Copyright 1989 AT&T Copyright (c) 2000, Sun Microsystems, Inc. All Rights Reserved
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]
#include <sys/types.h> #include <sys/ddi.h> int copyin(const void *userbuf, void *driverbuf, size_t cn);
This interface is obsolete. ddi_copyin(9F) should be used instead.
User program source address from which data is transferred.
Driver destination address to which data is transferred.
Number of bytes transferred.
copyin() copies data from a user program source address to a driver buffer. The driver developer must ensure that adequate space is allocated for the destination address.
Addresses that are word-aligned are moved most efficiently. However, the driver developer is not obligated to ensure alignment. This function automatically finds the most efficient move according to address alignment.
Under normal conditions, a 0 is returned indicating a successful copy. Otherwise, a -1 is returned if one of the following occurs:
Paging fault; the driver tried to access a page of memory for which it did not have read or write access.
Invalid user address, such as a user area or stack area.
Invalid address that would have resulted in data being copied into the user block.
Hardware fault; a hardware error prevented access to the specified user memory. For example, an uncorrectable parity or ECC error occurred.
If a -1 is returned to the caller, driver entry point routines should return EFAULT.
copyin() can be called from user context only.
Example 1 An ioctl() Routine
A driver ioctl(9E) routine (line 10) can be used to get or set device attributes or registers. In the XX_GETREGS condition (line 17), the driver copies the current device register values to a user data area (line 18). If the specified argument contains an invalid address, an error code is returned.
1 struct device { /* layout of physical device registers */
2 int control; /* physical device control word */
3 int status; /* physical device status word */
4 short recv_char; /* receive character from device */
5 short xmit_char; /* transmit character to device */
6 };
7
8 extern struct device xx_addr[]; /* phys. device regs. location */
9 ...
10 xx_ioctl(dev_t dev, int cmd, int arg, int mode,
11 cred_t *cred_p, int *rval_p)
12 ...
13 {
14 register struct device *rp = &xx_addr[getminor(dev) >> 4];
15 switch (cmd) {
16
17 case XX_GETREGS: /* copy device regs. to user program */
18 if (copyin(arg, rp, sizeof(struct device)))
19 return(EFAULT);
20 break;
21 ...
22 }
23 ...
24 }
See attributes(7) for a description of the following attributes:
| ATTRIBUTE TYPE ATTRIBUTE VALUE |
| Stability Level Obsolete |
attributes (7), ioctl (9E), bcopy (9F), copyout (9F), ddi_copyin (9F), ddi_copyout (9F), uiomove (9F)
Writing Device Drivers
Driver writers who intend to support layered ioctls in their ioctl(9E) routines should use ddi_copyin(9F) instead.
Driver defined locks should not be held across calls to this function.
copyin() should not be used from a streams driver. See M_COPYIN and M_COPYOUT in STREAMS Programming Guide.