Uninline find_task_by_xxx set of functions

The find_task_by_something is a set of macros are used to find task by pid
depending on what kind of pid is proposed - global or virtual one.  All of
them are wrappers above the most generic one - find_task_by_pid_type_ns() -
and just substitute some args for it.

It turned out, that dereferencing the current->nsproxy->pid_ns construction
and pushing one more argument on the stack inline cause kernel text size to
grow.

This patch moves all this stuff out-of-line into kernel/pid.c.  Together
with the next patch it saves a bit less than 400 bytes from the .text
section.

Signed-off-by: Pavel 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>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

12 files changed, 41 insertions, 38 deletions

diff --git a/fs/ioprio.c b/fs/ioprio.c
index 0a615f87142e..d6ff77e8e7ec 100644
--- a/fs/ioprio.c
+++ b/fs/ioprio.c
@@ -94,8 +94,7 @@ asmlinkage long sys_ioprio_set(int which, int who, int ioprio)
                         if (!who)
                                 p = current;
                         else
-                                p = find_task_by_pid_ns(who,
-                                                current->nsproxy->pid_ns);
+                                p = find_task_by_vpid(who);
                         if (p)
                                 ret = set_task_ioprio(p, ioprio);
                         break;
@@ -182,8 +181,7 @@ asmlinkage long sys_ioprio_get(int which, int who)
                         if (!who)
                                 p = current;
                         else
-                                p = find_task_by_pid_ns(who,
-                                                current->nsproxy->pid_ns);
+                                p = find_task_by_vpid(who);
                         if (p)
                                 ret = get_task_ioprio(p);
                         break;
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 1301c0875370..f4d969e85612 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1523,9 +1523,8 @@ extern struct pid_namespace init_pid_ns;
  *      type and namespace specified
  * find_task_by_pid_ns():
  *      finds a task by its pid in the specified namespace
- * find_task_by_pid_type():
- *      finds a task by its global id with the specified type, e.g.
- *      by global session id
+ * find_task_by_vpid():
+ *      finds a task by its virtual pid
  * find_task_by_pid():
  *      finds a task by its global pid
  *
@@ -1535,12 +1534,10 @@ extern struct pid_namespace init_pid_ns;
 extern struct task_struct *find_task_by_pid_type_ns(int type, int pid,
                 struct pid_namespace *ns);
 
-#define find_task_by_pid_ns(nr, ns)     \
-                find_task_by_pid_type_ns(PIDTYPE_PID, nr, ns)
-#define find_task_by_pid_type(type, nr) \
-                find_task_by_pid_type_ns(type, nr, &init_pid_ns)
-#define find_task_by_pid(nr)            \
-                find_task_by_pid_type(PIDTYPE_PID, nr)
+extern struct task_struct *find_task_by_pid(pid_t nr);
+extern struct task_struct *find_task_by_vpid(pid_t nr);
+extern struct task_struct *find_task_by_pid_ns(pid_t nr,
+                struct pid_namespace *ns);
 
 extern void __set_special_pids(pid_t session, pid_t pgrp);
 
diff --git a/kernel/capability.c b/kernel/capability.c
index d4377c5a36c9..0d0d886d1e84 100644
--- a/kernel/capability.c
+++ b/kernel/capability.c
@@ -63,8 +63,7 @@ asmlinkage long sys_capget(cap_user_header_t header, cap_user_data_t dataptr)
         read_lock(&tasklist_lock);
 
         if (pid && pid != task_pid_vnr(current)) {
-                target = find_task_by_pid_ns(pid,
-                                current->nsproxy->pid_ns);
+                target = find_task_by_vpid(pid);
                 if (!target) {
                         ret = -ESRCH;
                         goto out;
@@ -198,8 +197,7 @@ asmlinkage long sys_capset(cap_user_header_t header, const cap_user_data_t data)
         read_lock(&tasklist_lock);
 
         if (pid > 0 && pid != task_pid_vnr(current)) {
-                target = find_task_by_pid_ns(pid,
-                                current->nsproxy->pid_ns);
+                target = find_task_by_vpid(pid);
                 if (!target) {
                         ret = -ESRCH;
                         goto out;
diff --git a/kernel/futex.c b/kernel/futex.c
index 86b2600381b6..32710451dc20 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -446,9 +446,7 @@ static struct task_struct * futex_find_get_task(pid_t pid)
         struct task_struct *p;
 
         rcu_read_lock();
-        p = find_task_by_pid_ns(pid,
-                        current->nsproxy->pid_ns);
-
+        p = find_task_by_vpid(pid);
         if (!p || ((current->euid != p->euid) && (current->euid != p->uid)))
                 p = ERR_PTR(-ESRCH);
         else
@@ -1858,8 +1856,7 @@ sys_get_robust_list(int pid, struct robust_list_head __user * __user *head_ptr,
 
                 ret = -ESRCH;
                 rcu_read_lock();
-                p = find_task_by_pid_ns(pid,
-                                current->nsproxy->pid_ns);
+                p = find_task_by_vpid(pid);
                 if (!p)
                         goto err_unlock;
                 ret = -EPERM;
diff --git a/kernel/futex_compat.c b/kernel/futex_compat.c
index cc098e1de960..00b572666cc7 100644
--- a/kernel/futex_compat.c
+++ b/kernel/futex_compat.c
@@ -125,8 +125,7 @@ compat_sys_get_robust_list(int pid, compat_uptr_t __user *head_ptr,
 
                 ret = -ESRCH;
                 read_lock(&tasklist_lock);
-                p = find_task_by_pid_ns(pid,
-                                current->nsproxy->pid_ns);
+                p = find_task_by_vpid(pid);
                 if (!p)
                         goto err_unlock;
                 ret = -EPERM;
diff --git a/kernel/pid.c b/kernel/pid.c
index b3e6d7c41b97..73a60e265f52 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -369,6 +369,25 @@ struct task_struct *find_task_by_pid_type_ns(int type, int nr,
 
