On Tue, Oct 11, 2022 at 10:24:27AM +0200, Peter Zijlstra wrote: > On Mon, Oct 10, 2022 at 06:20:00PM -0700, Linus Torvalds wrote: > > The other thing I notice from just doing a build is that I now get > > > > vmlinux.o: warning: objtool: kasan_report+0x12: call to > > stackleak_track_stack() with UACCESS enabled > > So kasan_report() is already marked as being special; and it does the > mandatory user_access_save() / user_access_restore() things to fix it > up. > > But it looks like kasan code itself is now getting instrumented by the > stackleak stuff and that inserts a call outside of the > user_access_save()/restore() thing, and *that* is getting flagged. > > Looking at mm/kasan/Makefile it disables a lot of the instrumentation, > but perhaps not enough? I can recreate, but weirdly the below doesn't seem to fix it. diff --git a/mm/kasan/Makefile b/mm/kasan/Makefile index d4837bff3b60..a41cf1235032 100644 --- a/mm/kasan/Makefile +++ b/mm/kasan/Makefile @@ -1,5 +1,6 @@ # SPDX-License-Identifier: GPL-2.0 KASAN_SANITIZE := n +KMSAN_SANITIZE := n UBSAN_SANITIZE := n KCOV_INSTRUMENT := n