Add a bunch of cycle_kernel_lock() calls

All of the open() functions which don't need the BKL on their face may
still depend on its acquisition to serialize opens against driver
initialization.  So make those functions acquire then release the BKL to be
on the safe side.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>

8 files changed, 17 insertions, 42 deletions

diff --git a/drivers/char/cs5535_gpio.c b/drivers/char/cs5535_gpio.c
index 628e3d3..04ba906 100644
--- a/drivers/char/cs5535_gpio.c
+++ b/drivers/char/cs5535_gpio.c
@@ -17,6 +17,7 @@
 #include <linux/cdev.h>
 #include <linux/ioport.h>
 #include <linux/pci.h>
+#include <linux/smp_lock.h>
 #include <asm/uaccess.h>
 #include <asm/io.h>
 
@@ -153,12 +154,11 @@ static ssize_t cs5535_gpio_read(struct file *file, char __user *buf,
 	return count;
 }
 
-/* No BKL needed here - "mask" is the only global resource used
-   here and it's a boot-time parameter */
 static int cs5535_gpio_open(struct inode *inode, struct file *file)
 {
 	u32 m = iminor(inode);
 
+	cycle_kernel_lock();
 	/* the mask says which pins are usable by this driver */
 	if ((mask & (1 << m)) == 0)
 		return -EINVAL;
diff --git a/drivers/char/dtlk.c b/drivers/char/dtlk.c
index 433388c..6b900b2 100644
--- a/drivers/char/dtlk.c
+++ b/drivers/char/dtlk.c
@@ -56,6 +56,7 @@
 #include <linux/errno.h>	/* for -EBUSY */
 #include <linux/ioport.h>	/* for request_region */
 #include <linux/delay.h>	/* for loops_per_jiffy */
+#include <linux/smp_lock.h>	/* cycle_kernel_lock() */
 #include <asm/io.h>		/* for inb_p, outb_p, inb, outb, etc. */
 #include <asm/uaccess.h>	/* for get_user, etc. */
 #include <linux/wait.h>		/* for wait_queue */
@@ -288,12 +289,12 @@ static int dtlk_ioctl(struct inode *inode,
 	}
 }
 
-/* No BKL needed here; "dtlk_busy" is the only global resource,
-   and it is not ever set by anybody (test is broken) */
+/* Note that nobody ever sets dtlk_busy... */
 static int dtlk_open(struct inode *inode, struct file *file)
 {
 	TRACE_TEXT("(dtlk_open");
 
+	cycle_kernel_lock();
 	nonseekable_open(inode, file);
 	switch (iminor(inode)) {
 	case DTLK_MINOR:
diff --git a/drivers/char/ip2/ip2main.c b/drivers/char/ip2/ip2main.c
index 70957ac..a978c57 100644
--- a/drivers/char/ip2/ip2main.c
+++ b/drivers/char/ip2/ip2main.c
@@ -98,6 +98,7 @@
 #include <linux/major.h>
 #include <linux/wait.h>
 #include <linux/device.h>
+#include <linux/smp_lock.h>
 
 #include <linux/tty.h>
 #include <linux/tty_flip.h>
@@ -2931,42 +2932,11 @@ ip2_ipl_ioctl ( struct inode *pInode, struct file *pFile, UINT cmd, ULONG arg )
 static int
 ip2_ipl_open( struct inode *pInode, struct file *pFile )
 {
-	unsigned int iplminor = iminor(pInode);
-	i2eBordStrPtr pB;
-	i2ChanStrPtr  pCh;
 
 #ifdef IP2DEBUG_IPL
 	printk (KERN_DEBUG "IP2IPL: open\n" );
 #endif
-
-	switch(iplminor) {
-	// These are the IPL devices
-	case 0:
-	case 4:
-	case 8:
-	case 12:
-		break;
-
-	// These are the status devices
-	case 1:
-	case 5:
-	case 9:
-	case 13:
-		break;
-
-	// These are the debug devices
-	case 2:
-	case 6:
-	case 10:
-	case 14:
-		pB = i2BoardPtrTable[iplminor / 4];
-		pCh = (i2ChanStrPtr) pB->i2eChannelPtr;
-		break;
-
-	// This is the trace device
-	case 3:
-		break;
-	}
+	cycle_kernel_lock();
 	return 0;
 }
 
diff --git a/drivers/char/pc8736x_gpio.c b/drivers/char/pc8736x_gpio.c
index 8715dc9..b930de5 100644
--- a/drivers/char/pc8736x_gpio.c
+++ b/drivers/char/pc8736x_gpio.c
@@ -20,6 +20,7 @@
 #include <linux/mutex.h>
 #include <linux/nsc_gpio.h>
 #include <linux/platform_device.h>
+#include <linux/smp_lock.h>
 #include <asm/uaccess.h>
 
