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Makefile: add coccicheck target

Coccinelle is a program for static code analysis.
For details on Coccinelle see

Add scripts/coccicheck copied from Linux kernel v4.14.

The coccicheck script executes the tests *.cocci in
directory scripts/coccinelle by calling spatch.

In Makefile add a coccicheck target. You can use it with

	make coccicheck MODE=<mode>

	where mode in patch, report, context, org.

Add a copy of Linux v4.14 file Documentation/dev-tools/coccinelle.rst
as doc/README.coccinelle.

Cc: Simon Glass <>
Signed-off-by: Heinrich Schuchardt <>
Heinrich Schuchardt 2 years ago
committed by Tom Rini
3 changed files with 756 additions and 0 deletions
  1. +9
  2. +491
  3. +256

+ 9
- 0
Makefile View File

@@ -1572,6 +1572,7 @@ help:
@echo ''
@echo 'Static analysers'
@echo ' checkstack - Generate a list of stack hogs'
@echo ' coccicheck - Execute static code analysis with Coccinelle'
@echo ''
@echo 'Documentation targets:'
@$(MAKE) -f $(srctree)/doc/DocBook/Makefile dochelp
@@ -1664,6 +1665,14 @@ endif
$(build)=$(build-dir) $(@:.ko=.o)
$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost

# Consistency checks
# ---------------------------------------------------------------------------

PHONY += coccicheck

$(Q)$(CONFIG_SHELL) $(srctree)/scripts/$@

# FIXME Should go into a make.lib or something
# ===========================================================================

+ 491
- 0
doc/README.coccinelle View File

@@ -0,0 +1,491 @@
.. Copyright 2010 Nicolas Palix <>
.. Copyright 2010 Julia Lawall <>
.. Copyright 2010 Gilles Muller <>

.. highlight:: none


Coccinelle is a tool for pattern matching and text transformation that has
many uses in kernel development, including the application of complex,
tree-wide patches and detection of problematic programming patterns.

Getting Coccinelle

The semantic patches included in the kernel use features and options
which are provided by Coccinelle version 1.0.0-rc11 and above.
Using earlier versions will fail as the option names used by
the Coccinelle files and coccicheck have been updated.

Coccinelle is available through the package manager
of many distributions, e.g. :

- Debian
- Fedora
- Ubuntu
- OpenSUSE
- Arch Linux
- NetBSD
- FreeBSD

You can get the latest version released from the Coccinelle homepage at

Information and tips about Coccinelle are also provided on the wiki
pages at

Once you have it, run the following command::


as a regular user, and install it with::

sudo make install

Supplemental documentation

For supplemental documentation refer to the wiki:

The wiki documentation always refers to the linux-next version of the script.

Using Coccinelle on the Linux kernel

A Coccinelle-specific target is defined in the top level
Makefile. This target is named ``coccicheck`` and calls the ``coccicheck``
front-end in the ``scripts`` directory.

Four basic modes are defined: ``patch``, ``report``, ``context``, and
``org``. The mode to use is specified by setting the MODE variable with

- ``patch`` proposes a fix, when possible.

- ``report`` generates a list in the following format:
file:line:column-column: message

- ``context`` highlights lines of interest and their context in a
diff-like style.Lines of interest are indicated with ``-``.

- ``org`` generates a report in the Org mode format of Emacs.

Note that not all semantic patches implement all modes. For easy use
of Coccinelle, the default mode is "report".

Two other modes provide some common combinations of these modes.

- ``chain`` tries the previous modes in the order above until one succeeds.

- ``rep+ctxt`` runs successively the report mode and the context mode.
It should be used with the C option (described later)
which checks the code on a file basis.


To make a report for every semantic patch, run the following command::

make coccicheck MODE=report

To produce patches, run::

make coccicheck MODE=patch

The coccicheck target applies every semantic patch available in the
sub-directories of ``scripts/coccinelle`` to the entire Linux kernel.

