A checklist for submitting your first Linux kernel patch
======
One of the biggest—and the fastest moving—open source projects, the Linux kernel, is composed of about 53,600 files and nearly 20-million lines of code. With more than 15,600 programmers contributing to the project worldwide, the Linux kernel follows a maintainer model for collaboration.
In this article, I'll provide a quick checklist of steps involved with making your first kernel contribution, and look at what you should know before submitting a patch. For a more in-depth look at the submission process for contributing your first patch, read the [KernelNewbies First Kernel Patch tutorial][1].
### Contributing to the kernel
#### Step 1: Prepare your system.
Steps in this article assume you have the following tools on your system:
+ Text editor
+ Email client
+ Version control system (e.g., git)
#### Step 2: Download the Linux kernel code repository`:`
```
git clone -b staging-testing
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git
```
### Copy your current config: ````
```
cp /boot/config-`uname -r`* .config
```
### Step 3: Build/install your kernel.
```
make -jX
sudo make modules_install install
```
### Step 4: Make a branch and switch to it.
```
git checkout -b first-patch
```
### Step 5: Update your kernel to point to the latest code base.
```
git fetch origin
git rebase origin/staging-testing
```
### Step 6: Make a change to the code base.
Recompile using `make` command to ensure that your change does not produce errors.
### Step 7: Commit your changes and create a patch.
```
git add <file>
git commit -s -v
git format-patch -o /tmp/ HEAD^
```
The subject consists of the path to the file name separated by colons, followed by what the patch does in the imperative tense. After a blank line comes the description of the patch and the mandatory signed off tag and, lastly, a diff of your patch.
Here is another example of a simple patch:
Next, send the patch [using email from the command line][2] (in this case, Mutt): ``
```
mutt -H /tmp/0001-<whatever your filename is>
```
To know the list of maintainers to whom to send the patch, use the [get_maintainer.pl script][11].
### What to know before submitting your first patch
* [Greg Kroah-Hartman][3]'s [staging tree][4] is a good place to submit your [first patch][1] as he accepts easy patches from new contributors. When you get familiar with the patch-sending process, you could send subsystem-specific patches with increased complexity.
* You also could start with correcting coding style issues in the code. To learn more, read the [Linux kernel coding style documentation][5].
* The script [checkpatch.pl][6] detects coding style errors for you. For example, run:
```
perl scripts/checkpatch.pl -f drivers/staging/android/* | less
```
* You could complete TODOs left incomplete by developers:
```
find drivers/staging -name TODO
```
* [Coccinelle][7] is a helpful tool for pattern matching.
* Read the [kernel mailing archives][8].
* Go through the [linux.git log][9] to see commits by previous authors for inspiration.
* Note: Do not top-post to communicate with the reviewer of your patch! Here's an example:
**Wrong way:**
Chris,
_Yes let’s schedule the meeting tomorrow, on the second floor._
> On Fri, Apr 26, 2013 at 9:25 AM, Chris wrote:
> Hey John, I had some questions:
> 1\. Do you want to schedule the meeting tomorrow?
> 2\. On which floor in the office?
> 3\. What time is suitable to you?
(Notice that the last question was unintentionally left unanswered in the reply.)
**Correct way:**
Chris,
See my answers below...
> On Fri, Apr 26, 2013 at 9:25 AM, Chris wrote:
> Hey John, I had some questions:
> 1\. Do you want to schedule the meeting tomorrow?
_Yes tomorrow is fine._
> 2\. On which floor in the office?
_Let's keep it on the second floor._
> 3\. What time is suitable to you?
_09:00 am would be alright._
(All questions were answered, and this way saves reading time.)
* The [Eudyptula challenge][10] is a great way to learn kernel basics.
To learn more, read the [KernelNewbies First Kernel Patch tutorial][1]. After that, if you still have any questions, ask on the [kernelnewbies mailing list][12] or in the [#kernelnewbies IRC channel][13].
--------------------------------------------------------------------------------
via: https://opensource.com/article/18/8/first-linux-kernel-patch
作者：[Sayli Karnik][a]
选题：[lujun9972](https://github.com/lujun9972)
译者：[译者ID](https://github.com/译者ID)
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本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
[a]:https://opensource.com/users/sayli
[1]:https://kernelnewbies.org/FirstKernelPatch
[2]:https://opensource.com/life/15/8/top-4-open-source-command-line-email-clients
[3]:https://twitter.com/gregkh
[4]:https://www.kernel.org/doc/html/v4.15/process/2.Process.html
[5]:https://www.kernel.org/doc/html/v4.10/process/coding-style.html
[6]:https://github.com/torvalds/linux/blob/master/scripts/checkpatch.pl
[7]:http://coccinelle.lip6.fr/
[8]:linux-kernel@vger.kernel.org
[9]:https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/log/
[10]:http://eudyptula-challenge.org/
[11]:https://github.com/torvalds/linux/blob/master/scripts/get_maintainer.pl
[12]:https://kernelnewbies.org/MailingList
[13]:https://kernelnewbies.org/IRC