[tip:bkl/arch] um: Remove BKL from mmapper

From: tip-bot for Thomas Gleixner
Date: Wed Oct 14 2009 - 11:47:20 EST


Commit-ID: d63c489b881707adf9c0b89f771b30a1d78f4197
Gitweb: http://git.kernel.org/tip/d63c489b881707adf9c0b89f771b30a1d78f4197
Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate: Sat, 10 Oct 2009 15:36:34 +0000
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Wed, 14 Oct 2009 15:35:51 +0200

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@xxxxxxxxxxxxx>
LKML-Reference: <20091010153349.682213670@xxxxxxxxxxxxx>
Cc: Jeff Dike <jdike@xxxxxxxxxxx>
---
arch/um/drivers/mmapper_kern.c | 11 ++++-------
1 files changed, 4 insertions(+), 7 deletions(-)

diff --git a/arch/um/drivers/mmapper_kern.c b/arch/um/drivers/mmapper_kern.c
index eb24032..d22f9e5 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;
}

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