Uninline find_pid etc set of functions

The find_pid/_vpid/_pid_ns functions are used to find the struct pid by its
id, depending on whic id - global or virtual - is used.

The find_vpid() is a macro that pushes the current->nsproxy->pid_ns on the
stack to call another function - find_pid_ns().  It turned out, that this
dereference together with the push itself cause the kernel text size to
grow too much.

Move all these out-of-line.  Together with the previous patch this saves a
bit less that 400 bytes from .text section.
Signed-off-by: NPavel Emelyanov <xemul@openvz.org>
Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Paul Menage <menage@google.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

include/linux/pid.h

@@ -110,9 +110,8 @@ extern struct pid_namespace init_pid_ns;
  * see also find_task_by_pid() set in include/linux/sched.h
  */
 extern struct pid *FASTCALL(find_pid_ns(int nr, struct pid_namespace *ns));
-
-#define find_vpid(pid)	find_pid_ns(pid, current->nsproxy->pid_ns)
-#define find_pid(pid)	find_pid_ns(pid, &init_pid_ns)
+extern struct pid *find_vpid(int nr);
+extern struct pid *find_pid(int nr);
 
 /*
  * Lookup a PID in the hash table, and return with it's count elevated.

kernel/capability.c

@@ -96,7 +96,7 @@ static inline int cap_set_pg(int pgrp_nr, kernel_cap_t *effective,
 	int found = 0;
 	struct pid *pgrp;
 
-	pgrp = find_pid_ns(pgrp_nr, current->nsproxy->pid_ns);
+	pgrp = find_vpid(pgrp_nr);
 	do_each_pid_task(pgrp, PIDTYPE_PGID, g) {
 		target = g;
 		while_each_thread(g, target) {

kernel/pid.c

@@ -302,6 +302,18 @@ struct pid * fastcall find_pid_ns(int nr, struct pid_namespace *ns)
 }
 EXPORT_SYMBOL_GPL(find_pid_ns);
 
+struct pid *find_vpid(int nr)
+{
+	return find_pid_ns(nr, current->nsproxy->pid_ns);
+}
+EXPORT_SYMBOL_GPL(find_vpid);
+
+struct pid *find_pid(int nr)
+{
+	return find_pid_ns(nr, &init_pid_ns);
+}
+EXPORT_SYMBOL_GPL(find_pid);
+
 /*
  * attach_pid() must be called with the tasklist_lock write-held.
  */