Commit ee0acf90 authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Linus Torvalds
Browse files

[PATCH] setpgid: should work for sub-threads 



setpgid(0, pgid) or setpgid(forked_child_pid, pgid) does not work unless
the calling process is a thread_group_leader().

'man setpgid' does not tell anything about that, so I consider this
behaviour is a bug.

Signed-off-by: default avatarOleg Nesterov <oleg@tv-sign.ru>
Cc: Oren Laadan <orenl@cs.columbia.edu>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 9a5d3023

kernel/sys.c

+6 −5
Original line number Diff line number Diff line
@@ -1090,10 +1090,11 @@ asmlinkage long sys_times(struct tms __user * tbuf) 
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;



	if (!pid)

		pid = current->pid;

		pid = group_leader->pid;

	if (!pgid)

		pgid = pid;

	if (pgid < 0)
@@ -1113,16 +1114,16 @@ asmlinkage long sys_setpgid(pid_t pid, pid_t pgid) 
	if (!thread_group_leader(p))

		goto out;



	if (p->parent == current || p->real_parent == current) {

	if (p->parent == current || p->real_parent == group_leader) {

		err = -EPERM;

		if (p->signal->session != current->signal->session)

		if (p->signal->session != group_leader->signal->session)

			goto out;

		err = -EACCES;

		if (p->did_exec)

			goto out;

	} else {

		err = -ESRCH;

		if (p != current)

		if (p != group_leader)

			goto out;

	}
@@ -1134,7 +1135,7 @@ asmlinkage long sys_setpgid(pid_t pid, pid_t pgid) 
		struct task_struct *p;



		do_each_task_pid(pgid, PIDTYPE_PGID, p) {

			if (p->signal->session == current->signal->session)

			if (p->signal->session == group_leader->signal->session)

				goto ok_pgid;

		} while_each_task_pid(pgid, PIDTYPE_PGID, p);

		goto out;

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