For each semantic patch, a commit message is proposed. It gives a
description of the problem being checked by the semantic patch, and
includes a reference to Coccinelle.

As any static code analyzer, Coccinelle produces false
positives. Thus, reports must be carefully checked, and patches

To enable verbose messages set the V= variable, for example::

make coccicheck MODE=report V=1

Coccinelle parallelization

By default, coccicheck tries to run as parallel as possible. To change
the parallelism, set the J= variable. For example, to run across 4 CPUs::

make coccicheck MODE=report J=4

As of Coccinelle 1.0.2 Coccinelle uses Ocaml parmap for parallelization,
if support for this is detected you will benefit from parmap parallelization.

When parmap is enabled coccicheck will enable dynamic load balancing by using
``--chunksize 1`` argument, this ensures we keep feeding threads with work
one by one, so that we avoid the situation where most work gets done by only
a few threads. With dynamic load balancing, if a thread finishes early we keep
feeding it more work.

When parmap is enabled, if an error occurs in Coccinelle, this error
value is propagated back, the return value of the ``make coccicheck``
captures this return value.

Using Coccinelle with a single semantic patch

The optional make variable COCCI can be used to check a single
semantic patch. In that case, the variable must be initialized with
the name of the semantic patch to apply.

For instance::

make coccicheck COCCI=<my_SP.cocci> MODE=patch


make coccicheck COCCI=<my_SP.cocci> MODE=report

Controlling Which Files are Processed by Coccinelle

By default the entire kernel source tree is checked.

To apply Coccinelle to a specific directory, ``M=`` can be used.
For example, to check drivers/net/wireless/ one may write::

make coccicheck M=drivers/net/wireless/

To apply Coccinelle on a file basis, instead of a directory basis, the
following command may be used::

make C=1 CHECK="scripts/coccicheck"

To check only newly edited code, use the value 2 for the C flag, i.e.::

make C=2 CHECK="scripts/coccicheck"

In these modes, which works on a file basis, there is no information
about semantic patches displayed, and no commit message proposed.

This runs every semantic patch in scripts/coccinelle by default. The
COCCI variable may additionally be used to only apply a single
semantic patch as shown in the previous section.

The "report" mode is the default. You can select another one with the
MODE variable explained above.

Debugging Coccinelle SmPL patches

Using coccicheck is best as it provides in the spatch command line
include options matching the options used when we compile the kernel.
You can learn what these options are by using V=1, you could then
manually run Coccinelle with debug options added.

Alternatively you can debug running Coccinelle against SmPL patches
by asking for stderr to be redirected to stderr, by default stderr
is redirected to /dev/null, if you'd like to capture stderr you
can specify the ``DEBUG_FILE="file.txt"`` option to coccicheck. For

rm -f cocci.err
make coccicheck COCCI=scripts/coccinelle/free/kfree.cocci MODE=report DEBUG_FILE=cocci.err
cat cocci.err

You can use SPFLAGS to add debugging flags, for instance you may want to
add both --profile --show-trying to SPFLAGS when debugging. For instance
you may want to use::

rm -f err.log
export COCCI=scripts/coccinelle/misc/irqf_oneshot.cocci
make coccicheck DEBUG_FILE="err.log" MODE=report SPFLAGS="--profile --show-trying" M=./drivers/mfd/arizona-irq.c

err.log will now have the profiling information, while stdout will
provide some progress information as Coccinelle moves forward with

DEBUG_FILE support is only supported when using coccinelle >= 1.2.

.cocciconfig support

Coccinelle supports reading .cocciconfig for default Coccinelle options that
should be used every time spatch is spawned, the order of precedence for
variables for .cocciconfig is as follows:

- Your current user's home directory is processed first
- Your directory from which spatch is called is processed next
- The directory provided with the --dir option is processed last, if used

Since coccicheck runs through make, it naturally runs from the kernel
proper dir, as such the second rule above would be implied for picking up a
.cocciconfig when using ``make coccicheck``.

