On Fri, May 02, 2025 at 09:12:09AM -0700, Nathan Chancellor wrote: > Hi Kees, > > On Thu, May 01, 2025 at 12:48:17PM -0700, Kees Cook wrote: > > While the randstruct GCC plugin was being rebuilt if the randstruct > > seed changed, Clangs build did not notice the change. Include the hash > > header directly so that it becomes a universal build dependency and full > > rebuilds will happen if it changes. > > > > Signed-off-by: Kees Cook <[email protected]> > > --- > > Cc: Masahiro Yamada <[email protected]> > > Cc: Nathan Chancellor <[email protected]> > > Cc: Nicolas Schier <[email protected]> > > Cc: Petr Pavlu <[email protected]> > > Cc: Sebastian Andrzej Siewior <[email protected]> > > Cc: <[email protected]> > > --- > > include/linux/vermagic.h | 1 - > > scripts/Makefile.randstruct | 3 ++- > > scripts/basic/Makefile | 11 ++++++----- > > 3 files changed, 8 insertions(+), 7 deletions(-) > > > > diff --git a/include/linux/vermagic.h b/include/linux/vermagic.h > > index 939ceabcaf06..335c360d4f9b 100644 > > --- a/include/linux/vermagic.h > > +++ b/include/linux/vermagic.h > > @@ -33,7 +33,6 @@ > > #define MODULE_VERMAGIC_MODVERSIONS "" > > #endif > > #ifdef RANDSTRUCT > > -#include <generated/randstruct_hash.h> > > #define MODULE_RANDSTRUCT "RANDSTRUCT_" RANDSTRUCT_HASHED_SEED > > #else > > #define MODULE_RANDSTRUCT > > diff --git a/scripts/Makefile.randstruct b/scripts/Makefile.randstruct > > index 24e283e89893..ab87219c6149 100644 > > --- a/scripts/Makefile.randstruct > > +++ b/scripts/Makefile.randstruct > > @@ -12,6 +12,7 @@ randstruct-cflags-y \ > > += -frandomize-layout-seed-file=$(objtree)/scripts/basic/randstruct.seed > > endif > > > > -export RANDSTRUCT_CFLAGS := $(randstruct-cflags-y) > > +export RANDSTRUCT_CFLAGS := $(randstruct-cflags-y) \ > > + -include $(objtree)/scripts/basic/randstruct_hash.h > > As the kernel test robot points out (on a report that you weren't > included on for some reason...), this breaks the build in several > places on next-20250502. > > https://lore.kernel.org/[email protected]/ > > $ make -skj"$(nproc)" ARCH=arm LLVM=1 clean allmodconfig > arch/arm/vdso/vgettimeofday.o > clang: error: cannot specify -o when generating multiple output files > > There are places in the kernel that filter out RANDSTRUCT_CFLAGS and > this appears to cause other '-include' flags to be filtered out as well, > such as the one in the efistub that includes hidden.h.
Thanks! Yeah, I have been poking at it for most of today. 😠I think I have a viable solution, that I actually end up liking a bit better, which I just sent out: https://lore.kernel.org/lkml/[email protected]/ -- Kees Cook
