On 06/12/2015 04:24 PM, Carol Soto wrote:
>
>
> On 6/12/2015 3:08 PM, Doug Ledford wrote:
>> On 06/11/2015 12:06 PM, clsoto@xxxxxxxxxxxxxxxxxx wrote:
>>> From: Carol L Soto <clsoto@xxxxxxxxxxxxxxxxxx>
>>>
>>> ib_ucm_release_dev clears wrong bit if devnum is greater than
>>> IB_UCM_MAX_DEVICES.
>>>
>>> Signed-off-by: Carol L Soto <clsoto@xxxxxxxxxxxxxxxxxx>
>>> ---
>>> drivers/infiniband/core/ucm.c | 4 ++--
>>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/infiniband/core/ucm.c
>>> b/drivers/infiniband/core/ucm.c
>>> index f2f6393..e2fd085 100644
>>> --- a/drivers/infiniband/core/ucm.c
>>> +++ b/drivers/infiniband/core/ucm.c
>>> @@ -1193,6 +1193,7 @@ static int ib_ucm_close(struct inode *inode,
>>> struct file *filp)
>>> return 0;
>>> }
>>> +static DECLARE_BITMAP(overflow_map, IB_UCM_MAX_DEVICES);
>>> static void ib_ucm_release_dev(struct device *dev)
>>> {
>>> struct ib_ucm_device *ucm_dev;
>>> @@ -1202,7 +1203,7 @@ static void ib_ucm_release_dev(struct device *dev)
>>> if (ucm_dev->devnum < IB_UCM_MAX_DEVICES)
>>> clear_bit(ucm_dev->devnum, dev_map);
>>> else
>>> - clear_bit(ucm_dev->devnum - IB_UCM_MAX_DEVICES, dev_map);
>>> + clear_bit(ucm_dev->devnum - IB_UCM_MAX_DEVICES, overflow_map);
>>> kfree(ucm_dev);
>>> }
>>> @@ -1226,7 +1227,6 @@ static ssize_t show_ibdev(struct device *dev,
>>> struct device_attribute *attr,
>>> static DEVICE_ATTR(ibdev, S_IRUGO, show_ibdev, NULL);
>>> static dev_t overflow_maj;
>>> -static DECLARE_BITMAP(overflow_map, IB_UCM_MAX_DEVICES);
>>> static int find_overflow_devnum(void)
>>> {
>>> int ret;
>>>
>> This doesn't look right to me. In particular, you are creating a bitmap
>> and clearing bits, but I never see that bitmap get any bits set. So,
>> are you overflowing on the set routine and you just didn't bother to fix
>> that?
> I just moved the declaration of the bitmap before ib_ucm_release_dev to
> be able to compile. This bitmap is used in ib_ucm_add_one
> in the case of devnum > IB_UCM_MAX_DEVICES. The error path in
> ib_ucm_add_one did the clear bit correctly but not the
> ib_ucm_release_dev function. We saw an issue when using SRIOV. The case
> was that user has 2 Mellanox SRIOV cards and just did an
> unbind/bind a VF that was using a ib ucm device with devnum greater than
> 32. We saw this warning
Got it. For some reason I saw the add of the bitmap but missed the
removal of the original.
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