On Monday, February 06, 2012 2:44:23 pm PRATIK MOHANTY wrote:
> Hello sir,
> I need some example for ioctl to copy structure from user space to kernel
> space
In BSD the kernel copies the immediate ioctl argument into and out of userland
for you. Thus, you can do something like this:
struct foo {
...
};
#define MY_IOCTL _IOWR('M', 1, struct foo)
And in your kernel code:
int
foo_ioctl(..., u_long cmd, caddr_t data)
{
struct foo *f;
switch (cmd) {
case MY_IOCTL:
f = (struct foo *)data;
/*
* 'f' is now a pointer to an in-kernel copy of
* the structure. Any changes made to it will
* be copied back out to userland after your
* routine returns.
*/
break;
}
}
--
John Baldwin
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