scripts: objdiff: detect object code changes between two commits

objdiff is useful when doing large code cleanups. For example, when removing checkpatch warnings and errors from new drivers in the staging tree. objdiff can be used in conjunction with a git rebase to confirm that each commit made no changes to the resulting object code. It has the same return values as diff(1). This was written specifically to support adding the skein and threefish cryto drivers to the staging tree. I needed a programmatic way to confirm that commits changing >90% of the lines didn't inadvertently change the code. Temporary files (objdump output) are stored in /path/to/linux/.tmp_objdiff 'make mrproper' will remove this directory. Signed-off-by: Jason Cooper <jason@lakedaemon.net> Signed-off-by: Michal Marek <mmarek@suse.cz>

scripts: objdiff: detect object code changes between two commits
objdiff is useful when doing large code cleanups. For example, when removing checkpatch warnings and errors from new drivers in the staging tree. objdiff can be used in conjunction with a git rebase to confirm that each commit made no changes to the resulting object code. It has the same return values as diff(1). This was written specifically to support adding the skein and threefish cryto drivers to the staging tree. I needed a programmatic way to confirm that commits changing >90% of the lines didn't inadvertently change the code. Temporary files (objdump output) are stored in /path/to/linux/.tmp_objdiff 'make mrproper' will remove this directory. Signed-off-by: Jason Cooper <jason@lakedaemon.net> Signed-off-by: Michal Marek <mmarek@suse.cz>
Jason Cooper · Michal Marek
1 parent 0a830dad5e
Showing 2 changed files with 142 additions and 1 deletions Side-by-side Diff
Makefile
scripts/objdiff
@@ -1066,7 +1066,7 @@
  
 # Directories & files removed with 'make mrproper'
 MRPROPER_DIRS  += include/config usr/include include/generated          \
-                  arch/*/include/generated
+                  arch/*/include/generated .tmp_objdiff
 MRPROPER_FILES += .config .config.old .version .old_version $(version_h) \
 		  Module.symvers tags TAGS cscope* GPATH GTAGS GRTAGS GSYMS \
 		  signing_key.priv signing_key.x509 x509.genkey		\
+#!/bin/bash
+
+# objdiff - a small script for validating that a commit or series of commits
+# didn't change object code.
+#
+# Copyright 2014, Jason Cooper <jason@lakedaemon.net>
+#
+# Licensed under the terms of the GNU GPL version 2
+
+# usage example:
+#
+# $ git checkout COMMIT_A
+# $ <your fancy build command here>
+# $ ./scripts/objdiff record path/to/*.o
+#
+# $ git checkout COMMIT_B
+# $ <your fancy build command here>
+# $ ./scripts/objdiff record path/to/*.o
+#
+# $ ./scripts/objdiff diff COMMIT_A COMMIT_B
+# $
+
+# And to clean up (everything is in .tmp_objdiff/*)
+# $ ./scripts/objdiff clean all
+#
+# Note: 'make mrproper' will also remove .tmp_objdiff
+
+GIT_DIR="`git rev-parse --git-dir`"
+
+if [ -d "$GIT_DIR" ]; then
+	TMPD="${GIT_DIR%git}tmp_objdiff"
+
+	[ -d "$TMPD" ] || mkdir "$TMPD"
+else
+	echo "ERROR: git directory not found."
