Backport request: commit 168200b6 to fix perf build with gcc 10

Backport request: commit 168200b6 to fix perf build with gcc 10

[Paul Barker]

Hi folks,

I'm seeing errors building perf with gcc 10 on the linux-5.4.y branch.
The linker fails as the traceid_list symbol is defined in multiple
compilation units. It looks like commit
168200b6d6ea0cb5765943ec5da5b8149701f36a ("perf cs-etm: Move
definition of 'traceid_list' global variable from header file") was
added to master to fix this but it's not been backported yet.
Cherry-picking this commit locally fixed my build issues.

Looking at the Fixes tag in that commit, this should probably go into
every stable branch from 4.16.y onwards which is still maintained.

See https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=168200b6d6ea0cb5765943ec5da5b8149701f36a

Let me know if you need more info.

Thanks,

-- 
Paul Barker
Konsulko Group

Re: Backport request: commit 168200b6 to fix perf build with gcc 10

[Greg KH]

On Wed, Oct 14, 2020 at 12:48:42PM +0100, Paul Barker wrote:
> Hi folks,
> 
> I'm seeing errors building perf with gcc 10 on the linux-5.4.y branch.
> The linker fails as the traceid_list symbol is defined in multiple
> compilation units. It looks like commit
> 168200b6d6ea0cb5765943ec5da5b8149701f36a ("perf cs-etm: Move
> definition of 'traceid_list' global variable from header file") was
> added to master to fix this but it's not been backported yet.
> Cherry-picking this commit locally fixed my build issues.
> 
> Looking at the Fixes tag in that commit, this should probably go into
> every stable branch from 4.16.y onwards which is still maintained.
> 
> See https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=168200b6d6ea0cb5765943ec5da5b8149701f36a
> 
> Let me know if you need more info.

Now queued up, but perf does not seem to be building on the 4.19.y tree
at the moment, so I don't know how useful that will be there :)

thanks,

greg k-h