Messages in this thread Patch in this message | | | Date | Thu, 23 Oct 2008 21:34:57 -0700 | From | Greg KH <> | Subject | [patch 20/27] hvc_console: Fix free_irq in spinlocked section |
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2.6.27-stable review patch. If anyone has any objections, please let us know.
------------------ From: Christian Borntraeger <borntraeger@de.ibm.com>
commit eef2622a9fcfa964073333ea72c7c9cd20ad45e6 upstream
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> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- drivers/char/hvc_console.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)
--- a/drivers/char/hvc_console.c +++ b/drivers/char/hvc_console.c @@ -367,13 +367,13 @@ static void hvc_close(struct tty_struct 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 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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