Finally, the reason of build failure was founded. The kallsyms testcase use operating system parameters `kernel.kptr_restrict` and `kernel.perf_event_paranoid` to determine if a ordinary user could read the address info from /proc/kallsyms file. Obviously that's not true, because both machines of you and I have the same value for the two parameters, but on your machine a ordinary user can get address info from /proc/kallsyms which is not the case for mine.
`$ head /proc/kallsyms` from your mainche: > 0000000000000000 A irq_stack_union > 0000000000000000 A __per_cpu_start > 0000000000000000 A __per_cpu_user_mapped_start > 0000000000004000 A vector_irq > 0000000000004800 A unsafe_stack_register_backup > 0000000000004840 A cpu_debug_store > 00000000000048c0 A cpu_tss > 0000000000007000 A exception_stacks > 000000000000c000 A gdt_page > 000000000000d000 A espfix_waddr `$ head /proc/kallsyms` from my mainche: > 0000000000000000 A irq_stack_union > 0000000000000000 A __per_cpu_start > 0000000000000000 A cpu_debug_store > 0000000000000000 A cpu_tss_rw > 0000000000000000 A gdt_page > 0000000000000000 A exception_stacks > 0000000000000000 A entry_stack_storage > 0000000000000000 A espfix_waddr > 0000000000000000 A espfix_stack > 0000000000000000 A cpu_llc_id I need some extra time to find a new way to fix this problem. But for now I'd like to disable the kallsyms testcase temporarily and close this bug for successfully testing transition. Thanks again for letting me use your machine to test this.
