[Buildroot] [git commit] fs/tar: add support for xattrs (thus capabilties)

[Peter Korsgaard]

commit: https://git.buildroot.net/buildroot/commit/?id=6d688e2132f9feb63e325c2456d23edfc53f79a8
branch: https://git.buildroot.net/buildroot/commit/?id=refs/heads/master

By default, tar will not include any extended attribute (xattr) when
creating archives, and thus will not store capabilties either (as they
are stored in the xattr 'security.capability').

Using option --xattrs is enough to create a tarball with all the xattrs
attached to a file. However, extracting all xattrs from a tarball
requires that --xattrs-include='*' be used. This is not symetric (but on
purpose, as per the documentation), and so is confusing to some.

So, we use --xattrs-include='*' to create the archive, so as to be
explicit that we want all xattrs to be stored.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998 at free.fr>
Cc: Ricardo Martincoski <ricardo.martincoski at gmail.com>
Cc: Peter Korsgaard <peter at korsgaard.com>
Cc: Arnout Vandecappelle <arnout at mind.be>
Reviewed-by: Arnout Vandecappelle (Essensium/Mind) <arnout at mind.be>
Signed-off-by: Peter Korsgaard <peter at korsgaard.com>
---
 fs/tar/tar.mk | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/tar/tar.mk b/fs/tar/tar.mk
index 68149e9eb7..4c6327ace8 100644
--- a/fs/tar/tar.mk
+++ b/fs/tar/tar.mk
@@ -10,7 +10,7 @@ ROOTFS_TAR_DEPENDENCIES = $(BR2_TAR_HOST_DEPENDENCY)
 
 define ROOTFS_TAR_CMD
 	(cd $(TARGET_DIR); find -print0 | LC_ALL=C sort -z | \
-		tar $(TAR_OPTS) -cf $@ --null --no-recursion -T - --numeric-owner)
+		tar $(TAR_OPTS) -cf $@ --null --xattrs-include='*' --no-recursion -T - --numeric-owner)
 endef
 
 $(eval $(rootfs))