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OpenCloudOS-Kernel
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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>
This commit is contained in:
Thomas Gleixner 2009-10-10 15:36:34 +00:00
parent df502e3893
commit d63c489b88
1 changed files with 4 additions and 7 deletions
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11
arch/um/drivers/mmapper_kern.c
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@ -16,7 +16,7 @@
#include <linux/miscdevice.h> #include <linux/miscdevice.h>
#include <linux/module.h> #include <linux/module.h>
#include <linux/mm.h> #include <linux/mm.h>
#include <linux/smp_lock.h>
#include <asm/uaccess.h> #include <asm/uaccess.h>
#include "mem_user.h" #include "mem_user.h"
@ -78,7 +78,6 @@ out:
static int mmapper_open(struct inode *inode, struct file *file) static int mmapper_open(struct inode *inode, struct file *file)
{ {
cycle_kernel_lock();
return 0; return 0;
} }
@ -115,18 +114,16 @@ static int __init mmapper_init(void)
v_buf = (char *) find_iomem("mmapper", &mmapper_size); v_buf = (char *) find_iomem("mmapper", &mmapper_size);
if (mmapper_size == 0) { if (mmapper_size == 0) {
printk(KERN_ERR "mmapper_init - find_iomem failed\n"); printk(KERN_ERR "mmapper_init - find_iomem failed\n");
goto out; return -ENODEV;
} }
p_buf = __pa(v_buf);
err = misc_register(&mmapper_dev); err = misc_register(&mmapper_dev);
if (err) { if (err) {
printk(KERN_ERR "mmapper - misc_register failed, err = %d\n", printk(KERN_ERR "mmapper - misc_register failed, err = %d\n",
err); err);
goto out; return err;;
} }
p_buf = __pa(v_buf);
out:
return 0; return 0;
} }