diff options
| author | Alexandre Courbot <acourbot@nvidia.com> | 2015-08-17 11:23:52 +0300 |
|---|---|---|
| committer | Linus Walleij <linus.walleij@linaro.org> | 2015-08-17 11:56:24 +0300 |
| commit | 7fa25937542358bfa01ef5c5a1e9a00bd164c000 (patch) | |
| tree | d4edc6026912b6b8ad9450aa84f26f06d4b23794 /drivers/gpio | |
| parent | ac49fbd1f9d437cca7234473850aef4165779383 (diff) | |
| download | linux-7fa25937542358bfa01ef5c5a1e9a00bd164c000.tar.xz | |
gpio/grgpio: fix deadlock in grgpio_irq_unmap()
As reported by Alexey Khoroshilov:
grgpio_irq_unmap() code looks quite suspicious regarding usage of
priv->bgc.lock spinlock.
It locks the spinlock in line 310:
spin_lock_irqsave(&priv->bgc.lock, flags);
and then it can call grgpio_set_imask() in line 317:
grgpio_set_imask(priv, i, 0);
But grgpio_set_imask() unconditionally locks the spinlock by itself.
Fix this by moving the spinlock acquisition outside of
grgpio_set_imask().
Found by Linux Driver Verification project (linuxtesting.org).
Reported-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Cc: Alexey Khoroshilov <khoroshilov@ispras.ru>
Cc: Andreas Larsson <andreas@gaisler.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers/gpio')
| -rw-r--r-- | drivers/gpio/gpio-grgpio.c | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/drivers/gpio/gpio-grgpio.c b/drivers/gpio/gpio-grgpio.c index 77053d61466e..801423fe8143 100644 --- a/drivers/gpio/gpio-grgpio.c +++ b/drivers/gpio/gpio-grgpio.c @@ -104,17 +104,12 @@ static void grgpio_set_imask(struct grgpio_priv *priv, unsigned int offset, { struct bgpio_chip *bgc = &priv->bgc; unsigned long mask = bgc->pin2mask(bgc, offset); - unsigned long flags; - - spin_lock_irqsave(&bgc->lock, flags); if (val) priv->imask |= mask; else priv->imask &= ~mask; bgc->write_reg(priv->regs + GRGPIO_IMASK, priv->imask); - - spin_unlock_irqrestore(&bgc->lock, flags); } static int grgpio_to_irq(struct gpio_chip *gc, unsigned offset) @@ -180,16 +175,26 @@ static void grgpio_irq_mask(struct irq_data *d) { struct grgpio_priv *priv = irq_data_get_irq_chip_data(d); int offset = d->hwirq; + unsigned long flags; + + spin_lock_irqsave(&priv->bgc.lock, flags); grgpio_set_imask(priv, offset, 0); + + spin_unlock_irqrestore(&priv->bgc.lock, flags); } static void grgpio_irq_unmask(struct irq_data *d) { struct grgpio_priv *priv = irq_data_get_irq_chip_data(d); int offset = d->hwirq; + unsigned long flags; + + spin_lock_irqsave(&priv->bgc.lock, flags); grgpio_set_imask(priv, offset, 1); + + spin_unlock_irqrestore(&priv->bgc.lock, flags); } static struct irq_chip grgpio_irq_chip = { |