From eef2622a9fcfa964073333ea72c7c9cd20ad45e6 Mon Sep 17 00:00:00 2001
From: Christian Borntraeger <borntraeger@de.ibm.com>
Date: Sun, 12 Oct 2008 21:51:31 +0000
Subject: [PATCH] hvc_console: Fix free_irq in spinlocked section
commit 611e097d7707741a336a0677d9d69bec40f29f3d
Author: Christian Borntraeger <borntraeger@de.ibm.com>
hvc_console: rework setup to replace irq functions with callbacks
introduced a spinlock recursion problem. The notifier_del is
called with a lock held, and in turns calls free_irq which then
complains when manipulating procfs. This fixes it by moving the
call to the notifier to outside of the locked section.
Signed-off-by: Christian Borntraeger<borntraeger@de.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
drivers/char/hvc_console.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/char/hvc_console.c b/drivers/char/hvc_console.c
index fd64137b1ab9..f2e4caf70599 100644
--- a/drivers/char/hvc_console.c
+++ b/drivers/char/hvc_console.c
@@ -367,13 +367,13 @@ static void hvc_close(struct tty_struct *tty, struct file * filp)
spin_lock_irqsave(&hp->lock, flags);
if (--hp->count == 0) {
- if (hp->ops->notifier_del)
- hp->ops->notifier_del(hp, hp->data);
-
/* We are done with the tty pointer now. */
hp->tty = NULL;
spin_unlock_irqrestore(&hp->lock, flags);
+ if (hp->ops->notifier_del)
+ hp->ops->notifier_del(hp, hp->data);
+
/*
* Chain calls chars_in_buffer() and returns immediately if
* there is no buffered data otherwise sleeps on a wait queue
@@ -416,11 +416,11 @@ static void hvc_hangup(struct tty_struct *tty)
hp->n_outbuf = 0;
hp->tty = NULL;
+ spin_unlock_irqrestore(&hp->lock, flags);
+
if (hp->ops->notifier_del)
hp->ops->notifier_del(hp, hp->data);
- spin_unlock_irqrestore(&hp->lock, flags);
-
while(temp_open_count) {
--temp_open_count;
kref_put(&hp->kref, destroy_hvc_struct);
--
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