[PATCH] tee: fix tee_ioctl_object_invoke_arg padding

[Jens Wiklander]

Hi,

On Tue, Dec 16, 2025 at 11:56 AM Harshal Dev
<harshal.dev at oss.qualcomm.com> wrote:
>
> Hi Jens,
>
> On 12/16/2025 1:18 PM, Jens Wiklander wrote:
> > Hi,
> >
> > On Tue, Dec 9, 2025 at 4:54 AM Amirreza Zarrabi
> > <amirreza.zarrabi at oss.qualcomm.com> wrote:
> >>
> >> Hi,
> >>
> >> On 12/8/2025 11:54 PM, Harshal Dev wrote:
> >>>
> >>>
> >>> On 12/8/2025 5:50 PM, Sumit Garg via OP-TEE wrote:
> >>>> On Mon, Dec 08, 2025 at 04:24:17PM +1100, Amirreza Zarrabi wrote:
> >>>>> Hi,
> >>>>>
> >>>>> On 12/5/2025 12:27 AM, Jens Wiklander wrote:
> >>>>>> Hi,
> >>>>>>
> >>>>>> On Thu, Dec 4, 2025 at 11:17 AM Arnd Bergmann <arnd at kernel.org> wrote:
> >>>>>>>
> >>>>>>> From: Arnd Bergmann <arnd at arndb.de>
> >>>>>>>
> >>>>>>> The tee_ioctl_object_invoke_arg structure has padding on some
> >>>>>>> architectures but not on x86-32 and a few others:
> >>>>>>>
> >>>>>>> include/linux/tee.h:474:32: error: padding struct to align 'params' [-Werror=padded]
> >>>>>>>
> >>>>>>> I expect that all current users of this are on architectures that do
> >>>>>>> have implicit padding here (arm64, arm, x86, riscv), so make the padding
> >>>>>>> explicit in order to avoid surprises if this later gets used elsewhere.
> >>>>>>>
> >>>>>>> Fixes: d5b8b0fa1775 ("tee: add TEE_IOCTL_PARAM_ATTR_TYPE_OBJREF")
> >>>>>>> Signed-off-by: Arnd Bergmann <arnd at arndb.de>
> >>>>>>> ---
> >>>>>>> The new interface showed up in 6.18, but I only came across this after
> >>>>>>> that was released. Changing it now is technically an ABI change on
> >>>>>>> architectures with unusual padding rules, so please consider carefully
> >>>>>>> whether we want to do it this way or not.
> >>>>>>>
> >>>>>>> Working around the ABI differences without an ABI change is possible,
> >>>>>>> but adds a lot of complexity for compat handling.
> >>>>>>
> >>>>>> This is currently only used by the recently introduced qcomtee backend
> >>>>>> driver. So it's only used on a few arm64 Qualcomm platforms right now.
> >>>>>>
> >>>>>> I think we should take this patch, but let's hear what others think.
> >>>>
> >>>> Yeah since it's not an ABI issue on arm64 platforms where QTEE runs, so:
> >>>>
> >>>> Reviewed-by: Sumit Garg <sumit.garg at oss.qualcomm.com>
> >>>>
> >>>>>>
> >>>>>> Thanks,
> >>>>>> Jens
> >>>>>>
> >>>>>
> >>>>> I agree. We should take this patch. As noted, there are not many
> >>>>> clients relying on it yet, so updating the userspace should
> >>>>> be straightforward.
> >>>>
> >>>> You should rather test without any userspace library update to test it's
> >>>> not an ABI issue. Just for correctness sake, you can update the library
> >>>> too.
> >>>>
> >>>
> >>> I'll take the time to test it at some point this week both with and without updating
> >>> the library ABI.
> >>>
> >>
> >> Summit, that was the plan from the beginning, that's why I did not add "Reviewed-by:"
> >> in the first place. Thanks Harshal for volunteering.
> >
> > Are we good with this patch now?
> >
>
> Yes, this is good from our side.
>
> Tested-by: Harshal Dev <harshal.dev at oss.qualcomm.com>

Good, thank you, Harshal.

Reviewed-by: Jens Wiklander <jens.wiklander at linaro.org>

Arnd, what do you prefer, taking this directly or should I send it in
a pull request?

Cheers,
Jens