``make coccicheck`` also supports using M= targets.If you do not supply
any M= target, it is assumed you want to target the entire kernel.
The kernel coccicheck script has::

if [ "$KBUILD_EXTMOD" = "" ] ; then
OPTIONS="--dir $srctree $COCCIINCLUDE"

KBUILD_EXTMOD is set when an explicit target with M= is used. For both cases
the spatch --dir argument is used, as such third rule applies when whether M=
is used or not, and when M= is used the target directory can have its own
.cocciconfig file. When M= is not passed as an argument to coccicheck the
target directory is the same as the directory from where spatch was called.

If not using the kernel's coccicheck target, keep the above precedence
order logic of .cocciconfig reading. If using the kernel's coccicheck target,
override any of the kernel's .coccicheck's settings using SPFLAGS.

We help Coccinelle when used against Linux with a set of sensible defaults
options for Linux with our own Linux .cocciconfig. This hints to coccinelle
git can be used for ``git grep`` queries over coccigrep. A timeout of 200
seconds should suffice for now.

The options picked up by coccinelle when reading a .cocciconfig do not appear
as arguments to spatch processes running on your system, to confirm what
options will be used by Coccinelle run::

spatch --print-options-only

You can override with your own preferred index option by using SPFLAGS. Take
note that when there are conflicting options Coccinelle takes precedence for
the last options passed. Using .cocciconfig is possible to use idutils, however
given the order of precedence followed by Coccinelle, since the kernel now
carries its own .cocciconfig, you will need to use SPFLAGS to use idutils if
desired. See below section "Additional flags" for more details on how to use

Additional flags

Additional flags can be passed to spatch through the SPFLAGS
variable. This works as Coccinelle respects the last flags
given to it when options are in conflict. ::

make SPFLAGS=--use-glimpse coccicheck

Coccinelle supports idutils as well but requires coccinelle >= 1.0.6.
When no ID file is specified coccinelle assumes your ID database file
is in the file .id-utils.index on the top level of the kernel, coccinelle
carries a script scripts/ which creates the database with::

mkid -i C --output .id-utils.index

If you have another database filename you can also just symlink with this
name. ::

make SPFLAGS=--use-idutils coccicheck

Alternatively you can specify the database filename explicitly, for

make SPFLAGS="--use-idutils /full-path/to/ID" coccicheck

See ``spatch --help`` to learn more about spatch options.

Note that the ``--use-glimpse`` and ``--use-idutils`` options
require external tools for indexing the code. None of them is
thus active by default. However, by indexing the code with
one of these tools, and according to the cocci file used,
spatch could proceed the entire code base more quickly.

SmPL patch specific options

SmPL patches can have their own requirements for options passed
to Coccinelle. SmPL patch specific options can be provided by
providing them at the top of the SmPL patch, for instance::

// Options: --no-includes --include-headers

SmPL patch Coccinelle requirements

As Coccinelle features get added some more advanced SmPL patches
may require newer versions of Coccinelle. If an SmPL patch requires
at least a version of Coccinelle, this can be specified as follows,
as an example if requiring at least Coccinelle >= 1.0.5::

// Requires: 1.0.5

Proposing new semantic patches

New semantic patches can be proposed and submitted by kernel
developers. For sake of clarity, they should be organized in the
sub-directories of ``scripts/coccinelle/``.

