init

ass05/Makefile

@@ -0,0 +1,7 @@
+obj-m += main.o
+
+all:
+	make -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules
+
+clean:
+	make -C /lib/modules/$(shell uname -r)/build M=$(PWD) clean

ass05/main.c

@@ -0,0 +1,74 @@
+#include <linux/miscdevice.h>
+#include <linux/fs.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+
+#define STUDENT_LOGIN "cchauvet"
+
+MODULE_LICENSE("GPL");
+
+static ssize_t misc_write(struct file *file, const char __user *buf,
+               size_t len, loff_t *ppos)
+{
+	char data[10];
+	size_t len_red = 10 > len ? len : 10;
+
+	if (copy_from_user(data, buf, len_red))
+		return -EFAULT;
+	
+	if (strcmp(data, STUDENT_LOGIN))
+		return -EINVAL;
+
+	return len_red;
+}
+ 
+static ssize_t misc_read(struct file *file, char __user *buf,
+                    size_t count, loff_t *f_pos)
+{
+	char data[] = STUDENT_LOGIN;
+	size_t len = strlen(data);
+
+	if(*f_pos > 0)
+		return 0;
+
+	if (copy_to_user(buf, data, len))
+		return -EFAULT;
+
+	*f_pos += len;
+	return len;
+}
+
+const struct file_operations fops = {
+    .write          = misc_write,
+    .read           = misc_read,
+};
+
+static struct miscdevice misc_device = {
+    .name = "fortytwo",
+    .minor = MISC_DYNAMIC_MINOR,
+    .fops = &fops,
+};
+
+static int __init module_start(void)
+{
+    int error = misc_register(&misc_device);
+
+    if (error) {
+        pr_err("misc_register failed!!!\n");
+        return error;
+    }
+ 
+    pr_info("misc_register init done!!!\n");
+    return 0;
+}
+
+static void __exit module_end(void)
+{
+    misc_deregister(&misc_device);
+    pr_info("misc_register exit done!!!\n");
+}
+ 
+module_init(module_start)
+module_exit(module_end)
+