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: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Oleg Nesterov 2008-02-08 04:19:08 -08:00 committed by Linus Torvalds
parent c543f1ee08
commit 4e021306cf

View file

@ -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;