From f020bc468fe4a91d32046d448511978c7b611315 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Fri, 8 Dec 2006 02:38:02 -0800 Subject: [PATCH] [PATCH] sys_setpgid: eliminate unnecessary do_each_task_pid(PIDTYPE_PGID) All tasks in the process group have the same sid, we don't need to iterate them all to check that the caller of sys_setpgid() doesn't change its session. Signed-off-by: Oleg Nesterov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/sys.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) diff --git a/kernel/sys.c b/kernel/sys.c index 4f9d23a3095f..c7675c1bfdf2 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -1397,16 +1397,13 @@ asmlinkage long sys_setpgid(pid_t pid, pid_t pgid) goto out; if (pgid != pid) { - struct task_struct *p; + struct task_struct *g = + find_task_by_pid_type(PIDTYPE_PGID, pgid); - do_each_task_pid(pgid, PIDTYPE_PGID, p) { - if (process_session(p) == process_session(group_leader)) - goto ok_pgid; - } while_each_task_pid(pgid, PIDTYPE_PGID, p); - goto out; + if (!g || process_session(g) != process_session(group_leader)) + goto out; } -ok_pgid: err = security_task_setpgid(p, pgid); if (err) goto out; -- 2.30.2