 EXPORT_SYMBOL(find_task_by_pid_type_ns);
 
+struct task_struct *find_task_by_pid(pid_t nr)
+{
+        return find_task_by_pid_type_ns(PIDTYPE_PID, nr, &init_pid_ns);
+}
+EXPORT_SYMBOL(find_task_by_pid);
+
+struct task_struct *find_task_by_vpid(pid_t vnr)
+{
+        return find_task_by_pid_type_ns(PIDTYPE_PID, vnr,
+                        current->nsproxy->pid_ns);
+}
+EXPORT_SYMBOL(find_task_by_vpid);
+
+struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns)
+{
+        return find_task_by_pid_type_ns(PIDTYPE_PID, nr, ns);
+}
+EXPORT_SYMBOL(find_task_by_pid_ns);
+
 struct pid *get_task_pid(struct task_struct *task, enum pid_type type)
 {
         struct pid *pid;
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 66e99eb2d8a6..b0ace60ce596 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -444,8 +444,7 @@ struct task_struct *ptrace_get_task_struct(pid_t pid)
                 return ERR_PTR(-EPERM);
 
         read_lock(&tasklist_lock);
-        child = find_task_by_pid_ns(pid,
-                        current->nsproxy->pid_ns);
+        child = find_task_by_vpid(pid);
         if (child)
                 get_task_struct(child);
 
diff --git a/kernel/sched.c b/kernel/sched.c
index 4ac56fe3c394..5d5e107ebc4e 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -4168,8 +4168,7 @@ struct task_struct *idle_task(int cpu)
  */
 static struct task_struct *find_process_by_pid(pid_t pid)
 {
-        return pid ?
-                find_task_by_pid_ns(pid, current->nsproxy->pid_ns) : current;
+        return pid ? find_task_by_vpid(pid) : current;
 }
 
 /* Actually do priority change: must hold rq lock. */
diff --git a/kernel/signal.c b/kernel/signal.c
index d809cdd6c0f1..783b33a0af06 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -2237,7 +2237,7 @@ static int do_tkill(int tgid, int pid, int sig)
         info.si_uid = current->uid;
 
         read_lock(&tasklist_lock);
-        p = find_task_by_pid_ns(pid, current->nsproxy->pid_ns);
+        p = find_task_by_vpid(pid);
         if (p && (tgid <= 0 || task_tgid_vnr(p) == tgid)) {
                 error = check_kill_permission(sig, &info, p);
                 /*
diff --git a/kernel/sys.c b/kernel/sys.c
index 23620d52cf37..2befc299129d 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -152,8 +152,7 @@ asmlinkage long sys_setpriority(int which, int who, int niceval)
         switch (which) {
                 case PRIO_PROCESS:
                         if (who)
-                                p = find_task_by_pid_ns(who,
-                                                current->nsproxy->pid_ns);
+                                p = find_task_by_vpid(who);
                         else
                                 p = current;
                         if (p)
@@ -210,8 +209,7 @@ asmlinkage long sys_getpriority(int which, int who)
         switch (which) {
                 case PRIO_PROCESS:
                         if (who)
-                                p = find_task_by_pid_ns(who,
-                                                current->nsproxy->pid_ns);
+                                p = find_task_by_vpid(who);
                         else
                                 p = current;
                         if (p) {
@@ -1067,7 +1065,8 @@ asmlinkage long sys_setsid(void)
          * session id and so the check will always fail and make it so
          * init cannot successfully call setsid.
          */
-        if (session > 1 && find_task_by_pid_type(PIDTYPE_PGID, session))
+        if (session > 1 && find_task_by_pid_type_ns(PIDTYPE_PGID,
+                                session, &init_pid_ns))
                 goto out;
 
         group_leader->signal->leader = 1;
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index a09ca3b1cf9c..c1592a94582f 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -941,8 +941,7 @@ asmlinkage long sys_migrate_pages(pid_t pid, unsigned long maxnode,
 
         /* Find the mm_struct */
         read_lock(&tasklist_lock);
-        task = pid ?
-                find_task_by_pid_ns(pid, current->nsproxy->pid_ns) : current;
+        task = pid ? find_task_by_vpid(pid) : current;
         if (!task) {
                 read_unlock(&tasklist_lock);
                 return -ESRCH;
diff --git a/mm/migrate.c b/mm/migrate.c
index c479357b5480..4d6ee03db946 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -925,8 +925,7 @@ asmlinkage long sys_move_pages(pid_t pid, unsigned long nr_pages,
 
         /* Find the mm_struct */
         read_lock(&tasklist_lock);
-        task = pid ?
-                find_task_by_pid_ns(pid, current->nsproxy->pid_ns) : current;
+        task = pid ? find_task_by_vpid(pid) : current;
         if (!task) {
                 read_unlock(&tasklist_lock);
                 return -ESRCH;