From 44c4e1b2581f7273ab14ef30b6430618801c57b1 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Fri, 8 Feb 2008 04:19:15 -0800 Subject: [PATCH] pid: Extend/Fix pid_vnr pid_vnr returns the user space pid with respect to the pid namespace the struct pid was allocated in. What we want before we return a pid to user space is the user space pid with respect to the pid namespace of current. pid_vnr is a very nice optimization but because it isn't quite what we want it is easy to use pid_vnr at times when we aren't certain the struct pid was allocated in our pid namespace. Currently this describes at least tiocgpgrp and tiocgsid in ttyio.c the parent process reported in the core dumps and the parent process in get_signal_to_deliver. So unless the performance impact is huge having an interface that does what we want instead of always what we want should be much more reliable and much less error prone. Signed-off-by: Eric W. Biederman Cc: Oleg Nesterov Acked-by: Pavel Emelyanov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/pid.h | 14 +++----------- include/linux/sched.h | 5 ++--- kernel/pid.c | 6 ++++++ 3 files changed, 11 insertions(+), 14 deletions(-) diff --git a/include/linux/pid.h b/include/linux/pid.h index 061abb6c0796..b91f4732dc1b 100644 --- a/include/linux/pid.h +++ b/include/linux/pid.h @@ -127,9 +127,8 @@ extern void FASTCALL(free_pid(struct pid *pid)); * the helpers to get the pid's id seen from different namespaces * * pid_nr() : global id, i.e. the id seen from the init namespace; - * pid_vnr() : virtual id, i.e. the id seen from the namespace this pid - * belongs to. this only makes sence when called in the - * context of the task that belongs to the same namespace; + * pid_vnr() : virtual id, i.e. the id seen from the pid namespace of + * current. * pid_nr_ns() : id seen from the ns specified. * * see also task_xid_nr() etc in include/linux/sched.h @@ -144,14 +143,7 @@ static inline pid_t pid_nr(struct pid *pid) } pid_t pid_nr_ns(struct pid *pid, struct pid_namespace *ns); - -static inline pid_t pid_vnr(struct pid *pid) -{ - pid_t nr = 0; - if (pid) - nr = pid->numbers[pid->level].nr; - return nr; -} +pid_t pid_vnr(struct pid *pid); #define do_each_pid_task(pid, type, task) \ do { \ diff --git a/include/linux/sched.h b/include/linux/sched.h index d1c9b7f1d51e..3deb6e5d3096 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1332,9 +1332,8 @@ struct pid_namespace; * from various namespaces * * task_xid_nr() : global id, i.e. the id seen from the init namespace; - * task_xid_vnr() : virtual id, i.e. the id seen from the namespace the task - * belongs to. this only makes sence when called in the - * context of the task that belongs to the same namespace; + * task_xid_vnr() : virtual id, i.e. the id seen from the pid namespace of + * current. * task_xid_nr_ns() : id seen from the ns specified; * * set_task_vxid() : assigns a virtual id to a task; diff --git a/kernel/pid.c b/kernel/pid.c index 939746fb4ce7..a32859c4a3cd 100644 --- a/kernel/pid.c +++ b/kernel/pid.c @@ -443,6 +443,12 @@ pid_t pid_nr_ns(struct pid *pid, struct pid_namespace *ns) return nr; } +pid_t pid_vnr(struct pid *pid) +{ + return pid_nr_ns(pid, current->nsproxy->pid_ns); +} +EXPORT_SYMBOL_GPL(pid_vnr); + pid_t task_pid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns) { return pid_nr_ns(task_pid(tsk), ns); -- 2.20.1