CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX (not configurable)

configname: CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX

Linux Kernel Configuration
└─>HAVE_UNDERSCORE_SYMBOL_PREFIX
In linux kernel since version 3.1 (release Date: 2011-10-24)  
Some architectures generate an _ in front of C symbols; things like
module loading and assembly files need to know about this.