Re: [Qemu-devel] [PATCH v6 8/9] qemu-binfmt-conf.sh: add option --clear

[Laurent Vivier]

On 12/03/2019 20:03, 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 <address@hidden>
> ---
>   scripts/qemu-binfmt-conf.sh | 33 +++++++++++++++++++++++++++++++--
>   1 file changed, 31 insertions(+), 2 deletions(-)
>
> diff --git a/scripts/qemu-binfmt-conf.sh b/scripts/qemu-binfmt-conf.sh
> index 51c4c67799..c672ec4886 100755
> --- a/scripts/qemu-binfmt-conf.sh
> +++ b/scripts/qemu-binfmt-conf.sh
> @@ -197,7 +197,7 @@ 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)
> @@ -206,6 +206,8 @@ TARGETS              QEMU_TARGETS     A single arch name or 
> a list of them (see
>                                         uses are cloned from the open file.
>   -c|--credential      QEMU_CREDENTIAL  (yes) credential and security tokens 
> are calculated according
>                                         to the binary to interpret
> +-r|--clear           QEMU_CLEAR       (yes) remove registered interpreters for 
> target TARGETS;
> +                                      then exit.

please fix the indentation.

>   -e|--exportdir PATH                   define where to write configuration 
> files
>                                         (default: $SYSTEMDDIR or $DEBIANDIR)
>   -s|--systemd                          don't write into /proc, generate 
> file(s) for
> @@ -218,6 +220,7 @@ QEMU_PATH=$QEMU_PATH
>   QEMU_SUFFIX=$QEMU_SUFFIX
>   QEMU_PERSISTENT=$QEMU_PERSISTENT
>   QEMU_CREDENTIAL=$QEMU_CREDENTIAL
> +QEMU_CLEAR=$QEMU_CLEAR

please fix the indentation.

>   To import templates with update-binfmts, use :
>
> @@ -344,8 +347,19 @@ 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() {
> +    printf %s -1 > "/proc/sys/fs/binfmt_misc/$1"
> +}
> +
>   CHECK=qemu_check_bintfmt_misc
>   BINFMT_SET=qemu_register_interpreter
> +BINFMT_CLEAR=qemu_clear_interpreter

please fix the indentation.

>   SYSTEMDDIR="/etc/binfmt.d"
>   DEBIANDIR="/usr/share/binfmts"
> @@ -355,20 +369,26 @@ QEMU_PATH="${QEMU_PATH:-/usr/local/bin}"
>   QEMU_SUFFIX="${QEMU_SUFFIX:-}"
>   QEMU_PERSISTENT="${QEMU_PERSISTENT:-no}"
>   QEMU_CREDENTIAL="${QEMU_CREDENTIAL:-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 rdsQ:S:e:hcp -l 
> clear,debian,systemd,path:,suffix:,exportdir:,help,credential,persistent -- 
> "$@")
>   eval set -- "$options"
>
>   while true ; do
>       case "$1" in
> +    -r|--clear)

please fix the indentation.

> +        QEMU_CLEAR="yes"
> +        ;;
>       -d|--debian)
>           CHECK=qemu_check_debian
>           BINFMT_SET=qemu_generate_debian
> +        BINFMT_CLEAR=qemu_clear_notimplemented

please fix the indentation.

>           EXPORTDIR=${EXPORTDIR:-$DEBIANDIR}
>           ;;
>       -s|--systemd)
>           CHECK=qemu_check_systemd
>           BINFMT_SET=qemu_generate_systemd
> +        BINFMT_CLEAR=qemu_clear_notimplemented

please fix the indentation.

>           EXPORTDIR=${EXPORTDIR:-$SYSTEMDDIR}
>           ;;
>       -Q|--path)
> @@ -403,4 +423,13 @@ done
>   shift
>
>   $CHECK
> +
> +if [ "x$QEMU_CLEAR" = "xyes" ] ; then
> +    qemu_check_target_list "$@"
> +    for t in $checked_target_list ; do
> +        $BINFMT_CLEAR "qemu-$t"
> +    done
> +    exit
> +fi
> +
>   qemu_set_binfmts "$@"
> --
> 2.21.0

Except the indentation problems, it looks good.

Thanks,
Laurent