On Fri, 4 Mar 2016, Josh Poimboeuf wrote: > On Fri, Mar 04, 2016 at 10:53:39AM +0100, Miroslav Benes wrote: > > There is an #error in asm/livepatch.h for both x86 and s390 in > > !CONFIG_LIVEPATCH cases. It does not make much sense as pointed out by > > Michael Ellerman. One can happily include asm/livepatch.h with > > CONFIG_LIVEPATCH. Remove it as useless. > > > > Suggested-by: Michael Ellerman <[email protected]> > > Signed-off-by: Miroslav Benes <[email protected]> > > Looks fine to me. While we're at it, do we even need the '#ifdef > CONFIG_LIVEPATCH' in these files? And in include/linux/livepatch.h?
IIRC there was a reason to this. If you build a patch module on (against) the kernel with CONFIG_LIVEPATCH=n the build fails immediately with those ifdefs, because there is no declaration of needed symbols present (klp_register_patch(), data structures and such). Without ifdefs the build succeeds and modprobe/insmod fails. The former could be advantageous in some scenarios. But since the guard in include/linux/livepatch.h (which is the only important header file in fact) returns with Jessica's patches for better reason there is no point to discuss this further :) Miroslav
