On Wed, Dec 19, 2018 at 03:17:44PM +0100, Miroslav Benes wrote: > GCC 9 introduces a new option, -flive-patching. It disables certain > optimizations which could make a compilation unsafe for later live > patching of the running kernel. > > The option is used only if CONFIG_LIVEPATCH is enabled and $(CC) > supports it. > > Signed-off-by: Miroslav Benes <mbe...@suse.cz> > --- > Makefile | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/Makefile b/Makefile > index a0650bf79606..53f5ab810efe 100644 > --- a/Makefile > +++ b/Makefile > @@ -778,6 +778,10 @@ KBUILD_CFLAGS_KERNEL += $(call > cc-option,-ffunction-sections,) > KBUILD_CFLAGS_KERNEL += $(call cc-option,-fdata-sections,) > endif > > +ifdef CONFIG_LIVEPATCH > +KBUILD_CFLAGS += $(call cc-option, -flive-patching=inline-clone) > +endif > + > # arch Makefile may override CC so keep this after arch Makefile is included > NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)
This option only makes sense for source-based patch generation, so isn't it a bit premature to make this change without proper source-based patch tooling? Also the commit message needs an analysis of the performance impacts. -- Josh
