issue of building bitesize_kern.c under kenrel source tree

[zmj64351508]

bitesize_kern.c includes <linux/blkdev.h> which includes many "asm" files that are not compatible with bpf build. I'm wondering how do you fix these issues or could you share the Makefile for me?

Thanks.

The error reported is like:

In file included from /work/zmj/android/kernel/msm-4.9/../../bpftool/bitesize_kern.c:15:
In file included from /work/zmj/android/kernel/msm-4.9/include/linux/blkdev.h:4:
In file included from /work/zmj/android/kernel/msm-4.9/include/linux/sched.h:19:
In file included from /work/zmj/android/kernel/msm-4.9/include/linux/timex.h:56:
In file included from /work/zmj/android/kernel/msm-4.9/include/uapi/linux/timex.h:56:
In file included from /work/zmj/android/kernel/msm-4.9/include/linux/time.h:5:
In file included from /work/zmj/android/kernel/msm-4.9/include/linux/seqlock.h:35:
In file included from /work/zmj/android/kernel/msm-4.9/include/linux/spinlock.h:50:
In file included from /work/zmj/android/kernel/msm-4.9/include/linux/preempt.h:59:
In file included from ./arch/arm64/include/generated/asm/preempt.h:1:
In file included from /work/zmj/android/kernel/msm-4.9/include/asm-generic/preempt.h:4:
In file included from /work/zmj/android/kernel/msm-4.9/include/linux/thread_info.h:25:
In file included from /work/zmj/android/kernel/msm-4.9/arch/arm64/include/asm/thread_info.h:33:
/work/zmj/android/kernel/msm-4.9/arch/arm64/include/asm/stack_pointer.h:7:51: error: register 'sp' unsuitable for global register variables on this target
register unsigned long current_stack_pointer asm ("sp");
                                                  ^
In file included from /work/zmj/android/kernel/msm-4.9/../../bpftool/bitesize_kern.c:15:
In file included from /work/zmj/android/kernel/msm-4.9/include/linux/blkdev.h:4:
In file included from /work/zmj/android/kernel/msm-4.9/include/linux/sched.h:19:
In file included from /work/zmj/android/kernel/msm-4.9/include/linux/timex.h:56:
In file included from /work/zmj/android/kernel/msm-4.9/include/uapi/linux/timex.h:56:
In file included from /work/zmj/android/kernel/msm-4.9/include/linux/time.h:5:
In file included from /work/zmj/android/kernel/msm-4.9/include/linux/seqlock.h:35:
In file included from /work/zmj/android/kernel/msm-4.9/include/linux/spinlock.h:87:
/work/zmj/android/kernel/msm-4.9/arch/arm64/include/asm/spinlock.h:119:28: error: value '65536' out of range for constraint 'I'
        : "Q" (lock->owner), "I" (1 << TICKET_SHIFT)
                                  ^~~~~~~~~~~~~~~~~
/work/zmj/android/kernel/msm-4.9/arch/arm64/include/asm/spinlock.h:147:9: error: value '65536' out of range for constraint 'I'
        : "I" (1 << TICKET_SHIFT)