623   1.9   thorpej 
    624   1.9   thorpej 	uvm_vsunlock(l->l_proc->p_vmspace, uva, sizeof(*uaddr));
    625   1.9   thorpej 
    626   1.9   thorpej 	return error;
    627   1.9   thorpej }
    628   1.9   thorpej 
    629   1.9   thorpej #ifdef _LP64
    630   1.9   thorpej int
    631   1.9   thorpej _ucas_64(volatile uint64_t *uaddr, uint64_t old, uint64_t new, uint64_t *ret)
    632   1.9   thorpej {
    633   1.9   thorpej 	lwp_t * const l = curlwp;
    634   1.9   thorpej 	uint64_t *uva = ((void *)(uintptr_t)uaddr);
    635   1.9   thorpej 	int error;
    636   1.9   thorpej 
    637   1.9   thorpej 	/*
    638   1.9   thorpej 	 * Wire the user address down to avoid taking a page fault during
    639   1.9   thorpej 	 * the critical section.
    640   1.9   thorpej 	 */
    641   1.9   thorpej 	error = uvm_vslock(l->l_proc->p_vmspace, uva, sizeof(*uaddr),
    642   1.9   thorpej 			   VM_PROT_READ | VM_PROT_WRITE);
    643   1.9   thorpej 	if (error)
    644   1.9   thorpej 		return error;
    645   1.9   thorpej 
    646   1.9   thorpej 	ucas_critical_enter(l);
    647   1.9   thorpej 	error = _ufetch_64(uva, ret);
    648   1.9   thorpej 	if (error == 0 && *ret == old) {
    649   1.9   thorpej 		error = _ustore_64(uva, new);
    650   1.9   thorpej 	}
    651   1.9   thorpej 	ucas_critical_exit(l);
    652   1.9   thorpej 
    653   1.9   thorpej 	uvm_vsunlock(l->l_proc->p_vmspace, uva, sizeof(*uaddr));
    654   1.9   thorpej 
    655   1.9   thorpej 	return error;
    656   1.9   thorpej }
    657   1.9   thorpej #endif /* _LP64 */
    658  1.10   thorpej #endif /* ! __HAVE_UCAS_FULL && ! _RUMPKERNEL */
    659   1.9   thorpej 
    660   1.9   thorpej int
    661   1.9   thorpej ucas_32(volatile uint32_t *uaddr, uint32_t old, uint32_t new, uint32_t *ret)
    662   1.9   thorpej {
    663   1.9   thorpej 
    664   1.9   thorpej 	ASSERT_SLEEPABLE();
    665   1.9   thorpej 	CHECK_ALIGNMENT();
    666  1.11   thorpej #if (defined(__HAVE_UCAS_MP) && defined(MULTIPROCESSOR)) && \
    667  1.11   thorpej     !defined(_RUMPKERNEL)
    668   1.9   thorpej 	if (ncpu > 1) {
    669   1.9   thorpej 		return _ucas_32_mp(uaddr, old, new, ret);
    670   1.9   thorpej 	}
    671   1.9   thorpej #endif /* __HAVE_UCAS_MP && MULTIPROCESSOR */
    672   1.9   thorpej 	return _ucas_32(uaddr, old, new, ret);
    673   1.9   thorpej }
    674   1.9   thorpej 
    675   1.9   thorpej #ifdef _LP64
    676   1.9   thorpej int
    677   1.9   thorpej ucas_64(volatile uint64_t *uaddr, uint64_t old, uint64_t new, uint64_t *ret)
    678   1.9   thorpej {
    679   1.9   thorpej 
    680   1.9   thorpej 	ASSERT_SLEEPABLE();
    681   1.9   thorpej 	CHECK_ALIGNMENT();
    682  1.11   thorpej #if (defined(__HAVE_UCAS_MP) && defined(MULTIPROCESSOR)) && \
    683  1.11   thorpej     !defined(_RUMPKERNEL)
    684   1.9   thorpej 	if (ncpu > 1) {
    685   1.9   thorpej 		return _ucas_64_mp(uaddr, old, new, ret);
    686   1.9   thorpej 	}
    687   1.9   thorpej #endif /* __HAVE_UCAS_MP && MULTIPROCESSOR */
    688   1.9   thorpej 	return _ucas_64(uaddr, old, new, ret);
    689   1.9   thorpej }
    690   1.9   thorpej #endif /* _LP64 */
    691   1.9   thorpej 
    692   1.9   thorpej __strong_alias(ucas_int,ucas_32);
    693   1.9   thorpej #ifdef _LP64
    694   1.9   thorpej __strong_alias(ucas_ptr,ucas_64);
    695   1.9   thorpej #else
    696   1.9   thorpej __strong_alias(ucas_ptr,ucas_32);
    697   1.9   thorpej #endif /* _LP64 */
    698   1.9   thorpej 
    699   1.9   thorpej int
    700   1.9   thorpej ufetch_8(const uint8_t *uaddr, uint8_t *valp)
    701   1.9   thorpej {
    702   1.9   thorpej 
    703   1.9   thorpej 	ASSERT_SLEEPABLE();
    704   1.9   thorpej 	CHECK_ALIGNMENT();
