Commit 1b0f7ffd authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Linus Torvalds
Browse files

pids: kill signal_struct-> __pgrp/__session and friends 



We are wasting 2 words in signal_struct without any reason to implement
task_pgrp_nr() and task_session_nr().

task_session_nr() has no callers since
2e2ba22e, we can remove it.

task_pgrp_nr() is still (I believe wrongly) used in fs/autofsX and
fs/coda.

This patch reimplements task_pgrp_nr() via task_pgrp_nr_ns(), and kills
__pgrp/__session and the related helpers.

The change in drivers/char/tty_io.c is cosmetic, but hopefully makes sense
anyway.

Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
Acked-by: Alan Cox <number6@the-village.bc.nu>		[tty parts]
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Serge Hallyn <serue@us.ibm.com>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 52ee2dfd

drivers/char/tty_io.c

+2 −2
Original line number Diff line number Diff line
@@ -2681,7 +2681,7 @@ void __do_SAK(struct tty_struct *tty) 
	/* Kill the entire session */

	do_each_pid_task(session, PIDTYPE_SID, p) {

		printk(KERN_NOTICE "SAK: killed process %d"

			" (%s): task_session_nr(p)==tty->session\n",

			" (%s): task_session(p)==tty->session\n",

			task_pid_nr(p), p->comm);

		send_sig(SIGKILL, p, 1);

	} while_each_pid_task(session, PIDTYPE_SID, p);
@@ -2691,7 +2691,7 @@ void __do_SAK(struct tty_struct *tty) 
	do_each_thread(g, p) {

		if (p->signal->tty == tty) {

			printk(KERN_NOTICE "SAK: killed process %d"

			    " (%s): task_session_nr(p)==tty->session\n",

			    " (%s): task_session(p)==tty->session\n",

			    task_pid_nr(p), p->comm);

			send_sig(SIGKILL, p, 1);

			continue;

include/linux/sched.h

+6 −37
Original line number Diff line number Diff line
@@ -547,25 +547,8 @@ struct signal_struct { 


	struct list_head cpu_timers[3];



	/* job control IDs */



	/*

	 * pgrp and session fields are deprecated.

	 * use the task_session_Xnr and task_pgrp_Xnr routines below

	 */



	union {

		pid_t pgrp __deprecated;

		pid_t __pgrp;

	};



	struct pid *tty_old_pgrp;



	union {

		pid_t session __deprecated;

		pid_t __session;

	};



	/* boolean value for session group leader */

	int leader;
@@ -1469,16 +1452,6 @@ static inline int rt_task(struct task_struct *p) 
	return rt_prio(p->prio);

}



static inline void set_task_session(struct task_struct *tsk, pid_t session)

{

	tsk->signal->__session = session;

}



static inline void set_task_pgrp(struct task_struct *tsk, pid_t pgrp)

{

	tsk->signal->__pgrp = pgrp;

}



static inline struct pid *task_pid(struct task_struct *task)

{

	return task->pids[PIDTYPE_PID].pid;
@@ -1552,11 +1525,6 @@ static inline pid_t task_tgid_vnr(struct task_struct *tsk) 
}





static inline pid_t task_pgrp_nr(struct task_struct *tsk)

{

	return tsk->signal->__pgrp;

}



static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk,

					struct pid_namespace *ns)

{
@@ -1569,11 +1537,6 @@ static inline pid_t task_pgrp_vnr(struct task_struct *tsk) 
}





static inline pid_t task_session_nr(struct task_struct *tsk)

{

	return tsk->signal->__session;

}



static inline pid_t task_session_nr_ns(struct task_struct *tsk,

					struct pid_namespace *ns)

{
@@ -1585,6 +1548,12 @@ static inline pid_t task_session_vnr(struct task_struct *tsk) 
	return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);

}



/* obsolete, do not use */

static inline pid_t task_pgrp_nr(struct task_struct *tsk)

{

	return task_pgrp_nr_ns(tsk, &init_pid_ns);

}



/**

 * pid_alive - check that a task structure is not stale

 * @p: Task structure to be checked.

kernel/exit.c

+3 −7
Original line number Diff line number Diff line
@@ -357,16 +357,12 @@ static void reparent_to_kthreadd(void) 
void __set_special_pids(struct pid *pid)

{

	struct task_struct *curr = current->group_leader;

	pid_t nr = pid_nr(pid);



	if (task_session(curr) != pid) {

	if (task_session(curr) != pid)

		change_pid(curr, PIDTYPE_SID, pid);

		set_task_session(curr, nr);

	}

	if (task_pgrp(curr) != pid) {



	if (task_pgrp(curr) != pid)

		change_pid(curr, PIDTYPE_PGID, pid);

		set_task_pgrp(curr, nr);

	}

}



static void set_special_pids(struct pid *pid)

kernel/fork.c

+0 −2
Original line number Diff line number Diff line
@@ -1265,8 +1265,6 @@ static struct task_struct *copy_process(unsigned long clone_flags, 
			p->signal->leader_pid = pid;

			tty_kref_put(p->signal->tty);

			p->signal->tty = tty_kref_get(current->signal->tty);

			set_task_pgrp(p, task_pgrp_nr(current));

			set_task_session(p, task_session_nr(current));

			attach_pid(p, PIDTYPE_PGID, task_pgrp(current));

			attach_pid(p, PIDTYPE_SID, task_session(current));

			list_add_tail_rcu(&p->tasks, &init_task.tasks);

kernel/sys.c

+1 −3
Original line number Diff line number Diff line
@@ -1013,10 +1013,8 @@ SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid) 
	if (err)

		goto out;



	if (task_pgrp(p) != pgrp) {

	if (task_pgrp(p) != pgrp)

		change_pid(p, PIDTYPE_PGID, pgrp);

		set_task_pgrp(p, pid_nr(pgrp));

	}



	err = 0;

out:

CRA Git | Maintained and supported by SUSTech CRA and CCSE