mkinitramfs: warn if TMPDIR is mounted noexec + fall back to not cache run scripts then

If the TMPDIR (/tmp by default) is mounted with noexec
the user will notify several lines like:

  /usr/sbin/mkinitramfs: 276: /tmp/mkinitramfs_Ck5cpl/scripts/init-top/all_generic_ide: Permission denied

To get rid of that the user can either point $TMPDIR to
a filesystem that's mounted with exec permission or
otherwise the cache_run_scripts() feature won't be
used. Notify user accordingly with a warning message.

[Closes: #576678]

Signed-off-by: Michael Prokop <mika@debian.org>

1 files changed, 15 insertions, 3 deletions

diff --git a/mkinitramfs b/mkinitramfs
index 04eae42..baf69dd 100755
--- a/mkinitramfs
+++ b/mkinitramfs
@@ -164,6 +164,14 @@ fi
 
 DESTDIR="$(mktemp -d ${TMPDIR:-/tmp}/mkinitramfs_XXXXXX)" || exit 1
 chmod 755 "${DESTDIR}"
+
+# do not execute cache_run_scripts() if mounted with noexec
+NOEXEC=""
+fs=$(df $DESTDIR | tail -1 | awk '{print $6}')
+if [ -n "$fs" ] && mount | grep -q "on $fs .*noexec" ; then
+	NOEXEC=1
+fi
+
 __TMPCPIOGZ="$(mktemp ${TMPDIR:-/tmp}/mkinitramfs-OL_XXXXXX)" || exit 1
 
 DPKG_ARCH=`dpkg --print-architecture`
@@ -277,9 +285,13 @@ run_scripts /usr/share/initramfs-tools/hooks
 run_scripts "${CONFDIR}"/hooks
 
 # cache boot run order
-for b in $(cd "${DESTDIR}/scripts" && find . -mindepth 1 -type d); do
-	cache_run_scripts "${DESTDIR}" "/scripts/${b#./}"
-done
+if [ -n "$NOEXEC" ]; then
+	echo "Warning: TMPDIR is mounted noexec, will not cache run scripts."
+else
+	for b in $(cd "${DESTDIR}/scripts" && find . -mindepth 1 -type d); do
+		cache_run_scripts "${DESTDIR}" "/scripts/${b#./}"
+	done
+fi
 
 # generate module deps
 depmod -a -b "${DESTDIR}" ${version}