From 81d17a19c48724368bde8b6d63edb17f2ee4b6c8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Johannes=20W=C3=BCrbach?= <johannes.wuerbach@googlemail.com>
Date: Sat, 22 Dec 2018 15:12:32 +0100
Subject: [PATCH] Add s390x support to binfmt_misc
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Signed-off-by: Johannes Würbach <johannes.wuerbach@googlemail.com>
---
 pkg/binfmt/Dockerfile                    | 3 ++-
 pkg/binfmt/etc/binfmt.d/00_linuxkit.conf | 5 +++++
 pkg/binfmt/main.go                       | 4 ++++
 3 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/pkg/binfmt/Dockerfile b/pkg/binfmt/Dockerfile
index ee00a5354..cafe936a9 100644
--- a/pkg/binfmt/Dockerfile
+++ b/pkg/binfmt/Dockerfile
@@ -3,7 +3,8 @@ FROM debian@sha256:de3eac83cd481c04c5d6c7344cd7327625a1d8b2540e82a8231b5675cef0a
 RUN apt-get update && apt-get install -y qemu-user-static && \
     mv /usr/bin/qemu-aarch64-static /usr/bin/qemu-aarch64 && \
     mv /usr/bin/qemu-arm-static /usr/bin/qemu-arm && \
-    mv /usr/bin/qemu-ppc64le-static /usr/bin/qemu-ppc64le
+    mv /usr/bin/qemu-ppc64le-static /usr/bin/qemu-ppc64le && \
+    mv /usr/bin/qemu-s390x-static /usr/bin/qemu-s390x
 
 FROM linuxkit/alpine:3683c9a66cd4da40bd7d6c7da599b2dcd738b559 AS mirror
 
diff --git a/pkg/binfmt/etc/binfmt.d/00_linuxkit.conf b/pkg/binfmt/etc/binfmt.d/00_linuxkit.conf
index f0187ab91..a87e9ff00 100644
--- a/pkg/binfmt/etc/binfmt.d/00_linuxkit.conf
+++ b/pkg/binfmt/etc/binfmt.d/00_linuxkit.conf
@@ -1,3 +1,8 @@
+# Register other architecture binary formats https://www.kernel.org/doc/html/latest/admin-guide/binfmt-misc.html
+# Architecture masks and magics can be found here
+# https://github.com/qemu/qemu/blob/master/scripts/qemu-binfmt-conf.sh
+# Replace ELF with `\x45\x4c\x46`
 :qemu-aarch64:M:0:\x7f\x45\x4c\x46\x02\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\xb7:\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff:/usr/bin/qemu-aarch64:CF
 :qemu-arm:M:0:\x7f\x45\x4c\x46\x01\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x28\x00:\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff\xff:/usr/bin/qemu-arm:CF
 :qemu-ppc64le:M:0:\x7f\x45\x4c\x46\x02\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x15\x00:\xff\xff\xff\xff\xff\xff\xff\xfc\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff\x00:/usr/bin/qemu-ppc64le:CF
+:qemu-s390x:M:0:\x7f\x45\x4c\x46\x02\x02\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x16:\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff:/usr/bin/qemu-s390x:CF
diff --git a/pkg/binfmt/main.go b/pkg/binfmt/main.go
index 4df469a2d..97046edb9 100644
--- a/pkg/binfmt/main.go
+++ b/pkg/binfmt/main.go
@@ -89,6 +89,10 @@ func main() {
 			if len(line) == 0 {
 				continue
 			}
+			// ignore comments
+			if line[0] == '#' {
+				continue
+			}
 			err = binfmt(line)
 			if err != nil {
 				log.Fatal(err)