diff --git a/scripts/setlocalversion b/scripts/setlocalversion
index 8564bedd1a7..c1c04352674 100755
--- a/scripts/setlocalversion
+++ b/scripts/setlocalversion
@@ -1,4 +1,5 @@
 #!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
 #
 # This scripts adds local version information from the version
 # control systems git, mercurial (hg) and subversion (svn).
@@ -44,11 +45,11 @@ scm_version()
 
 	# Check for git and a git repo.
 	if test -z "$(git rev-parse --show-cdup 2>/dev/null)" &&
-	   head=`git rev-parse --verify --short HEAD 2>/dev/null`; then
+	   head=$(git rev-parse --verify --short HEAD 2>/dev/null); then
 
 		# If we are at a tagged commit (like "v2.6.30-rc6"), we ignore
 		# it, because this version is defined in the top level Makefile.
-		if [ -z "`git describe --exact-match 2>/dev/null`" ]; then
+		if [ -z "$(git describe --exact-match 2>/dev/null)" ]; then
 
 			# If only the short version is requested, don't bother
 			# running further git commands
@@ -58,7 +59,7 @@ scm_version()
 			fi
 			# If we are past a tagged commit (like
 			# "v2.6.30-rc5-302-g72357d5"), we pretty print it.
-			if atag="`git describe 2>/dev/null`"; then
+			if atag="$(git describe 2>/dev/null)"; then
 				echo "$atag" | awk -F- '{printf("-%05d-%s", $(NF-1),$(NF))}'
 
 			# If we don't have a tag at all we print -g{commitish}.
@@ -69,11 +70,19 @@ scm_version()
 
 		# Is this git on svn?
 		if git config --get svn-remote.svn.url >/dev/null; then
-			printf -- '-svn%s' "`git svn find-rev $head`"
+			printf -- '-svn%s' "$(git svn find-rev $head)"
 		fi
 
-		# Check for uncommitted changes
-		if git diff-index --name-only HEAD | grep -qv "^scripts/package"; then
+		# Check for uncommitted changes.
+		# First, with git-status, but --no-optional-locks is only
+		# supported in git >= 2.14, so fall back to git-diff-index if
+		# it fails. Note that git-diff-index does not refresh the
+		# index, so it may give misleading results. See
+		# git-update-index(1), git-diff-index(1), and git-status(1).
+		if {
+			git --no-optional-locks status -uno --porcelain 2>/dev/null ||
+			git diff-index --name-only HEAD
+		} | grep -qvE '^(.. )?scripts/package'; then
 			printf '%s' -dirty
 		fi
 
@@ -82,15 +91,15 @@ scm_version()
 	fi
 
 	# Check for mercurial and a mercurial repo.
-	if test -d .hg && hgid=`hg id 2>/dev/null`; then
+	if test -d .hg && hgid=$(hg id 2>/dev/null); then
 		# Do we have an tagged version?  If so, latesttagdistance == 1
-		if [ "`hg log -r . --template '{latesttagdistance}'`" == "1" ]; then
-			id=`hg log -r . --template '{latesttag}'`
+		if [ "$(hg log -r . --template '{latesttagdistance}')" = "1" ]; then
+			id=$(hg log -r . --template '{latesttag}')
 			printf '%s%s' -hg "$id"
 		else
-			tag=`printf '%s' "$hgid" | cut -d' ' -f2`
+			tag=$(printf '%s' "$hgid" | cut -d' ' -f2)
 			if [ -z "$tag" -o "$tag" = tip ]; then
-				id=`printf '%s' "$hgid" | sed 's/[+ ].*//'`
+				id=$(printf '%s' "$hgid" | sed 's/[+ ].*//')
 				printf '%s%s' -hg "$id"
 			fi
 		fi
@@ -106,8 +115,8 @@ scm_version()
 	fi
 
 	# Check for svn and a svn repo.
-	if rev=`LANG= LC_ALL= LC_MESSAGES=C svn info 2>/dev/null | grep '^Last Changed Rev'`; then
-		rev=`echo $rev | awk '{print $NF}'`
+	if rev=$(LANG= LC_ALL= LC_MESSAGES=C svn info 2>/dev/null | grep '^Last Changed Rev'); then
+		rev=$(echo $rev | awk '{print $NF}')
 		printf -- '-svn%s' "$rev"
 
 		# All done with svn
@@ -117,7 +126,7 @@ scm_version()
 
 collect_files()
 {
-	local file res
+	local file res=
 
 	for file; do
 		case "$file" in
@@ -142,12 +151,12 @@ fi
 
 if test -e include/config/auto.conf; then
 	# We are interested only in CONFIG_LOCALVERSION and
-        # CONFIG_LOCALVERSION_AUTO, so extract these in a safe
-        # way (i.e. w/o sourcing auto.conf)
+	# CONFIG_LOCALVERSION_AUTO, so extract these in a safe
+	# way (i.e. w/o sourcing auto.conf)
 	CONFIG_LOCALVERSION=`cat include/config/auto.conf | awk -F '=' '/^CONFIG_LOCALVERSION=/ {print $2}'`
 	CONFIG_LOCALVERSION_AUTO=`cat include/config/auto.conf | awk -F '=' '/^CONFIG_LOCALVERSION_AUTO=/ {print $2}'`
 else
-	echo "Error: kernelrelease not valid - run 'make prepare' to update it"
+	echo "Error: kernelrelease not valid - run 'make prepare' to update it" >&2
 	exit 1
 fi