On Sun, Dec 27, 2020 at 10:27:43AM +0100, Salvatore Bonaccorso wrote:
Hi Greg, Sasha and all,
This is a resubmit of the patches already done in https://lore.kernel.org/stable/20201125201215.26455-1-carnil@debian.org/ and https://lore.kernel.org/stable/20201125201215.26455-2-carnil@debian.org/
The issue can be explained as this. In
https://lore.kernel.org/stable/20201014135627.GA3698844@kroah.com/
on request 168200b6d6ea ("perf cs-etm: Move definition of 'traceid_list' global variable from header file") was queued back to 4.19.y to fix build failures for perf with more recent GCCs.
But for 4.19.y this was wrong because it missed to pick as well a dependency needed, and in turn it caused build failures with older GCC (8.3.0 as used in Debian stable in that case).
The commit was reverted in a later in 4.19.159.
It as though requested to try to allow as well compilation with more recent GCCs (while obviously not breaking older GCC builds) and found that the cause was just the missing dependency to pick up, namely pick 95c6fe970a01 ("perf cs-etm: Change tuple from traceID-CPU# to traceID-metadata") before 168200b6d6ea ("perf cs-etm: Move definition of 'traceid_list' global variable from header file").
Thanks for these, both now queued up.
greg k-h