Re: [PATCH 7/7] pid: get pid_t ppid of task in init_pid_ns
On 01/23, Richard Guy Briggs wrote:
Added the functions task_ppid_nr_ns() and task_ppid_nr() to abstract the lookup
of the PPID (real_parent's pid_t) of a process, including rcu locking, in the
arbitrary and init_pid_ns.
This provides an alternative to sys_getppid(), which is relative to the child
process' pid namespace.
I agree, this makes sense.
imho it would be better to send this patch along with sys_getppid()
conversions, but I won't argue.
+static int pid_alive(const struct task_struct *p);
+static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace
*ns)
+{
+ pid_t pid = 0;
+
+ rcu_read_lock();
+ if (pid_alive(tsk))
+ pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns);
+ rcu_read_unlock();
+
+ return pid;
+}
Perhaps it should be named task_ptgid_nr_ns() or even parent_tgid_nr_ns().
Since it returns tgid, not pid (== tid).
But this is cosmetic, I won't insist.
Oleg.