On Fri, Jan 11, 2019 at 09:58:42PM +0300, Andrey Ryabinin wrote: > Use after scope bugs detector seems to be almost entirely useless > for the linux kernel. It exists over two years, but I've seen only > one valid bug so far [1]. And the bug was fixed before it has been > reported. There were some other use-after-scope reports, but they > were false-positives due to different reasons like incompatibility > with structleak plugin. > > This feature significantly increases stack usage, especially with > GCC < 9 version, and causes a 32K stack overflow. It probably > adds performance penalty too. > > Given all that, let's remove use-after-scope detector entirely. > > While preparing this patch I've noticed that we mistakenly enable > use-after-scope detection for clang compiler regardless of > CONFIG_KASAN_EXTRA setting. This is also fixed now. > > [1] http://lkml.kernel.org/r/<20171129052106.rhgbjhhis53hkgfn@xxxxxxxxxxxxxxxxxxxxxx> > > Signed-off-by: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx> > Cc: Qian Cai <cai@xxxxxx> > Cc: Alexander Potapenko <glider@xxxxxxxxxx> > Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx> > Cc: Catalin Marinas <catalin.marinas@xxxxxxx> > Cc: Will Deacon <will.deacon@xxxxxxx> > --- > arch/arm64/include/asm/memory.h | 4 ---- > lib/Kconfig.debug | 1 - > lib/Kconfig.kasan | 10 ---------- > lib/test_kasan.c | 24 ------------------------ > mm/kasan/generic.c | 19 ------------------- > mm/kasan/generic_report.c | 3 --- > mm/kasan/kasan.h | 3 --- > scripts/Makefile.kasan | 5 ----- > scripts/gcc-plugins/Kconfig | 4 ---- > 9 files changed, 73 deletions(-) For the arm64 part: Acked-by: Will Deacon <will.deacon@xxxxxxx> but I defer to you and Dmitry as to whether or not you go ahead with this. Will