Detailed description of the ``report`` mode

``report`` generates a list in the following format::

file:line:column-column: message



make coccicheck MODE=report COCCI=scripts/coccinelle/api/err_cast.cocci

will execute the following part of the SmPL script::

@r depends on !context && !patch && (org || report)@
expression x;
position p;


@script:python depends on report@
p << r.p;
x << r.x;

msg="ERR_CAST can be used with %s" % (x)[0], msg)

This SmPL excerpt generates entries on the standard output, as
illustrated below::

/home/user/linux/crypto/ctr.c:188:9-16: ERR_CAST can be used with alg
/home/user/linux/crypto/authenc.c:619:9-16: ERR_CAST can be used with auth
/home/user/linux/crypto/xts.c:227:9-16: ERR_CAST can be used with alg

Detailed description of the ``patch`` mode

When the ``patch`` mode is available, it proposes a fix for each problem



make coccicheck MODE=patch COCCI=scripts/coccinelle/api/err_cast.cocci

will execute the following part of the SmPL script::

@ depends on !context && patch && !org && !report @
expression x;


This SmPL excerpt generates patch hunks on the standard output, as
illustrated below::

diff -u -p a/crypto/ctr.c b/crypto/ctr.c
--- a/crypto/ctr.c 2010-05-26 10:49:38.000000000 +0200
+++ b/crypto/ctr.c 2010-06-03 23:44:49.000000000 +0200
@@ -185,7 +185,7 @@ static struct crypto_instance *crypto_ct
alg = crypto_attr_alg(tb[1], CRYPTO_ALG_TYPE_CIPHER,
if (IS_ERR(alg))
- return ERR_PTR(PTR_ERR(alg));
+ return ERR_CAST(alg);

/* Block size must be >= 4 bytes. */
err = -EINVAL;

Detailed description of the ``context`` mode

``context`` highlights lines of interest and their context
in a diff-like style.

**NOTE**: The diff-like output generated is NOT an applicable patch. The
intent of the ``context`` mode is to highlight the important lines
(annotated with minus, ``-``) and gives some surrounding context
lines around. This output can be used with the diff mode of
Emacs to review the code.



make coccicheck MODE=context COCCI=scripts/coccinelle/api/err_cast.cocci

will execute the following part of the SmPL script::

@ depends on context && !patch && !org && !report@
expression x;


This SmPL excerpt generates diff hunks on the standard output, as
illustrated below::

diff -u -p /home/user/linux/crypto/ctr.c /tmp/nothing
--- /home/user/linux/crypto/ctr.c 2010-05-26 10:49:38.000000000 +0200
+++ /tmp/nothing
@@ -185,7 +185,6 @@ static struct crypto_instance *crypto_ct
alg = crypto_attr_alg(tb[1], CRYPTO_ALG_TYPE_CIPHER,
if (IS_ERR(alg))
- return ERR_PTR(PTR_ERR(alg));

/* Block size must be >= 4 bytes. */
err = -EINVAL;

Detailed description of the ``org`` mode

``org`` generates a report in the Org mode format of Emacs.



make coccicheck MODE=org COCCI=scripts/coccinelle/api/err_cast.cocci

will execute the following part of the SmPL script::

@r depends on !context && !patch && (org || report)@
expression x;
position p;


@script:python depends on org@
p << r.p;
x << r.x;

msg="ERR_CAST can be used with %s" % (x)
msg_safe=msg.replace("[","@(").replace("]",")")[0], msg_safe)

This SmPL excerpt generates Org entries on the standard output, as
illustrated below::

* TODO [[view:/home/user/linux/crypto/ctr.c::face=ovl-face1::linb=188::colb=9::cole=16][ERR_CAST can be used with alg]]
* TODO [[view:/home/user/linux/crypto/authenc.c::face=ovl-face1::linb=619::colb=9::cole=16][ERR_CAST can be used with auth]]
* TODO [[view:/home/user/linux/crypto/xts.c::face=ovl-face1::linb=227::colb=9::cole=16][ERR_CAST can be used with alg]]

+ 256
- 0
scripts/coccicheck View File

@@ -0,0 +1,256 @@
# SPDX-License-Identifier: GPL-2.0
# Linux kernel coccicheck
# Read doc/README.coccinelle
# This script requires at least spatch
# version 1.0.0-rc11.

