[Bug sanitizer/78513] New: [7 Regression] Failure to build linux kernel with KASAN support

[ktkachov at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78513

            Bug ID: 78513
           Summary: [7 Regression] Failure to build linux kernel with
                    KASAN support
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: sanitizer
          Assignee: unassigned at gcc dot gnu.org
          Reporter: ktkachov at gcc dot gnu.org
                CC: dodji at gcc dot gnu.org, dvyukov at gcc dot gnu.org,
                    jakub at gcc dot gnu.org, kcc at gcc dot gnu.org
  Target Milestone: ---

I'm trying to build the Linux kernel 4.8.10, downloaded from kernel.org using
an aarch64-none-linux-gnu trunk toolchain (r242837).
I'm building a defconfig kernel with the additional:
 CONFIG_KASAN=y
 CONFIG_KASAN_OUTLINE=y

in the .config file to enable KASAN.
This works with a GCC 6 compiler. With trunk this fails to link with many
undefined references, for example:
net/built-in.o: In function `ethtool_set_per_queue':
ncsi-manage.c:(.text+0x5e2a8): undefined reference to
`__asan_unpoison_stack_memory'
ncsi-manage.c:(.text+0x5e398): undefined reference to
`__asan_poison_stack_memory'

I guess this has something to do with the libsanitizer merge?