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Commit 54066a57 authored by Arnd Bergmann's avatar Arnd Bergmann
Browse files

hpet: kill BKL, add compat_ioctl 



hpet uses the big kernel lock in its ioctl and open
functions. Replace this with a private mutex to be
sure. Since we're already touching the ioctl function,
add the compat_ioctl version as well -- all commands
except HPET_INFO are compatible and that one is easy
to add.

Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Cc: Clemens Ladisch <clemens@ladisch.de>
Cc: Bob Picco <bob.picco@hp.com>
parent 49553c2e

drivers/char/hpet.c

+64 −34
Original line number Diff line number Diff line
@@ -30,6 +30,7 @@ 
#include <linux/bcd.h>

#include <linux/seq_file.h>

#include <linux/bitops.h>

#include <linux/compat.h>

#include <linux/clocksource.h>

#include <linux/slab.h>
@@ -67,6 +68,7 @@ 
#define	read_counter(MC)	readl(MC)

#endif



static DEFINE_MUTEX(hpet_mutex); /* replaces BKL */

static u32 hpet_nhpet, hpet_max_freq = HPET_USER_FREQ;



/* This clocksource driver currently only works on ia64 */
@@ -250,7 +252,7 @@ static int hpet_open(struct inode *inode, struct file *file) 
	if (file->f_mode & FMODE_WRITE)

		return -EINVAL;



	lock_kernel();

	mutex_lock(&hpet_mutex);

	spin_lock_irq(&hpet_lock);



	for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next)
@@ -264,7 +266,7 @@ static int hpet_open(struct inode *inode, struct file *file) 


	if (!devp) {

		spin_unlock_irq(&hpet_lock);

		unlock_kernel();

		mutex_unlock(&hpet_mutex);

		return -EBUSY;

	}
@@ -272,7 +274,7 @@ static int hpet_open(struct inode *inode, struct file *file) 
	devp->hd_irqdata = 0;

	devp->hd_flags |= HPET_OPEN;

	spin_unlock_irq(&hpet_lock);

	unlock_kernel();

	mutex_unlock(&hpet_mutex);



	hpet_timer_set_irq(devp);
@@ -429,22 +431,6 @@ static int hpet_release(struct inode *inode, struct file *file) 
	return 0;

}



static int hpet_ioctl_common(struct hpet_dev *, int, unsigned long, int);



static long hpet_ioctl(struct file *file, unsigned int cmd,

			unsigned long arg)

{

	struct hpet_dev *devp;

	int ret;



	devp = file->private_data;

	lock_kernel();

	ret = hpet_ioctl_common(devp, cmd, arg, 0);

	unlock_kernel();



	return ret;

}



static int hpet_ioctl_ieon(struct hpet_dev *devp)

{

	struct hpet_timer __iomem *timer;
@@ -553,7 +539,8 @@ static inline unsigned long hpet_time_div(struct hpets *hpets, 
}



static int

hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg, int kernel)

hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg,

		  struct hpet_info *info)

{

	struct hpet_timer __iomem *timer;

	struct hpet __iomem *hpet;
@@ -594,23 +581,15 @@ hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg, int kernel) 
		break;

	case HPET_INFO:

		{

			struct hpet_info info;



			if (devp->hd_ireqfreq)

				info.hi_ireqfreq =

				info->hi_ireqfreq =

					hpet_time_div(hpetp, devp->hd_ireqfreq);

			else

				info.hi_ireqfreq = 0;

			info.hi_flags =

				info->hi_ireqfreq = 0;

			info->hi_flags =

			    readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK;

			info.hi_hpet = hpetp->hp_which;

			info.hi_timer = devp - hpetp->hp_dev;

			if (kernel)

				memcpy((void *)arg, &info, sizeof(info));

			else

				if (copy_to_user((void __user *)arg, &info,

						 sizeof(info)))

					err = -EFAULT;

			info->hi_hpet = hpetp->hp_which;

			info->hi_timer = devp - hpetp->hp_dev;

			break;

		}

	case HPET_EPI:
@@ -636,7 +615,7 @@ hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg, int kernel) 
		devp->hd_flags &= ~HPET_PERIODIC;

		break;

	case HPET_IRQFREQ:

		if (!kernel && (arg > hpet_max_freq) &&

		if ((arg > hpet_max_freq) &&

		    !capable(CAP_SYS_RESOURCE)) {

			err = -EACCES;

			break;
@@ -653,12 +632,63 @@ hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg, int kernel) 
	return err;

}



static long

hpet_ioctl(struct file *file, unsigned int cmd, unsigned long arg)

{

	struct hpet_info info;

	int err;



	mutex_lock(&hpet_mutex);

	err = hpet_ioctl_common(file->private_data, cmd, arg, &info);

	mutex_unlock(&hpet_mutex);



	if ((cmd == HPET_INFO) && !err &&

	    (copy_to_user((void __user *)arg, &info, sizeof(info))))

		err = -EFAULT;



	return err;

}



#ifdef CONFIG_COMPAT

struct compat_hpet_info {

	compat_ulong_t hi_ireqfreq;	/* Hz */

	compat_ulong_t hi_flags;	/* information */

	unsigned short hi_hpet;

	unsigned short hi_timer;

};



static long

hpet_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)

{

	struct hpet_info info;

	int err;



	mutex_lock(&hpet_mutex);

	err = hpet_ioctl_common(file->private_data, cmd, arg, &info);

	mutex_unlock(&hpet_mutex);



	if ((cmd == HPET_INFO) && !err) {

		struct compat_hpet_info __user *u = compat_ptr(arg);

		if (put_user(info.hi_ireqfreq, &u->hi_ireqfreq) ||

		    put_user(info.hi_flags, &u->hi_flags) ||

		    put_user(info.hi_hpet, &u->hi_hpet) ||

		    put_user(info.hi_timer, &u->hi_timer))

			err = -EFAULT;

	}



	return err;

}

#endif



static const struct file_operations hpet_fops = {

	.owner = THIS_MODULE,

	.llseek = no_llseek,

	.read = hpet_read,

	.poll = hpet_poll,

	.unlocked_ioctl = hpet_ioctl,

#ifdef CONFIG_COMPAT

	.compat_ioctl = hpet_compat_ioctl,

#endif

	.open = hpet_open,

	.release = hpet_release,

	.fasync = hpet_fasync,