On Mon, Sep 11, 2017 at 09:59:36PM +0200, Arnd Bergmann wrote: > When KMEMCHECK is enabled, we always build with frame pointers, > which is incompatible with ORC_UNWINDER and GUESS_UNWINDER, as > Kconfig points out: > > warning: (FAULT_INJECTION_STACKTRACE_FILTER && LATENCYTOP && KMEMCHECK && > LOCKDEP && FRAME_POINTER_UNWINDER) selects FRAME_POINTER which has unmet > direct dependencies (DEBUG_KERNEL && (CRIS || M68K || FRV || UML || SUPERH || > BLACKFIN || MN10300 || METAG) || ARCH_WANT_FRAME_POINTERS || !ORC_UNWINDER && > !GUESS_UNWINDER) > > This works around it by making those two unwinders depend on > !KMEMCHECK. The other three options that enable frame pointers > (FAULT_INJECTION_STACKTRACE_FILTER, LATENCYTOP and LOCKDEP) only > do that on some architectures but not on x86. > > It's possible that KMEMCHECK doesn't actually require frame pointers > but only requires some unwinder. If that is the case, we should drop > the 'select FRAME_POINTER' there. KMEMCHECK is currenly used only > on x86.
KMEMCHECK should work with *any* of the unwinders because it uses the unwinder-agnostic save_stack_trace() interface. So removing the 'select FRAME_POINTER' sounds like the right fix. -- Josh
