IA32 Emulation

modulename: sys_ia32.ko

and/or

tls.ko

and/or

entry_64_compat.ko

configname: CONFIG_IA32_EMULATION

Linux Kernel Configuration
└─>Binary Emulations
└─>IA32 Emulation
In linux kernel since version 2.6.12  
Include code to run legacy 32-bit programs under a
64-bit kernel. You should likely turn this on, unless you're
100% sure that you don't have any 32-bit programs left.

source code: