On Tue, Jun 18, 2019 at 11:47:13AM +0200, Arnd Bergmann wrote:

The combination of KASAN_STACK and GCC_PLUGIN_STRUCTLEAK_BYREF_ALL
leads to much larger kernel stack usage, as seen from the warnings
about functions that now exceed the 2048 byte limit:

Is the preference that this go into v5.2 (there's not much time left),
or should this be v5.3? (You didn't mark it as Cc: stable?)

one. I picked the dependency in GCC_PLUGIN_STRUCTLEAK_BYREF_ALL, as
this option is designed to make uninitialized stack usage less harmful
when enabled on its own, but it also prevents KASAN from detecting those
cases in which it was in fact needed.

Right -- there's not much sense in both being enabled. I'd agree with
this rationale.

-- 
Kees Cook