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@vger.kernel.org
Acked-by: Barry Song <baohua@kernel.org>
Signed-off-by: Qinxin Xia <xiaqinxin@huawei.com>
---
include/linux/map_benchmark.h | 1 +
1 file changed, 1 insertion(+)
diff --git a/include/linux/map_benchmark.h b/include/linux/map_benchmark.h
index 62674c83bde4..2ac2fe52f248 100644
--- a/include/linux/map_benchmark.h
+++ b/include/linux/map_benchmark.h
@@ -27,5 +27,6 @@ struct map_benchmark {
__u32 dma_dir; /* DMA data direction */
__u32 dma_trans_ns; /* time for DMA transmission in ns */
__u32 granule; /* how many PAGE_SIZE will do map/unmap once a time */
+ __u8 expansion[76]; /* For future use */
};
#endif /* _KERNEL_DMA_BENCHMARK_H */
--
2.33.0On Thu, Jul 24, 2025 at 4:56 PM Qinxin Xia <xiaqinxin@huawei.com> 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@vger.kernel.org
> Acked-by: Barry Song <baohua@kernel.org>
> Signed-off-by: Qinxin Xia <xiaqinxin@huawei.com>
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?
> ---
> include/linux/map_benchmark.h | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/include/linux/map_benchmark.h b/include/linux/map_benchmark.h
> index 62674c83bde4..2ac2fe52f248 100644
> --- a/include/linux/map_benchmark.h
> +++ b/include/linux/map_benchmark.h
> @@ -27,5 +27,6 @@ struct map_benchmark {
> __u32 dma_dir; /* DMA data direction */
> __u32 dma_trans_ns; /* time for DMA transmission in ns */
> __u32 granule; /* how many PAGE_SIZE will do map/unmap once a time */
> + __u8 expansion[76]; /* For future use */
> };
> #endif /* _KERNEL_DMA_BENCHMARK_H */
> --
> 2.33.0
>
Thanks
Barry
On 2025/7/24 17:07:08, Barry Song <21cnbao@gmail.com> wrote:
> On Thu, Jul 24, 2025 at 4:56 PM Qinxin Xia <xiaqinxin@huawei.com> 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@vger.kernel.org
>> Acked-by: Barry Song <baohua@kernel.org>
>> Signed-off-by: Qinxin Xia <xiaqinxin@huawei.com>
>
> 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?
>
>> ---
>> include/linux/map_benchmark.h | 1 +
>> 1 file changed, 1 insertion(+)
>>
>> diff --git a/include/linux/map_benchmark.h b/include/linux/map_benchmark.h
>> index 62674c83bde4..2ac2fe52f248 100644
>> --- a/include/linux/map_benchmark.h
>> +++ b/include/linux/map_benchmark.h
>> @@ -27,5 +27,6 @@ struct map_benchmark {
>> __u32 dma_dir; /* DMA data direction */
>> __u32 dma_trans_ns; /* time for DMA transmission in ns */
>> __u32 granule; /* how many PAGE_SIZE will do map/unmap once a time */
>> + __u8 expansion[76]; /* For future use */
>> };
>> #endif /* _KERNEL_DMA_BENCHMARK_H */
>> --
>> 2.33.0
>>
>
> Thanks
> Barry
Ok, I will send a new version to fix it.
Thanks
On Thu, Jul 24, 2025 at 5:35 PM Qinxin Xia <xiaqinxin@huawei.com> wrote:
>
>
>
> On 2025/7/24 17:07:08, Barry Song <21cnbao@gmail.com> wrote:
> > On Thu, Jul 24, 2025 at 4:56 PM Qinxin Xia <xiaqinxin@huawei.com> 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@vger.kernel.org
> >> Acked-by: Barry Song <baohua@kernel.org>
> >> Signed-off-by: Qinxin Xia <xiaqinxin@huawei.com>
> >
> > 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
On 24.07.2025 11:42, Barry Song wrote:
> On Thu, Jul 24, 2025 at 5:35 PM Qinxin Xia <xiaqinxin@huawei.com> wrote:
>> On 2025/7/24 17:07:08, Barry Song <21cnbao@gmail.com> wrote:
>>> On Thu, Jul 24, 2025 at 4:56 PM Qinxin Xia <xiaqinxin@huawei.com> 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@vger.kernel.org
>>>> Acked-by: Barry Song <baohua@kernel.org>
>>>> Signed-off-by: Qinxin Xia <xiaqinxin@huawei.com>
>>> 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.
I'm sorry, I wasn't aware that this need to go via dma-mapping tree. I
will take it after this merge window.
Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland
On Tue, Jul 29, 2025 at 8:32 PM Marek Szyprowski
<m.szyprowski@samsung.com> wrote:
>
> On 24.07.2025 11:42, Barry Song wrote:
> > On Thu, Jul 24, 2025 at 5:35 PM Qinxin Xia <xiaqinxin@huawei.com> wrote:
> >> On 2025/7/24 17:07:08, Barry Song <21cnbao@gmail.com> wrote:
> >>> On Thu, Jul 24, 2025 at 4:56 PM Qinxin Xia <xiaqinxin@huawei.com> 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@vger.kernel.org
> >>>> Acked-by: Barry Song <baohua@kernel.org>
> >>>> Signed-off-by: Qinxin Xia <xiaqinxin@huawei.com>
> >>> 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.
>
> I'm sorry, I wasn't aware that this need to go via dma-mapping tree. I
> will take it after this merge window.
Thank you, Marek! I also noticed that Xiang Chen’s email has been invalid
for quite a while, likely he moved to another company some time ago. It looks
like Yicong has volunteered to take this on:
https://lkml.indiana.edu/2408.1/08865.html
I'm not sure if that's still the case. If it is, would Yicong be able to
resend the email with my ack?
>
> Best regards
> --
> Marek Szyprowski, PhD
> Samsung R&D Institute Poland
>
Thanks
Barry
Hi Barry,
On 2025/8/4 12:47, Barry Song wrote:
> On Tue, Jul 29, 2025 at 8:32 PM Marek Szyprowski
> <m.szyprowski@samsung.com> wrote:
>>
>> On 24.07.2025 11:42, Barry Song wrote:
>>> On Thu, Jul 24, 2025 at 5:35 PM Qinxin Xia <xiaqinxin@huawei.com> wrote:
>>>> On 2025/7/24 17:07:08, Barry Song <21cnbao@gmail.com> wrote:
>>>>> On Thu, Jul 24, 2025 at 4:56 PM Qinxin Xia <xiaqinxin@huawei.com> 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@vger.kernel.org
>>>>>> Acked-by: Barry Song <baohua@kernel.org>
>>>>>> Signed-off-by: Qinxin Xia <xiaqinxin@huawei.com>
>>>>> 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.
>>
>> I'm sorry, I wasn't aware that this need to go via dma-mapping tree. I
>> will take it after this merge window.
>
> Thank you, Marek! I also noticed that Xiang Chen’s email has been invalid
> for quite a while, likely he moved to another company some time ago. It looks
> like Yicong has volunteered to take this on:
>
> https://lkml.indiana.edu/2408.1/08865.html
>
> I'm not sure if that's still the case. If it is, would Yicong be able to
> resend the email with my ack?
>
thanks for reminding. I think currently Qinxin is more suitable to help with this.
she's working on the smmu stuffs and help look after this benchmark tool internally
for some time :)
Maybe she can help along with you (ack the fact that you're always helping to review
the codes) if it's ok with you.
Thanks.
On Mon, Aug 4, 2025 at 8:12 PM Yicong Yang <yangyicong@huawei.com> wrote:
>
> Hi Barry,
>
> On 2025/8/4 12:47, Barry Song wrote:
> > On Tue, Jul 29, 2025 at 8:32 PM Marek Szyprowski
> > <m.szyprowski@samsung.com> wrote:
> >>
> >> On 24.07.2025 11:42, Barry Song wrote:
> >>> On Thu, Jul 24, 2025 at 5:35 PM Qinxin Xia <xiaqinxin@huawei.com> wrote:
> >>>> On 2025/7/24 17:07:08, Barry Song <21cnbao@gmail.com> wrote:
> >>>>> On Thu, Jul 24, 2025 at 4:56 PM Qinxin Xia <xiaqinxin@huawei.com> 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@vger.kernel.org
> >>>>>> Acked-by: Barry Song <baohua@kernel.org>
> >>>>>> Signed-off-by: Qinxin Xia <xiaqinxin@huawei.com>
> >>>>> 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.
> >>
> >> I'm sorry, I wasn't aware that this need to go via dma-mapping tree. I
> >> will take it after this merge window.
> >
> > Thank you, Marek! I also noticed that Xiang Chen’s email has been invalid
> > for quite a while, likely he moved to another company some time ago. It looks
> > like Yicong has volunteered to take this on:
> >
> > https://lkml.indiana.edu/2408.1/08865.html
> >
> > I'm not sure if that's still the case. If it is, would Yicong be able to
> > resend the email with my ack?
> >
>
> thanks for reminding. I think currently Qinxin is more suitable to help with this.
> she's working on the smmu stuffs and help look after this benchmark tool internally
> for some time :)
>
> Maybe she can help along with you (ack the fact that you're always helping to review
> the codes) if it's ok with you.
Certainly, Qinxin is welcome to take over. I will be glad to review
the code when time
permits, although my schedule is typically quite occupied with mm.
Thanks
Barry
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