CONFIG_COMPAT_FOR_U64_ALIGNMENT (not configurable)

configname: CONFIG_COMPAT_FOR_U64_ALIGNMENT

Linux Kernel Configuration
└─>Executable file formats / Emulations
└─>COMPAT_FOR_U64_ALIGNMENT
In linux kernel since version 2.6.23 (release Date: 2007-10-09)  
depends
CONFIG_COMPAT

is selected by
CONFIG_XFRM_USER_COMPAT