UPSTREAM: https://github.com/zeromq/libzmq/pull/4486
BUG: https://bugs.gentoo.org/899986
From: Han Gao <gaohan@iscas.ac.cn>

In qemu-user, CACHELINE_SIZE probe is undefined

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8672d61799..072a6507e9 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -481,7 +481,8 @@ execute_process(
   ERROR_QUIET OUTPUT_STRIP_TRAILING_WHITESPACE)
 if(CACHELINE_SIZE STREQUAL ""
    OR CACHELINE_SIZE EQUAL 0
-   OR CACHELINE_SIZE EQUAL -1)
+   OR CACHELINE_SIZE EQUAL -1
+   OR CACHELINE_SIZE EQUAL "undefined")
   set(ZMQ_CACHELINE_SIZE 64)
 else()
   set(ZMQ_CACHELINE_SIZE ${CACHELINE_SIZE})
diff --git a/RELICENSE/hangao.md b/RELICENSE/hangao.md
new file mode 100644
index 0000000000..de100bb59a
--- /dev/null
+++ b/RELICENSE/hangao.md
@@ -0,0 +1,13 @@
+# Permission to Relicense under MPLv2 or any other OSI approved license chosen by the current ZeroMQ BDFL
+
+This is a statement by Han Gao that grants permission to relicense its copyrights in the libzmq C++
+library (ZeroMQ) under the Mozilla Public License v2 (MPLv2) or any other 
+Open Source Initiative approved license chosen by the current ZeroMQ 
+BDFL (Benevolent Dictator for Life).
+
+A portion of the commits made by the Github handle "Rabenda", with
+commit author "Han Gao <gaohan@iscas.ac.cn>" or "Han Gao <rabenda.cn@gmail.com>", are copyright of Han Gao .
+This document hereby grants the libzmq project team to relicense libzmq, 
+including all past, present and future contributions of the author listed above.
+
+Han Gao 2023/01/10
diff --git a/acinclude.m4 b/acinclude.m4
index ac55776e53..f27fc8e831 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -1254,7 +1254,7 @@ AC_DEFUN([LIBZMQ_CHECK_CACHELINE], [{
     AC_CHECK_TOOL(libzmq_getconf, getconf)
     if ! test "x$libzmq_getconf" = "x"; then
         zmq_cacheline_size=$($libzmq_getconf LEVEL1_DCACHE_LINESIZE 2>/dev/null || echo 64)
-        if test "x$zmq_cacheline_size" = "x0" -o  "x$zmq_cacheline_size" = "x-1"; then
+        if test "x$zmq_cacheline_size" = "x0" -o  "x$zmq_cacheline_size" = "x-1" -o "x$zmq_cacheline_size" = "xundefined"; then
             # getconf on some architectures does not know the size, try to fallback to
             # the value the kernel knows on Linux
             zmq_cacheline_size=$(cat /sys/devices/system/cpu/cpu0/cache/index0/coherency_line_size 2>/dev/null || echo 64)