The patch titled pid: implement ns_of_pid has been added to the -mm tree. Its filename is pid-implement-ns_of_pid.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find out what to do about this The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: pid: implement ns_of_pid From: Sukadev Bhattiprolu <sukadev@xxxxxxxxxxxxxxxxxx> A current problem with the pid namespace is that it is easy to do pid related work after exit_task_namespaces which drops the nsproxy pointer. However if we are doing pid namespace related work we are always operating on some struct pid which retains the pid_namespace pointer of the pid namespace it was allocated in. So provide ns_of_pid which allows us to find the pid namespace a pid was allocated in. Using this we have the needed infrastructure to do pid namespace related work at anytime we have a struct pid, removing the chance of accidentally having a NULL pointer dereference when accessing current->nsproxy. Signed-off-by: Eric W. Biederman <ebiederm@xxxxxxxxxxxx> Cc: Oleg Nesterov <oleg@xxxxxxxxxx> Cc: Roland McGrath <roland@xxxxxxxxxx> Cc: Bastian Blank <bastian@xxxxxxxxxxxx> Cc: Pavel Emelyanov <xemul@xxxxxxxxxx> Cc: Nadia Derbey <Nadia.Derbey@xxxxxxxx> Acked-by: Serge Hallyn <serue@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/pid.h | 11 +++++++++++ 1 file changed, 11 insertions(+) diff -puN include/linux/pid.h~pid-implement-ns_of_pid include/linux/pid.h --- a/include/linux/pid.h~pid-implement-ns_of_pid +++ a/include/linux/pid.h @@ -122,6 +122,17 @@ int next_pidmap(struct pid_namespace *pi extern struct pid *alloc_pid(struct pid_namespace *ns); extern void free_pid(struct pid *pid); +/* ns_of_pid returns the pid namespace in which the specified + * pid was allocated. + */ +static inline struct pid_namespace *ns_of_pid(struct pid *pid) +{ + struct pid_namespace *ns = NULL; + if (pid) + ns = pid->numbers[pid->level].ns; + return ns; +} + /* * the helpers to get the pid's id seen from different namespaces * _ Patches currently in -mm which might be from sukadev@xxxxxxxxxxxxxxxxxx are linux-next.patch pid-implement-ns_of_pid.patch pid-generalize-task_active_pid_ns.patch mqueue-fix-si_pid-value-in-mqueue-do_notify.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html