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HID: remove BKL from hidraw

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Remove BKL from hidraw, which is possible through fixing the
locking of minors_lock mutex properly -- it is now used to
guard all accessess to hidraw_table[], preventing it to becoming
NULL unexpectedly by unregistering the device.

Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This commit is contained in:
Jiri Kosina 2010-03-25 14:15:11 +01:00
parent 3971047930
commit 2e57480b2a
1 changed files with 30 additions and 21 deletions
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51
drivers/hid/hidraw.c
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@ -105,38 +105,48 @@ out:
static ssize_t hidraw_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos) static ssize_t hidraw_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
{ {
unsigned int minor = iminor(file->f_path.dentry->d_inode); unsigned int minor = iminor(file->f_path.dentry->d_inode);
/* FIXME: What stops hidraw_table going NULL */ struct hid_device *dev;
struct hid_device *dev = hidraw_table[minor]->hid;
__u8 *buf; __u8 *buf;
int ret = 0; int ret = 0;
if (!dev->hid_output_raw_report) mutex_lock(&minors_lock);
return -ENODEV; dev = hidraw_table[minor]->hid;
if (!dev->hid_output_raw_report) {
ret = -ENODEV;
goto out;
}
if (count > HID_MAX_BUFFER_SIZE) { if (count > HID_MAX_BUFFER_SIZE) {
printk(KERN_WARNING "hidraw: pid %d passed too large report\n", printk(KERN_WARNING "hidraw: pid %d passed too large report\n",
task_pid_nr(current)); task_pid_nr(current));
return -EINVAL; ret = -EINVAL;
goto out;
} }
if (count < 2) { if (count < 2) {
printk(KERN_WARNING "hidraw: pid %d passed too short report\n", printk(KERN_WARNING "hidraw: pid %d passed too short report\n",
task_pid_nr(current)); task_pid_nr(current));
return -EINVAL; ret = -EINVAL;
}
buf = kmalloc(count * sizeof(__u8), GFP_KERNEL);
if (!buf)
return -ENOMEM;
if (copy_from_user(buf, buffer, count)) {
ret = -EFAULT;
goto out; goto out;
} }
buf = kmalloc(count * sizeof(__u8), GFP_KERNEL);
if (!buf) {
ret = -ENOMEM;
goto out;
}
if (copy_from_user(buf, buffer, count)) {
ret = -EFAULT;
goto out_free;
}
ret = dev->hid_output_raw_report(dev, buf, count, HID_OUTPUT_REPORT); ret = dev->hid_output_raw_report(dev, buf, count, HID_OUTPUT_REPORT);
out: out_free:
kfree(buf); kfree(buf);
out:
mutex_unlock(&minors_lock);
return ret; return ret;
} }
@ -164,7 +174,6 @@ static int hidraw_open(struct inode *inode, struct file *file)
goto out; goto out;
} }
lock_kernel();
mutex_lock(&minors_lock); mutex_lock(&minors_lock);
if (!hidraw_table[minor]) { if (!hidraw_table[minor]) {
printk(KERN_EMERG "hidraw device with minor %d doesn't exist\n", printk(KERN_EMERG "hidraw device with minor %d doesn't exist\n",
@ -196,7 +205,6 @@ static int hidraw_open(struct inode *inode, struct file *file)
out_unlock: out_unlock:
mutex_unlock(&minors_lock); mutex_unlock(&minors_lock);
unlock_kernel();
out: out:
return err; return err;
@ -237,11 +245,12 @@ static long hidraw_ioctl(struct file *file, unsigned int cmd,
struct inode *inode = file->f_path.dentry->d_inode; struct inode *inode = file->f_path.dentry->d_inode;
unsigned int minor = iminor(inode); unsigned int minor = iminor(inode);
long ret = 0; long ret = 0;
/* FIXME: What stops hidraw_table going NULL */ struct hidraw *dev;
struct hidraw *dev = hidraw_table[minor];
void __user *user_arg = (void __user*) arg; void __user *user_arg = (void __user*) arg;
lock_kernel(); mutex_lock(&minors_lock);
dev = hidraw_table[minor];
switch (cmd) { switch (cmd) {
case HIDIOCGRDESCSIZE: case HIDIOCGRDESCSIZE:
if (put_user(dev->hid->rsize, (int __user *)arg)) if (put_user(dev->hid->rsize, (int __user *)arg))
@ -314,7 +323,7 @@ static long hidraw_ioctl(struct file *file, unsigned int cmd,
ret = -ENOTTY; ret = -ENOTTY;
} }
unlock_kernel(); mutex_unlock(&minors_lock);
return ret; return ret;
} }