On 9/13/05, raja <vnagaraju@xxxxxxxxxxxx> wrote: > Hi, > I am implementing the ioctl function for my own character device driver. > In that I want to get the size of the device. > ioctl takes the last argument as long int. > i have to use the copy_to_user() symbol > > the second and third arguments for this symbol is the address of the > device size and the size of the long int. > (i.e) > copy_to_user(,&DEVICE_SIZE,sizeof(long int)); > where DEVICE_SIZE is the size of my device.How can i use the first argument? > In ioctl (kernel) you got four arguments in which 3rd one is for the command and 4th one is the pointer/address of the user space buffer (in unsigned long arg) .... so for call copy_to_user in this manner : copy_to_user((void __user *)arg, &DEVICE_SIZE, sizeof(long)); -- Fawad Lateef -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
