[PATCH] signal: rewrite kill_something_info so it uses newer helpers

The goal is to remove users of the old signal helper functions so they can be
removed.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/signal.c

@@ -1191,8 +1191,10 @@ EXPORT_SYMBOL_GPL(kill_pid_info_as_uid);
 
 static int kill_something_info(int sig, struct siginfo *info, int pid)
 {
+	int ret;
+	rcu_read_lock();
 	if (!pid) {
-		return kill_pg_info(sig, info, process_group(current));
+		ret = kill_pgrp_info(sig, info, task_pgrp(current));
 	} else if (pid == -1) {
 		int retval = 0, count = 0;
 		struct task_struct * p;
@@ -1207,12 +1209,14 @@ static int kill_something_info(int sig, struct siginfo *info, int pid)
 			}
 		}
 		read_unlock(&tasklist_lock);
-		return count ? retval : -ESRCH;
+		ret = count ? retval : -ESRCH;
 	} else if (pid < 0) {
-		return kill_pg_info(sig, info, -pid);
+		ret = kill_pgrp_info(sig, info, find_pid(-pid));
 	} else {
-		return kill_proc_info(sig, info, pid);
+		ret = kill_pid_info(sig, info, find_pid(pid));
 	}
+	rcu_read_unlock();
+	return ret;
 }
 
 /*