[rcu:dev.2020.04.05b 101/101] kprobes.c:undefined reference to `.synchronize_rcu_tasks'

[kbuild test robot]

Hi Paul,

It's probably a bug fix that unveils the link errors.

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git dev.2020.04.05b
head:   805020c8028f6e95a8fc57132af5f896a8ad6391
commit: 805020c8028f6e95a8fc57132af5f896a8ad6391 [101/101] squash! rcu-tasks: Add an RCU Tasks Trace to simplify protection of tracing hooks
config: powerpc-defconfig (attached as .config)
compiler: powerpc64-linux-gcc (GCC) 9.3.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        git checkout 805020c8028f6e95a8fc57132af5f896a8ad6391
        # save the attached .config to linux build tree
        GCC_VERSION=9.3.0 make.cross ARCH=powerpc 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kbuild test robot <lkp@xxxxxxxxx>

All errors (new ones prefixed by >>):

   powerpc64-linux-ld: warning: orphan section `.gnu.hash' from `linker stubs' being placed in section `.gnu.hash'
   powerpc64-linux-ld: kernel/kprobes.o: in function `.kprobe_optimizer':
>> kprobes.c:(.text+0x2bc8): undefined reference to `.synchronize_rcu_tasks'
   powerpc64-linux-ld: kernel/bpf/trampoline.o: in function `.bpf_trampoline_put':
>> trampoline.c:(.text+0x630): undefined reference to `.synchronize_rcu_tasks'
   powerpc64-linux-ld: kernel/bpf/trampoline.o: in function `.bpf_trampoline_update':
   trampoline.c:(.text+0x908): undefined reference to `.synchronize_rcu_tasks'

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx

Attachment: .config.gz
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