Re: [PATCH 2/2] dma-mapping: benchmark: Add padding to ensure uABI remained consistent

[Barry Song]

On Thu, Jul 24, 2025 at 5:35 PM Qinxin Xia <xiaqinxin@xxxxxxxxxx> wrote:
>
>
>
> On 2025/7/24 17:07:08, Barry Song <21cnbao@xxxxxxxxx> wrote:
> > On Thu, Jul 24, 2025 at 4:56 PM Qinxin Xia <xiaqinxin@xxxxxxxxxx> wrote:
> >>
> >> The padding field in the structure was previously reserved to
> >> maintain a stable interface for potential new fields, ensuring
> >> compatibility with user-space shared data structures.
> >> However,it was accidentally removed by tiantao in a prior commit,
> >> which may lead to incompatibility between user space and the kernel.
> >>
> >> This patch reinstates the padding to restore the original structure
> >> layout and preserve compatibility.
> >>
> >> Fixes: 8ddde07a3d28 ("dma-mapping: benchmark: extract a common header file for map_benchmark definition")
> >> Cc: stable@xxxxxxxxxxxxxxx
> >> Acked-by: Barry Song <baohua@xxxxxxxxxx>
> >> Signed-off-by: Qinxin Xia <xiaqinxin@xxxxxxxxxx>
> >
> > I don’t think these two patches should be part of the same series. This
> > one is a bug fix and should be handled separately—ideally picked up on
> > its own and backported to stable.
> >
> > Also, the subject should not say "Add"—it should be "Restore". I assume
> > Marek can handle it?
...
> Ok, I will send a new version to fix it.

If Marek can help fix it while picking it up into the dma-mapping tree, you
might not need to send a new version.

Honestly, I hope this gets merged soon—it feels like it's been
overdue for quite a while.

Thanks
Barry