[PATCH] powerpc/security: Provide stubs for when PPC_BARRIER_NOSPEC isn't enabled

[Christophe Leroy]

Le 10/01/2022 à 11:07, Naveen N. Rao a écrit :
> kernel test robot reported the below build error with a randconfig:
>    powerpc64-linux-ld: arch/powerpc/net/bpf_jit_comp64.o:(.toc+0x0):
>    undefined reference to `powerpc_security_features'
> 
> This can happen if CONFIG_PPC_BARRIER_NOSPEC is not enabled. Address
> this by providing stub functions for security_ftr_enabled() and related
> helpers when the config option is not enabled.

Looks like this can happen only when E500 is not selected.

But what kind of CPU do we have if it's not a E500 ?

AFAICS in cputable.c, if not a PPC32 and not a BOOK3S_64 is must be a 
E500 otherwise there's just no CPU.

Should we make Kconfig stricter instead to avoid the Robot selecting a 
crazy config ?

Christophe