linux-kernel - [PATCH 3/3] fbcon: fix situation where fbcon gets deinitialised and can't reinit.

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Tue, 21 Dec 2010 11:41:17 +1000
From:	Dave Airlie <airlied@...il.com>
To:	linux-fbdev@...r.kernel.org
Cc:	dri-devel@...ts.sf.net, linux-kernel@...r.kernel.org,
	Dave Airlie <airlied@...hat.com>
Subject: [PATCH 3/3] fbcon: fix situation where fbcon gets deinitialised and can't reinit.

From: Dave Airlie <airlied@...hat.com>

Situation as follow:
2 GPUs + vesafb + kms.

GPU 1 is primary, vesafb binds to it as fb0
radeon loads
GPU 0 loads as fb1
GPU 1 loads, vesafb gets kicked off which causes fb0 to unbind
console, which causes the dummy console to rebind.

this means fbcon_deinit gets called, which calls fbcon_exit
since the console isn't bound anymore and we set fbcon_has_exited.

GPU 1 creates a new fb0 which is primary and we want to be console.
fbcon_fb_registered gets called sets the primary up and calls set_con2fb_map,
however as fbcon_has_exited is set nothing further ever happens.

This patch bypasses the fbcon_has_exited and checks if the console is unbound,
if its unbound it calls the fbcon_takeover which calls the vt layer to
call the fbcon_startup method and everthing works.

Signed-off-by: Dave Airlie <airlied@...hat.com>
---
 drivers/video/console/fbcon.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/video/console/fbcon.c b/drivers/video/console/fbcon.c
index 7ccc967..6662687 100644
--- a/drivers/video/console/fbcon.c
+++ b/drivers/video/console/fbcon.c
@@ -823,10 +823,10 @@ static int set_con2fb_map(int unit, int newidx, int user)
 	if (oldidx == newidx)
 		return 0;

-	if (!info || fbcon_has_exited)
+	if (!info)
 		return -EINVAL;

- 	if (!err && !search_for_mapped_con()) {
+	if (!search_for_mapped_con() || !con_is_bound(&fb_con)) {
 		info_idx = newidx;
 		return fbcon_takeover(0);
 	}
-- 
1.7.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/