vt: fix vc_resize locking
Lockdep says we can't take tasklist lock or sighand lock inside ctrl_lock.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: Alan Cox <alan@redhat.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
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>
diff --git a/drivers/char/vt.c b/drivers/char/vt.c
index b8b2498..935f1c2 100644
--- a/drivers/char/vt.c
+++ b/drivers/char/vt.c
@@ -909,7 +909,7 @@
if (vc->vc_tty) {
struct winsize ws, *cws = &vc->vc_tty->winsize;
- unsigned long flags;
+ struct pid *pgrp = NULL;
memset(&ws, 0, sizeof(ws));
ws.ws_row = vc->vc_rows;
@@ -917,11 +917,14 @@
ws.ws_ypixel = vc->vc_scan_lines;
mutex_lock(&vc->vc_tty->termios_mutex);
- spin_lock_irqsave(&vc->vc_tty->ctrl_lock, flags);
- if ((ws.ws_row != cws->ws_row || ws.ws_col != cws->ws_col) &&
- vc->vc_tty->pgrp)
+ spin_lock_irq(&vc->vc_tty->ctrl_lock);
+ if ((ws.ws_row != cws->ws_row || ws.ws_col != cws->ws_col))
+ pgrp = get_pid(vc->vc_tty->pgrp);
+ spin_unlock_irq(&vc->vc_tty->ctrl_lock);
+ if (pgrp) {
kill_pgrp(vc->vc_tty->pgrp, SIGWINCH, 1);
- spin_unlock_irqrestore(&vc->vc_tty->ctrl_lock, flags);
+ put_pid(pgrp);
+ }
*cws = ws;
mutex_unlock(&vc->vc_tty->termios_mutex);
}