Submitting (Trivial) Linux Kernel Patches

So, I've submitted my first patch to the Linux Kernel! It's trivial set of documentation improvements - mostly done so I could see if I've got everything set up correctly.

This blog post is more of an aide memoire than a fool proof guide - I hope future me finds it useful!

Install and Configure git

I'll leave you to figure out how to install git on your system - one thing you will need to is run this command once you've finished setting it up.

git config --global format.signoff true

That will format the patches so they are acceptable to the kernel gods.

Clone The Linux Kernel

Nice and easy - will take a little bit of time as the kernel is quite large.

git clone -b staging-next git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git

Then, of course, cd into the directory.

A New Branch

We need to create a branch to work on.

git branch mypatch

Then, let's switch to the new branch.

git checkout mypatch

Make The Edits

Open up your favourite code editor, and make the changes :-)

Check The Diff

Double check that the changes are what we expect.

git diff

Commit The Changes

git commit -a

Create The Patch

We want to create a patch for master from the spelling branch.

git format-patch master..mypatch

That will create a file called something like:

0001-Your-commit-message.patch

Check Your Working

There are some scripts which will make sure everything is hunk-dory.

./scripts/checkpatch.pl 0001-Your-commit-message.patch

Who To Mail?

The patch has to be emailed to the maintainer of the code. Optionally, it can go to other people as well.

For a "trivial" patch - we can send it to the Linux Kernel Trivial Patch Monkey - trivial๑kernel.org.

./scripts/get_maintainer.pl 0001-Your-commit-message.patch

Out should pop an email address!

Setting Up Email

If you haven't already, git needs to be able to send email.

Install git-email

sudo apt-get install git-email

This needs adding to ~/.gitconfig

[sendemail]
from = YourName < email@example.com >
smtpserver = smtp.gmail.com
smtpuser = email@gmail.com
smtpencryption = tls
smtppass = PASSWORD
chainreplyto = false
smtpserverport = 587

Personally, I set an app specific password in the Gmail Security panel.

Ok, so let's send this puppy!

git send-email --to whoever@example.org --cc someoneelse@example.com 0001-Your-commit-message.patch

This will launch an interactive interface where you can double-check everything and, if you're happy, send the email.

That's All Folks

Well, that's all it takes to send in a patch request.

Here's the video that I followed.