297 lines
8.1 KiB
Plaintext
297 lines
8.1 KiB
Plaintext
Copyright 2010 Nicolas Palix <npalix@diku.dk>
|
|
Copyright 2010 Julia Lawall <julia@diku.dk>
|
|
Copyright 2010 Gilles Muller <Gilles.Muller@lip6.fr>
|
|
|
|
|
|
Getting Coccinelle
|
|
~~~~~~~~~~~~~~~~~~~~
|
|
|
|
The semantic patches included in the kernel use the 'virtual rule'
|
|
feature which was introduced in Coccinelle version 0.1.11.
|
|
|
|
Coccinelle (>=0.2.0) is available through the package manager
|
|
of many distributions, e.g. :
|
|
|
|
- Debian (>=squeeze)
|
|
- Fedora (>=13)
|
|
- Ubuntu (>=10.04 Lucid Lynx)
|
|
- OpenSUSE
|
|
- Arch Linux
|
|
- NetBSD
|
|
- FreeBSD
|
|
|
|
|
|
You can get the latest version released from the Coccinelle homepage at
|
|
http://coccinelle.lip6.fr/
|
|
|
|
Information and tips about Coccinelle are also provided on the wiki
|
|
pages at http://cocci.ekstranet.diku.dk/wiki/doku.php
|
|
|
|
Once you have it, run the following command:
|
|
|
|
./configure
|
|
make
|
|
|
|
as a regular user, and install it with
|
|
|
|
sudo make install
|
|
|
|
The semantic patches in the kernel will work best with Coccinelle version
|
|
0.2.4 or later. Using earlier versions may incur some parse errors in the
|
|
semantic patch code, but any results that are obtained should still be
|
|
correct.
|
|
|
|
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 modes are defined: patch, report, context, and org. The mode to
|
|
use is specified by setting the MODE variable with 'MODE=<mode>'.
|
|
|
|
'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 "chain" which tries the previous
|
|
modes in the order above until one succeeds.
|
|
|
|
To make a report for every semantic patch, run the following command:
|
|
|
|
make coccicheck MODE=report
|
|
|
|
NB: The 'report' mode is the default one.
|
|
|
|
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
|
|
reviewed.
|
|
|
|
|
|
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
|
|
or
|
|
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"
|
|
|
|
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 "chain" mode is the default. You can select another one with the
|
|
MODE variable explained above.
|
|
|
|
In this mode, there is no information about semantic patches
|
|
displayed, and no commit message proposed.
|
|
|
|
|
|
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
|
|
|
|
Example:
|
|
|
|
Running
|
|
|
|
make coccicheck MODE=report COCCI=scripts/coccinelle/api/err_cast.cocci
|
|
|
|
will execute the following part of the SmPL script.
|
|
|
|
<smpl>
|
|
@r depends on !context && !patch && (org || report)@
|
|
expression x;
|
|
position p;
|
|
@@
|
|
|
|
ERR_PTR@p(PTR_ERR(x))
|
|
|
|
@script:python depends on report@
|
|
p << r.p;
|
|
x << r.x;
|
|
@@
|
|
|
|
msg="ERR_CAST can be used with %s" % (x)
|
|
coccilib.report.print_report(p[0], msg)
|
|
</smpl>
|
|
|
|
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
|
|
identified.
|
|
|
|
Example:
|
|
|
|
Running
|
|
make coccicheck MODE=patch COCCI=scripts/coccinelle/api/err_cast.cocci
|
|
|
|
will execute the following part of the SmPL script.
|
|
|
|
<smpl>
|
|
@ depends on !context && patch && !org && !report @
|
|
expression x;
|
|
@@
|
|
|
|
- ERR_PTR(PTR_ERR(x))
|
|
+ ERR_CAST(x)
|
|
</smpl>
|
|
|
|
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,
|
|
CRYPTO_ALG_TYPE_MASK);
|
|
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.
|
|
|
|
Example:
|
|
|
|
Running
|
|
make coccicheck MODE=context COCCI=scripts/coccinelle/api/err_cast.cocci
|
|
|
|
will execute the following part of the SmPL script.
|
|
|
|
<smpl>
|
|
@ depends on context && !patch && !org && !report@
|
|
expression x;
|
|
@@
|
|
|
|
* ERR_PTR(PTR_ERR(x))
|
|
</smpl>
|
|
|
|
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,
|
|
CRYPTO_ALG_TYPE_MASK);
|
|
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.
|
|
|
|
Example:
|
|
|
|
Running
|
|
make coccicheck MODE=org COCCI=scripts/coccinelle/api/err_cast.cocci
|
|
|
|
will execute the following part of the SmPL script.
|
|
|
|
<smpl>
|
|
@r depends on !context && !patch && (org || report)@
|
|
expression x;
|
|
position p;
|
|
@@
|
|
|
|
ERR_PTR@p(PTR_ERR(x))
|
|
|
|
@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("]",")")
|
|
coccilib.org.print_todo(p[0], msg_safe)
|
|
</smpl>
|
|
|
|
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]]
|