um: Remove BKL from mmapper

cycle_kernel_lock() was added during the big BKL pushdown. It should
ensure the serializiation against driver init code.

mmapper_open() cannot be called before misc_register() succeeded, but
p_buf might be uninitialized.

Move the initialization of p_buf before the misc_register() call and
get rid of cycle_kernel_lock().

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
LKML-Reference: <20091010153349.682213670@linutronix.de>
Cc: Jeff Dike <jdike@addtoit.com>

1 files changed, 4 insertions, 7 deletions

diff --git a/arch/um/drivers/mmapper_kern.c b/arch/um/drivers/mmapper_kern.c
index eb240323c40a..d22f9e5c0eac 100644
--- a/arch/um/drivers/mmapper_kern.c
+++ b/arch/um/drivers/mmapper_kern.c
@@ -16,7 +16,7 @@
 #include <linux/miscdevice.h>
 #include <linux/module.h>
 #include <linux/mm.h>
-#include <linux/smp_lock.h>
+
 #include <asm/uaccess.h>
 #include "mem_user.h"
 
@@ -78,7 +78,6 @@ out:
 
 static int mmapper_open(struct inode *inode, struct file *file)
 {
-        cycle_kernel_lock();
         return 0;
 }
 
@@ -115,18 +114,16 @@ static int __init mmapper_init(void)
         v_buf = (char *) find_iomem("mmapper", &mmapper_size);
         if (mmapper_size == 0) {
                 printk(KERN_ERR "mmapper_init - find_iomem failed\n");
-                goto out;
+                return -ENODEV;
         }
+        p_buf = __pa(v_buf);
 
         err = misc_register(&mmapper_dev);
         if (err) {
                 printk(KERN_ERR "mmapper - misc_register failed, err = %d\n",
                        err);
-                goto out;
+                return err;;
         }
-
-        p_buf = __pa(v_buf);
-out:
         return 0;
 }