On Fri, 2018-02-16 at 21:28 +0100, Arnd Bergmann wrote:
On Fri, Feb 16, 2018 at 7:21 PM, kbuild test robot fengguang.wu@intel.com wrote:
[...]
All errors (new ones prefixed by >>):
arch/x86/kernel/head64.o: In function `_GLOBAL__sub_D_00100_1_early_pmd_flags':
head64.c:(.text.exit+0x5): undefined reference to `__gcov_exit'
arch/x86/kernel/head.o: In function `_GLOBAL__sub_D_00100_1_reserve_ebda_region': head.c:(.text.exit+0x5): undefined reference to `__gcov_exit' init/built-in.o: In function `_GLOBAL__sub_D_00100_1___ksymtab_system_state': main.c:(.text.exit+0x5): undefined reference to `__gcov_exit' init/built-in.o: In function `_GLOBAL__sub_D_00100_1_root_mountflags': do_mounts.c:(.text.exit+0x10): undefined reference to `__gcov_exit' init/built-in.o: In function `_GLOBAL__sub_D_00100_1_initrd_load': do_mounts_initrd.c:(.text.exit+0x1b): undefined reference to `__gcov_exit' init/built-in.o:initramfs.c:(.text.exit+0x26): more undefined references to `__gcov_exit' follow
I think this is a result of using a too new compiler with the old 3.16 kernel. In order to build with gcc-7.3, you need to backport
05384213436a ("gcov: support GCC 7.1")
It's already part of stable-3.18 and later, but not 3.2 and 3.16.
Thanks. I've queued up the following for 3.16:
3e44c471a2da gcov: add support for GCC 5.1 d02038f97253 gcov: add support for gcc version >= 6 05384213436a gcov: support GCC 7.1
Ben.