Commit 4e021306 authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Linus Torvalds
Browse files

sys_setpgid(): simplify pid/ns interaction 



sys_setpgid() does unneeded conversions from pid_t to "struct pid" and vice
versa.  Use "struct pid" more consistently.  Saves one find_vpid() and
eliminates the explicit usage of ->nsproxy->pid_ns.  Imho, cleanups the
code.

Also use the same_thread_group() helper.

Signed-off-by: default avatarOleg Nesterov <oleg@tv-sign.ru>
Acked-by: default avatarPavel Emelyanov <xemul@openvz.org>
Acked-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent c543f1ee

kernel/sys.c

+10 −13
Original line number Diff line number Diff line
@@ -916,8 +916,8 @@ asmlinkage long sys_setpgid(pid_t pid, pid_t pgid) 
{

	struct task_struct *p;

	struct task_struct *group_leader = current->group_leader;

	int err = -EINVAL;

	struct pid_namespace *ns;

	struct pid *pgrp;

	int err;



	if (!pid)

		pid = task_pid_vnr(group_leader);
@@ -929,12 +929,10 @@ asmlinkage long sys_setpgid(pid_t pid, pid_t pgid) 
	/* From this point forward we keep holding onto the tasklist lock

	 * so that our parent does not change from under us. -DaveM

	 */

	ns = current->nsproxy->pid_ns;



	write_lock_irq(&tasklist_lock);



	err = -ESRCH;

	p = find_task_by_pid_ns(pid, ns);

	p = find_task_by_vpid(pid);

	if (!p)

		goto out;
@@ -942,7 +940,7 @@ asmlinkage long sys_setpgid(pid_t pid, pid_t pgid) 
	if (!thread_group_leader(p))

		goto out;



	if (p->real_parent->tgid == group_leader->tgid) {

	if (same_thread_group(p->real_parent, group_leader)) {

		err = -EPERM;

		if (task_session(p) != task_session(group_leader))

			goto out;
@@ -959,10 +957,12 @@ asmlinkage long sys_setpgid(pid_t pid, pid_t pgid) 
	if (p->signal->leader)

		goto out;



	pgrp = task_pid(p);

	if (pgid != pid) {

		struct task_struct *g;



		g = find_task_by_pid_type_ns(PIDTYPE_PGID, pgid, ns);

		pgrp = find_vpid(pgid);

		g = pid_task(pgrp, PIDTYPE_PGID);

		if (!g || task_session(g) != task_session(group_leader))

			goto out;

	}
@@ -971,13 +971,10 @@ asmlinkage long sys_setpgid(pid_t pid, pid_t pgid) 
	if (err)

		goto out;



	if (task_pgrp_nr_ns(p, ns) != pgid) {

		struct pid *pid;



	if (task_pgrp(p) != pgrp) {

		detach_pid(p, PIDTYPE_PGID);

		pid = find_vpid(pgid);

		attach_pid(p, PIDTYPE_PGID, pid);

		set_task_pgrp(p, pid_nr(pid));

		attach_pid(p, PIDTYPE_PGID, pgrp);

		set_task_pgrp(p, pid_nr(pgrp));

	}



	err = 0;

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