On 24/11/2022 09:45, David Hildenbrand wrote:
> On 24.11.22 09:29, Hans Verkuil wrote:
>> Commit 707947247e95 ("media: videobuf2-vmalloc: get_userptr: buffers are
>> always writable") caused problems in a corner case (passing read-only
>> shmem memory as a userptr). So revert this patch.
>>
>> The original problem for which that commit was originally made is
>> something that I could not reproduce after reverting it. So just go
>> back to the way it was for many years, and if problems arise in
>> the future, then another approach should be taken to resolve it.
>>
>> This patch is based on a patch from Hirokazu.
>>
>> Fixes: 707947247e95 ("media: videobuf2-vmalloc: get_userptr: buffers are always writable")
>> Signed-off-by: Hirokazu Honda <hiroh@xxxxxxxxxxxx>
>> Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
>> ---
>
> Regarding possible merge conflicts with the FOLL_FORCE patch [1] that's already in -next, would it make sense to base this patch on the FOLL_FORCE patch and routing it through the -mm tree? Or what's
> the best way to move forward?
>
> CCing Andrew
>
> [1] https://lkml.kernel.org/r/20221116102659.70287-17-david@xxxxxxxxxx
>
My preference would be to apply the removal of FOLL_FORCE *after* this
patch has been merged. This patch will likely be something that will be
backported to older kernels as well, and that's easier to do if it is
applied before your patch.
I think it is best to apply your patch for this after v6.2-rc1 is released.
If you post a patch removing FOLL_FORCE to linux-media once v6.2-rc1 is released,
then I can ensure it will be merged in a later v6.2-rcX.
Regards,
Hans