DIR="$(dirname $(readlink -f $0))/.."
SPATCH="`which ${SPATCH:=spatch}`"

if [ ! -x "$SPATCH" ]; then
echo 'spatch is part of the Coccinelle project and is available at'
exit 1

SPATCH_VERSION=$($SPATCH --version | head -1 | awk '{print $3}')

$SPATCH --help | grep "\-\-jobs" > /dev/null && USE_JOBS="yes"

# The verbosity may be set by the environmental parameter V=
# as for example with 'make V=1 coccicheck'

if [ -n "$V" -a "$V" != "0" ]; then

if [ -z "$J" ]; then


# You can use SPFLAGS to append extra arguments to coccicheck or override any
# heuristics done in this file as Coccinelle accepts the last options when
# options conflict.
# A good example for use of SPFLAGS is if you want to debug your cocci script,
# you can for instance use the following:
# $ export COCCI=scripts/coccinelle/misc/irqf_oneshot.cocci
# $ make coccicheck MODE=report DEBUG_FILE="all.err" SPFLAGS="--profile --show-trying" M=./drivers/mfd/arizona-irq.c
# "--show-trying" should show you what rule is being processed as it goes to
# stdout, you do not need a debug file for that. The profile output will be
# be sent to stdout, if you provide a DEBUG_FILE the profiling data can be
# inspected there.
# --profile will not output if --very-quiet is used, so avoid it.
echo $SPFLAGS | egrep -e "--profile|--show-trying" 2>&1 > /dev/null
if [ $? -eq 0 ]; then

# spatch only allows include directories with the syntax "-I include"
# while gcc also allows "-Iinclude" and "-include include"
COCCIINCLUDE=${COCCIINCLUDE// -include/ --include}

if [ "$C" = "1" -o "$C" = "2" ]; then

# Take only the last argument, which is the C file to test
shift $(( $# - 1 ))
if [ "$KBUILD_EXTMOD" = "" ] ; then
OPTIONS="--dir $srctree $COCCIINCLUDE"

if [ "$KBUILD_EXTMOD" != "" ] ; then
OPTIONS="--patch $srctree $OPTIONS"

# You can override by using SPFLAGS
if [ "$USE_JOBS" = "no" ]; then
trap kill_running SIGTERM SIGINT
declare -a SPATCH_PID
elif [ "$NPROC" != "1" ]; then
# Using 0 should work as well, refer to _SC_NPROCESSORS_ONLN use on
OPTIONS="$OPTIONS --jobs $NPROC --chunksize 1"

if [ "$MODE" = "" ] ; then
if [ "$ONLINE" = "0" ] ; then
echo 'You have not explicitly specified the mode to use. Using default "report" mode.'
echo 'Available modes are the following: patch, report, context, org'
echo 'You can specify the mode with "make coccicheck MODE=<mode>"'
echo 'Note however that some modes are not implemented by some semantic patches.'

if [ "$MODE" = "chain" ] ; then
if [ "$ONLINE" = "0" ] ; then
echo 'You have selected the "chain" mode.'
echo 'All available modes will be tried (in that order): patch, report, context, org'
elif [ "$MODE" = "report" -o "$MODE" = "org" ] ; then
FLAGS="--no-show-diff $FLAGS"

if [ "$ONLINE" = "0" ] ; then
echo ''
echo 'Please check for false positives in the output before submitting a patch.'
echo 'When using "patch" mode, carefully review the patch before submitting it.'
echo ''

run_cmd_parmap() {
if [ $VERBOSE -ne 0 ] ; then
echo "Running ($NPROC in parallel): $@"
if [ "$DEBUG_FILE" != "/dev/null" -a "$DEBUG_FILE" != "" ]; then
if [ -f $DEBUG_FILE ]; then
echo "Debug file $DEBUG_FILE exists, bailing"
if [[ $? -ne 0 ]]; then
echo "coccicheck failed"
exit $?

