Linux can store a gzip’ed copy of the kernel configuration file used to build the kernel in the kernel itself, and make it available to users via /proc/config.gz. This file is not always present in a Linux distribution. It is only present when /proc support is enabled and CONFIG_IKCONFIG and CONFIG_IKCONFIG_PROC are set to Y in the kernel configuration file. Most distributions do not enable it by default; instead they include the kernel configuration file under /boot. If in-kernel configuration support is built as a kernel module, then before you can use /proc/config.gz, the configs module needs to be loaded
