linux-kernel - [PATCH] kgdboc,input: Fix regression with keyboard release key and early debugging

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Date:	Mon, 13 Dec 2010 23:04:52 -0600
From:	Jason Wessel <jason.wessel@...driver.com>
To:	torvalds@...ux-foundation.org
Cc:	linux-kernel@...r.kernel.org, kgdb-bugreport@...ts.sourceforge.net
Subject: [PATCH] kgdboc,input: Fix regression with keyboard release key and early debugging

The commit 111c182340cd22e238ab1cc6564df336c6ebd7cb (kgdboc: reset
input devices (keyboards) when exiting debugger) introduced a
regression in early debugging such that you get a kernel oops on
continue (with the go command) if you boot a kernel with:

    earlyprintk=vga ekgdboc=kbd kgdbwait

The restore kgdboc_restore_input() routine schedules work for the
purpose of sending key release events for any keys that were in the
depressed state prior to entering the kernel debugger.  A simple fix
to the crash is to not invoke the schedule_work() if the kernel
system_state is anything other than SYSTEM_RUNNING.

Signed-off-by: Jason Wessel <jason.wessel@...driver.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@...il.com>
Reviewed-by: Sergei Shtylyov <sshtylyov@...sta.com>
---
 drivers/serial/kgdboc.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/drivers/serial/kgdboc.c b/drivers/serial/kgdboc.c
index 3374618..25a8bc5 100644
--- a/drivers/serial/kgdboc.c
+++ b/drivers/serial/kgdboc.c
@@ -90,7 +90,8 @@ static DECLARE_WORK(kgdboc_restore_input_work, kgdboc_restore_input_helper);
 
 static void kgdboc_restore_input(void)
 {
-	schedule_work(&kgdboc_restore_input_work);
+	if (likely(system_state == SYSTEM_RUNNING))
+		schedule_work(&kgdboc_restore_input_work);
 }
 
 static int kgdboc_register_kbd(char **cptr)
-- 
1.7.0.4

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