xserver-nodm-init: Fix the start failure for non-root user

In order to start the xserver, a non-root user should have the
cap_sys_admin capability to set the drm master. We try to get
the cap_sys_admin capability by setting it in both the thread
and file inheritable set. The side effect of this is that we
would have to add the "pam" to the distro features if we want
use the xserver-nodm-init for a non-root user.

[Yocto #11526]

Signed-off-by: Kevin Hao <kexin.hao@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
(cherry picked from commit cfd71a68a4931c8bda15357ebb1e9ebcf0e302dc)
Signed-off-by: Armin Kuster <akuster808@gmail.com>

3 files changed, 15 insertions, 2 deletions

diff --git a/meta/recipes-graphics/x11-common/xserver-nodm-init/capability.conf b/meta/recipes-graphics/x11-common/xserver-nodm-init/capability.conf
new file mode 100644
index 0000000000..7ab7460816
--- /dev/null
+++ b/meta/recipes-graphics/x11-common/xserver-nodm-init/capability.conf
@@ -0,0 +1,2 @@
+cap_sys_admin	@USER@
+none	*
diff --git a/meta/recipes-graphics/x11-common/xserver-nodm-init/xserver-nodm b/meta/recipes-graphics/x11-common/xserver-nodm-init/xserver-nodm
index 6c548551b8..116bb278bc 100755
--- a/meta/recipes-graphics/x11-common/xserver-nodm-init/xserver-nodm
+++ b/meta/recipes-graphics/x11-common/xserver-nodm-init/xserver-nodm
@@ -38,6 +38,14 @@ case "$1" in
            if [ -e /dev/hidraw0 ]; then
                chmod o+rw /dev/hidraw*
            fi
+           # Make sure that the Xorg has the cap_sys_admin capability which is
+           # needed for setting the drm master
+           if ! grep -q "^auth.*pam_cap\.so" /etc/pam.d/su; then
+               echo "auth	optional	pam_cap.so" >>/etc/pam.d/su
+           fi
+           if ! /usr/sbin/getcap $XSERVER |  grep -q cap_sys_admin; then
+               /usr/sbin/setcap cap_sys_admin+eip $XSERVER
+           fi
        fi
 
        # Using su rather than sudo as latest 1.8.1 cause failure [YOCTO #1211]
diff --git a/meta/recipes-graphics/x11-common/xserver-nodm-init_3.0.bb b/meta/recipes-graphics/x11-common/xserver-nodm-init_3.0.bb
index a77c56445c..7f4e1e29f1 100644
--- a/meta/recipes-graphics/x11-common/xserver-nodm-init_3.0.bb
+++ b/meta/recipes-graphics/x11-common/xserver-nodm-init_3.0.bb
@@ -10,6 +10,7 @@ SRC_URI = "file://xserver-nodm \
            file://gplv2-license.patch \
            file://xserver-nodm.service.in \
            file://xserver-nodm.conf.in \
+           file://capability.conf \
 "
 
 S = "${WORKDIR}"
@@ -19,7 +20,7 @@ PACKAGE_ARCH = "${MACHINE_ARCH}"
 
 inherit update-rc.d systemd distro_features_check
 
-REQUIRED_DISTRO_FEATURES = "x11"
+REQUIRED_DISTRO_FEATURES = "x11 ${@oe.utils.conditional('ROOTLESS_X', '1', 'pam', '', d)}"
 
 PACKAGECONFIG ??= "blank"
 # dpms and screen saver will be on only if 'blank' is in PACKAGECONFIG
@@ -40,6 +41,8 @@ do_install() {
     if [ "${ROOTLESS_X}" = "1" ] ; then
         XUSER_HOME="/home/xuser"
         XUSER="xuser"
+        install -D capability.conf ${D}${sysconfdir}/security/capability.conf
+        sed -i "s:@USER@:${XUSER}:" ${D}${sysconfdir}/security/capability.conf
     else
         XUSER_HOME=${ROOT_HOME}
         XUSER="root"
@@ -60,7 +63,7 @@ do_install() {
     fi
 }
 
-RDEPENDS_${PN} = "xinit ${@oe.utils.conditional('ROOTLESS_X', '1', 'xuser-account', '', d)}"
+RDEPENDS_${PN} = "xinit ${@oe.utils.conditional('ROOTLESS_X', '1', 'xuser-account libcap libcap-bin', '', d)}"
 
 INITSCRIPT_NAME = "xserver-nodm"
 INITSCRIPT_PARAMS = "start 9 5 . stop 20 0 1 2 3 6 ."