xref: /netbsd-src/sys/kern/subr_copy.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /*	$NetBSD: subr_copy.c,v 1.1 2009/11/04 16:54:00 pooka Exp $	*/
2 
3 /*-
4  * Copyright (c) 1997, 1998, 1999, 2002, 2007, 2008 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
9  * NASA Ames Research Center.
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  *
20  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30  * POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 /*
34  * Copyright (c) 1982, 1986, 1991, 1993
35  *	The Regents of the University of California.  All rights reserved.
36  * (c) UNIX System Laboratories, Inc.
37  * All or some portions of this file are derived from material licensed
38  * to the University of California by American Telephone and Telegraph
39  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
40  * the permission of UNIX System Laboratories, Inc.
41  *
42  * Copyright (c) 1992, 1993
43  *	The Regents of the University of California.  All rights reserved.
44  *
45  * This software was developed by the Computer Systems Engineering group
46  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
47  * contributed to Berkeley.
48  *
49  * All advertising materials mentioning features or use of this software
50  * must display the following acknowledgement:
51  *	This product includes software developed by the University of
52  *	California, Lawrence Berkeley Laboratory.
53  *
54  * Redistribution and use in source and binary forms, with or without
55  * modification, are permitted provided that the following conditions
56  * are met:
57  * 1. Redistributions of source code must retain the above copyright
58  *    notice, this list of conditions and the following disclaimer.
59  * 2. Redistributions in binary form must reproduce the above copyright
60  *    notice, this list of conditions and the following disclaimer in the
61  *    documentation and/or other materials provided with the distribution.
62  * 3. Neither the name of the University nor the names of its contributors
63  *    may be used to endorse or promote products derived from this software
64  *    without specific prior written permission.
65  *
66  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
67  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
68  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
69  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
70  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
71  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
72  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
73  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
74  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
75  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
76  * SUCH DAMAGE.
77  *
78  *	@(#)kern_subr.c	8.4 (Berkeley) 2/14/95
79  */
80 
81 #include <sys/cdefs.h>
82 __KERNEL_RCSID(0, "$NetBSD: subr_copy.c,v 1.1 2009/11/04 16:54:00 pooka Exp $");
83 
84 #include <sys/param.h>
85 #include <sys/fcntl.h>
86 #include <sys/proc.h>
87 #include <sys/systm.h>
88 
89 #include <uvm/uvm_extern.h>
90 
91 void
92 uio_setup_sysspace(struct uio *uio)
93 {
94 
95 	uio->uio_vmspace = vmspace_kernel();
96 }
97 
98 int
99 uiomove(void *buf, size_t n, struct uio *uio)
100 {
101 	struct vmspace *vm = uio->uio_vmspace;
102 	struct iovec *iov;
103 	size_t cnt;
104 	int error = 0;
105 	char *cp = buf;
106 
107 	ASSERT_SLEEPABLE();
108 
109 #ifdef DIAGNOSTIC
110 	if (uio->uio_rw != UIO_READ && uio->uio_rw != UIO_WRITE)
111 		panic("uiomove: mode");
112 #endif
113 	while (n > 0 && uio->uio_resid) {
114 		iov = uio->uio_iov;
115 		cnt = iov->iov_len;
116 		if (cnt == 0) {
117 			KASSERT(uio->uio_iovcnt > 0);
118 			uio->uio_iov++;
119 			uio->uio_iovcnt--;
120 			continue;
121 		}
122 		if (cnt > n)
123 			cnt = n;
124 		if (!VMSPACE_IS_KERNEL_P(vm)) {
125 			if (curcpu()->ci_schedstate.spc_flags &
126 			    SPCF_SHOULDYIELD)
127 				preempt();
128 		}
129 
130 		if (uio->uio_rw == UIO_READ) {
131 			error = copyout_vmspace(vm, cp, iov->iov_base,
132 			    cnt);
133 		} else {
134 			error = copyin_vmspace(vm, iov->iov_base, cp,
135 			    cnt);
136 		}
137 		if (error) {
138 			break;
139 		}
140 		iov->iov_base = (char *)iov->iov_base + cnt;
141 		iov->iov_len -= cnt;
142 		uio->uio_resid -= cnt;
143 		uio->uio_offset += cnt;
144 		cp += cnt;
145 		KDASSERT(cnt <= n);
146 		n -= cnt;
147 	}
148 
149 	return (error);
150 }
151 
152 /*
153  * Wrapper for uiomove() that validates the arguments against a known-good
154  * kernel buffer.
155  */
156 int
157 uiomove_frombuf(void *buf, size_t buflen, struct uio *uio)
158 {
159 	size_t offset;
160 
161 	if (uio->uio_offset < 0 || /* uio->uio_resid < 0 || */
162 	    (offset = uio->uio_offset) != uio->uio_offset)
163 		return (EINVAL);
164 	if (offset >= buflen)
165 		return (0);
166 	return (uiomove((char *)buf + offset, buflen - offset, uio));
167 }
168 
169 /*
170  * Give next character to user as result of read.
