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comedi: get rid of compat_alloc_user_space() mess in COMEDI_RANGEINFO compat 

Just take copy_from_user() out of do_rangeing_ioctl() into the caller and
have compat_rangeinfo() build a native version and pass it to do_rangeinfo_ioctl()
directly.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2020-04-25 18:44:30 -04:00
parent 3fbfd2223a
commit 388138764e
3 changed files with 27 additions and 35 deletions
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43
drivers/staging/comedi/comedi_fops.c
View File

@ -2210,9 +2210,14 @@ static long comedi_unlocked_ioctl(struct file *file, unsigned int cmd,
rc = do_chaninfo_ioctl(dev, &it);
break;
}
case COMEDI_RANGEINFO:
rc = do_rangeinfo_ioctl(dev, (void __user *)arg);
case COMEDI_RANGEINFO: {
struct comedi_rangeinfo it;
if (copy_from_user(&it, (void __user *)arg, sizeof(it)))
rc = -EFAULT;
else
rc = do_rangeinfo_ioctl(dev, &it);
break;
}
case COMEDI_BUFINFO:
rc = do_bufinfo_ioctl(dev,
(struct comedi_bufinfo __user *)arg,
@ -2900,32 +2905,22 @@ static int compat_chaninfo(struct file *file, unsigned long arg)
/* Handle 32-bit COMEDI_RANGEINFO ioctl. */
static int compat_rangeinfo(struct file *file, unsigned long arg)
{
struct comedi_rangeinfo __user *rangeinfo;
struct comedi32_rangeinfo_struct __user *rangeinfo32;
struct comedi_file *cfp = file->private_data;
struct comedi_device *dev = cfp->dev;
struct comedi32_rangeinfo_struct rangeinfo32;
struct comedi_rangeinfo rangeinfo;
int err;
union {
unsigned int uint;
compat_uptr_t uptr;
} temp;
rangeinfo32 = compat_ptr(arg);
rangeinfo = compat_alloc_user_space(sizeof(*rangeinfo));
/* Copy rangeinfo structure. */
if (!access_ok(rangeinfo32, sizeof(*rangeinfo32)) ||
!access_ok(rangeinfo, sizeof(*rangeinfo)))
if (copy_from_user(&rangeinfo32, compat_ptr(arg), sizeof(rangeinfo32)))
return -EFAULT;
memset(&rangeinfo, 0, sizeof(rangeinfo));
rangeinfo.range_type = rangeinfo32.range_type;
rangeinfo.range_ptr = compat_ptr(rangeinfo32.range_ptr);
err = 0;
err |= __get_user(temp.uint, &rangeinfo32->range_type);
err |= __put_user(temp.uint, &rangeinfo->range_type);
err |= __get_user(temp.uptr, &rangeinfo32->range_ptr);
err |= __put_user(compat_ptr(temp.uptr), &rangeinfo->range_ptr);
if (err)
return -EFAULT;
return comedi_unlocked_ioctl(file, COMEDI_RANGEINFO,
(unsigned long)rangeinfo);
mutex_lock(&dev->mutex);
err = do_rangeinfo_ioctl(dev, &rangeinfo);
mutex_unlock(&dev->mutex);
return err;
}
/* Copy 32-bit cmd structure to native cmd structure. */

2
drivers/staging/comedi/comedi_internal.h
View File

@ -18,7 +18,7 @@ struct comedi_subdevice;
struct device;
int do_rangeinfo_ioctl(struct comedi_device *dev,
struct comedi_rangeinfo __user *arg);
struct comedi_rangeinfo *it);
struct comedi_device *comedi_alloc_board_minor(struct device *hardware_device);
void comedi_release_hardware_device(struct device *hardware_device);
int comedi_alloc_subdevice_minor(struct comedi_subdevice *s);

17
drivers/staging/comedi/range.c
View File

@ -46,17 +46,14 @@ EXPORT_SYMBOL_GPL(range_unknown);
* array of comedi_krange structures to rangeinfo->range_ptr pointer
*/
int do_rangeinfo_ioctl(struct comedi_device *dev,
struct comedi_rangeinfo __user *arg)
struct comedi_rangeinfo *it)
{
struct comedi_rangeinfo it;
int subd, chan;
const struct comedi_lrange *lr;
struct comedi_subdevice *s;
if (copy_from_user(&it, arg, sizeof(struct comedi_rangeinfo)))
return -EFAULT;
subd = (it.range_type >> 24) & 0xf;
chan = (it.range_type >> 16) & 0xff;
subd = (it->range_type >> 24) & 0xf;
chan = (it->range_type >> 16) & 0xff;
if (!dev->attached)
return -EINVAL;
@ -73,15 +70,15 @@ int do_rangeinfo_ioctl(struct comedi_device *dev,
return -EINVAL;
}
if (RANGE_LENGTH(it.range_type) != lr->length) {
if (RANGE_LENGTH(it->range_type) != lr->length) {
dev_dbg(dev->class_dev,
"wrong length %d should be %d (0x%08x)\n",
RANGE_LENGTH(it.range_type),
lr->length, it.range_type);
RANGE_LENGTH(it->range_type),
lr->length, it->range_type);
return -EINVAL;
}
if (copy_to_user(it.range_ptr, lr->range,
if (copy_to_user(it->range_ptr, lr->range,
sizeof(struct comedi_krange) * lr->length))
return -EFAULT;