I run 32-bit. I changed .config to built 64-bit. It errors out complaining about stackprotector support. Can I do this or must I download a built kernel?

multilib and using -m64 is what I found on the question, compiling 64bit on a 32bit platform.

I don't understand this answer. Those are gcc switches. I suspect that building in 64-bit may require 64-bit libraries to build with, perhaps other 64-bit support.

let me check real quick, yep this is a Linux Forum, Linux default compiler is gcc. so yes, you need multilib and directive to tell it to compile for 64bit hence

multilib and using -m64

How much more plain can I get?

When I add -m64 to HOSTCFLAGS in the kernel's Makefile, cc1 tells me 64-bit mode isn't compiled in.


I don't find 'multilib' in the kernel docs. gcc's man page tells me too little to see its purpose.

What are multilib? Your lack in understanding basic terminology is the programming arena does cast a shadow on your ability to grasp basic things relating to programming in general. Research what is multilib, or what does a multilib system consists of? Not the kernel specifically.

With certain versions of gcc and certain versions of debian-based distros, configuring stack protection to anything but 'none' breaks the build.

You can't build the Linux kernel without a specific toolchain for the target system. The README file in the top level source directory will point you to the build requirements. Although it is technically possible to build on a 32-bit system, I think it will be much easier to boot a 64-bit live distro and do it from there.

there's a "stack canary" option you could try turning off

(i first saw that in win95 visual c++ 6.0 release. it's from microsoft. i wouldn't use it if you paid me. it's "speculative" and prevents this: a C program calling Pascal library routiines) (speculative: it checks the return and guesses if the value would be correct. it only is if programs are not allowed to load cross compatible libraries)

how it got in linux in the 2000's, is anyone's guess

HOWEVER - if your building using LFS (copies ubuntu setup kinda), ubuntu or other major distros: you might not get around it. there are many sidewinder "dependancies" built in to those things.

SUMMARY: try the option once if it doesn't work maybe you should get the pre-built one

What exactly is in a toolchain? I assume gcc and its buddies, but what else? Do I need the 64-bit gcc & pals? The README in the kernel source does not point me to the build requirements.

Hmmm... I just booted into 64-bit and get the same stackprotector error.

take a look into tutorials regarding "cross-compilation", that will most likely cover your issue too. But as written it might be easier to create a live-distro on a USB-stick and boot into a real 64bit system. Such a live-distro might come in handy later on (to chroot into the original system in case that anything goes wrong with the new kernel).

A toolchain, as the name implies, is a set of tools used in specific order (chain). For compilation, you need more than one tool like gcc and make and so on. The wording "toolchain" is used in every industry, and does not only mean "software".