1 files changed, 37 insertions, 57 deletions

diff --git a/drivers/s390/char/vmcp.c b/drivers/s390/char/vmcp.c
index 2f419b0ea62..0fdedadff7b 100644
--- a/drivers/s390/char/vmcp.c
+++ b/drivers/s390/char/vmcp.c
@@ -1,32 +1,29 @@
 /*
- * Copyright IBM Corp. 2004,2007
+ * Copyright IBM Corp. 2004, 2010
  * Interface implementation for communication with the z/VM control program
- * Author(s): Christian Borntraeger <borntraeger@de.ibm.com>
  *
+ * Author(s): Christian Borntraeger <borntraeger@de.ibm.com>
  *
  * z/VMs CP offers the possibility to issue commands via the diagnose code 8
  * this driver implements a character device that issues these commands and
  * returns the answer of CP.
-
+ *
  * The idea of this driver is based on cpint from Neale Ferguson and #CP in CMS
  */
 
 #include <linux/fs.h>
 #include <linux/init.h>
+#include <linux/compat.h>
 #include <linux/kernel.h>
 #include <linux/miscdevice.h>
-#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/export.h>
+#include <asm/compat.h>
 #include <asm/cpcmd.h>
 #include <asm/debug.h>
 #include <asm/uaccess.h>
 #include "vmcp.h"
 
-MODULE_LICENSE("GPL");
-MODULE_AUTHOR("Christian Borntraeger <borntraeger@de.ibm.com>");
-MODULE_DESCRIPTION("z/VM CP interface");
-
-#define PRINTK_HEADER "vmcp: "
-
 static debug_info_t *vmcp_debug;
 
 static int vmcp_open(struct inode *inode, struct file *file)
@@ -39,6 +36,7 @@ static int vmcp_open(struct inode *inode, struct file *file)
 	session = kmalloc(sizeof(*session), GFP_KERNEL);
 	if (!session)
 		return -ENOMEM;
+
 	session->bufsize = PAGE_SIZE;
 	session->response = NULL;
 	session->resp_size = 0;
@@ -51,7 +49,7 @@ static int vmcp_release(struct inode *inode, struct file *file)
 {
 	struct vmcp_session *session;
 
-	session = (struct vmcp_session *)file->private_data;
+	session = file->private_data;
 	file->private_data = NULL;
 	free_pages((unsigned long)session->response, get_order(session->bufsize));
 	kfree(session);
@@ -61,30 +59,24 @@ static int vmcp_release(struct inode *inode, struct file *file)
 static ssize_t
 vmcp_read(struct file *file, char __user *buff, size_t count, loff_t *ppos)
 {
-	size_t tocopy;
+	ssize_t ret;
+	size_t size;
 	struct vmcp_session *session;
 
-	session = (struct vmcp_session *)file->private_data;
+	session = file->private_data;
 	if (mutex_lock_interruptible(&session->mutex))
 		return -ERESTARTSYS;
 	if (!session->response) {
 		mutex_unlock(&session->mutex);
 		return 0;
 	}
-	if (*ppos > session->resp_size) {
-		mutex_unlock(&session->mutex);
-		return 0;
-	}
-	tocopy = min(session->resp_size - (size_t) (*ppos), count);
-	tocopy = min(tocopy, session->bufsize - (size_t) (*ppos));
+	size = min_t(size_t, session->resp_size, session->bufsize);
+	ret = simple_read_from_buffer(buff, count, ppos,
+					session->response, size);
 
-	if (copy_to_user(buff, session->response + (*ppos), tocopy)) {
-		mutex_unlock(&session->mutex);
-		return -EFAULT;
-	}
 	mutex_unlock(&session->mutex);
-	*ppos += tocopy;
-	return tocopy;
+
+	return ret;
 }
 
 static ssize_t
@@ -104,7 +96,7 @@ vmcp_write(struct file *file, const char __user *buff, size_t count,
 		return -EFAULT;
 	}
 	cmd[count] = '\0';
-	session = (struct vmcp_session *)file->private_data;
+	session = file->private_data;
 	if (mutex_lock_interruptible(&session->mutex)) {
 		kfree(cmd);
 		return -ERESTARTSYS;
@@ -143,21 +135,26 @@ vmcp_write(struct file *file, const char __user *buff, size_t count,
 static long vmcp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
 	struct vmcp_session *session;
+	int __user *argp;
 	int temp;
 
-	session = (struct vmcp_session *)file->private_data;
+	session = file->private_data;
+	if (is_compat_task())
+		argp = compat_ptr(arg);
+	else
+		argp = (int __user *)arg;
 	if (mutex_lock_interruptible(&session->mutex))
 		return -ERESTARTSYS;
 	switch (cmd) {
 	case VMCP_GETCODE:
 		temp = session->resp_code;
 		mutex_unlock(&session->mutex);
-		return put_user(temp, (int __user *)arg);
+		return put_user(temp, argp);
 	case VMCP_SETBUF:
 		free_pages((unsigned long)session->response,
 				get_order(session->bufsize));
 		session->response=NULL;
-		temp = get_user(session->bufsize, (int __user *)arg);
+		temp = get_user(session->bufsize, argp);
 		if (get_order(session->bufsize) > 8) {
 			session->bufsize = PAGE_SIZE;
 			temp = -EINVAL;
@@ -167,7 +164,7 @@ static long vmcp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 	case VMCP_GETSIZE:
 		temp = session->resp_size;
 		mutex_unlock(&session->mutex);
-		return put_user(temp, (int __user *)arg);
+		return put_user(temp, argp);
 	default:
 		mutex_unlock(&session->mutex);
 		return -ENOIOCTLCMD;
@@ -182,6 +179,7 @@ static const struct file_operations vmcp_fops = {
 	.write		= vmcp_write,
 	.unlocked_ioctl	= vmcp_ioctl,
 	.compat_ioctl	= vmcp_ioctl,
+	.llseek		= no_llseek,
 };
 
 static struct miscdevice vmcp_dev = {
@@ -194,40 +192,22 @@ static int __init vmcp_init(void)
 {
 	int ret;
 
-	if (!MACHINE_IS_VM) {
-		PRINT_WARN("z/VM CP interface is only available under z/VM\n");
-		return -ENODEV;
-	}
+	if (!MACHINE_IS_VM)
+		return 0;
+
 	vmcp_debug = debug_register("vmcp", 1, 1, 240);
-	if (!vmcp_debug) {
-		PRINT_ERR("z/VM CP interface not loaded. Could not register "
-			   "debug feature\n");
+	if (!vmcp_debug)
 		return -ENOMEM;
-	}
+
 	ret = debug_register_view(vmcp_debug, &debug_hex_ascii_view);
 	if (ret) {
-		PRINT_ERR("z/VM CP interface not loaded. Could not register "
-			  "debug feature view. Error code: %d\n", ret);
 		debug_unregister(vmcp_debug);
 		return ret;
 	}
+
 	ret = misc_register(&vmcp_dev);
-	if (ret) {
-		PRINT_ERR("z/VM CP interface not loaded. Could not register "
-			   "misc device. Error code: %d\n", ret);
+	if (ret)
 		debug_unregister(vmcp_debug);
-		return ret;
-	}
-	PRINT_INFO("z/VM CP interface loaded\n");
-	return 0;
+	return ret;
 }
-
-static void __exit vmcp_exit(void)
-{
-	misc_deregister(&vmcp_dev);
-	debug_unregister(vmcp_debug);
-	PRINT_INFO("z/VM CP interface unloaded.\n");
-}
-
-module_init(vmcp_init);
-module_exit(vmcp_exit);
+device_initcall(vmcp_init);