Documentation/dev-tools/checkpatch.rst

1 .. SPDX-License-Identifier: GPL-2.0-only
27  - -q,  --quiet
31  - -v,  --verbose
35  - --no-tree
39  - --no-signoff
41    Disable the 'Signed-off-by' line check.  The sign-off is a simple line at
43    or otherwise have the right to pass it on as an open-source patch.
47 	 Signed-off-by: Random J Developer <random@developer.example.org>
49    Setting this flag effectively stops a message for a missing signed-off-by
52  - --patch
57  - --emacs
63  - --terse
67  - --showfile
71  - -g,  --git
77    - <rev>
78    - <rev>^
79    - <rev>~n
83    - <rev1>..<rev2>
84    - <rev1>...<rev2>
85    - <rev>-<count>
87  - -f,  --file
92  - --subjective,  --strict
97  - --list-types
105  - --types TYPE(,TYPE2...)
111      ./scripts/checkpatch.pl mypatch.patch --types EMAIL_SUBJECT,BRACES
113  - --ignore TYPE(,TYPE2...)
119      ./scripts/checkpatch.pl mypatch.patch --ignore EMAIL_SUBJECT,BRACES
121  - --show-types
126  - --max-line-length=n
134    file contexts, the --strict flag must also be enabled.
136  - --min-conf-desc-length=n
140  - --tab-size=n
144  - --root=PATH
151  - --no-summary
155  - --mailback
160  - --summary-file
164  - --debug KEY=[0|1]
169  - --fix
172    <inputfile>.EXPERIMENTAL-checkpatch-fixes is created which has the
175  - --fix-inplace
177    EXPERIMENTAL - Similar to --fix but input file is overwritten with fixes.
182  - --ignore-perl-version
187  - --codespell
191  - --codespellfile
196  - --typedefsfile
200  - --color[=WHEN]
205  - --kconfig-prefix=WORD
209  - -h, --help, --version
219  - ERROR
224  - WARNING
229  - CHECK
243 ----------------
250     See: https://www.kernel.org/doc/html/latest/core-api/memory-allocation.html
263     See: https://www.kernel.org/doc/html/latest/process/coding-style.html#allocating-memory
269     See: https://www.kernel.org/doc/html/latest/core-api/memory-allocation.html
273 ---------
290     See: https://www.kernel.org/doc/html/latest/process/deprecated.html#bug-and-bug-on
299 …nel.org/doc/html/latest/process/deprecated.html#simple-strtol-simple-strtoll-simple-strtoul-simple…
335     See: https://lore.kernel.org/lkml/1400106425.12666.6.camel@joe-AO725/
339     old flavourful RCU APIs by their new vanilla-RCU counterparts.
343     See: https://www.kernel.org/doc/html/latest/RCU/whatisRCU.html#full-list-of-rcu-apis
347     flags added via commit f77bf01425b1 ("kbuild: introduce ccflags-y,
348     asflags-y and ldflags-y").
352       EXTRA_AFLAGS    ->  asflags-y
353       EXTRA_CFLAGS    ->  ccflags-y
354       EXTRA_CPPFLAGS  ->  cppflags-y
355       EXTRA_LDFLAGS   ->  ldflags-y
360       2. https://lore.kernel.org/lkml/1313384834-24433-12-git-send-email-lacombar@gmail.com/
361       3. https://www.kernel.org/doc/html/latest/kbuild/makefiles.html#compilation-flags
375     See: https://www.kernel.org/doc/html/latest/driver-api/driver-model/device.html#attributes
384     See: https://www.kernel.org/doc/html/latest/driver-api/driver-model/device.html#attributes
393     See: https://www.kernel.org/doc/html/latest/driver-api/driver-model/device.html#attributes
402     See: https://www.kernel.org/doc/html/latest/driver-api/driver-model/device.html#attributes
413       &zero     ->  SYSCTL_ZERO
414       &one      ->  SYSCTL_ONE
415       &int_max  ->  SYSCTL_INT_MAX
419       1. https://lore.kernel.org/lkml/20190430180111.10688-1-mcroce@redhat.com/
420       2. https://lore.kernel.org/lkml/20190531131422.14970-1-mcroce@redhat.com/
423     ENOSYS means that a nonexistent system call was called.
446     See: https://lore.kernel.org/lkml/20080320201723.b87b3732.akpm@linux-foundation.org/
450     prevent warnings on conversion of device->sem to device->mutex.
464     See: https://www.kernel.org/doc/html/latest/locking/lockdep-design.html#annotations
473 …www.kernel.org/doc/html/latest/timers/timers-howto.html#delays-information-on-the-various-kernel-d…
477 --------
480     The comment style is incorrect.  The preferred style for multi-
495     See: https://www.kernel.org/doc/html/latest/process/coding-style.html#commenting
501     See: https://www.kernel.org/doc/html/latest/process/coding-style.html#commenting
507     See: https://lore.kernel.org/lkml/20200401101714.44781-1-elver@google.com/
520 --------------
523     The signed-off-by line does not fall in line with the standards
526 …//www.kernel.org/doc/html/latest/process/submitting-patches.html#developer-s-certificate-of-origin…
548 …  See: https://www.kernel.org/doc/html/latest/process/submitting-patches.html#describe-your-changes
555 …  See: https://www.kernel.org/doc/html/latest/process/submitting-patches.html#describe-your-changes
558     The author's email does not match with that in the Signed-off-by:
564       - The email names do not match.
565       - The email addresses do not match.
