mbuto has two ways of building the initramfs. One is the typical approach of staging its contents in a temporary directory, then building the initramfs with cpio. The other is to create an empty initramfs, mount it with archivemount, and copy things into the mounted archive. However, the archivemount approach is broken. I'm not entirely sure why, but it appears not to properly unmount the archive and retrieve the final. filled version. The upshot is that if archivemount is installed, then mbuto generates an empty, gzip-compressed initramfs instead of whatever it was supposed to. It appears the archivemount approach was there to allow some later changes to the archive without re-running mbuto. However, it's essentially impossible to use this safely - if archivemount still has the archive open for writing, it's not safe to read it concurrently. This appears to have worked by accident with some earlier versions, but doesn't work now. Just remove the archivemount approach entirely. Reported-by: Laurent Vivier Signed-off-by: David Gibson --- mbuto | 41 +++++------------------------------------ 1 file changed, 5 insertions(+), 36 deletions(-) diff --git a/mbuto b/mbuto index a6f80ab..49d032c 100755 --- a/mbuto +++ b/mbuto @@ -368,7 +368,6 @@ cmd_check() { # cleanup() - Remove left-overs on exit, used from trap cleanup() { - [ -n "${ARCHIVEMOUNT}" ] && "${UMOUNT}" "${wd}" 2>/dev/null "${RM}" -rf "${wd}" [ -n "${pkg_tmp}" ] && "${RM}" -f "${pkg_tmp}" [ -n "${compress_test1}" ] && "${RM}" -f "${compress_test1}" @@ -564,16 +563,6 @@ cpio_init() { else OUT="$("${REALPATH}" "${OUT}")" fi - - if [ -n "${ARCHIVEMOUNT}" ]; then - : | "${CPIO}" --create -H newc --quiet | \ - "${GZIP}" > "${OUT}" - fi - fi - - if [ -n "${ARCHIVEMOUNT}" ]; then - "${ARCHIVEMOUNT}" "${OUT}" "${wd}" - info "Mounted CPIO archive ${OUT} at ${wd}" fi } @@ -1099,26 +1088,17 @@ cmds() { [ "${NOSTRIP}" != "y" ] && strip_all - if [ -z "${ARCHIVEMOUNT}" ]; then - ( __out="$("${REALPATH}" "${OUT}")" - "${CD}" "${wd}" - "${FIND}" . | "${CPIO}" --create -H newc --quiet > "${OUT}" - cpio_compress "${__out}" - ) - else - "${SYNC}" - fi + ( __out="$("${REALPATH}" "${OUT}")" + "${CD}" "${wd}" + "${FIND}" . | "${CPIO}" --create -H newc --quiet > "${OUT}" + cpio_compress "${__out}" + ) stats printf "%s" "${OUTPUT}" | \ sed 's,__INITRD__,'"$("${REALPATH}" "${OUT}")"',g' | \ sed 's,__KERNEL__,/boot/vmlinuz-'"${KERNEL}"',g' - - if [ -n "${ARCHIVEMOUNT}" ]; then - trap - EXIT - notice "initramfs mounted at: ${wd}" - fi } # usage() - Print usage and exit @@ -1271,17 +1251,6 @@ else eval "profile_${PROFILE}" || err "profile ${PROFILE} not found" fi -# Check if we can keep the CPIO mounted for convenience as we exit. This isn't -# safe with fakeroot, as contents can't be touched before the environment -# save-file is loaded again, so it needs root (and archivemount). -if [ "${LD_PRELOAD}" = "libfakeroot-sysv.so" ]; then - if command -v archivemount >/dev/null 2>&1; then - notice "Not running as root, won't keep cpio mounted" - fi -elif ! ARCHIVEMOUNT="$(command -v archivemount)"; then - warn "archivemount not available, won't keep cpio mounted" -fi - trap cleanup EXIT cmds "$@" -- 2.44.0

The cpio_init function is now only every called with the "discard" option. But, moreover, what it does is create an initial mostly empty archive which will just get overwritten by the final archive. So, it's entirely unnecessary except for one subtlety. Our use of realpath when generating the final output requires that a file already exist in the output location. We can fix that by shuffling some things out of a subshell, removing the need for realpath. This removes functionality to modify an existing initramfs image. However that was already broken in a several ways. Just remove it, and update the help messages to match. Signed-off-by: David Gibson --- mbuto | 39 +++++++-------------------------------- 1 file changed, 7 insertions(+), 32 deletions(-) diff --git a/mbuto b/mbuto index eb559fb..247b63d 100755 --- a/mbuto +++ b/mbuto @@ -544,28 +544,6 @@ subopts_get() { ### CPIO ####################################################################### -# cpio_init() - Source existing CPIO archive, or create if needed -# $1: Path to CPIO archive, might exist, might be discarded if existing -cpio_init() { - if [ -f "${OUT}" ] && [ "${1}" != "discard" ]; then - info "Sourcing CPIO archive from ${OUT}" - - if ! "${GZIP}" -dfc "${OUT}" | - "${CPIO}" --quiet -iD "${wd}"; then - err "Invalid CPIO archive ${OUT}" - fi - else - info "Creating new CPIO archive" - - if [ -z "${OUT}" ]; then - OUT="$("${MKTEMP}")" - notice "Creating image: ${OUT}" - else - OUT="$("${REALPATH}" "${OUT}")" - fi - fi -} - # compress_select() - Try compressors and pick the fastest to decompress image # $1: Existing CPIO archive compress_select() { @@ -987,7 +965,6 @@ pkg_add() { # build() - Build a new image, sourcing contents build() { - cpio_init discard kmod_init for __d in ${DIRS}; do @@ -1083,11 +1060,11 @@ cmds() { [ "${NOSTRIP}" != "y" ] && strip_all - ( __out="$("${REALPATH}" "${OUT}")" + ( "${CD}" "${wd}" - "${FIND}" . | "${CPIO}" --create -H newc --quiet > "${OUT}" - cpio_compress "${__out}" - ) + "${FIND}" . | "${CPIO}" --create -H newc --quiet + ) > "${OUT}" + cpio_compress "${OUT}" stats @@ -1139,9 +1116,9 @@ usage() { echo " -v: verbose" echo " -h: show this help" echo - echo "Build initramfs image unless an existing one is passed." - echo "Additional programs, kernel modules, device nodes, generic files" - echo "can be passed as a list of ADD_ON parameters." + echo "Build initramfs image. Additional programs, kernel modules," + echo "device nodes, generic files can be passed as a list of ADD_ON" + echo "parameters." echo echo "Distribution packages (deb and RPM currently supported) can be" echo "added too, but they will simply be extracted, not installed." @@ -1173,8 +1150,6 @@ usage() { echo " Build a base image as a temporary file" echo " ${0} grep" echo " Build a new image including grep and needed libraries" - echo " ${0} -f kata.img zsh_5.6.2-3_amd64.deb" - echo " Install zsh package to pre-existing kata.img" echo " ${0} -v -f kata.img -p kata_debug -c lz4" echo " Use lz4 compression, run a shell before proceeding" exit 1 -- 2.44.0