Comment 24 for bug 1958770

Just a couple of other suggestions.

You can generate a patch file from the upstream kernel repo. eg

cd linux-jammy
curl https://github.com/torvalds/linux/commit/8d3a6c37d50d5a0504c126c932cc749e6dd9c78f.patch -o ./atlantic.patch
git diff
git apply ./atlantic.patch
git diff

I was wrong about printf. You need to use printk

printk(KERN_INFO "HERE!\n");

I expect printk just will work although you might need to "#include <linux/kernel.h>"