[PATCH 3/5] vt: Don't ignore unbind errors in vt_unbind

Daniel Vetter
2014-06-05T14:59:57Z

Otherwise the loop will never stop since we don't make any
forward progress. Noticed while breaking this accidentally
in a painful attempt to make vga_con unregistering work.

With this patch we'll bail out on the first attempt, which
at least leaves a useful enough system behind for debugging.
Livelocks on console_lock just aren't fun.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
---
drivers/tty/vt/vt.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index 5077fe87324d..3c00dcb3b145 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -3260,6 +3260,7 @@ static int vt_unbind(struct con_driver *con)
{
const struct consw *csw = NULL;
int i, more = 1, first = -1, last = -1, deflt = 0;
+ int ret;

if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE) ||
con_is_graphics(con->con, con->first, con->last))
@@ -3285,8 +3286,10 @@ static int vt_unbind(struct con_driver *con)

if (first != -1) {
console_lock();
- do_unbind_con_driver(csw, first, last, deflt);
+ ret = do_unbind_con_driver(csw, first, last, deflt);
console_unlock();
+ if (ret != 0)
+ return ret;
}

first = -1;
--
1.8.1.4