566       - The email subaddresses do not match.
567       - The email comments do not match.
570     The patch is missing a Signed-off-by line.  A signed-off-by
574 ….kernel.org/doc/html/latest/process/submitting-patches.html#sign-your-work-the-developer-s-certifi…
583 ….kernel.org/doc/html/latest/process/submitting-patches.html#sign-your-work-the-developer-s-certifi…
591     See: https://lore.kernel.org/lkml/20150611134006.9df79a893e3636019ad2759e@linux-foundation.org/
595     have a Change-Id like::
597       Change-Id: Ic8aaa0728a43936cd4c6e1ed590e01ba8f0fbf5b
598       Signed-off-by: A. U. Thor <author@example.com>
600     The Change-Id line must be removed before submitting.
613 …  See: https://www.kernel.org/doc/html/latest/process/submitting-patches.html#describe-your-changes
620 …  See: https://www.kernel.org/doc/html/latest/process/submitting-patches.html#describe-your-changes
624 ----------------
641     See: https://lore.kernel.org/lkml/1365563834.27174.12.camel@joe-AO722/
653 ---------------------------
660     See: https://www.kernel.org/doc/html/latest/process/coding-style.html#indentation
692     See: https://www.kernel.org/doc/html/latest/process/coding-style.html#indentation
696     To use a different maximum line length, the --max-line-length=n option
700     ("checkpatch/coding-style: deprecate 80-column warning") increased the
704 …See: https://www.kernel.org/doc/html/latest/process/coding-style.html#breaking-long-lines-and-stri…
708     To use a different maximum line length, the --max-line-length=n option
711 …See: https://www.kernel.org/doc/html/latest/process/coding-style.html#breaking-long-lines-and-stri…
715     To use a different maximum line length, the --max-line-length=n option
718 …See: https://www.kernel.org/doc/html/latest/process/coding-style.html#breaking-long-lines-and-stri…
729       struct_identifier->member[index].
742       member1->member2->member3.foo1;
743       member1->member2->member3.foo2;
745     then store the member1->member2->member3 part in a temporary variable.
767 ------------------------------
806     read-only.  The __read_mostly annotation thus should be removed.
815     non-deterministic builds.
817     See: https://www.kernel.org/doc/html/latest/kbuild/reproducible-builds.html#timestamps
869     See: https://lore.kernel.org/lkml/1377655732.3619.19.camel@joe-AO722/
873     do - while block.  Same should also be the case for macros
882     See: https://www.kernel.org/doc/html/latest/process/coding-style.html#macros-enums-and-rtl
907     See: https://lore.kernel.org/lkml/1399671106.2912.21.camel@joe-AO725/
910     For the multi-statement macros, it is necessary to use the do-while
911     loop to avoid unpredictable code paths. The do-while loop helps to
913     function-like macro can be used as a function only.
916     do-while loop. Although the code is syntactically correct but using
917     the do-while loop is redundant. So remove the do-while loop for single
926 -----------------------
931     See: https://www.kernel.org/doc/html/latest/process/coding-style.html#naming
945     See: https://lore.kernel.org/lkml/alpine.DEB.2.10.1608281509480.3321@hadrien/
952     Note that this does not work with -f (--file) checkpatch option
1011 -----------
1015     Typically only three permissions are used - 0644 (RW), 0444 (RO)
1028     any local user to write arbitrary values into device registers - a
1031     See: https://lore.kernel.org/linux-arm-kernel/cover.1296818921.git.segoon@openwall.com/
1039     understand than their symbolic counterparts because many command-line
1046 …See: https://lore.kernel.org/lkml/CA+55aFw5v23T-zvDZp-MmD_EYxF8WbafwwB59934FV7g21uMGQ@mail.gmail.c…
1050 --------------------
1065     This applies for all non-functional blocks.
1074     See: https://www.kernel.org/doc/html/latest/process/coding-style.html#placing-braces-and-spaces
1105     See: https://www.kernel.org/doc/html/latest/process/coding-style.html#placing-braces-and-spaces
1111     See: https://www.kernel.org/doc/html/latest/process/coding-style.html#spaces
1115     next line.  For any non-functional block it should be on the same line
1118     See: https://www.kernel.org/doc/html/latest/process/coding-style.html#placing-braces-and-spaces
1130     See: https://www.kernel.org/doc/html/latest/process/coding-style.html#spaces
1135     See: https://www.kernel.org/doc/html/latest/process/coding-style.html#spaces
1142     See: https://www.kernel.org/doc/html/latest/process/coding-style.html#spaces
1149           (foo->bar)();
1153           foo->bar();
1157           if ((foo->bar) && (foo->baz))
1162           if (foo->bar && foo->baz)
1167           &(foo->bar)
1168           *(foo->bar)
1172           &foo->bar
1173           *foo->bar
1182     See: https://www.kernel.org/doc/html/latest/process/coding-style.html#placing-braces-and-spaces
1186 ------
1209     For DOS-formatted patches, there are extra ^M symbols at the end of
1213     DT bindings moved to a json-schema based format instead of
1216     See: https://www.kernel.org/doc/html/latest/devicetree/bindings/writing-schema.html
1223     DT only tree created with git-filter-branch.
1225 …//www.kernel.org/doc/html/latest/devicetree/bindings/submitting-patches.html#i-for-patch-submitters
1242     The patch file does not appear to be in unified-diff format.  Please
1253     See: https://www.kernel.org/doc/html/latest/process/license-rules.html