Messages in this thread | | | Date | Thu, 26 Sep 2019 11:25:30 +0200 | From | Borislav Petkov <> | Subject | Re: [PATCH] arch/x86/boot: use prefix map to avoid embedded paths |
| |
Don't forget to CC: lkml and x86@kernel.org on x86 patches.
On Thu, Sep 26, 2019 at 10:11:32AM +0100, Ross Burton wrote: > From: Bruce Ashfield <bruce.ashfield@gmail.com> > > It was observed that the kernel embeds the path in the x86 boot > artifacts. > > From https://bugzilla.yoctoproject.org/show_bug.cgi?id=13458: > > [ > If you turn on the buildpaths QA test, or try a reproducible build, you > discover that the kernel image contains build paths. > > $ strings bzImage-5.0.19-yocto-standard |grep tmp/ > out of pgt_buf in > /data/poky-tmp/reproducible/tmp/work-shared/qemux86-64/kernel-source/arch/x86/boot/compressed/kaslr_64.c!? > > But what's this in the top-level Makefile: > > $ git grep prefix-map > Makefile:KBUILD_CFLAGS += $(call > cc-option,-fmacro-prefix-map=$(srctree)/=) > > So the __FILE__ shouldn't be using the full path. However > arch/x86/boot/compressed/Makefile has this: > > KBUILD_CFLAGS := -m$(BITS) -O2 > > So that clears KBUILD_FLAGS, removing the -fmacro-prefix-map option. > ] > > Other architectures do not clear the flags, but instead prune before > adding boot or specific options. There's no obvious reason why x86 isn't > doing the same thing (pruning vs clearing) and no build or boot issues > have been observed. > > So we make x86 can do the same thing, and we no longer have embedded paths. > > Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com> > Signed-off-by: Ross Burton <ross.burton@intel.com> > --- > arch/x86/boot/compressed/Makefile | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile > index 6b84afdd7538..b246f18c5857 100644 > --- a/arch/x86/boot/compressed/Makefile > +++ b/arch/x86/boot/compressed/Makefile > @@ -38,6 +38,7 @@ KBUILD_CFLAGS += $(call cc-option,-fno-stack-protector) > KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member) > KBUILD_CFLAGS += $(call cc-disable-warning, gnu) > KBUILD_CFLAGS += -Wno-pointer-sign > +KBUILD_CFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=) > > KBUILD_AFLAGS := $(KBUILD_CFLAGS) -D__ASSEMBLY__ > GCOV_PROFILE := n > --
What about arch/x86/boot/Makefile ?
-- Regards/Gruss, Boris.
https://people.kernel.org/tglx/notes-about-netiquette
| |