+	exit 1
+fi
+
+usage() {
+	echo "Usage: $0 <command> <args>"
+	echo "  record    <list of object files>"
+	echo "  diff      <commitA> <commitB>"
+	echo "  clean     all | <commit>"
+	exit 1
+}
+
+dorecord() {
+	[ $# -eq 0 ] && usage
+
+	FILES="$*"
+
+	CMT="`git rev-parse --short HEAD`"
+
+	OBJDUMP="${CROSS_COMPILE}objdump"
+	OBJDIFFD="$TMPD/$CMT"
+
+	[ ! -d "$OBJDIFFD" ] && mkdir -p "$OBJDIFFD"
+
+	for f in $FILES; do
+		dn="${f%/*}"
+		bn="${f##*/}"
+
+		[ ! -d "$OBJDIFFD/$dn" ] && mkdir -p "$OBJDIFFD/$dn"
+
+		# remove addresses for a more clear diff
+		# http://dummdida.tumblr.com/post/60924060451/binary-diff-between-libc-from-scientificlinux-and
+		$OBJDUMP -D "$f" | sed "s/^[[:space:]]\+[0-9a-f]\+//" \
+			>"$OBJDIFFD/$dn/$bn"
+	done
+}
+
+dodiff() {
+	[ $# -ne 2 ] && [ $# -ne 0 ] && usage
+
+	if [ $# -eq 0 ]; then
+		SRC="`git rev-parse --short HEAD^`"
+		DST="`git rev-parse --short HEAD`"
+	else
+		SRC="`git rev-parse --short $1`"
+		DST="`git rev-parse --short $2`"
+	fi
+
+	DIFF="`which colordiff`"
+
+	if [ ${#DIFF} -eq 0 ] || [ ! -x "$DIFF" ]; then
+		DIFF="`which diff`"
+	fi
+
+	SRCD="$TMPD/$SRC"
+	DSTD="$TMPD/$DST"
+
+	if [ ! -d "$SRCD" ]; then
+		echo "ERROR: $SRCD doesn't exist"
+		exit 1
+	fi
+
+	if [ ! -d "$DSTD" ]; then
+		echo "ERROR: $DSTD doesn't exist"
+		exit 1
+	fi
+
+	$DIFF -Nurd $SRCD $DSTD
+}
+
+doclean() {
+	[ $# -eq 0 ] && usage
+	[ $# -gt 1 ] && usage
+
+	if [ "x$1" = "xall" ]; then
+		rm -rf $TMPD/*
+	else
+		CMT="`git rev-parse --short $1`"
+
+		if [ -d "$TMPD/$CMT" ]; then
+			rm -rf $TMPD/$CMT
+		else
+			echo "$CMT not found"
+		fi
+	fi
+}
+
+[ $# -eq 0 ] &&	usage
+
+case "$1" in
+	record)
+		shift
+		dorecord $*
+		;;
+	diff)
+		shift
+		dodiff $*
+		;;
+	clean)
+		shift
+		doclean $*
+		;;
+	*)
+		echo "Unrecognized command '$1'"
+		exit 1
+		;;
+esac
...	...	@@ -1066,7 +1066,7 @@
1066	1066
1067	1067	# Directories & files removed with 'make mrproper'
1068	1068	MRPROPER_DIRS += include/config usr/include include/generated \
1069		- arch/*/include/generated
	1069	+ arch/*/include/generated .tmp_objdiff
1070	1070	MRPROPER_FILES += .config .config.old .version .old_version $(version_h) \
1071	1071	Module.symvers tags TAGS cscope* GPATH GTAGS GRTAGS GSYMS \
1072	1072	signing_key.priv signing_key.x509 x509.genkey \
	1	+#!/bin/bash
	2	+
	3	+# objdiff - a small script for validating that a commit or series of commits
	4	+# didn't change object code.
	5	+#
	6	+# Copyright 2014, Jason Cooper <jason@lakedaemon.net>
	7	+#
	8	+# Licensed under the terms of the GNU GPL version 2
	9	+
	10	+# usage example:
	11	+#
	12	+# $ git checkout COMMIT_A
	13	+# $ <your fancy build command here>
	14	+# $ ./scripts/objdiff record path/to/*.o
	15	+#
	16	+# $ git checkout COMMIT_B
	17	+# $ <your fancy build command here>
	18	+# $ ./scripts/objdiff record path/to/*.o
	19	+#
	20	+# $ ./scripts/objdiff diff COMMIT_A COMMIT_B
	21	+# $
	22	+
	23	+# And to clean up (everything is in .tmp_objdiff/*)
	24	+# $ ./scripts/objdiff clean all
	25	+#
	26	+# Note: 'make mrproper' will also remove .tmp_objdiff
	27	+
	28	+GIT_DIR="`git rev-parse --git-dir`"
	29	+
	30	+if [ -d "$GIT_DIR" ]; then
	31	+ TMPD="${GIT_DIR%git}tmp_objdiff"
	32	+
	33	+ [ -d "$TMPD" ] \|\| mkdir "$TMPD"
	34	+else
	35	+ echo "ERROR: git directory not found."
