kpatch-build: allow list of patches on command line

It can be convenient to build a patchset into a single kpatch module, so
teach kpatch-build to accept a list of .patch files on the commandline.

Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>

kpatch-build/kpatch-build

@@ -45,11 +45,12 @@ RPMTOPDIR="$CACHEDIR/buildroot"
 VERSIONFILE="$CACHEDIR/version"
 TEMPDIR="$CACHEDIR/tmp"
 LOGFILE="$CACHEDIR/build.log"
-APPLIEDPATCHFILE="kpatch.patch"
 DEBUG=0
 SKIPCLEANUP=0
 SKIPGCCCHECK=0
 ARCH_KCFLAGS=""
+declare -a PATCH_LIST
+APPLIED_PATCHES=0
 
 warn() {
 	echo "ERROR: $1" >&2
@@ -71,15 +72,34 @@ die() {
 	exit 1
 }
 
+apply_patches() {
+	local patch
+
+	for patch in "${PATCH_LIST[@]}"; do
+		patch -N -p1 --dry-run < "$patch" >> "$LOGFILE" 2>&1 || die "$patch file failed to apply"
+		patch -N -p1 < "$patch" >> "$LOGFILE" 2>&1 || die "$patch file failed to apply"
+		(( APPLIED_PATCHES++ ))
+	done
+}
+
+remove_patches() {
+	local patch
+	local idx
+
+	for (( ; APPLIED_PATCHES>0; APPLIED_PATCHES-- )); do
+		idx=$(( APPLIED_PATCHES - 1))
+		patch="${PATCH_LIST[$idx]}"
+		patch -p1 -R -d "$SRCDIR" < "$patch" &> /dev/null
+	done
+}
+
 cleanup() {
 	rm -f "$SRCDIR/.scmversion"
-	if [[ -e "$SRCDIR/$APPLIEDPATCHFILE" ]]; then
+
-		patch -p1 -R -d "$SRCDIR" < "$SRCDIR/$APPLIEDPATCHFILE" &> /dev/null
+	remove_patches
-		rm -f "$SRCDIR/$APPLIEDPATCHFILE"
 	# If $SRCDIR was a git repo, make sure git actually sees that
-		# we've reverted our patch above.
+	# we've reverted our patch(es).
 	[[ -d $SRCDIR/.git ]] && (cd $SRCDIR && git update-index -q --refresh)
-	fi
 
 	# restore original .config and vmlinux if they were removed with mrproper
 	[[ -e $TEMPDIR/.config ]] && mv -f $TEMPDIR/.config $SRCDIR/
@@ -327,7 +347,8 @@ module_name_string() {
 }
 
 usage() {
-	echo "usage: $(basename $0) [options] <patch file>" >&2
+	echo "usage: $(basename $0) [options] <patch1 ... patchN>" >&2
+	echo "		patchN		   Input patchfile(s)" >&2
 	echo "		-h, --help	   Show this help message" >&2
 	echo "		-r, --sourcerpm	   Specify kernel source RPM" >&2
 	echo "		-s, --sourcedir	   Specify kernel source directory" >&2
@@ -406,16 +427,21 @@ while [[ $# -gt 0 ]]; do
 		echo "WARNING: Skipping gcc version matching check (not recommended)"
 		SKIPGCCCHECK=1
 		;;
-	--)
+	*)
-		[[ -z "$2" ]] && die "no patch file specified"
+		[[ "$1" = "--" ]] && shift && continue
-		[[ ! -f "$2" ]] && die "patch file '$2' not found"
+		[[ ! -f "$1" ]] && die "patch file '$1' not found"
-		PATCHFILE=$(readlink -f "$2")
+		PATCH_LIST+=($(readlink -f "$1"))
-		break
 		;;
 	esac
 	shift
 done
 
+if [[ ${#PATCH_LIST[@]} -eq 0 ]]; then
+	warn "no patch file(s) specified"
+	usage
+	exit 1
+fi
+
 # ensure cachedir and tempdir are setup properly and cleaned
 mkdir -p "$TEMPDIR" || die "Couldn't create $TEMPDIR"
 rm -rf "$TEMPDIR"/*
@@ -441,13 +467,18 @@ fi
 
 [[ -z $TARGETS ]] && TARGETS="vmlinux modules"
 
-# If no kpatch module name was provided on the command line, derive one
+# If no kpatch module name was provided on the command line:
-# from the .patch filename
+#   - For single input .patch, use the patch filename
+#   - For multiple input .patches, use "patch"
 if [[ -z $MODNAME ]] ; then
-	MODNAME=$(basename "$PATCHFILE")
+	if [[ ${#PATCH_LIST[@]} -eq 1 ]]; then
+		MODNAME=$(basename "${PATCH_LIST[0]}")
 		if [[ "$MODNAME" =~ \.patch$ ]] || [[ "$MODNAME" =~ \.diff$ ]]; then
 			MODNAME="${MODNAME%.*}"
 		fi
+	else
+		MODNAME="patch"
+	fi
 
 	MODNAME=$(module_name_string "$MODNAME")
 fi
@@ -604,10 +635,11 @@ fi
 # unsupported kernel option checking: CONFIG_DEBUG_INFO_SPLIT
 grep -q "CONFIG_DEBUG_INFO_SPLIT=y" "$CONFIGFILE" && die "kernel option 'CONFIG_DEBUG_INFO_SPLIT' not supported"
 
-echo "Testing patch file"
+echo "Testing patch file(s)"
 cd "$SRCDIR" || die
-patch -N -p1 --dry-run < "$PATCHFILE" || die "source patch file failed to apply"
+apply_patches
-cp "$PATCHFILE" "$APPLIEDPATCHFILE" || die
+remove_patches
+
 cp -LR "$DATADIR/patch" "$TEMPDIR" || die
 
 if [[ $ARCH = "ppc64le" ]]; then
@@ -627,7 +659,7 @@ unset KPATCH_GCC_TEMPDIR
 CROSS_COMPILE="$TOOLSDIR/kpatch-gcc " make "-j$CPUS" $TARGETS >> "$LOGFILE" 2>&1 || die
 
 echo "Building patched kernel"
-patch -N -p1 < "$APPLIEDPATCHFILE" >> "$LOGFILE" 2>&1 || die
+apply_patches
 mkdir -p "$TEMPDIR/orig" "$TEMPDIR/patched"
 KPATCH_GCC_TEMPDIR=$TEMPDIR
 export KPATCH_GCC_TEMPDIR