From 0d9aff9bd305d18625c322a1a891aba278049862 Mon Sep 17 00:00:00 2001
From: Kyle K <kylek389@gmail.com>
Date: Mon, 24 Dec 2012 12:53:20 -0600
Subject: spawn char device at /dev/, implement read

---
 debug.c | 22 +++++++++++++++-------
 1 file changed, 15 insertions(+), 7 deletions(-)

(limited to 'debug.c')

diff --git a/debug.c b/debug.c
index 40ee10c..5c746d1 100644
--- a/debug.c
+++ b/debug.c
@@ -10,6 +10,8 @@
 #include <linux/types.h>
 #include <linux/errno.h>
 
+#include <linux/uaccess.h>
+
 #include <debug.h>
 #include <main.h>
 
@@ -24,7 +26,7 @@ char kernel_buff[BUFF_LEN] = {'f','o','o','b','a','r','\0'};
 int fileprv = 1; /* hmm */
 
 /* struct file, an abstract open file, not on disk, which would be a an inode */
-static ssize_t debugfs_read(struct file *fp, char __user /* userspace */ *ubuff, size_t c, loff_t *pos)
+static ssize_t hello_hello_debugfs_read(struct file *fp, char __user /* userspace */ *ubuff, size_t c, loff_t *pos)
 {
     /**
      * simple_read_from_buffer - copy data from the buffer to user space
@@ -43,7 +45,7 @@ static ssize_t debugfs_read(struct file *fp, char __user /* userspace */ *ubuff,
     return simple_read_from_buffer(ubuff, c, pos, kernel_buff, BUFF_LEN);
 }
 
-static ssize_t debugfs_write(struct file *fp, const char __user *ubuff, size_t c, loff_t *pos)
+static ssize_t hello_debugfs_write(struct file *fp, const char __user *ubuff, size_t c, loff_t *pos)
 {
     /**
      * simple_write_to_buffer - copy data from user space to the buffer
@@ -64,14 +66,20 @@ static ssize_t debugfs_write(struct file *fp, const char __user *ubuff, size_t c
         return (-EINVAL);
 
     return simple_write_to_buffer(kernel_buff, BUFF_LEN, pos, ubuff, c);
+
+#if 0
+    printk(KERN_INFO "count %lu, offset %u", c, *pos);
+    copy_from_user(kernel_buff + *pos, ubuff, c);
+    return c;
+#endif
 }
 
-int debug_init(struct dentry **dir, struct dentry **file)
+int hello_debugfs_init(struct dentry **dir, struct dentry **file)
 {
     /* func ptrs that perform various operations on the device, in this case char device, well not even */
     struct file_operations fops = {
-        .read = debugfs_read,
-        .write = debugfs_write
+        .read = hello_hello_debugfs_read,
+        .write = hello_debugfs_write
     };
     /* omitted fields are initialized to NULL */
 
@@ -82,12 +90,12 @@ int debug_init(struct dentry **dir, struct dentry **file)
     /* regular file, read by user/group/other, write by user */
     *file = debugfs_create_file("magic", S_IFREG | S_IRUGO | S_IWUSR, *dir, &fileprv, &fops);
     if (!*file)
-        printk("debugfs: error creating file\n");
+        printk(KERN_WARNING "[hello] debugfs: error creating file\n");
 
     return 0;
 }
 
-int debug_destroy(struct dentry *dir, struct dentry *file)
+int hello_debugfs_destroy(struct dentry *dir, struct dentry *file)
 {
     if (file)
         debugfs_remove(file);
-- 
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