On 11/03/2019 11:31, Unai Martinez-Corral wrote:
> This is a partial implementation.
>
> Allows to remove a single or a list of already registered binfmt
> interpreters. Valid values are those in qemu_target_list.
> If TARGETS is empty, all the existing 'qemu-*' interpreters are
> removed.
>
> This is partial because 'debian' and 'systemd' configurations are not
> supported. The script will exit with error 'option clear not
> implemented for this mode yet'.
>
> Removal is done by printing '-1' as explained at:
> https://www.kernel.org/doc/Documentation/admin-guide/binfmt-misc.rst
>
> Signed-off-by: Unai Martinez-Corral <unai.martinezcor...@ehu.eus>
> ---
> scripts/qemu-binfmt-conf.sh | 41 ++++++++++++++++++++++++++++++++++---
> 1 file changed, 38 insertions(+), 3 deletions(-)
>
> diff --git a/scripts/qemu-binfmt-conf.sh b/scripts/qemu-binfmt-conf.sh
> index fde78517ff..07d1ee1f04 100755
> --- a/scripts/qemu-binfmt-conf.sh
> +++ b/scripts/qemu-binfmt-conf.sh
> @@ -196,7 +196,7 @@ Options and associated environment variables:
>
> Argument Env-variable Description
> TARGETS QEMU_TARGETS A single arch name or a list of them
> (see all names below);
> - if empty, configure all known targets;
> + if empty, configure/clear all known
> targets;
> if 'NONE', no interpreter is
> configured.
> -h|--help display this usage
> -Q|--path PATH: QEMU_PATH set path to qemu interpreter(s)
> @@ -206,9 +206,10 @@ TARGETS QEMU_TARGETS A single arch name
> or a list of them (see
> systemd-binfmt.service; environment
> variable HOST_ARCH
> allows to override 'uname' to generate
> configuration files
> for a different architecture than the
> current one.
> -
> -e|--exportdir PATH: DEBIANDIR define where to write configuration
> files
> SYSTEMDDIR
> +-c|--clear: QEMU_CLEAR (yes) remove registered interpreters
> for target TARGETS;
> + then exit.
> -c|--credential: QEMU_CREDENTIAL (yes) credential and security tokens
> are calculated according
> to the binary to interpret
> -p|--persistent: QEMU_PERSISTENT (yes) load the interpreter and keep it
> in memory; all future
> @@ -336,6 +337,25 @@ qemu_set_binfmts() {
> done
> }
>
> +qemu_clear_notimplemented() {
> + echo "ERROR: option clear not implemented for this mode yet" 1>&2
> + usage
> + exit 1
> +}
> +
> +qemu_clear_interpreter() {
> + names='qemu-*'
> + if [ $# -ne 0 ] ; then
> + qemu_check_target_list $1
> + unset names pre
> + for t in $checked_target_list ; do
> + names="${names}${pre}qemu-$t"
> + pre=' -o -name '
> + done
> + fi
> + find /proc/sys/fs/binfmt_misc/ -type f -name $names -exec sh -c 'printf
> %s -1 > {}' \;
The qemu-* will be expanded here if you have a qemu-XXX in the current
directory. You must use "$names".
But:
To remove all, you can do:
sh -c 'printf %s -1 > /proc/sys/fs/binfmt_misc/status'
so something like
if [ $# -eq 0 ] ; then
sh -c 'printf %s -1 > /proc/sys/fs/binfmt_misc/status
fi
qemu_check_target_list $1
for t in $checked_target_list ; do
sh -c 'printf %s -1 > /proc/sys/fs/binfmt_misc/qemu-$t'
done
But I think you should also taking care of the suffix.
> +}
> +
> CHECK=qemu_check_bintfmt_misc
> BINFMT_SET=qemu_register_interpreter
>
> @@ -347,12 +367,16 @@ QEMU_PATH="${QEMU_PATH:-/usr/local/bin}"
> QEMU_SUFFIX="${QEMU_SUFFIX:-}"
> QEMU_CREDENTIAL="${QEMU_CREDENTIAL:-no}"
> QEMU_PERSISTENT="${QEMU_PERSISTENT:-no}"
> +QEMU_CLEAR="${QEMU_CLEAR:-no}"
>
> -options=$(getopt -o dsQ:S:e:hcp -l
> debian,systemd,path:,suffix:,exportdir:,help,credential,persistent -- "$@")
> +options=$(getopt -o cdsQ:S:e:hcp -l
> clear,debian,systemd,path:,suffix:,exportdir:,help,credential,persistent --
> "$@")
> eval set -- "$options"
>
> while true ; do
> case "$1" in
> + -c|--clear)
> + QEMU_CLEAR="yes"
> + ;;
> -d|--debian)
> CHECK=qemu_check_debian
> BINFMT_SET=qemu_generate_debian
> @@ -395,4 +419,15 @@ done
> shift
>
> $CHECK
> +
> +if [ "x$QEMU_CLEAR" = "xyes" ] ; then
> + case "$BINFMT_SET" in
> + *debian) BINFMT_CLEAR=qemu_clear_notimplemented ;;
> + *systemd) BINFMT_CLEAR=qemu_clear_notimplemented ;;
> + *) BINFMT_CLEAR=qemu_clear_interpreter
> + esac
Put this in the previous case for decoding options, please.
> + $BINFMT_CLEAR "$@"
> + exit
> +fi
> +
> qemu_set_binfmts "$@"
> --
> 2.21.0
>
