On 01/23/2018 05:20 AM, Andrew Morton wrote: > On Fri, 19 Jan 2018 18:58:12 +0100 Andrey Konovalov <andreyk...@google.com> > wrote: > >> With KASAN enabled the kernel has two different memset() functions, one >> with KASAN checks (memset) and one without (__memset). KASAN uses some >> macro tricks to use the proper version where required. For example memset() >> calls in mm/slub.c are without KASAN checks, since they operate on poisoned >> slab object metadata. >> >> The issue is that clang emits memset() calls even when there is no memset() >> in the source code. They get linked with improper memset() implementation >> and the kernel fails to boot due to a huge amount of KASAN reports during >> early boot stages. >> >> The solution is to add -fno-builtin flag for files with KASAN_SANITIZE := n >> marker. > > This clashes somewhat with Arnd's asan-rework-kconfig-settings.patch. > Could you two please put heads together and decide what we want for a > final result? > > Meanwhile I'll "fix" the reject with > > +ifdef CONFIG_KASAN_EXTRA > CFLAGS_KASAN += $(call cc-option, -fsanitize-address-use-after-scope) > +endif >
Looks correct.
