diff --git a/build-aux/config.sub b/build-aux/config.sub
index dba16e84..baf1512b 100644
--- a/build-aux/config.sub
+++ b/build-aux/config.sub
@@ -4,7 +4,7 @@
 
 # shellcheck disable=SC2006,SC2268 # see below for rationale
 
-timestamp='2022-01-03'
+timestamp='2022-09-17'
 
 # This file is free software; you can redistribute it and/or modify it
 # under the terms of the GNU General Public License as published by
@@ -145,7 +145,7 @@ case $1 in
 			nto-qnx* | linux-* | uclinux-uclibc* \
 			| uclinux-gnu* | kfreebsd*-gnu* | knetbsd*-gnu* | netbsd*-gnu* \
 			| netbsd*-eabi* | kopensolaris*-gnu* | cloudabi*-eabi* \
-			| storm-chaos* | os2-emx* | rtmk-nova*)
+			| storm-chaos* | os2-emx* | rtmk-nova* | managarm-*)
 				basic_machine=$field1
 				basic_os=$maybe_os
 				;;
@@ -1207,7 +1207,7 @@ case $cpu-$vendor in
 			| k1om \
 			| le32 | le64 \
 			| lm32 \
-			| loongarch32 | loongarch64 | loongarchx32 \
+			| loongarch32 | loongarch64 \
 			| m32c | m32r | m32rle \
 			| m5200 | m68000 | m680[012346]0 | m68360 | m683?2 | m68k \
 			| m6811 | m68hc11 | m6812 | m68hc12 | m68hcs12x \
@@ -1341,6 +1341,10 @@ EOF
 		kernel=linux
 		os=`echo "$basic_os" | sed -e 's|linux|gnu|'`
 		;;
+	managarm*)
+		kernel=managarm
+		os=`echo "$basic_os" | sed -e 's|managarm|mlibc|'`
+		;;
 	*)
 		kernel=
 		os=$basic_os
@@ -1754,7 +1758,7 @@ case $os in
 	     | onefs* | tirtos* | phoenix* | fuchsia* | redox* | bme* \
 	     | midnightbsd* | amdhsa* | unleashed* | emscripten* | wasi* \
 	     | nsk* | powerunix* | genode* | zvmoe* | qnx* | emx* | zephyr* \
-	     | fiwix* )
+	     | fiwix* | mlibc* )
 		;;
 	# This one is extra strict with allowed versions
 	sco3.2v2 | sco3.2v[4-9]* | sco5v6*)
@@ -1762,6 +1766,9 @@ case $os in
 		;;
 	none)
 		;;
+	kernel* )
+		# Restricted further below
+		;;
 	*)
 		echo Invalid configuration \`"$1"\': OS \`"$os"\' not recognized 1>&2
 		exit 1
@@ -1772,16 +1779,26 @@ esac
 # (given a valid OS), if there is a kernel.
 case $kernel-$os in
 	linux-gnu* | linux-dietlibc* | linux-android* | linux-newlib* \
-		   | linux-musl* | linux-relibc* | linux-uclibc* )
+		   | linux-musl* | linux-relibc* | linux-uclibc* | linux-mlibc* )
 		;;
 	uclinux-uclibc* )
 		;;
-	-dietlibc* | -newlib* | -musl* | -relibc* | -uclibc* )
+	managarm-mlibc* | managarm-kernel* )
+		;;
+	-dietlibc* | -newlib* | -musl* | -relibc* | -uclibc* | -mlibc* )
 		# These are just libc implementations, not actual OSes, and thus
 		# require a kernel.
 		echo "Invalid configuration \`$1': libc \`$os' needs explicit kernel." 1>&2
 		exit 1
 		;;
+	-kernel* )
+		echo "Invalid configuration \`$1': \`$os' needs explicit kernel." 1>&2
+		exit 1
+		;;
+	*-kernel* )
+		echo "Invalid configuration \`$1': \`$kernel' does not support \`$os'." 1>&2
+		exit 1
+		;;
 	kfreebsd*-gnu* | kopensolaris*-gnu*)
 		;;
 	vxworks-simlinux | vxworks-simwindows | vxworks-spe)