From f2b9857eee17797541b845782ade4d7a9d50f843 Mon Sep 17 00:00:00 2001
From: Jonathan Corbet <corbet@lwn.net>
Date: Sun, 18 May 2008 15:32:43 -0600
Subject: [PATCH] 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>
---
 arch/cris/arch-v10/drivers/eeprom.c          |  4 +--
 arch/cris/arch-v10/drivers/i2c.c             |  2 ++
 arch/cris/arch-v32/drivers/cryptocop.c       |  3 +-
 arch/cris/arch-v32/drivers/i2c.c             |  2 ++
 drivers/char/cs5535_gpio.c                   |  4 +--
 drivers/char/dtlk.c                          |  5 +--
 drivers/char/ip2/ip2main.c                   | 34 ++------------------
 drivers/char/pc8736x_gpio.c                  |  3 +-
 drivers/char/ppdev.c                         |  3 +-
 drivers/char/scx200_gpio.c                   |  3 +-
 drivers/char/tb0219.c                        |  3 +-
 drivers/char/vr41xx_giu.c                    |  4 +--
 drivers/infiniband/core/ucm.c                |  3 +-
 drivers/infiniband/hw/ipath/ipath_file_ops.c |  3 +-
 drivers/isdn/hardware/eicon/divasi.c         |  2 ++
 drivers/isdn/hardware/eicon/divasmain.c      |  2 ++
 drivers/net/ppp_generic.c                    |  3 +-
 drivers/scsi/3w-9xxx.c                       |  5 +--
 drivers/scsi/3w-xxxx.c                       |  5 +--
 drivers/scsi/megaraid.c                      |  4 +--
 drivers/scsi/megaraid/megaraid_sas.c         |  3 +-
 21 files changed, 45 insertions(+), 55 deletions(-)

diff --git a/arch/cris/arch-v10/drivers/eeprom.c b/arch/cris/arch-v10/drivers/eeprom.c
index 40c6fe4c06f4..1f2ae909d3e6 100644
--- a/arch/cris/arch-v10/drivers/eeprom.c
+++ b/arch/cris/arch-v10/drivers/eeprom.c
@@ -28,6 +28,7 @@
 #include <linux/init.h>
 #include <linux/delay.h>
 #include <linux/interrupt.h>
+#include <linux/smp_lock.h>
 #include <linux/wait.h>
 #include <asm/uaccess.h>
 #include "i2c.h"
@@ -375,10 +376,9 @@ int __init eeprom_init(void)
 }
 
 /* Opens the device. */
-/* BKL not needed: no global resources accessed */
 static int eeprom_open(struct inode * inode, struct file * file)
 {
-
+  cycle_kernel_lock();
   if(iminor(inode) != EEPROM_MINOR_NR)
      return -ENXIO;
   if(imajor(inode) != EEPROM_MAJOR_NR)
diff --git a/arch/cris/arch-v10/drivers/i2c.c b/arch/cris/arch-v10/drivers/i2c.c
index d6d22067d0c8..2797e67ce4f4 100644
--- a/arch/cris/arch-v10/drivers/i2c.c
+++ b/arch/cris/arch-v10/drivers/i2c.c
@@ -15,6 +15,7 @@
 #include <linux/module.h>
 #include <linux/sched.h>
 #include <linux/slab.h>
+#include <linux/smp_lock.h>
 #include <linux/errno.h>
 #include <linux/kernel.h>
 #include <linux/fs.h>
@@ -566,6 +567,7 @@ i2c_readreg(unsigned char theSlave, unsigned char theReg)
 static int
 i2c_open(struct inode *inode, struct file *filp)
 {
+	cycle_kernel_lock();
 	return 0;
 }
 
diff --git a/arch/cris/arch-v32/drivers/cryptocop.c b/arch/cris/arch-v32/drivers/cryptocop.c
index c17204289575..67c61ea86813 100644
--- a/arch/cris/arch-v32/drivers/cryptocop.c
+++ b/arch/cris/arch-v32/drivers/cryptocop.c
@@ -11,6 +11,7 @@
 #include <linux/string.h>
 #include <linux/fs.h>
 #include <linux/mm.h>
+#include <linux/smp_lock.h>
 #include <linux/spinlock.h>
 #include <linux/stddef.h>
 
@@ -2302,11 +2303,11 @@ static int cryptocop_job_setup(struct cryptocop_prio_job **pj, struct cryptocop_
 	return 0;
 }
 
-/* No BKL needed here - no global resources accessed */
 static int cryptocop_open(struct inode *inode, struct file *filp)
 {
 	int p = iminor(inode);
 
+	cycle_kernel_lock();
 	if (p != CRYPTOCOP_MINOR) return -EINVAL;
 
 	filp->private_data = NULL;
diff --git a/arch/cris/arch-v32/drivers/i2c.c b/arch/cris/arch-v32/drivers/i2c.c
index c2fb7a5c1396..179e7b804331 100644
--- a/arch/cris/arch-v32/drivers/i2c.c
+++ b/arch/cris/arch-v32/drivers/i2c.c
@@ -33,6 +33,7 @@
 #include <linux/fs.h>
 #include <linux/string.h>
 #include <linux/init.h>
+#include <linux/smp_lock.h>
 
