Re: Simple Misc Driver - Problem with string copy to user

I think it is good for you to read LDD3 or google some corresponding materials at first. 2014-05-27 20:48 GMT+08:00 Lucas Tanure <tanure@linux.com>:

Hi!

Goal, when the user do : # head -1 /dev/miscdrv

The driver prints: Hello World!

Steps: # Make # insmod misc.ko # head -1 /dev/miscdrv

Why my driver doesn't work ?

What is worg with my read operation?

static ssize_t misc_drv_read(struct file *filp, char __user * buf, size_t count, loff_t * offp){ int nbytes; char * string = "hello World"; nbytes = copy_to_user(buf, string, 12); return nbytes; }

-- Lucas Tanure Brazil

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