Le 24/10/2018 à 19:15, Laurent Vivier a écrit : > On 16/10/2018 17:22, Andrei Vagin wrote: >> On Wed, Oct 10, 2018 at 06:14:30PM +0200, Laurent Vivier wrote: >>> This patch allows to have a different binfmt_misc configuration >>> for each new user namespace. By default, the binfmt_misc configuration >>> is the one of the previous level, but if the binfmt_misc filesystem is >>> mounted in the new namespace a new empty binfmt instance is created and >>> used in this namespace. >>> >>> For instance, using "unshare" we can start a chroot of another >>> architecture and configure the binfmt_misc interpreter without being root >>> to run the binaries in this chroot. >>> >>> Signed-off-by: Laurent Vivier <laurent@xxxxxxxxx> >> >> Acked-by: Andrei Vagin <avagin@xxxxxxxxx> >> >> Thanks, >> Andrei >> > > I don't konw who is the maintainer for this part, but is there any > chance to have this merged in 4.20? > I'd really want to have this merged. I have some real use cases for this: 1- to allow a non root user to run a container (with "unshare" for instance) with its own binfmt_misc configuration. For instance, like we provide a disk image and ask an ordinary user to run it with his favorite VM hypervisor, we can provide a tar.gz containing our own interpreter and just ask him to unshare+chroot to the exploded file tree, 2- to allow to run automatic tests of an interpreter on a machine without having to change the global configuration of the system. I have in mind to add some tests in Avocado to automatically test qemu-linux-user in containers, so the interpreter path can depend on the build path and possibly run them concurrently, 3- to select an interpreter by container. For instance, on the qemu-devel mailing list, we have a waiting patch to add the bFLT interpreter binfmt_misc configuration, but the bFLT doesn't provide the CPU type in magic/mask. So it would be interesting to be able to select also a bFLT interpreter by container, as we know the CPU architecture we have in each chroot/container, 4- another example to select an interpreter by container is qemu-mips and qemu-misn32 share the same magic/mask because only the kernel API changes, so we can't configure both on the system (but I agree it's a QEMU bug: they should be merged and the kernel API be selected at runtime). Thanks, Laurent