 #include <asm/etraxi2c.h>
 
@@ -636,6 +637,7 @@ i2c_readreg(unsigned char theSlave, unsigned char theReg)
 static int
 i2c_open(struct inode *inode, struct file *filp)
 {
+	cycle_kernel_lock();
 	return 0;
 }
 
diff --git a/drivers/char/cs5535_gpio.c b/drivers/char/cs5535_gpio.c
index 628e3d3249d2..04ba906b4880 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 433388c60235..6b900b297cc6 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 70957acaa960..a978c57b6b2b 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 8715dc9f4a53..b930de50407a 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 ce1987574888..f6e6acadd9a0 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 be2c623a9862..1d9100561c8a 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 db8c2ca2ce4c..6062b62800fd 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 412937fdb958..ffe9b4e3072e 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;
diff --git a/drivers/infiniband/core/ucm.c b/drivers/infiniband/core/ucm.c
index 3e6a8ff6d76c..b25675faaaf5 100644
--- a/drivers/infiniband/core/ucm.c
+++ b/drivers/infiniband/core/ucm.c
@@ -45,6 +45,7 @@
 #include <linux/cdev.h>
 #include <linux/idr.h>
 #include <linux/mutex.h>
+#include <linux/smp_lock.h>
 
 #include <asm/uaccess.h>
 
@@ -1155,11 +1156,11 @@ static unsigned int ib_ucm_poll(struct file *filp,
 	return mask;
 }
 
-/* No BKL needed here: no global resources used */
 static int ib_ucm_open(struct inode *inode, struct file *filp)
 {
 	struct ib_ucm_file *file;
 
+	cycle_kernel_lock();
 	file = kmalloc(sizeof(*file), GFP_KERNEL);
 	if (!file)
 		return -ENOMEM;
diff --git a/drivers/infiniband/hw/ipath/ipath_file_ops.c b/drivers/infiniband/hw/ipath/ipath_file_ops.c
index e80cfbd4f3fd..35f301c88b57 100644
--- a/drivers/infiniband/hw/ipath/ipath_file_ops.c
+++ b/drivers/infiniband/hw/ipath/ipath_file_ops.c
@@ -39,6 +39,7 @@
 #include <linux/highmem.h>
 #include <linux/io.h>
 #include <linux/jiffies.h>
+#include <linux/smp_lock.h>
 #include <asm/pgtable.h>
 
 #include "ipath_kernel.h"
@@ -1812,10 +1813,10 @@ static int find_shared_port(struct file *fp,
 	return ret;
 }
 
-/* No BKL needed here */
 static int ipath_open(struct inode *in, struct file *fp)
 {
 	/* The real work is performed later in ipath_assign_port() */
+	cycle_kernel_lock();
 	fp->private_data = kzalloc(sizeof(struct ipath_filedata), GFP_KERNEL);
 	return fp->private_data ? 0 : -ENOMEM;
 }
diff --git a/drivers/isdn/hardware/eicon/divasi.c b/drivers/isdn/hardware/eicon/divasi.c
index 78f141e77466..f4969fe0a055 100644
--- a/drivers/isdn/hardware/eicon/divasi.c
+++ b/drivers/isdn/hardware/eicon/divasi.c
@@ -17,6 +17,7 @@
 #include <linux/poll.h>
 #include <linux/proc_fs.h>
 #include <linux/skbuff.h>
+#include <linux/smp_lock.h>
 #include <asm/uaccess.h>
 
 #include "platform.h"
@@ -400,6 +401,7 @@ static unsigned int um_idi_poll(struct file *file, poll_table * wait)
 
 static int um_idi_open(struct inode *inode, struct file *file)
 {
+	cycle_kernel_lock();
 	return (0);
 }
 
diff --git a/drivers/isdn/hardware/eicon/divasmain.c b/drivers/isdn/hardware/eicon/divasmain.c
index 5fcbdccd7a53..65c95019a9ae 100644
--- a/drivers/isdn/hardware/eicon/divasmain.c
+++ b/drivers/isdn/hardware/eicon/divasmain.c
@@ -21,6 +21,7 @@
 #include <linux/list.h>
 #include <linux/poll.h>
 #include <linux/kmod.h>
+#include <linux/smp_lock.h>
 
