From 47f86834bbd4193139d61d659bebf9ab9d691e37 Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Wed, 30 Apr 2008 00:53:30 -0700 Subject: redo locking of tty->pgrp Historically tty->pgrp and friends were pid_t and the code "knew" they were safe. The change to pid structs opened up a few races and the removal of the BKL in places made them quite hittable. We put tty->pgrp under the ctrl_lock for the tty. Signed-off-by: Alan Cox Cc: Oleg Nesterov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/char/vt.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'drivers/char/vt.c') diff --git a/drivers/char/vt.c b/drivers/char/vt.c index e64f0bf3624..c71d1d0f13b 100644 --- a/drivers/char/vt.c +++ b/drivers/char/vt.c @@ -909,15 +909,21 @@ int vc_resize(struct vc_data *vc, unsigned int cols, unsigned int lines) if (vc->vc_tty) { struct winsize ws, *cws = &vc->vc_tty->winsize; + unsigned long flags; memset(&ws, 0, sizeof(ws)); ws.ws_row = vc->vc_rows; ws.ws_col = vc->vc_cols; 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) kill_pgrp(vc->vc_tty->pgrp, SIGWINCH, 1); + spin_unlock_irqrestore(&vc->vc_tty->ctrl_lock, flags); *cws = ws; + mutex_unlock(&vc->vc_tty->termios_mutex); } if (CON_IS_VISIBLE(vc)) -- cgit v1.2.3