linux-lowlatency fails to build on arm64 due to kernel option settings

[Frank Heimes]

The 'linux-lowlatency' kernel build (incl. autopkgtest) was triggered in a kinetic-proposed migration process (for zlib) and runs into a 'regression':
"autopkgtest for linux-lowlatency/5.19.0-1001.1: amd64: Pass, arm64: Regression ♻"

The regression is highly likely not due to zlib itself, but due to NEW kernel options, that don't have a default yet and a check-config FAIL, see:
...
check-config: /tmp/autopkgtest.ZQs9si/build.cYo/src/debian/build/build-lowlatency/.config: loading config
check-config: /tmp/autopkgtest.ZQs9si/build.cYo/src/debian.lowlatency/config/annotations loading annotations
check-config: FAIL (n != -): CONFIG_KCOV policy<{'amd64': 'n', 'arm64':
 -, 'armhf': 'n', 'ppc64el': '-', 'riscv64': 'n', 's390x': '-'}>
check-config: 11323/11324 checks passed -- exit 1
...
Shadow Call Stack (SHADOW_CALL_STACK) [N/y/?] (NEW)
Error in reading or end of file.
...
Initialize kernel stack variables at function entry
> 1. no automatic stack variable initialization (weakest) (INIT_STACK_NONE)
  2. pattern-init everything (strongest) (INIT_STACK_ALL_PATTERN) (NEW)
  3. zero-init everything (strongest and safest) (INIT_STACK_ALL_ZERO) (NEW)
choice[1-3?]:
Error in reading or end of file.
...

Full log is here:
https://autopkgtest.ubuntu.com/results/autopkgtest-kinetic/kinetic/arm64/l/linux-lowlatency/20220728_135536_c2061@/log.gz

(this might be caused by the recent compiler update)

[Frank Heimes (fheimes)]

So yes, this is a new feature / kernel option for (arm only) introduced with the migration to gcc 12:
[v3,1/2] AARCH64: Add gcc Shadow Call Stack support
https://patchwork.kernel.org/project/linu
<email address hidden>/#24774364

[Frank Heimes (fheimes)]

set to invails, since this was for a previous proposed migrations issue that was meanwhile solved