 #include "platform.h"
 #undef ID_MASK
@@ -580,6 +581,7 @@ xdi_copy_from_user(void *os_handle, void *dst, const void __user *src, int lengt
  */
 static int divas_open(struct inode *inode, struct file *file)
 {
+	cycle_kernel_lock();
 	return (0);
 }
 
diff --git a/drivers/net/ppp_generic.c b/drivers/net/ppp_generic.c
index dc8505062da7..83625fdff3dd 100644
--- a/drivers/net/ppp_generic.c
+++ b/drivers/net/ppp_generic.c
@@ -39,6 +39,7 @@
 #include <linux/if_arp.h>
 #include <linux/ip.h>
 #include <linux/tcp.h>
+#include <linux/smp_lock.h>
 #include <linux/spinlock.h>
 #include <linux/rwsem.h>
 #include <linux/stddef.h>
@@ -351,9 +352,9 @@ static const int npindex_to_ethertype[NUM_NP] = {
  * Open instances of /dev/ppp can be in one of three states:
  * unattached, attached to a ppp unit, or attached to a ppp channel.
  */
-/* No BKL needed here */
 static int ppp_open(struct inode *inode, struct file *file)
 {
+	cycle_kernel_lock();
 	/*
 	 * This could (should?) be enforced by the permissions on /dev/ppp.
 	 */
diff --git a/drivers/scsi/3w-9xxx.c b/drivers/scsi/3w-9xxx.c
index 2239d16fb9b5..eaa805df5b00 100644
--- a/drivers/scsi/3w-9xxx.c
+++ b/drivers/scsi/3w-9xxx.c
@@ -84,6 +84,7 @@
 #include <linux/pci.h>
 #include <linux/time.h>
 #include <linux/mutex.h>
+#include <linux/smp_lock.h>
 #include <asm/io.h>
 #include <asm/irq.h>
 #include <asm/uaccess.h>
@@ -862,13 +863,13 @@ static int twa_chrdev_ioctl(struct inode *inode, struct file *file, unsigned int
 } /* End twa_chrdev_ioctl() */
 
 /* This function handles open for the character device */
-/* NOTE that this function will race with remove; adding BKL
-   will not help. */
+/* NOTE that this function will race with remove. */
 static int twa_chrdev_open(struct inode *inode, struct file *file)
 {
 	unsigned int minor_number;
 	int retval = TW_IOCTL_ERROR_OS_ENODEV;
 
+	cycle_kernel_lock();
 	minor_number = iminor(inode);
 	if (minor_number >= twa_device_extension_count)
 		goto out;
diff --git a/drivers/scsi/3w-xxxx.c b/drivers/scsi/3w-xxxx.c
index bbff029536ea..a0537f09aa21 100644
--- a/drivers/scsi/3w-xxxx.c
+++ b/drivers/scsi/3w-xxxx.c
@@ -198,6 +198,7 @@
 
 #include <linux/module.h>
 #include <linux/reboot.h>
+#include <linux/smp_lock.h>
 #include <linux/spinlock.h>
 #include <linux/interrupt.h>
 #include <linux/moduleparam.h>
@@ -1027,12 +1028,12 @@ static int tw_chrdev_ioctl(struct inode *inode, struct file *file, unsigned int
 } /* End tw_chrdev_ioctl() */
 
 /* This function handles open for the character device */
-/* NOTE that this function races with remove - adding BKL
-   won't help */
+/* NOTE that this function races with remove. */
 static int tw_chrdev_open(struct inode *inode, struct file *file)
 {
 	unsigned int minor_number;
 
+	cycle_kernel_lock();
 	dprintk(KERN_WARNING "3w-xxxx: tw_ioctl_open()\n");
 
 	minor_number = iminor(inode);
diff --git a/drivers/scsi/megaraid.c b/drivers/scsi/megaraid.c
index c9aa2c45a699..28c9da7d4a5c 100644
--- a/drivers/scsi/megaraid.c
+++ b/drivers/scsi/megaraid.c
@@ -46,6 +46,7 @@
 #include <linux/pci.h>
 #include <linux/init.h>
 #include <linux/dma-mapping.h>
+#include <linux/smp_lock.h>
 #include <scsi/scsicam.h>
 
 #include "scsi.h"
@@ -3273,12 +3274,11 @@ mega_init_scb(adapter_t *adapter)
  *
  * Routines for the character/ioctl interface to the driver. Find out if this
  * is a valid open. 
- *
- * No BKL needed here.
  */
 static int
 megadev_open (struct inode *inode, struct file *filep)
 {
+	cycle_kernel_lock();
 	/*
 	 * Only allow superuser to access private ioctl interface
 	 */
diff --git a/drivers/scsi/megaraid/megaraid_sas.c b/drivers/scsi/megaraid/megaraid_sas.c
index 81374b7c555c..fc7ac158476c 100644
--- a/drivers/scsi/megaraid/megaraid_sas.c
+++ b/drivers/scsi/megaraid/megaraid_sas.c
@@ -33,6 +33,7 @@
 #include <linux/spinlock.h>
 #include <linux/interrupt.h>
 #include <linux/delay.h>
+#include <linux/smp_lock.h>
 #include <linux/uio.h>
 #include <asm/uaccess.h>
 #include <linux/fs.h>
@@ -2860,10 +2861,10 @@ static void megasas_shutdown(struct pci_dev *pdev)
 
 /**
  * megasas_mgmt_open -	char node "open" entry point
- * No BKL is needed here.
  */
 static int megasas_mgmt_open(struct inode *inode, struct file *filep)
 {
+	cycle_kernel_lock();
 	/*
 	 * Allow only those users with admin rights
 	 */
-- 
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