gpio/grgpio: fix deadlock in grgpio_irq_unmap() (7fa25937) · Commits · 戴 / test

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>

drivers/gpio/gpio-grgpio.c

+10 −5

Original line number	Diff line number	Diff line
		@@ -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 = {

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