gpio: gpio-grgpio: fix possible sleep-in-atomic-context bugs in grgpio_irq_map/unmap()
[ Upstream commit e36eaf94be
]
The driver may sleep while holding a spinlock.
The function call path (from bottom to top) in Linux 4.19 is:
drivers/gpio/gpio-grgpio.c, 261:
request_irq in grgpio_irq_map
drivers/gpio/gpio-grgpio.c, 255:
_raw_spin_lock_irqsave in grgpio_irq_map
drivers/gpio/gpio-grgpio.c, 318:
free_irq in grgpio_irq_unmap
drivers/gpio/gpio-grgpio.c, 299:
_raw_spin_lock_irqsave in grgpio_irq_unmap
request_irq() and free_irq() can sleep at runtime.
To fix these bugs, request_irq() and free_irq() are called without
holding the spinlock.
These bugs are found by a static analysis tool STCheck written by myself.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Link: https://lore.kernel.org/r/20191218132605.10594-1-baijiaju1990@gmail.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
5.4-rM2-2.2.x-imx-squashed
parent
e715aa99c5
commit
739abce96d
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@ -253,17 +253,16 @@ static int grgpio_irq_map(struct irq_domain *d, unsigned int irq,
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lirq->irq = irq;
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lirq->irq = irq;
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uirq = &priv->uirqs[lirq->index];
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uirq = &priv->uirqs[lirq->index];
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if (uirq->refcnt == 0) {
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if (uirq->refcnt == 0) {
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spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);
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ret = request_irq(uirq->uirq, grgpio_irq_handler, 0,
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ret = request_irq(uirq->uirq, grgpio_irq_handler, 0,
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dev_name(priv->dev), priv);
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dev_name(priv->dev), priv);
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if (ret) {
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if (ret) {
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dev_err(priv->dev,
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dev_err(priv->dev,
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"Could not request underlying irq %d\n",
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"Could not request underlying irq %d\n",
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uirq->uirq);
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uirq->uirq);
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spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);
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return ret;
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return ret;
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}
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}
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spin_lock_irqsave(&priv->gc.bgpio_lock, flags);
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}
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}
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uirq->refcnt++;
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uirq->refcnt++;
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@ -309,8 +308,11 @@ static void grgpio_irq_unmap(struct irq_domain *d, unsigned int irq)
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if (index >= 0) {
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if (index >= 0) {
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uirq = &priv->uirqs[lirq->index];
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uirq = &priv->uirqs[lirq->index];
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uirq->refcnt--;
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uirq->refcnt--;
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if (uirq->refcnt == 0)
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if (uirq->refcnt == 0) {
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spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);
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free_irq(uirq->uirq, priv);
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free_irq(uirq->uirq, priv);
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return;
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}
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}
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}
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spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);
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spin_unlock_irqrestore(&priv->gc.bgpio_lock, flags);
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