1.. _submitchecklist:
2
3Linux Kernel patch submission checklist
4~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
5
6Here are some basic things that developers should do if they want to see their
7kernel patch submissions accepted more quickly.
8
9These are all above and beyond the documentation that is provided in
10:ref:`Documentation/process/submitting-patches.rst <submittingpatches>`
11and elsewhere regarding submitting Linux kernel patches.
12
13
141) If you use a facility then #include the file that defines/declares
15   that facility.  Don't depend on other header files pulling in ones
16   that you use.
17
182) Builds cleanly:
19
20  a) with applicable or modified ``CONFIG`` options ``=y``, ``=m``, and
21     ``=n``.  No ``gcc`` warnings/errors, no linker warnings/errors.
22
23  b) Passes ``allnoconfig``, ``allmodconfig``
24
25  c) Builds successfully when using ``O=builddir``
26
27  d) Any Documentation/ changes build successfully without new warnings/errors.
28     Use ``make htmldocs`` or ``make pdfdocs`` to check the build and
29     fix any issues.
30
313) Builds on multiple CPU architectures by using local cross-compile tools
32   or some other build farm.
33
344) ppc64 is a good architecture for cross-compilation checking because it
35   tends to use ``unsigned long`` for 64-bit quantities.
36
375) Check your patch for general style as detailed in
38   :ref:`Documentation/process/coding-style.rst <codingstyle>`.
39   Check for trivial violations with the patch style checker prior to
40   submission (``scripts/checkpatch.pl``).
41   You should be able to justify all violations that remain in
42   your patch.
43
446) Any new or modified ``CONFIG`` options do not muck up the config menu and
45   default to off unless they meet the exception criteria documented in
46   ``Documentation/kbuild/kconfig-language.rst`` Menu attributes: default value.
47
487) All new ``Kconfig`` options have help text.
49
508) Has been carefully reviewed with respect to relevant ``Kconfig``
51   combinations.  This is very hard to get right with testing -- brainpower
52   pays off here.
53
549) Check cleanly with sparse.
55
5610) Use ``make checkstack`` and fix any problems that it finds.
57
58    .. note::
59
60       ``checkstack`` does not point out problems explicitly,
61       but any one function that uses more than 512 bytes on the stack is a
62       candidate for change.
63
6411) Include :ref:`kernel-doc <kernel_doc>` to document global  kernel APIs.
65    (Not required for static functions, but OK there also.) Use
66    ``make htmldocs`` or ``make pdfdocs`` to check the
67    :ref:`kernel-doc <kernel_doc>` and fix any issues.
68
6912) Has been tested with ``CONFIG_PREEMPT``, ``CONFIG_DEBUG_PREEMPT``,
70    ``CONFIG_DEBUG_SLAB``, ``CONFIG_DEBUG_PAGEALLOC``, ``CONFIG_DEBUG_MUTEXES``,
71    ``CONFIG_DEBUG_SPINLOCK``, ``CONFIG_DEBUG_ATOMIC_SLEEP``,
72    ``CONFIG_PROVE_RCU`` and ``CONFIG_DEBUG_OBJECTS_RCU_HEAD`` all
73    simultaneously enabled.
74
7513) Has been build- and runtime tested with and without ``CONFIG_SMP`` and
76    ``CONFIG_PREEMPT.``
77
7814) All codepaths have been exercised with all lockdep features enabled.
79
8015) All new ``/proc`` entries are documented under ``Documentation/``
81
8216) All new kernel boot parameters are documented in
83    ``Documentation/admin-guide/kernel-parameters.rst``.
84
8517) All new module parameters are documented with ``MODULE_PARM_DESC()``
86
8718) All new userspace interfaces are documented in ``Documentation/ABI/``.
88    See ``Documentation/ABI/README`` for more information.
89    Patches that change userspace interfaces should be CCed to
90    linux-api@vger.kernel.org.
91
9219) Has been checked with injection of at least slab and page-allocation
93    failures.  See ``Documentation/fault-injection/``.
94
95    If the new code is substantial, addition of subsystem-specific fault
96    injection might be appropriate.
97
9820) Newly-added code has been compiled with ``gcc -W`` (use
99    ``make KCFLAGS=-W``).  This will generate lots of noise, but is good
100    for finding bugs like "warning: comparison between signed and unsigned".
101
10221) Tested after it has been merged into the -mm patchset to make sure
103    that it still works with all of the other queued patches and various
104    changes in the VM, VFS, and other subsystems.
105
10622) All memory barriers {e.g., ``barrier()``, ``rmb()``, ``wmb()``} need a
107    comment in the source code that explains the logic of what they are doing
108    and why.
109
11023) If any ioctl's are added by the patch, then also update
111    ``Documentation/userspace-api/ioctl/ioctl-number.rst``.
112
11324) If your modified source code depends on or uses any of the kernel
114    APIs or features that are related to the following ``Kconfig`` symbols,
115    then test multiple builds with the related ``Kconfig`` symbols disabled
116    and/or ``=m`` (if that option is available) [not all of these at the
117    same time, just various/random combinations of them]:
118
119    ``CONFIG_SMP``, ``CONFIG_SYSFS``, ``CONFIG_PROC_FS``, ``CONFIG_INPUT``, ``CONFIG_PCI``, ``CONFIG_BLOCK``, ``CONFIG_PM``, ``CONFIG_MAGIC_SYSRQ``,
120    ``CONFIG_NET``, ``CONFIG_INET=n`` (but latter with ``CONFIG_NET=y``).
121