[PATCH v2 0/4] nsproxy: support CLONE_NEWTIME with setns()

[Christian Brauner <christian.brauner@ubuntu.com>]

Hey,

After having synced with Andrei with the ARM time namespace support
patchset we've decided to make vdso_join_timens() a function that cannot
fail but not yet change its return type so the changes for ARM can
proceed independently. We will simply have a follow-up patch right after
these changes land during the v5.9 merge window that changes
vdso_join_timens() from returning an int to void.

So far setns() with pidfds was missing time namespace support. This was
partially due to it simply not being implemented but also because
vdso_join_timens() could still fail which made switching to multiple
namespaces atomically problematic. This series first fixes
vdso_join_timens() to never fail, introduces timens_commit() and finally
adds CLONE_NEWTIME support for setns().

Thanks!
Christian

Christian Brauner (4):
  timens: make vdso_join_timens() always succeed
  timens: add timens_commit() helper
  nsproxy: support CLONE_NEWTIME with setns()
  tests: add CLONE_NEWTIME setns tests

 arch/x86/entry/vdso/vma.c                     |  5 +-
 include/linux/time_namespace.h                |  6 ++
 kernel/nsproxy.c                              | 21 ++++-
 kernel/time/namespace.c                       | 22 ++----
 tools/testing/selftests/pidfd/pidfd.h         |  4 +
 .../selftests/pidfd/pidfd_setns_test.c        | 76 +++++++++++++++++++
 6 files changed, 115 insertions(+), 19 deletions(-)


base-commit: dcb7fd82c75ee2d6e6f9d8cc71c52519ed52e258
-- 
2.27.0