Send your patches to the mailing list or to the upstream maintainer (see the README file in project root directory), but sending to the mailing list is more preferable.

Email attachments are difficult to review and not recommended. Hint: use git send-email.

Email is accepted as an inline patch with, or without, a git pull request. Pull request emails need to include the patch set for review purposes. See howto-pull-request and README for git repository instructions.

Many small patches are preferred over a single large patch. Split patch sets based upon logical functionality.

Don't include generated (autotools) files in your patches. Hint: use git clean -Xd.

Neutrality: the files in kbd should be distribution-neutral. Packages like RPMs, DEBs, and the rest, are not provided. They should be available from the distribution.

Make sure that after applying your patch the file(s) will compile without errors on top of the ‘master’ branch.

Test that the previously existing program behavior is not altered. If the patch intentionally alters the behavior explain what changed, and the reason for it, in the changelog/commit message.

Sending Patches

Subject: [PATCH] subsystem: description.

Start the message body with an explanation of the patch, that is, a changelog/commit entry.

Add a Signed-off-by line. Hint: use git commit -s

The sign-off is a simple line at the end of the explanation for the patch; which certifies that you wrote it or otherwise have the right to pass it on as an open-source patch. The rules are pretty simple; if you can certify the following:

By making a contribution to this project, I certify that:

  1. The contribution was created in whole or in part by me and I have the right to submit it under the open source license indicated in the file; or

  2. The contribution is based upon previous work that, to the best of my knowledge, is covered under an appropriate open source license and I have the right under that license to submit that work with modifications, whether created in whole or in part by me, under the same open source license (unless I am permitted to submit under a different license), as indicated in the file; or

  3. The contribution was provided directly to me by some other person who certified (1), (2) or (3) and I have not modified it.

  4. I understand and agree that this project and the contribution are public and that a record of the contribution (including all personal information I submit with it, including my sign-off) is maintained indefinitely and may be redistributed consistent with this project or the open source license(s) involved.

Then you just add a line like:

Signed-off-by: Random J Developer <>

Use your real name (sorry, no pseudonyms or anonymous contributions).

Coding Style

The clang-format used to format the code. Please use it before submitting patches. The preferred coding style described in the .clang-format in project root directory.

Use ‘FIXME:’ with a good description, if you want to inform others that something is not quite right, and you are unwilling to fix the issue in the submitted change.

Various Notes

Patches relying on kernel features that are not in Linus Torvalds's tree are not accepted.