CONFIG_HAVE_GENERIC_VDSO (not configurable)

modulename: vsyscall.ko

configname: CONFIG_HAVE_GENERIC_VDSO

Linux Kernel Configuration
└─>Library routines
└─>HAVE_GENERIC_VDSO
In linux kernel since version 5.1 (release Date: 2019-05-05)  
source code:
kernel/time/vsyscall.c