The patch titled
8250.c: port.lock is irq-safe
has been added to the -mm tree. Its filename is
8250c-portlock-is-irq-safe.patch
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------------------------------------------------------
Subject: 8250.c: port.lock is irq-safe
From: Borislav Petkov <petkovbb@xxxxxxxxxxxxxx>
serial8250_startup() doesn't disable interrupts while taking the &up->port.lock
which might race against the interrupt handler serial8250_interrupt(), which
when entered, will deadlock waiting for the lock to be released.
Signed-off-by: Borislav Petkov <petkovbb@xxxxxxxxx>
Tested-by: Ingo Molnar <mingo@xxxxxxx>
Cc: Alan Cox <alan@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/serial/8250.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff -puN drivers/serial/8250.c~8250c-portlock-is-irq-safe drivers/serial/8250.c
--- a/drivers/serial/8250.c~8250c-portlock-is-irq-safe
+++ a/drivers/serial/8250.c
@@ -1885,7 +1885,7 @@ static int serial8250_startup(struct uar
* the interrupt is enabled. Delays are necessary to
* allow register changes to become visible.
*/
- spin_lock(&up->port.lock);
+ spin_lock_irqsave(&up->port.lock, flags);
if (up->port.flags & UPF_SHARE_IRQ)
disable_irq_nosync(up->port.irq);
@@ -1901,7 +1901,7 @@ static int serial8250_startup(struct uar
if (up->port.flags & UPF_SHARE_IRQ)
enable_irq(up->port.irq);
- spin_unlock(&up->port.lock);
+ spin_unlock_irqrestore(&up->port.lock, flags);
/*
* If the interrupt is not reasserted, setup a timer to
_
Patches currently in -mm which might be from petkovbb@xxxxxxxxxxxxxx are
origin.patch
8250c-portlock-is-irq-safe.patch
cdrom-dont-check-cdc_play_audio-in-cdrom_count_tracks.patch
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