Hi Greg,
On 14 April 2017 at 14:49, Greg KH <greg@xxxxxxxxx> wrote:
> On Fri, Apr 14, 2017 at 11:23:20AM +0530, Sumit Semwal wrote:
>> Hello,
>>
>> Upstream commit 888022c0473d079bff9b47fb50434b1f20f8f37f
>> Subject: dma-buf: add support for compat ioctl
>> Applicable to: 4.5+ stable kernels
>>
>> The cc:stable got missed while this patch got applied for mainline; it
>> allows a 32-bit application to use DMA_BUF_IOCTL_SYNC with 64-bit
>> kernel.
>
> Is this a new feature being added? Why is this a stable kernel patch?
>
So commit
c11e391da2a8fe973c3c2398452000bed505851e: ("dma-buf: Add ioctls to
allow userspace to flush") added ioctls to dma-buf in 4.5 kernel to
support DMA_BUF_IOCTL_SYNC, but we missed adding the compat_ioctl
support at the time. This obviously meant that we weren't able to use
this IOCTL from a 32-bit application with a 64-bit kernel.
This patch adds the missing compat_ioctl support for dma-buf.
> And always cc: the authors of the patch involved when asking for a
> stable backport, it keeps me from having to add them to the cc: when
> asking questions like this :)
>
Clearly, I'm a newbie to the whole stable process :) - I will keep
this in mind as well!
> thanks,
>
> greg k-h
Best regards,
Sumit.