[PATCH v4 0/3] nsproxy: attach to multiple namespaces

[Christian Brauner]

This is v4.

/* v4 */
There are no major changes. There's a fix for the nstype == 0 case Eric
spotted when porting setns() to struct nsset in the first patch.
I've also added a few lines to the second patch that we want the ability
to attach to subsets of namespaces with pidfds. I also mentioned the
possible future extension that Eric pointed at which amounts to assuming
even more of the callers context. But let's wait for users with that
one.

/* v3 */
The permission bits have already seen some vetting which has been
helpful and allowed us to drop the ns_capable_cred() patch. That's the
only major change.

All selftests pass. People interested in playing with this can get it
from three locations as usual (it's not yet in my for-next):
https://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux.git/log/?h=setns_pidfd
https://gitlab.com/brauner/linux/-/commits/setns_pidfd
https://github.com/brauner/linux/tree/setns_pidfd
                                                                  
Thanks!
Christian

Christian Brauner (3):
  nsproxy: add struct nsset
  nsproxy: attach to namespaces via pidfds
  selftests/pidfd: add pidfd setns tests

 fs/namespace.c                                |  15 +-
 fs/nsfs.c                                     |   5 +
 include/linux/mnt_namespace.h                 |   2 +
 include/linux/nsproxy.h                       |  24 +
 include/linux/proc_fs.h                       |   6 +
 include/linux/proc_ns.h                       |   4 +-
 ipc/namespace.c                               |   7 +-
 kernel/cgroup/namespace.c                     |   5 +-
 kernel/nsproxy.c                              | 305 ++++++++++-
 kernel/pid_namespace.c                        |   5 +-
 kernel/time/namespace.c                       |   5 +-
 kernel/user_namespace.c                       |   8 +-
 kernel/utsname.c                              |   5 +-
 net/core/net_namespace.c                      |   5 +-
 tools/testing/selftests/pidfd/.gitignore      |   1 +
 tools/testing/selftests/pidfd/Makefile        |   3 +-
 tools/testing/selftests/pidfd/config          |   6 +
 .../selftests/pidfd/pidfd_setns_test.c        | 473 ++++++++++++++++++
 18 files changed, 837 insertions(+), 47 deletions(-)
 create mode 100644 tools/testing/selftests/pidfd/config
 create mode 100644 tools/testing/selftests/pidfd/pidfd_setns_test.c


base-commit: ae83d0b416db002fe95601e7f97f64b59514d936
-- 
2.26.2