Deadlock in grgpio_irq_unmap()

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Dear colleagus,

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.

static void grgpio_set_imask(struct grgpio_priv *priv, unsigned int offset,
			     int val)
{
	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);
}

So, it looks like unavoidable deadlock here.

Found by Linux Driver Verification project (linuxtesting.org).

--
Alexey Khoroshilov
Linux Verification Center, ISPRAS
web: http://linuxtesting.org

--
To unsubscribe from this list: send the line "unsubscribe linux-gpio" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Linux SPI]     [Linux Kernel]     [Linux ARM (vger)]     [Linux ARM MSM]     [Linux Omap]     [Linux Arm]     [Linux Tegra]     [Fedora ARM]     [Linux for Samsung SOC]     [eCos]     [Linux Fastboot]     [Gcc Help]     [Git]     [DCCP]     [IETF Announce]     [Security]     [Linux MIPS]     [Yosemite Campsites]

  Powered by Linux