Merge branch 'kbuild/coccinelle' into kbuild/misc

Documentation/coccinelle.txt

@@ -0,0 +1,258 @@
+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 Karmic Koala)
+ - OpenSUSE
+ - Arch Linux
+ - NetBSD
+ - FreeBSD
+
+
+You can get the latest version released from the Coccinelle homepage at
+http://coccinelle.lip6.fr/
+
+Once you have it, run the following command:
+
+     	./configure
+        make
+
+as a regular user, and install it with
+
+        sudo make install
+
+
+ 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: report, patch, context, and org. The mode to
+use is specified by setting the MODE variable with 'MODE=<mode>'.
+
+'report' generates a list in the following format:
+  file:line:column-column: message
+
+'patch' proposes a fix, when possible.
+
+'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.
+
+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
+subdirectories of 'scripts/coccinelle' to the entire Linux kernel.
+
+For each semantic patch, a changelog 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
+
+
+ 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
+subdirectories 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/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/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/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/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]]

MAINTAINERS

@@ -1476,6 +1476,16 @@ M:	Daniel Oliveira Nascimento <don@syst.com.br>
 S:	Supported
 F:	drivers/platform/x86/classmate-laptop.c
 
+COCCINELLE/Semantic Patches (SmPL)
+M:	Julia Lawall <julia@diku.dk>
+M:	Gilles Muller <Gilles.Muller@lip6.fr>
+M:	Nicolas Palix <npalix@diku.dk>
+L:	cocci@diku.dk (moderated for non-subscribers)
+W:	http://coccinelle.lip6.fr/
+S:	Supported
+F:	scripts/coccinelle/
+F:	scripts/coccicheck
+
 CODA FILE SYSTEM
 M:	Jan Harkes <jaharkes@cs.cmu.edu>
 M:	coda@cs.cmu.edu

Makefile

@@ -412,7 +412,7 @@ endif
 # of make so .config is not included in this case either (for *config).
 
 no-dot-config-targets := clean mrproper distclean \
-			 cscope TAGS tags help %docs check% \
+			 cscope TAGS tags help %docs check% coccicheck \
 			 include/linux/version.h headers_% \
 			 kernelrelease kernelversion
 
@@ -1279,8 +1279,9 @@ help:
 	@echo  '  includecheck    - Check for duplicate included header files'
 	@echo  '  export_report   - List the usages of all exported symbols'
 	@echo  '  headers_check   - Sanity check on exported headers'
-	@echo  '  headerdep       - Detect inclusion cycles in headers'; \
-	 echo  ''
+	@echo  '  headerdep       - Detect inclusion cycles in headers'
+	@$(MAKE) -f $(srctree)/scripts/Makefile.help checker-help
+	@echo  ''
 	@echo  'Kernel packaging:'
 	@$(MAKE) $(build)=$(package-dir) help
 	@echo  ''
@@ -1439,6 +1440,9 @@ versioncheck:
 		-name '*.[hcS]' -type f -print | sort \
 		| xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
 
+coccicheck:
+	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/$@
+
 namespacecheck:
 	$(PERL) $(srctree)/scripts/namespace.pl
 

scripts/Makefile.help

@@ -0,0 +1,3 @@
+
+checker-help:
+	@echo  '  coccicheck      - Check with Coccinelle.'

scripts/coccicheck

@@ -0,0 +1,54 @@
+#!/bin/sh
+
+SPATCH="`which ${SPATCH:=spatch}`"
+
+if [ ! -x "$SPATCH" ]; then
+    echo 'spatch is part of the Coccinelle project and is available at http://coccinelle.lip6.fr/'
+    exit 1
+fi
+
+if [ "$MODE" = "" ] ; then
+    echo 'You have not explicitly specify the mode to use. Fallback to "report".'
+    echo 'You can specify the mode with "make coccicheck MODE=<mode>"'
+    echo 'Available modes are: report, patch, context, org'
+    MODE="report"
+fi
+
+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 ''
+
+function coccinelle {
+    COCCI="$1"
+    DIR="$2"
+
+    OPT=`grep "Option" $COCCI | cut -d':' -f2`
+    FILE=`echo $COCCI | sed "s|$DIR/||"`
+
+    echo "Processing `basename $COCCI` with option(s) \"$OPT\""
+    echo 'Message example to submit a patch:'
+
+    sed -e '/\/\/\//!d' -e 's|^///||' $COCCI
+
+    echo ' The semantic patch that makes this change is available'
+    echo " in $FILE."
+    echo ''
+    echo ' More information about semantic patching is available at'
+    echo ' http://coccinelle.lip6.fr/'
+    echo ''
+
+#   The option '-parse_cocci' can be used to syntaxically check the SmPL files.
+#
+#    $SPATCH -D $MODE -very_quiet -parse_cocci $COCCI $OPT > /dev/null
+
+    $SPATCH -D $MODE -very_quiet -sp_file $COCCI $OPT -dir $DIR
+}
+
+if [ "$COCCI" = "" ] ; then
+    for f in `find $srctree/scripts/coccinelle/ -name '*.cocci' -type f | sort`; do
+	coccinelle $f $srctree;
+    done
+else
+    coccinelle $COCCI $srctree
+fi