[PATCH] session_of_pgrp: kill unnecessary do_each_task_pid(PIDTYPE_PGID)

All members of the process group have the same sid and it can't be == 0.

NOTE: this code (and a similar one in sys_setpgid) was needed because it
was possibe to have ->session == 0. It's not possible any longer since

	[PATCH] pidhash: don't use zero pids
	Commit: c7c6464117a02b0d54feb4ebeca4db70fa493678

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 8 insertions, 11 deletions

diff --git a/kernel/exit.c b/kernel/exit.c
index fd0e067952ab..03e64fe4a14a 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -189,21 +189,18 @@ repeat:
 int session_of_pgrp(int pgrp)
 {
         struct task_struct *p;
-        int sid = -1;
+        int sid = 0;
 
         read_lock(&tasklist_lock);
-        do_each_task_pid(pgrp, PIDTYPE_PGID, p) {
-                if (process_session(p) > 0) {
-                        sid = process_session(p);
-                        goto out;
-                }
-        } while_each_task_pid(pgrp, PIDTYPE_PGID, p);
-        p = find_task_by_pid(pgrp);
-        if (p)
+
+        p = find_task_by_pid_type(PIDTYPE_PGID, pgrp);
+        if (p == NULL)
+                p = find_task_by_pid(pgrp);
+        if (p != NULL)
                 sid = process_session(p);
-out:
+
         read_unlock(&tasklist_lock);
-        
+
         return sid;
 }