On Tue, May 30, 2023, at 21:02, Arnd Bergmann wrote:
>
> CONFIG_COMPILE_TEST=y forces a number of options to be
> hidden from build tests, which is generally super useful.
> The one that ended up hiding the stack growth above is
> CONFIG_GCOV_PROFILE_ALL. I'll try enabling it for a few
> builds to see what else shows up with it.
Update: you already pointed to UBSAN_SANITIZE_ALL causing
this, I can confirm that this is also the case. With your
config, the combination of CONFIG_GCOV_PROFILE_ALL and
CONFIG_UBSAN_SANITIZE_ALL causes the compiler to completely
mess up register allocation in this code, disabling either
of the two gets it below the boundary.
Arnd
