Documentation/process/submit-checklist.rst

   1 .. _submitchecklist:
   2
   3 Linux Kernel patch submission checklist
   4 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   5
   6 Here are some basic things that developers should do if they want to see their
   7 kernel patch submissions accepted more quickly.
   8
   9 These are all above and beyond the documentation that is provided in
  10 :ref:`Documentation/process/submitting-patches.rst <submittingpatches>`
  11 and elsewhere regarding submitting Linux kernel patches.
  12
  13
  14 1) 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
  18 2) 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
  31 3) Builds on multiple CPU architectures by using local cross-compile tools
  32    or some other build farm.
  33
  34 4) ppc64 is a good architecture for cross-compilation checking because it
  35    tends to use ``unsigned long`` for 64-bit quantities.
  36
  37 5) 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
  44 6) 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
  48 7) All new ``Kconfig`` options have help text.
  49
  50 8) 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
  54 9) Check cleanly with sparse.
  55
  56 10) 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
  64 11) 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
  69 12) 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
  75 13) Has been build- and runtime tested with and without ``CONFIG_SMP`` and
  76     ``CONFIG_PREEMPT.``
  77
  78 14) All codepaths have been exercised with all lockdep features enabled.
  79
  80 15) All new ``/proc`` entries are documented under ``Documentation/``
  81
  82 16) All new kernel boot parameters are documented in
  83     ``Documentation/admin-guide/kernel-parameters.rst``.
  84
  85 17) All new module parameters are documented with ``MODULE_PARM_DESC()``
  86
  87 18) 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
  92 19) 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
  98 20) 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
 102 21) 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
 106 22) 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
 110 23) If any ioctl's are added by the patch, then also update
 111     ``Documentation/userspace-api/ioctl/ioctl-number.rst``.
 112
 113 24) 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``).