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>

8 files changed, 31 insertions, 21 deletions

diff --git a/kernel/capability.c b/kernel/capability.c
index d4377c5..0d0d886 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 86b2600..3271045 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 cc098e1..00b5726 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 b3e6d7c..73a60e2 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 66e99eb..b0ace60 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 4ac56fe..5d5e107 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 d809cdd..783b33a 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 23620d5..2befc29 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;