    705   1.9   thorpej 	return _ufetch_8(uaddr, valp);
    706   1.9   thorpej }
    707   1.9   thorpej 
    708   1.9   thorpej int
    709   1.9   thorpej ufetch_16(const uint16_t *uaddr, uint16_t *valp)
    710   1.9   thorpej {
    711   1.9   thorpej 
    712   1.9   thorpej 	ASSERT_SLEEPABLE();
    713   1.9   thorpej 	CHECK_ALIGNMENT();
    714   1.9   thorpej 	return _ufetch_16(uaddr, valp);
    715   1.9   thorpej }
    716   1.9   thorpej 
    717   1.9   thorpej int
    718   1.9   thorpej ufetch_32(const uint32_t *uaddr, uint32_t *valp)
    719   1.9   thorpej {
    720   1.9   thorpej 
    721   1.9   thorpej 	ASSERT_SLEEPABLE();
    722   1.9   thorpej 	CHECK_ALIGNMENT();
    723   1.9   thorpej 	return _ufetch_32(uaddr, valp);
    724   1.9   thorpej }
    725   1.9   thorpej 
    726   1.9   thorpej #ifdef _LP64
    727   1.9   thorpej int
    728   1.9   thorpej ufetch_64(const uint64_t *uaddr, uint64_t *valp)
    729   1.9   thorpej {
    730   1.9   thorpej 
    731   1.9   thorpej 	ASSERT_SLEEPABLE();
    732   1.9   thorpej 	CHECK_ALIGNMENT();
    733   1.9   thorpej 	return _ufetch_64(uaddr, valp);
    734   1.9   thorpej }
    735   1.9   thorpej #endif /* _LP64 */
    736   1.9   thorpej 
    737   1.9   thorpej __strong_alias(ufetch_char,ufetch_8);
    738   1.9   thorpej __strong_alias(ufetch_short,ufetch_16);
    739   1.9   thorpej __strong_alias(ufetch_int,ufetch_32);
    740   1.9   thorpej #ifdef _LP64
    741   1.9   thorpej __strong_alias(ufetch_long,ufetch_64);
    742   1.9   thorpej __strong_alias(ufetch_ptr,ufetch_64);
    743   1.9   thorpej #else
    744   1.9   thorpej __strong_alias(ufetch_long,ufetch_32);
    745   1.9   thorpej __strong_alias(ufetch_ptr,ufetch_32);
    746   1.9   thorpej #endif /* _LP64 */
    747   1.9   thorpej 
    748   1.9   thorpej int
    749   1.9   thorpej ustore_8(uint8_t *uaddr, uint8_t val)
    750   1.9   thorpej {
    751   1.9   thorpej 
    752   1.9   thorpej 	ASSERT_SLEEPABLE();
    753   1.9   thorpej 	CHECK_ALIGNMENT();
    754   1.9   thorpej 	return _ustore_8(uaddr, val);
    755   1.9   thorpej }
    756   1.9   thorpej 
    757   1.9   thorpej int
    758   1.9   thorpej ustore_16(uint16_t *uaddr, uint16_t val)
    759   1.9   thorpej {
    760   1.9   thorpej 
    761   1.9   thorpej 	ASSERT_SLEEPABLE();
    762   1.9   thorpej 	CHECK_ALIGNMENT();
    763   1.9   thorpej 	return _ustore_16(uaddr, val);
    764   1.9   thorpej }
    765   1.9   thorpej 
    766   1.9   thorpej int
    767   1.9   thorpej ustore_32(uint32_t *uaddr, uint32_t val)
    768   1.9   thorpej {
    769   1.9   thorpej 
    770   1.9   thorpej 	ASSERT_SLEEPABLE();
    771   1.9   thorpej 	CHECK_ALIGNMENT();
    772   1.9   thorpej 	return _ustore_32(uaddr, val);
    773   1.9   thorpej }
    774   1.9   thorpej 
    775   1.9   thorpej #ifdef _LP64
    776   1.9   thorpej int
    777   1.9   thorpej ustore_64(uint64_t *uaddr, uint64_t val)
    778   1.9   thorpej {
    779   1.9   thorpej 
    780   1.9   thorpej 	ASSERT_SLEEPABLE();
    781   1.9   thorpej 	CHECK_ALIGNMENT();
    782   1.9   thorpej 	return _ustore_64(uaddr, val);
    783   1.9   thorpej }
    784   1.9   thorpej #endif /* _LP64 */
    785   1.9   thorpej 
    786   1.9   thorpej __strong_alias(ustore_char,ustore_8);
    787   1.9   thorpej __strong_alias(ustore_short,ustore_16);
    788   1.9   thorpej __strong_alias(ustore_int,ustore_32);
    789   1.9   thorpej #ifdef _LP64
    790   1.9   thorpej __strong_alias(ustore_long,ustore_64);
    791   1.9   thorpej __strong_alias(ustore_ptr,ustore_64);
    792   1.9   thorpej #else
    793   1.9   thorpej __strong_alias(ustore_long,ustore_32);
    794   1.9   thorpej __strong_alias(ustore_ptr,ustore_32);
    795   1.9   thorpej #endif /* _LP64 */
    796