• Pavel Emelyanov's avatar
    pid namespaces: initialize the namespace's proc_mnt · 6f4e6433
    Pavel Emelyanov authored
    The namespace's proc_mnt must be kern_mount-ed to make this pointer always
    valid, independently of whether the user space mounted the proc or not.  This
    solves raced in proc_flush_task, etc.  with the proc_mnt switching from NULL
    to not-NULL.
    
    The initialization is done after the init's pid is created and hashed to make
    proc_get_sb() finr it and get for root inode.
    
    Sice the namespace holds the vfsmnt, vfsmnt holds the superblock and the
    superblock holds the namespace we must explicitly break this circle to destroy
    all the stuff.  This is done after the init of the namespace dies.  Running a
    few steps forward - when init exits it will kill all its children, so no
    proc_mnt will be needed after its death.
    Signed-off-by: default avatarPavel Emelyanov <xemul@openvz.org>
    Cc: Oleg Nesterov <oleg@tv-sign.ru>
    Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com>
    Cc: Paul Menage <menage@google.com>
    Cc: "Eric W. Biederman" <ebiederm@xmission.com>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    6f4e6433
base.c 62.9 KB