mini-os: use BSD sys/queue.h instead of Linux list.h

The latter is GPL which makes the whole of mini-os GPL rather than BSD
as intended. In tree users are all GPL or GPL-compatible but we should
fix this so that mini-os is BSD. Do so by using the same BSD
sys/queue.h as we use in libxl.

Tested with the builtin mini-os test app and qemu stubdomain, both of which
appear to still function as expected.

Move tools/libxl/external and the associated sed script to
tools/include/xen-external to allow more sensible access from mini-os.

Also add s/NULL/0/ in the sed script due to NULL not always being
defined in stubdom code when mini-os/wait.h is included.

As well as the obvious ABI changes there are a few API updates
associated with the change:

  - struct rw_semaphore.wait_list is unused
  - remove_waiter needs to take the wait_queue_head

The latter requires a qemu update, so there is also a QEMU_TAG
update in this changeset.

I sprinkled some extra-emacs local variables around the files I edited
which didn't have them.

I think this should be backported to the stable branches since
external users of mini-os may have been mislead into thinking they
could safely link mini-os against GPL-incompatible code.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Committed-by: Ian Jackson <Ian.Jackson@eu.citrix.com>

6 files changed, 16 insertions, 4 deletions

diff --git a/tools/libxl/external/README b/tools/include/xen-external/README
index 8c8beea3f9..93c2bc9cd8 100644
--- a/tools/libxl/external/README
+++ b/tools/include/xen-external/README
@@ -1,5 +1,5 @@
-WARNING - DO NOT EDIT THINGS IN THIS DIRECTORY (apart from this README)
------------------------------------------------------------------------
+WARNING - DO NOT EDIT THINGS IN THIS DIRECTORY
+----------------------------------------------
 
 These files were obtained elsewhere and should only be updated by
 copying new versions from the source location, as documented below:
@@ -12,3 +12,13 @@ bsd-queue.3
     svn co -r 221843 svn://svn.freebsd.org/base/head/sys/sys/
     svn co -r 221843 svn://svn.freebsd.org/base/head/share/man/man3
     svn cat -r 221843 http://svn.freebsd.org/base/head/COPYRIGHT >tools/libxl/external/bsd-COPYRIGHT
+
+Exceptions:
+
+README
+
+  This file
+
+bsd-sys-queue-h-seddery
+
+  Script to transform the above into a new namespace.
diff --git a/tools/libxl/external/bsd-COPYRIGHT b/tools/include/xen-external/bsd-COPYRIGHT
index 6dc5d16b46..6dc5d16b46 100644
--- a/tools/libxl/external/bsd-COPYRIGHT
+++ b/tools/include/xen-external/bsd-COPYRIGHT
diff --git a/tools/libxl/external/bsd-queue.3 b/tools/include/xen-external/bsd-queue.3
index 007ca5c629..007ca5c629 100644
--- a/tools/libxl/external/bsd-queue.3
+++ b/tools/include/xen-external/bsd-queue.3
diff --git a/tools/libxl/bsd-sys-queue-h-seddery b/tools/include/xen-external/bsd-sys-queue-h-seddery
index c0aa079cbe..7a957e3a10 100755
--- a/tools/libxl/bsd-sys-queue-h-seddery
+++ b/tools/include/xen-external/bsd-sys-queue-h-seddery
@@ -68,3 +68,5 @@ s/\b(
 s/\b struct \s+ type \b/type/xg;
 
 s,^\#include.*sys/cdefs.*,/* $& */,xg;
+
+s/\b( NULL )/0/xg;
diff --git a/tools/libxl/external/bsd-sys-queue.h b/tools/include/xen-external/bsd-sys-queue.h
index 274e636c53..274e636c53 100644
--- a/tools/libxl/external/bsd-sys-queue.h
+++ b/tools/include/xen-external/bsd-sys-queue.h
diff --git a/tools/libxl/Makefile b/tools/libxl/Makefile
index b58c43ecb7..d0b6fda277 100644
--- a/tools/libxl/Makefile
+++ b/tools/libxl/Makefile
@@ -93,8 +93,8 @@ _libxl_paths.h: genpath
 	rm -f $@.tmp
 	$(call move-if-changed,$@.2.tmp,$@)
 
-_libxl_list.h: bsd-sys-queue-h-seddery external/bsd-sys-queue.h
-	perl ./$^ --prefix=libxl >$@.new
+_libxl_list.h: $(XEN_INCLUDE)/xen-external/bsd-sys-queue-h-seddery $(XEN_INCLUDE)/xen-external/bsd-sys-queue.h
+	perl $^ --prefix=libxl >$@.new
 	$(call move-if-changed,$@.new,$@)
 
 libxl_paths.c: _libxl_paths.h