1/fopdrv.c


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#include "fopdrv.h"

// driver/char/mem.c read_null (/dev/null)
ssize_t fop_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) {
	return 0;
}

// driver/char/mem.c write_null
ssize_t fop_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) {
	return count;
}

int fop_open(struct inode * inode, struct file * file) {
	printk("%s\n", __PRETTY_FUNCTION__);
	return 0;
	// 0 seems to be a safe return value as it's used in driver/char/mem.c. The
	// manual page for open(2) says that the system call returns a nonnegative
	// integer representing the file descriptor on success, but it does not
	// appears to be required.
}

int fop_release(struct inode * inode, struct file * file) {
	printk("%s\n", __PRETTY_FUNCTION__);
	return 0;
	// same as above, but found in driver/char/lp.c
}