From: Alan Cox Date: Mon, 4 Aug 2008 16:47:07 +0000 (+0100) Subject: vt: Deadlock workaround X-Git-Tag: firefly_0821_release~18449 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=d5cae364148088911bdf007a8aaefb46a92f16f7;p=firefly-linux-kernel-4.4.55.git vt: Deadlock workaround 2.6.26 corrected the mutex locking on tty resizing to fix the case where you could get the tty/vt sizing out of sync. That turns out to have a deadlock. The actual fix is really major and I've got it lined up as part of the ops changes for 2.6.28 so for 2.6.26/2.6.27 it is safer to reintroduce this ages old minor bug. Signed-off-by: Alan Cox Signed-off-by: Linus Torvalds --- diff --git a/drivers/char/vt.c b/drivers/char/vt.c index 82a51f38a546..1bc00c9d860d 100644 --- a/drivers/char/vt.c +++ b/drivers/char/vt.c @@ -916,7 +916,6 @@ int vc_resize(struct vc_data *vc, unsigned int cols, unsigned int lines) ws.ws_col = vc->vc_cols; ws.ws_ypixel = vc->vc_scan_lines; - mutex_lock(&vc->vc_tty->termios_mutex); 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); @@ -926,7 +925,6 @@ int vc_resize(struct vc_data *vc, unsigned int cols, unsigned int lines) put_pid(pgrp); } *cws = ws; - mutex_unlock(&vc->vc_tty->termios_mutex); } if (CON_IS_VISIBLE(vc))