	36	+ exit 1
	37	+fi
	38	+
	39	+usage() {
	40	+ echo "Usage: $0 <command> <args>"
	41	+ echo " record <list of object files>"
	42	+ echo " diff <commitA> <commitB>"
	43	+ echo " clean all \| <commit>"
	44	+ exit 1
	45	+}
	46	+
	47	+dorecord() {
	48	+ [ $# -eq 0 ] && usage
	49	+
	50	+ FILES="$*"
	51	+
	52	+ CMT="`git rev-parse --short HEAD`"
	53	+
	54	+ OBJDUMP="${CROSS_COMPILE}objdump"
	55	+ OBJDIFFD="$TMPD/$CMT"
	56	+
	57	+ [ ! -d "$OBJDIFFD" ] && mkdir -p "$OBJDIFFD"
	58	+
	59	+ for f in $FILES; do
	60	+ dn="${f%/*}"
	61	+ bn="${f##*/}"
	62	+
	63	+ [ ! -d "$OBJDIFFD/$dn" ] && mkdir -p "$OBJDIFFD/$dn"
	64	+
	65	+ # remove addresses for a more clear diff
	66	+ # http://dummdida.tumblr.com/post/60924060451/binary-diff-between-libc-from-scientificlinux-and
	67	+ $OBJDUMP -D "$f" \| sed "s/^[[:space:]]\+[0-9a-f]\+//" \
	68	+ >"$OBJDIFFD/$dn/$bn"
	69	+ done
	70	+}
	71	+
	72	+dodiff() {
	73	+ [ $# -ne 2 ] && [ $# -ne 0 ] && usage
	74	+
	75	+ if [ $# -eq 0 ]; then
	76	+ SRC="`git rev-parse --short HEAD^`"
	77	+ DST="`git rev-parse --short HEAD`"
	78	+ else
	79	+ SRC="`git rev-parse --short $1`"
	80	+ DST="`git rev-parse --short $2`"
	81	+ fi
	82	+
	83	+ DIFF="`which colordiff`"
	84	+
	85	+ if [ ${#DIFF} -eq 0 ] \|\| [ ! -x "$DIFF" ]; then
	86	+ DIFF="`which diff`"
	87	+ fi
	88	+
	89	+ SRCD="$TMPD/$SRC"
	90	+ DSTD="$TMPD/$DST"
	91	+
	92	+ if [ ! -d "$SRCD" ]; then
	93	+ echo "ERROR: $SRCD doesn't exist"
	94	+ exit 1
	95	+ fi
	96	+
	97	+ if [ ! -d "$DSTD" ]; then
	98	+ echo "ERROR: $DSTD doesn't exist"
	99	+ exit 1
	100	+ fi
	101	+
	102	+ $DIFF -Nurd $SRCD $DSTD
	103	+}
	104	+
	105	+doclean() {
	106	+ [ $# -eq 0 ] && usage
	107	+ [ $# -gt 1 ] && usage
	108	+
	109	+ if [ "x$1" = "xall" ]; then
	110	+ rm -rf $TMPD/*
	111	+ else
	112	+ CMT="`git rev-parse --short $1`"
	113	+
	114	+ if [ -d "$TMPD/$CMT" ]; then
	115	+ rm -rf $TMPD/$CMT
	116	+ else
	117	+ echo "$CMT not found"
	118	+ fi
	119	+ fi
	120	+}
	121	+
	122	+[ $# -eq 0 ] && usage
	123	+
	124	+case "$1" in
	125	+ record)
	126	+ shift
	127	+ dorecord $*
	128	+ ;;
	129	+ diff)
	130	+ shift
	131	+ dodiff $*
	132	+ ;;
	133	+ clean)
	134	+ shift
	135	+ doclean $*
	136	+ ;;
	137	+ *)
	138	+ echo "Unrecognized command '$1'"
	139	+ exit 1
	140	+ ;;
	141	+esac