171  */
172 int
173 ureadc(int c, struct uio *uio)
174 {
175 	struct iovec *iov;
176 
177 	if (uio->uio_resid <= 0)
178 		panic("ureadc: non-positive resid");
179 again:
180 	if (uio->uio_iovcnt <= 0)
181 		panic("ureadc: non-positive iovcnt");
182 	iov = uio->uio_iov;
183 	if (iov->iov_len <= 0) {
184 		uio->uio_iovcnt--;
185 		uio->uio_iov++;
186 		goto again;
187 	}
188 	if (!VMSPACE_IS_KERNEL_P(uio->uio_vmspace)) {
189 		if (subyte(iov->iov_base, c) < 0)
190 			return (EFAULT);
191 	} else {
192 		*(char *)iov->iov_base = c;
193 	}
194 	iov->iov_base = (char *)iov->iov_base + 1;
195 	iov->iov_len--;
196 	uio->uio_resid--;
197 	uio->uio_offset++;
198 	return (0);
199 }
200 
201 /*
202  * Like copyin(), but operates on an arbitrary vmspace.
203  */
204 int
205 copyin_vmspace(struct vmspace *vm, const void *uaddr, void *kaddr, size_t len)
206 {
207 	struct iovec iov;
208 	struct uio uio;
209 	int error;
210 
211 	if (len == 0)
212 		return (0);
213 
214 	if (VMSPACE_IS_KERNEL_P(vm)) {
215 		return kcopy(uaddr, kaddr, len);
216 	}
217 	if (__predict_true(vm == curproc->p_vmspace)) {
218 		return copyin(uaddr, kaddr, len);
219 	}
220 
221 	iov.iov_base = kaddr;
222 	iov.iov_len = len;
223 	uio.uio_iov = &iov;
224 	uio.uio_iovcnt = 1;
225 	uio.uio_offset = (off_t)(uintptr_t)uaddr;
226 	uio.uio_resid = len;
227 	uio.uio_rw = UIO_READ;
228 	UIO_SETUP_SYSSPACE(&uio);
229 	error = uvm_io(&vm->vm_map, &uio);
230 
231 	return (error);
232 }
233 
234 /*
235  * Like copyout(), but operates on an arbitrary vmspace.
236  */
237 int
238 copyout_vmspace(struct vmspace *vm, const void *kaddr, void *uaddr, size_t len)
239 {
240 	struct iovec iov;
241 	struct uio uio;
242 	int error;
243 
244 	if (len == 0)
245 		return (0);
246 
247 	if (VMSPACE_IS_KERNEL_P(vm)) {
248 		return kcopy(kaddr, uaddr, len);
249 	}
250 	if (__predict_true(vm == curproc->p_vmspace)) {
251 		return copyout(kaddr, uaddr, len);
252 	}
253 
254 	iov.iov_base = __UNCONST(kaddr); /* XXXUNCONST cast away const */
255 	iov.iov_len = len;
256 	uio.uio_iov = &iov;
257 	uio.uio_iovcnt = 1;
258 	uio.uio_offset = (off_t)(uintptr_t)uaddr;
259 	uio.uio_resid = len;
260 	uio.uio_rw = UIO_WRITE;
261 	UIO_SETUP_SYSSPACE(&uio);
262 	error = uvm_io(&vm->vm_map, &uio);
263 
264 	return (error);
265 }
266 
267 /*
268  * Like copyin(), but operates on an arbitrary process.
269  */
270 int
271 copyin_proc(struct proc *p, const void *uaddr, void *kaddr, size_t len)
272 {
273 	struct vmspace *vm;
274 	int error;
275 
276 	error = proc_vmspace_getref(p, &vm);
277 	if (error) {
278 		return error;
279 	}
280 	error = copyin_vmspace(vm, uaddr, kaddr, len);
281 	uvmspace_free(vm);
282 
283 	return error;
284 }
285 
286 /*
287  * Like copyout(), but operates on an arbitrary process.
288  */
289 int
290 copyout_proc(struct proc *p, const void *kaddr, void *uaddr, size_t len)
291 {
292 	struct vmspace *vm;
293 	int error;
294 
295 	error = proc_vmspace_getref(p, &vm);
296 	if (error) {
297 		return error;
298 	}
299 	error = copyout_vmspace(vm, kaddr, uaddr, len);
300 	uvmspace_free(vm);
301 
302 	return error;
303 }
304 
305 /*
306  * Like copyin(), except it operates on kernel addresses when the FKIOCTL
307  * flag is passed in `ioctlflags' from the ioctl call.
308  */
309 int
310 ioctl_copyin(int ioctlflags, const void *src, void *dst, size_t len)
311 {
312 	if (ioctlflags & FKIOCTL)
313 		return kcopy(src, dst, len);
314 	return copyin(src, dst, len);
315 }
316 
317 /*
318  * Like copyout(), except it operates on kernel addresses when the FKIOCTL
319  * flag is passed in `ioctlflags' from the ioctl call.
320  */
321 int
322 ioctl_copyout(int ioctlflags, const void *src, void *dst, size_t len)
323 {
324 	if (ioctlflags & FKIOCTL)
325 		return kcopy(src, dst, len);
326 	return copyout(src, dst, len);
327 }
328