How do I check what kernel options were compiled without looking at /boot/config-*

How do I check what options are compiled into a Linux kernel without looking at /boot/config-* and if I don't have access to the /boot/config-* file that's left over?

Solution 1:

Unless your kernel was built with CONFIG_IKCONFIG_PROC, which would make the config available in /proc as sysadmin1138 mentioned above, you're pretty much out of luck. Debian and RH based kernel packages do, however, generally install a config-$version file in /boot. So unless it's a custom kernel, it should be available there.

Solution 2:

I believe /proc/config.gz contains the .config file the kernel was compiled with.