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#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This interface is obsolete.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(5) for a description of the following attributes:
| ATTRIBUTE TYPE ATTRIBUTE VALUE |
| Stability Level Obsolete |
attributes(5), 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.