overlay_path: Fix resolution of symbolic link under /sys/

Change-Id: I650e72fb335aa72256d3b129a65c09bbd7cf26d3
Refs: #1463

test/issues/1463/C1463.sh

@@ -0,0 +1,58 @@
+#/bin/sh
+
+USELTP=0
+USEOSTEST=0
+
+. ../../common.sh
+
+issue="1463"
+tid=01
+
+TEST_DIR="/tmp/test"
+ABS_PATH="${TEST_DIR}"
+REL_PATH="./test"
+ABS_LN="${TEST_DIR}_1463_abs_ln"
+REL_LN="${TEST_DIR}_1463_rel_ln"
+
+mkdir -p ${TEST_DIR}
+touch ${TEST_DIR}/L.dir
+
+tname=`printf "C${issue}T%02d" ${tid}`
+echo "*** ${tname} start *******************************"
+ln -fns ${ABS_PATH} ${ABS_LN}
+mcexec readlink ${ABS_LN}/L.dir | tee ./${tname}.txt
+cnt=`grep "a.dir" ./${tname}.txt | wc -l`
+if [ ${cnt} -eq 1 ]; then
+	echo "*** ${tname} PASSED ******************************"
+else
+	echo "*** ${tname} FAILED ******************************"
+fi
+let tid++
+echo ""
+
+tname=`printf "C${issue}T%02d" ${tid}`
+echo "*** ${tname} start *******************************"
+ln -fns ${REL_PATH} ${REL_LN}
+mcexec readlink ${REL_LN}/L.dir | tee ./${tname}.txt
+cnt=`grep "a.dir" ./${tname}.txt | wc -l`
+if [ ${cnt} -eq 1 ]; then
+	echo "*** ${tname} PASSED ******************************"
+else
+	echo "*** ${tname} FAILED ******************************"
+fi
+let tid++
+echo ""
+
+tname=`printf "C${issue}T%02d" ${tid}`
+echo "*** ${tname} start *******************************"
+mcexec cat /sys/devices/system/cpu/offline | tee ./${tname}.txt
+echo "** (expected blank output)"
+lines=`grep -e "[0-9]" ./${tname}.txt | wc -l`
+if [ ${lines} -eq 0 ]; then
+	echo "*** ${tname} PASSED ******************************"
+else
+	echo "*** ${tname} FAILED ******************************"
+fi
+let tid++
+echo ""
+