On Fri, Apr 9, 2021 at 10:27 PM Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > > From: Arnd Bergmann <arnd@xxxxxxxx> > Subject: kasan: fix hwasan build for gcc > > gcc-11 adds support for -fsanitize=kernel-hwaddress, so it becomes > possible to enable CONFIG_KASAN_SW_TAGS. > > Unfortunately this fails to build at the moment, because the corresponding > command line arguments use llvm specific syntax. > > Change it to use the cc-param macro instead, which works on both clang and > gcc. > > Link: https://lkml.kernel.org/r/20210323124112.1229772-1-arnd@xxxxxxxxxx > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> > Reviewed-by: Marco Elver <elver@xxxxxxxxxx> > Cc: Masahiro Yamada <masahiroy@xxxxxxxxxx> > Cc: Michal Marek <michal.lkml@xxxxxxxxxxx> > Cc: Andrey Ryabinin <ryabinin.a.a@xxxxxxxxx> > Cc: Nathan Chancellor <nathan@xxxxxxxxxx> > Cc: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> > Cc: Alexander Potapenko <glider@xxxxxxxxxx> > Cc: Andrey Konovalov <andreyknvl@xxxxxxxxx> > Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx> > Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > --- > > scripts/Makefile.kasan | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > --- a/scripts/Makefile.kasan~kasan-fix-hwasan-build-for-gcc > +++ a/scripts/Makefile.kasan > @@ -36,14 +36,14 @@ endif # CONFIG_KASAN_GENERIC > ifdef CONFIG_KASAN_SW_TAGS > > ifdef CONFIG_KASAN_INLINE > - instrumentation_flags := -mllvm -hwasan-mapping-offset=$(KASAN_SHADOW_OFFSET) > + instrumentation_flags := $(call cc-param,hwasan-mapping-offset=$(KASAN_SHADOW_OFFSET)) > else > - instrumentation_flags := -mllvm -hwasan-instrument-with-calls=1 > + instrumentation_flags := $(call cc-param,hwasan-instrument-with-calls=1) > endif > > CFLAGS_KASAN := -fsanitize=kernel-hwaddress \ > - -mllvm -hwasan-instrument-stack=$(CONFIG_KASAN_STACK) \ > - -mllvm -hwasan-use-short-granules=0 \ > + $(call cc-param,hwasan-instrument-stack=$(CONFIG_KASAN_STACK)) \ > + $(call cc-param,hwasan-use-short-granules=0) \ > $(instrumentation_flags) > > endif # CONFIG_KASAN_SW_TAGS > _ Hi, As I commented on the patch, this breaks SW_TAGS build with Clang for me with: arch/arm64/include/asm/current.h:19: undefined reference to `__hwasan_tls' The reason for this is that cc-param is only defined for KASAN_GENERIC, the definition needs to be moved. Thanks!
