Isolate some explicit usage of task->tgid

With pid namespaces this field is now dangerous to use explicitly, so hide
it behind the helpers.

Also the pid and pgrp fields o task_struct and signal_struct are to be
deprecated.  Unfortunately this patch cannot be sent right now as this
leads to tons of warnings, so start isolating them, and deprecate later.

Actually the p->tgid == pid has to be changed to has_group_leader_pid(),
but Oleg pointed out that in case of posix cpu timers this is the same, and
thread_group_leader() is more preferable.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/kernel/signal.c b/kernel/signal.c
index 783b33a0af06..08364e75bb58 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1150,7 +1150,7 @@ static int kill_something_info(int sig, struct siginfo *info, int pid)
 
                 read_lock(&tasklist_lock);
                 for_each_process(p) {
-                        if (p->pid > 1 && p->tgid != current->tgid) {
+                        if (p->pid > 1 && !same_thread_group(p, current)) {
                                 int err = group_send_sig_info(sig, info, p);
                                 ++count;
                                 if (err != -EPERM)