diff options
| author | Kirill Tkhai <ktkhai@virtuozzo.com> | 2017-05-09 00:56:38 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-05-09 02:15:12 +0200 |
| commit | 25b14e92af1a563c7331466ca59188f88050bbf0 (patch) | |
| tree | 3bf6e81e06b3d9186a620b2ad7327193f0eb7b52 /fs/nsfs.c | |
| parent | pidns: disable pid allocation if pid_ns_prepare_proc() is failed in alloc_pid() (diff) | |
| download | linux-25b14e92af1a563c7331466ca59188f88050bbf0.tar.xz linux-25b14e92af1a563c7331466ca59188f88050bbf0.zip | |
ns: allow ns_entries to have custom symlink content
Patch series "Expose task pid_ns_for_children to userspace".
pid_ns_for_children set by a task is known only to the task itself, and
it's impossible to identify it from outside.
It's a big problem for checkpoint/restore software like CRIU, because it
can't correctly handle tasks, that do setns(CLONE_NEWPID) in proccess of
their work. If they have a custom pid_ns_for_children before dump, they
must have the same ns after restore. Otherwise, restored task bumped
into enviroment it does not expect.
This patchset solves the problem. It exposes pid_ns_for_children to ns
directory in standard way with the name "pid_for_children":
~# ls /proc/5531/ns -l | grep pid
lrwxrwxrwx 1 root root 0 Jan 14 16:38 pid -> pid:[4026531836]
lrwxrwxrwx 1 root root 0 Jan 14 16:38 pid_for_children -> pid:[4026532286]
This patch (of 2):
Make possible to have link content prefix yyy different from the link
name xxx:
$ readlink /proc/[pid]/ns/xxx
yyy:[4026531838]
This will be used in next patch.
Link: http://lkml.kernel.org/r/149201120318.6007.7362655181033883000.stgit@localhost.localdomain
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Reviewed-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Andrei Vagin <avagin@virtuozzo.com>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Michael Kerrisk <mtk.manpages@googlemail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/nsfs.c')
| -rw-r--r-- | fs/nsfs.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/fs/nsfs.c b/fs/nsfs.c index 323f492e0822..f3db56e83dd2 100644 --- a/fs/nsfs.c +++ b/fs/nsfs.c @@ -196,9 +196,11 @@ int ns_get_name(char *buf, size_t size, struct task_struct *task, { struct ns_common *ns; int res = -ENOENT; + const char *name; ns = ns_ops->get(task); if (ns) { - res = snprintf(buf, size, "%s:[%u]", ns_ops->name, ns->inum); + name = ns_ops->real_ns_name ? : ns_ops->name; + res = snprintf(buf, size, "%s:[%u]", name, ns->inum); ns_ops->put(ns); } return res; |