run_cmd_old() {
local i
if [ $VERBOSE -ne 0 ] ; then
echo "Running ($NPROC in parallel): $@"
for i in $(seq 0 $(( NPROC - 1)) ); do
eval "$@ --max $NPROC --index $i &"
if [ $VERBOSE -eq 2 ] ; then
echo "${SPATCH_PID[$i]} running"

run_cmd() {
if [ "$USE_JOBS" = "yes" ]; then
run_cmd_parmap $@
run_cmd_old $@

kill_running() {
for i in $(seq 0 $(( NPROC - 1 )) ); do
if [ $VERBOSE -eq 2 ] ; then
echo "Killing ${SPATCH_PID[$i]}"
kill ${SPATCH_PID[$i]} 2>/dev/null

# You can override heuristics with SPFLAGS, these must always go last

coccinelle () {

OPT=`grep "Option" $COCCI | cut -d':' -f2`
REQ=`grep "Requires" $COCCI | cut -d':' -f2 | sed "s| ||"`
REQ_NUM=$(echo $REQ | ${DIR}/scripts/
if [ "$REQ_NUM" != "0" ] ; then
if [ "$SPATCH_VERSION_NUM" -lt "$REQ_NUM" ] ; then
echo "Skipping coccinele SmPL patch: $COCCI"
echo "You have coccinelle: $SPATCH_VERSION"
echo "This SmPL patch requires: $REQ"

# The option '--parse-cocci' can be used to syntactically check the SmPL files.
# $SPATCH -D $MODE $FLAGS -parse_cocci $COCCI $OPT > /dev/null

if [ $VERBOSE -ne 0 -a $ONLINE -eq 0 ] ; then

FILE=`echo $COCCI | sed "s|$srctree/||"`

echo "Processing `basename $COCCI`"
echo "with option(s) \"$OPT\""
echo ''
echo 'Message example to submit a patch:'

sed -ne 's|^///||p' $COCCI

if [ "$MODE" = "patch" ] ; then
echo ' The semantic patch that makes this change is available'
elif [ "$MODE" = "report" ] ; then
echo ' The semantic patch that makes this report is available'
elif [ "$MODE" = "context" ] ; then
echo ' The semantic patch that spots this code is available'
elif [ "$MODE" = "org" ] ; then
echo ' The semantic patch that makes this Org report is available'
echo ' The semantic patch that makes this output is available'
echo " in $FILE."
echo ''
echo ' More information about semantic patching is available at'
echo ''
echo ''

if [ "`sed -ne 's|^//#||p' $COCCI`" ] ; then
echo 'Semantic patch information:'
sed -ne 's|^//#||p' $COCCI
echo ''

if [ "$MODE" = "chain" ] ; then
run_cmd $SPATCH -D patch \
$FLAGS --cocci-file $COCCI $OPT $OPTIONS || \
run_cmd $SPATCH -D report \
$FLAGS --cocci-file $COCCI $OPT $OPTIONS --no-show-diff || \
run_cmd $SPATCH -D context \
$FLAGS --cocci-file $COCCI $OPT $OPTIONS || \
run_cmd $SPATCH -D org \
$FLAGS --cocci-file $COCCI $OPT $OPTIONS --no-show-diff || exit 1
elif [ "$MODE" = "rep+ctxt" ] ; then
run_cmd $SPATCH -D report \
$FLAGS --cocci-file $COCCI $OPT $OPTIONS --no-show-diff && \
run_cmd $SPATCH -D context \
$FLAGS --cocci-file $COCCI $OPT $OPTIONS || exit 1
run_cmd $SPATCH -D $MODE $FLAGS --cocci-file $COCCI $OPT $OPTIONS || exit 1


if [ "$COCCI" = "" ] ; then
for f in `find $srctree/scripts/coccinelle/ -name '*.cocci' -type f | sort`; do
coccinelle $f
coccinelle $COCCI