 #define DEVNAME "pc8736x_gpio"
@@ -212,12 +213,12 @@ static struct nsc_gpio_ops pc8736x_gpio_ops = {
 	.gpio_current	= pc8736x_gpio_current
 };
 
-/* No BKL needed here; no global resources accessed */
 static int pc8736x_gpio_open(struct inode *inode, struct file *file)
 {
 	unsigned m = iminor(inode);
 	file->private_data = &pc8736x_gpio_ops;
 
+	cycle_kernel_lock();
 	dev_dbg(&pdev->dev, "open %d\n", m);
 
 	if (m >= PC8736X_GPIO_CT)
diff --git a/drivers/char/ppdev.c b/drivers/char/ppdev.c
index ce19875..f6e6aca 100644
--- a/drivers/char/ppdev.c
+++ b/drivers/char/ppdev.c
@@ -66,6 +66,7 @@
 #include <linux/poll.h>
 #include <linux/major.h>
 #include <linux/ppdev.h>
+#include <linux/smp_lock.h>
 #include <asm/uaccess.h>
 
 #define PP_VERSION "ppdev: user-space parallel port driver"
@@ -633,12 +634,12 @@ static int pp_ioctl(struct inode *inode, struct file *file,
 	return 0;
 }
 
-/* No BKL needed here: only local resources used */
 static int pp_open (struct inode * inode, struct file * file)
 {
 	unsigned int minor = iminor(inode);
 	struct pp_struct *pp;
 
+	cycle_kernel_lock();
 	if (minor >= PARPORT_MAX)
 		return -ENXIO;
 
diff --git a/drivers/char/scx200_gpio.c b/drivers/char/scx200_gpio.c
index be2c623..1d91005 100644
--- a/drivers/char/scx200_gpio.c
+++ b/drivers/char/scx200_gpio.c
@@ -12,6 +12,7 @@
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/platform_device.h>
+#include <linux/smp_lock.h>
 #include <asm/uaccess.h>
 #include <asm/io.h>
 
@@ -46,12 +47,12 @@ struct nsc_gpio_ops scx200_gpio_ops = {
 };
 EXPORT_SYMBOL_GPL(scx200_gpio_ops);
 
-/* No BKL needed here: no global resources used */
 static int scx200_gpio_open(struct inode *inode, struct file *file)
 {
 	unsigned m = iminor(inode);
 	file->private_data = &scx200_gpio_ops;
 
+	cycle_kernel_lock();
 	if (m >= MAX_PINS)
 		return -EINVAL;
 	return nonseekable_open(inode, file);
diff --git a/drivers/char/tb0219.c b/drivers/char/tb0219.c
index db8c2ca..6062b62 100644
--- a/drivers/char/tb0219.c
+++ b/drivers/char/tb0219.c
@@ -21,6 +21,7 @@
 #include <linux/fs.h>
 #include <linux/init.h>
 #include <linux/module.h>
+#include <linux/smp_lock.h>
 
 #include <asm/io.h>
 #include <asm/reboot.h>
@@ -232,11 +233,11 @@ static ssize_t tanbac_tb0219_write(struct file *file, const char __user *data,
 	return i;
 }
 
-/* No BKL needed here; no global resources accessed */
 static int tanbac_tb0219_open(struct inode *inode, struct file *file)
 {
 	unsigned int minor;
 
+	cycle_kernel_lock();
 	minor = iminor(inode);
 	switch (minor) {
 	case 0:
diff --git a/drivers/char/vr41xx_giu.c b/drivers/char/vr41xx_giu.c
index 412937f..ffe9b4e 100644
--- a/drivers/char/vr41xx_giu.c
+++ b/drivers/char/vr41xx_giu.c
@@ -27,6 +27,7 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
+#include <linux/smp_lock.h>
 #include <linux/spinlock.h>
 #include <linux/types.h>
 
@@ -543,12 +544,11 @@ static ssize_t gpio_write(struct file *file, const char __user *data,
 	return i;
 }
 
-/* No BKL needed here; only global (giu_nr_pins) is only set
-   at probe time */
 static int gpio_open(struct inode *inode, struct file *file)
 {
 	unsigned int pin;
 
+	cycle_kernel_lock();
 	pin = iminor(inode);
 	if (pin >= giu_nr_pins)
 		return -EBADF;