set permisson

lab6/Makefile

@@ -1,4 +1,4 @@
-obj-m += mypipe.o
+obj-m += wendy.o
 OUT_DIR := build
 
 .PHONY: all kern_mod install uninstall clean reader writer
@@ -6,14 +6,14 @@ OUT_DIR := build
 all: kern_mod
 	@true
 
-kern_mod: mypipe.c
+kern_mod: wendy.c
 	make -C /lib/modules/$(shell uname -r)/build M=$(PWD) MO=$(PWD)/build/kern
 
 install:
-	insmod ./build/mypipe.ko
+	sudo insmod ./build/kern/wendy.ko
 
 uninstall:
-	rmmod mypipe
+	sudo rmmod wendy
 
 reader:
 	mkdir -p $(OUT_DIR)

lab6/wendy.c

@@ -39,12 +39,12 @@ static DECLARE_WAIT_QUEUE_HEAD(read_queue);
 static DECLARE_WAIT_QUEUE_HEAD(write_queue);
 
 static int mypipe_open(struct inode *inode, struct file *file) {
-    printk("Mypipe opened.");
+    printk(KERN_INFO "Wendy opened.");
     return 0;
 }
 
 static int mypipe_release(struct inode *inode, struct file *file) {
-    printk("Mypipe released.");
+    printk(KERN_INFO "Wendy released.");
     return 0;
 }
 
@@ -102,8 +102,8 @@ out:
     return ret;
 }
 
-static ssize_t mypipe_write(struct file *filep, const char __user *buf, size_t size,
-                        loff_t *offset) {
+static ssize_t mypipe_write(struct file *filep, const char __user *buf,
+                            size_t size, loff_t *offset) {
     // This is very similar to read(), just write instead of read
 
     ssize_t ret = 0;
@@ -164,6 +164,12 @@ const struct file_operations mypipe_fops = {.owner = THIS_MODULE,
                                             .write = mypipe_write,
                                             .release = mypipe_release};
 
+// Used to set the permission to allow any user to r/w
+static int mypipe_uevent(const struct device *dev, struct kobj_uevent_env *env) {
+    add_uevent_var(env, "DEVMODE=%#o", 0666);
+    return 0;
+}
+
 static int __init mypipe_init(void) {
     int ret;
     dev_t dev;
@@ -183,6 +189,7 @@ static int __init mypipe_init(void) {
         ret = PTR_ERR(mypipedev_class);
         goto del_cdev;
     }
+    mypipedev_class->dev_uevent = mypipe_uevent;
 
     // Create a cdev in our pdata
     cdev_init(&pdata.cdev, &mypipe_fops);