From d79b6f4de5db0103ceb4734e42ad101d836d61d9 Mon Sep 17 00:00:00 2001
From: Frederic Weisbecker
Date: Tue, 30 Mar 2010 07:27:50 +0200
Subject: procfs: Push down the bkl from ioctl

Push down the bkl from procfs's ioctl main handler to its users.
Only three procfs users implement an ioctl (non unlocked) handler.
Turn them into unlocked_ioctl and push down the Devil inside.

v2: PDE(inode)->data doesn't need to be under bkl
v3: And don't forget to git-add the result
v4: Use wrappers to pushdown instead of an invasive and error prone
    handlers surgery.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: John Kacur <jkacur@redhat.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
---
 drivers/char/i8k.c                  | 21 ++++++++++++++++-----
 drivers/isdn/divert/divert_procfs.c | 18 ++++++++++++++----
 2 files changed, 30 insertions(+), 9 deletions(-)

(limited to 'drivers')

diff --git a/drivers/char/i8k.c b/drivers/char/i8k.c
index fc8cf7ac7f2b..4cd8b227c11f 100644
--- a/drivers/char/i8k.c
+++ b/drivers/char/i8k.c
@@ -23,6 +23,7 @@
 #include <linux/seq_file.h>
 #include <linux/dmi.h>
 #include <linux/capability.h>
+#include <linux/smp_lock.h>
 #include <asm/uaccess.h>
 #include <asm/io.h>
 
@@ -82,8 +83,7 @@ module_param(fan_mult, int, 0);
 MODULE_PARM_DESC(fan_mult, "Factor to multiply fan speed with");
 
 static int i8k_open_fs(struct inode *inode, struct file *file);
-static int i8k_ioctl(struct inode *, struct file *, unsigned int,
-		     unsigned long);
+static long i8k_ioctl(struct file *, unsigned int, unsigned long);
 
 static const struct file_operations i8k_fops = {
 	.owner		= THIS_MODULE,
@@ -91,7 +91,7 @@ static const struct file_operations i8k_fops = {
 	.read		= seq_read,
 	.llseek		= seq_lseek,
 	.release	= single_release,
-	.ioctl		= i8k_ioctl,
+	.unlocked_ioctl	= i8k_ioctl,
 };
 
 struct smm_regs {
@@ -307,8 +307,8 @@ static int i8k_get_dell_signature(int req_fn)
 	return regs.eax == 1145651527 && regs.edx == 1145392204 ? 0 : -1;
 }
 
-static int i8k_ioctl(struct inode *ip, struct file *fp, unsigned int cmd,
-		     unsigned long arg)
+static int
+i8k_ioctl_unlocked(struct file *fp, unsigned int cmd, unsigned long arg)
 {
 	int val = 0;
 	int speed;
@@ -395,6 +395,17 @@ static int i8k_ioctl(struct inode *ip, struct file *fp, unsigned int cmd,
 	return 0;
 }
 
+static long i8k_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
+{
+	long ret;
+
+	lock_kernel();
+	ret = i8k_ioctl_unlocked(fp, cmd, arg);
+	unlock_kernel();
+
+	return ret;
+}
+
 /*
  * Print the information for /proc/i8k.
  */
diff --git a/drivers/isdn/divert/divert_procfs.c b/drivers/isdn/divert/divert_procfs.c
index 3697c409bec6..724693c4d975 100644
--- a/drivers/isdn/divert/divert_procfs.c
+++ b/drivers/isdn/divert/divert_procfs.c
@@ -19,6 +19,7 @@
 #include <linux/sched.h>
 #include <linux/isdnif.h>
 #include <net/net_namespace.h>
+#include <linux/smp_lock.h>
 #include "isdn_divert.h"
 
 
@@ -176,9 +177,7 @@ isdn_divert_close(struct inode *ino, struct file *filep)
 /*********/
 /* IOCTL */
 /*********/
-static int
-isdn_divert_ioctl(struct inode *inode, struct file *file,
-		  uint cmd, ulong arg)
+static int isdn_divert_ioctl_unlocked(struct file *file, uint cmd, ulong arg)
 {
 	divert_ioctl dioctl;
 	int i;
@@ -257,6 +256,17 @@ isdn_divert_ioctl(struct inode *inode, struct file *file,
 	return copy_to_user((void __user *)arg, &dioctl, sizeof(dioctl)) ? -EFAULT : 0;
 }				/* isdn_divert_ioctl */
 
+static long isdn_divert_ioctl(struct file *file, uint cmd, ulong arg)
+{
+	long ret;
+
+	lock_kernel();
+	ret = isdn_divert_ioctl_unlocked(file, cmd, arg);
+	unlock_kernel();
+
+	return ret;
+}
+
 static const struct file_operations isdn_fops =
 {
 	.owner          = THIS_MODULE,
@@ -264,7 +274,7 @@ static const struct file_operations isdn_fops =
 	.read           = isdn_divert_read,
 	.write          = isdn_divert_write,
 	.poll           = isdn_divert_poll,
-	.ioctl          = isdn_divert_ioctl,
+	.unlocked_ioctl = isdn_divert_ioctl,
 	.open           = isdn_divert_open,
 	.release        = isdn_divert_close,                                      
 };
-- 
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