From c4bcc17dc3d9400f93d710d5881c4b39aca4e7b9 Mon Sep 17 00:00:00 2001
From: Marc Andre Tanner <mat@brain-dump.org>
Date: Sat, 27 Feb 2010 00:33:46 +0100
Subject: [PATCH] Remove unreferenced shared libraries prior to initramfs
 generation

Signed-off-by: Marc Andre Tanner <mat@brain-dump.org>
---
 initramfs.sh | 72 +++++++++++++++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 64 insertions(+), 8 deletions(-)

diff --git a/initramfs.sh b/initramfs.sh
index c4a20e1..b44fa89 100755
--- a/initramfs.sh
+++ b/initramfs.sh
@@ -8,15 +8,71 @@ cd $TOP || dienow
 
 tar -C "$ROOT_OVERLAY" -cf - . | tar -C "$ROOT_DIR" -xf -
 
+libs=""
+
+# remove all shared libraries which aren't needed
+
 if [ -z "$NO_STRIP" ]; then
-	# strip all binaries
-	${STRIP} "$ROOT_DIR"/usr/{bin/*,sbin/*} 2> /dev/null
-	find "$ROOT_DIR/usr/lib" -name '*.so' | xargs ${STRIP} --strip-unneeded 2>/dev/null
-	[ -e "$ROOT_DIR/lib/modules" ] &&  find "$ROOT_DIR/lib/modules" -name '*.ko' | xargs ${STRIP}
-
-	# remove libthread_db which is used for cross debuging with gdb
-	rm -f "$ROOT_DIR"/lib/libthread_db*
-fi
+
+# get library dependencies of binaries
+
+for f in `find $ROOT_DIR/usr/bin $ROOT_DIR/usr/sbin -type f -perm +0111`; do
+	if [ ! -z "`file $f | grep ELF | grep executable`" ]; then
+		for l in `${CROSS}objdump -p $f | awk '/NEEDED/ { print $2 }'`; do
+			libs="$libs $l"
+		done
+	fi
+done
+
+# get dependencies of the dependencies (should use recursion) 
+
+for l in `find $ROOT_DIR/usr/lib -type f -perm +0111`; do
+	soname="`${CROSS}objdump -p $l | awk '/SONAME/ { print $2 }'`"
+	if [[ ! -z $soname && ! -z "`echo $libs | grep $soname`" ]]; then
+		needed="`${CROSS}objdump -p $l | awk '/NEEDED/ { print $2 }'`"
+		libs="$libs $needed"
+	fi
+done
+
+# remove unused sub directories which contain plugin/modules
+
+for l in `find $ROOT_DIR/usr/lib -mindepth 1 -maxdepth 1 -type d -perm +0111`; do
+	if [ ! -z "`echo $libs | grep $l`" ]; then
+		echo deleteing $l
+		rm -rf "$l"
+	else
+		# modules required so get all dependencies
+		for m in `find $l -type f -perm +0111`; do
+			for ml in `${CROSS}objdump -p $m | awk '/NEEDED/ { print $2 }'`; do
+				libs="$libs $ml"
+			done
+		done
+	fi
+done
+
+# delete all libraries which aren't referenced by others
+
+for l in `find $ROOT_DIR/usr/lib -maxdepth 1 ! -type d -perm +0111`; do
+	if [ ! -e "$l" ]; then # remove broken symlinks
+		rm -f "$l"
+	else
+		soname="`${CROSS}objdump -p $l | awk '/SONAME/ { print $2 }' 2> /dev/null`"
+		if [[ ! -z $soname && -z "`echo $libs | grep $soname`" ]]; then
+			rm "$l"
+		fi
+	fi
+done
+
+# strip binaries and libraries
+
+${STRIP} -s -R .note -R .comment "$ROOT_DIR"/usr/{bin/*,sbin/*} 2> /dev/null
+find "$ROOT_DIR/usr/lib" -name '*.so' | xargs ${STRIP} --strip-unneeded 2>/dev/null
+[ -e "$ROOT_DIR/lib/modules" ] &&  find "$ROOT_DIR/lib/modules" -name '*.ko' | xargs ${STRIP}
+
+# remove libthread_db which is used for cross debuging with gdb
+rm -f "$ROOT_DIR"/lib/libthread_db*
+
+fi # $NO_STRIP
 
 # generate file with the contents of the initramfs it's later used
 # by the kernel build system to create a gziped cpio archive which
-- 
2.11.4.GIT