On Sat, Mar 27, 2021 at 3:08 PM Cong Wang <xiyou.wangcong@xxxxxxxxx> wrote: > BTFIDS vmlinux > FAILED unresolved symbol cubictcp_state > make: *** [Makefile:1199: vmlinux] Error 255 > > I suspect it is related to the kernel config or linker version. > > # grep TCP_CONG .config > CONFIG_TCP_CONG_ADVANCED=y > CONFIG_TCP_CONG_BIC=m > CONFIG_TCP_CONG_CUBIC=y .. > > # pahole --version > v1.17 That is the most likely reason. In lib/Kconfig.debug we have pahole >= 1.19 requirement for BTF in modules. Though your config has CUBIC=y I suspect something odd goes on. Could you please try the latest pahole 1.20 ?