linux-libc-header version mismatch?

linux-libc-header version mismatch?

[Hans Beckérus]

Hi. We are using a 3.6 based kernel in our builds using a custom
kernel recipe. However, I can see that the linux-libc-headers built
but based on a 3.8 kernel?
Is this really how it should be? Are we supposed to also make a custom
recipe for the linux-libc-headers? The image seems to be executing
fine but I am a bit worried about the version mismatch :(

Hans

PS. I believe I posted this question before but I am no longer 100%
convinced it actually left my outbox. At least I never got a response,
which usually happens very quickly :)

Re: linux-libc-header version mismatch?

[Bruce Ashfield]

On 13-06-24 11:59 AM, Hans Beckérus wrote:
> Hi. We are using a 3.6 based kernel in our builds using a custom
> kernel recipe. However, I can see that the linux-libc-headers built
> but based on a 3.8 kernel?
> Is this really how it should be? Are we supposed to also make a custom
> recipe for the linux-libc-headers? The image seems to be executing
> fine but I am a bit worried about the version mismatch :(

You shouldn't need to do this. We use a single libc-headers version
for all of a given linux-yocto kernels in a release. The userspace /
libc ABI is stable, and backwards compatible (generally speaking of
course). New interfaces typically have a fallback if the kernel
interface is missing, and we don't currently have any issues either.

Of course older headers with newer kernels is even safer, since
typically at most you are missing out on being able to use new APIs
versus potential for missing APIs.

Summary: you can match them if you want, but we are testing across
several kernel versions and haven't found any issues (yet).

Cheers,

Bruce

>
> Hans
>
> PS. I believe I posted this question before but I am no longer 100%
> convinced it actually left my outbox. At least I never got a response,
> which usually happens very quickly :)
> _______________________________________________
> yocto mailing list
> yocto@yoctoproject.org
> https://lists.yoctoproject.org/listinfo/yocto
>

Re: linux-libc-header version mismatch?

[Paul Barker]

On 24 June 2013 17:19, Bruce Ashfield <bruce.ashfield@windriver.com> wrote:
> On 13-06-24 11:59 AM, Hans Beckérus wrote:
>>
>> Hi. We are using a 3.6 based kernel in our builds using a custom
>> kernel recipe. However, I can see that the linux-libc-headers built
>> but based on a 3.8 kernel?
>> Is this really how it should be? Are we supposed to also make a custom
>> recipe for the linux-libc-headers? The image seems to be executing
>> fine but I am a bit worried about the version mismatch :(
>
> Summary: you can match them if you want, but we are testing across
> several kernel versions and haven't found any issues (yet).
>

Just to point out - this is pretty common across linux distros as
well, otherwise all your software would have to be re-built every time
you updated the kernel.

--
Paul Barker

Email: paul@paulbarker.me.uk
http://www.paulbarker.me.uk

Re: linux-libc-header version mismatch?

[Hans Beckérus]

On Mon, Jun 24, 2013 at 6:29 PM, Paul Barker <paul@paulbarker.me.uk> wrote:
> On 24 June 2013 17:19, Bruce Ashfield <bruce.ashfield@windriver.com> wrote:
>> On 13-06-24 11:59 AM, Hans Beckérus wrote:
>>>
>>> Hi. We are using a 3.6 based kernel in our builds using a custom
>>> kernel recipe. However, I can see that the linux-libc-headers built
>>> but based on a 3.8 kernel?
>>> Is this really how it should be? Are we supposed to also make a custom
>>> recipe for the linux-libc-headers? The image seems to be executing
>>> fine but I am a bit worried about the version mismatch :(
>>
>> Summary: you can match them if you want, but we are testing across
>> several kernel versions and haven't found any issues (yet).
>>
>
> Just to point out - this is pretty common across linux distros as
> well, otherwise all your software would have to be re-built every time
> you updated the kernel.
>
> --
> Paul Barker
>
> Email: paul@paulbarker.me.uk
> http://www.paulbarker.me.uk

Thanks Paul (and Bruce of course).
I now realize that this would break most systems after a major kernel upgrade ;)
From what I know/experienced so far is that the only thing that
usually breaks with a new major kernel version is our own kernel
drivers...

Hans


On Mon, Jun 24, 2013 at 6:29 PM, Paul Barker <paul@paulbarker.me.uk> wrote:
> On 24 June 2013 17:19, Bruce Ashfield <bruce.ashfield@windriver.com> wrote:
>> On 13-06-24 11:59 AM, Hans Beckérus wrote:
>>>
>>> Hi. We are using a 3.6 based kernel in our builds using a custom
>>> kernel recipe. However, I can see that the linux-libc-headers built
>>> but based on a 3.8 kernel?
>>> Is this really how it should be? Are we supposed to also make a custom
>>> recipe for the linux-libc-headers? The image seems to be executing
>>> fine but I am a bit worried about the version mismatch :(
>>
>> Summary: you can match them if you want, but we are testing across
>> several kernel versions and haven't found any issues (yet).
>>
>
> Just to point out - this is pretty common across linux distros as
> well, otherwise all your software would have to be re-built every time
> you updated the kernel.
>
> --
> Paul Barker
>
> Email: paul@paulbarker.me.uk
> http://www.paulbarker.me.uk