ioctl support copy_to_user_variant_buffer

source/module/monitor_kernel.c

@@ -1,12 +1,12 @@
-#include <linux/cdev.h> // for cdev
+#include "monitor_kernel.h"
+
+#include <linux/cdev.h>  // for cdev
 #include <linux/device.h>
 #include <linux/fs.h>
 #include <linux/kernel.h>
 #include <linux/mm.h>
 #include <linux/module.h>
-#include <linux/slab.h> // for kmalloc
-
-#include "monitor_kernel.h"
+#include <linux/slab.h>  // for kmalloc
 
 #define DEVICE_NAME "variable_monitor"
 
@@ -21,11 +21,11 @@ struct my_device_data {
 
 static int device_open(struct inode *inode, struct file *file) {
   struct my_device_data *data;
-  printk(KERN_INFO "variable_monitor fun: %s with pid %d\n", __FUNCTION__, current->pid);
+  printk(KERN_INFO "variable_monitor fun: %s with pid %d\n", __FUNCTION__,
+         current->pid);
   // save pid
   data = kmalloc(sizeof(*data), GFP_KERNEL);
-  if (!data)
-    return -ENOMEM;
+  if (!data) return -ENOMEM;
   data->pid = current->pid;
   file->private_data = data;
   return 0;
@@ -34,26 +34,49 @@ static int device_open(struct inode *inode, struct file *file) {
 static int device_release(struct inode *inode, struct file *file) {
   // load pid
   struct my_device_data *data = file->private_data;
-  printk(KERN_INFO "variable_monitor fun: %s with pid %d\n", __FUNCTION__, data->pid);
+  printk(KERN_INFO "variable_monitor fun: %s with pid %d\n", __FUNCTION__,
+         data->pid);
   // clear watch with pid
   clear_watch(data->pid);
-  kfree(data); // free data memory
+  kfree(data);  // free data memory
   return 0;
 }
 
 static long device_ioctl(struct file *file, unsigned int ioctl_num,
                          unsigned long ioctl_param) {
+  int ret = 0;
   watch_arg warg;
-  // copy watch_arg
-  if (copy_from_user(&warg, (watch_arg *)ioctl_param, sizeof(warg))) {
-    return -EACCES;
+  ioctl_dump_param dump_param;
+
+  switch (ioctl_num) {
+    case 0:
+      // copy watch_arg
+      if (copy_from_user(&warg, (watch_arg *)ioctl_param, sizeof(warg))) {
+        return -EACCES;
+      }
+      printk(KERN_INFO
+             "Watch_arg: task_id=%d, name=%s, ptr=%p, length_byte=%d, "
+             "time_ns=%ld, threshold=%lld\n",
+             warg.task_id, warg.name, warg.ptr, warg.length_byte, warg.time_ns,
+             warg.threshold);
+      // start watch variable
+      start_watch_variable(warg);
+      break;
+    case 1:
+      ret = copy_from_user(&dump_param, (void *)ioctl_param,
+                           sizeof(ioctl_dump_param));
+      if (!ret) {
+        ret = copy_to_user_variant_buffer(
+            &load_monitor_variant_buffer, dump_param.user_ptr_len,
+            dump_param.user_buf, dump_param.user_buf_len);
+      }
+      printk(KERN_INFO "copy_to_user \n");
+
+      /* code */
+      break;
+    default:
+      break;
   }
-  printk(KERN_INFO "Watch_arg: task_id=%d, name=%s, ptr=%p, length_byte=%d, "
-                   "time_ns=%ld, threshold=%lld\n",
-         warg.task_id, warg.name, warg.ptr, warg.length_byte, warg.time_ns,
-         warg.threshold);
-  // start watch variable
-  start_watch_variable(warg);
   return 0;
 }
 

source/module/monitor_mem.h

@@ -3,6 +3,12 @@
 // for memory access
 // #include <linux/sched.h>
 
+typedef struct {
+	int __user *user_ptr_len;
+	size_t __user user_buf_len;
+	void __user *user_buf;
+} ioctl_dump_param;
+
 typedef struct {
   pid_t task_id; // current process id
   struct page *page;

source/uapi/monitor_user.c

@@ -19,7 +19,7 @@ int start_watch(watch_arg w_arg) {
     return -1;
   }
 
-  if (ioctl(file_desc, 1, &w_arg) < 0) {
+  if (ioctl(file_desc, 0, &w_arg) < 0) {
     printf("ioctl failed\n");
     close(file_desc);
     return -1;