submit-checklist.rst

  1.. _submitchecklist:
  2
  3=======================================
  4Linux Kernel patch submission checklist
  5=======================================
  6
  7Here are some basic things that developers should do if they want to see their
  8kernel patch submissions accepted more quickly.
  9
 10These are all above and beyond the documentation that is provided in
 11:ref:`Documentation/process/submitting-patches.rst <submittingpatches>`
 12and elsewhere regarding submitting Linux kernel patches.
 13
 14Review your code
 15================
 16
 171) If you use a facility then #include the file that defines/declares
 18   that facility.  Don't depend on other header files pulling in ones
 19   that you use.
 20
 212) Check your patch for general style as detailed in
 22   :ref:`Documentation/process/coding-style.rst <codingstyle>`.
 23
 243) All memory barriers {e.g., ``barrier()``, ``rmb()``, ``wmb()``} need a
 25   comment in the source code that explains the logic of what they are doing
 26   and why.
 27
 28Review Kconfig changes
 29======================
 30
 311) Any new or modified ``CONFIG`` options do not muck up the config menu and
 32   default to off unless they meet the exception criteria documented in
 33   ``Documentation/kbuild/kconfig-language.rst`` Menu attributes: default value.
 34
 352) All new ``Kconfig`` options have help text.
 36
 373) Has been carefully reviewed with respect to relevant ``Kconfig``
 38   combinations.  This is very hard to get right with testing---brainpower
 39   pays off here.
 40
 41Provide documentation
 42=====================
 43
 441) Include :ref:`kernel-doc <kernel_doc>` to document global kernel APIs.
 45   (Not required for static functions, but OK there also.)
 46
 472) All new ``/proc`` entries are documented under ``Documentation/``
 48
 493) All new kernel boot parameters are documented in
 50   ``Documentation/admin-guide/kernel-parameters.rst``.
 51
 524) All new module parameters are documented with ``MODULE_PARM_DESC()``
 53
 545) All new userspace interfaces are documented in ``Documentation/ABI/``.
 55   See Documentation/admin-guide/abi.rst (or ``Documentation/ABI/README``)
 56   for more information.
 57   Patches that change userspace interfaces should be CCed to
 58   linux-api@vger.kernel.org.
 59
 606) If any ioctl's are added by the patch, then also update
 61   ``Documentation/userspace-api/ioctl/ioctl-number.rst``.
 62
 63Check your code with tools
 64==========================
 65
 661) Check for trivial violations with the patch style checker prior to
 67   submission (``scripts/checkpatch.pl``).
 68   You should be able to justify all violations that remain in
 69   your patch.
 70
 712) Check cleanly with sparse.
 72
 733) Use ``make checkstack`` and fix any problems that it finds.
 74   Note that ``checkstack`` does not point out problems explicitly,
 75   but any one function that uses more than 512 bytes on the stack is a
 76   candidate for change.
 77
 78Build your code
 79===============
 80
 811) Builds cleanly:
 82
 83  a) with applicable or modified ``CONFIG`` options ``=y``, ``=m``, and
 84     ``=n``.  No ``gcc`` warnings/errors, no linker warnings/errors.
 85
 86  b) Passes ``allnoconfig``, ``allmodconfig``
 87
 88  c) Builds successfully when using ``O=builddir``
 89
 90  d) Any Documentation/ changes build successfully without new warnings/errors.
 91     Use ``make htmldocs`` or ``make pdfdocs`` to check the build and
 92     fix any issues.
 93
 942) Builds on multiple CPU architectures by using local cross-compile tools
 95   or some other build farm.
 96   Note that testing against architectures of different word sizes
 97   (32- and 64-bit) and different endianness (big- and little-) is effective
 98   in catching various portability issues due to false assumptions on
 99   representable quantity range, data alignment, or endianness, among
100   others.
101
1023) Newly-added code has been compiled with ``gcc -W`` (use
103   ``make KCFLAGS=-W``).  This will generate lots of noise, but is good
104   for finding bugs like "warning: comparison between signed and unsigned".
105
1064) If your modified source code depends on or uses any of the kernel
107   APIs or features that are related to the following ``Kconfig`` symbols,
108   then test multiple builds with the related ``Kconfig`` symbols disabled
109   and/or ``=m`` (if that option is available) [not all of these at the
110   same time, just various/random combinations of them]:
111
112   ``CONFIG_SMP``, ``CONFIG_SYSFS``, ``CONFIG_PROC_FS``, ``CONFIG_INPUT``,
113   ``CONFIG_PCI``, ``CONFIG_BLOCK``, ``CONFIG_PM``, ``CONFIG_MAGIC_SYSRQ``,
114   ``CONFIG_NET``, ``CONFIG_INET=n`` (but latter with ``CONFIG_NET=y``).
115
116Test your code
117==============
118
1191) Has been tested with ``CONFIG_PREEMPT``, ``CONFIG_DEBUG_PREEMPT``,
120   ``CONFIG_SLUB_DEBUG``, ``CONFIG_DEBUG_PAGEALLOC``, ``CONFIG_DEBUG_MUTEXES``,
121   ``CONFIG_DEBUG_SPINLOCK``, ``CONFIG_DEBUG_ATOMIC_SLEEP``,
122   ``CONFIG_PROVE_RCU`` and ``CONFIG_DEBUG_OBJECTS_RCU_HEAD`` all
123   simultaneously enabled.
124
1252) Has been build- and runtime tested with and without ``CONFIG_SMP`` and
126   ``CONFIG_PREEMPT.``
127
1283) All codepaths have been exercised with all lockdep features enabled.
129
1304) Has been checked with injection of at least slab and page-allocation
131   failures.  See ``Documentation/fault-injection/``.
132   If the new code is substantial, addition of subsystem-specific fault
133   injection might be appropriate.
134
1355) Tested with the most recent tag of linux-next to make sure that it still
136   works with all of the other queued patches and various changes in the VM,
137   VFS, and other subsystems.